Tag Archives: UFO

__Chapter 10: SRAPO Survey Templates

(SRAPO/Chapter 10: Survey Templates)

Having reached Chapter 10: Survey Templates, you have been exposed to the information necessary to create:
1.  A template for:
 _ a) the general star – planet system where intelligent life could evolve,
_b) the general climate and other macro environmental factors found on the model planet and,
 _c) u aspects of that planet’s life form morphology.
2.  Approaching this from a different direction: If you hypothesize how an alien might appear, you can plug those characteristics into the SRAPO templates and work backwards to the type world and a range of stars he would likely have developed on.
.
Comparing a completed a set of Survey Templates, with the closest similar environment found on Earth, you will have the information to visualize major portions of the alien world in your ‘minds eye’.
As you stand or visually float in that strange new world, look about yourself and see it at dusk.
Its twilight, colors are fading into grays. You look about, while feeling the temperature and humidity; you can generally identify the type of environment you are in. You can tell whether the vegetation is tall or short, thick or spindly, dense or thinly spread about, there may be sounds and smells carried in the air. Large planets are wet, small planets are dry; hot and dry environments have water or temperature as limiting factors; high relative gravity favors short and squat; high relative ultra violet ‘sunlight’ favors protective pigmentation; increasing planetary axial inclination favors life form mobility and hibernation…
The things you sense and see about you are the way they are for a reason.
.

SURVEY TEMPLATE I 

.

SURVEY TEMPLATE II

.

 SURVEY TEMPLATE III


The things you sense and see about you are the way they are for a reason…

 

End of SRAPO

Leave a comment

Filed under SRAPO (Stellar Radii and Planetary Orbits), __Chapter 10: Templates

Chapter 9: Data Compilation

(SRAPO/Chapter 9: Data Compilation)

In Chapter 9: Data Compilation, we’ll draw together data covering the spectrum of our model alien worlds. Using the templates provided in Chapter 10 Templates, you can create a good conceptual model of any habitable planet covered in this study.

Initial Environments Compilation Table
The Initial Environments Compilation Table, below, provides the specific conditions within the physical or biological environments of our model worlds. Firstly, we’ll examine a small section of the table as seen in the cells at left.
The table’s columns are labeled with the APST (average planetary surface temperature); rows are labeled with  Planetary Mass (relative to Earth which =1.0).
Every combination of APST & Planetary Mass contains a box with a list of numbers; these numbers, become line numbers in a list of specific surface conditions found within the environment of that particular planet.
In order to extract information from the table, choose a planetary mass and an associated APST, then read the numbers in the corresponding data box.  If for example we chose a ‘damp’, 0.5 Earth mass planet with a ‘cold’ 0ºC APST, we’d find the data box containing the numbers, see box at left: 12,16,19, 27, 28, 31, 33, 37, 40.

Next, look ahead to The Initial Environments Compilation List and read the associated line numbers, for example;
>  #12 from the Initial Environments Compilation Table is read from line number 12 in the Initial Environments Compilation List, which states; “The planet’s light cloud cover allows for large day and night temperature fluctuations.”
> # 16 in the Initial Environments Compilation Table references, #16 in the List, stating; “The planet carries large polar ice caps, whose formation subsequently increases the dry land area in lower latitudes.”

Initial Environments Compilation Table


Initial Environments Compilation List
1. Life as we know it may not exist.
2. This is a desert world.
3. Free water may temporarily exist in various locations.
4.  High  average surface temperatures and low planetary escape velocity have resulted in most of the liquid surface water being lost.
5.  Life forms display specialized water use adoptions.
6.  Most of the planets free water has probably been lost.
7.  This is an arid world that has been slowly losing its water.
8.  This is an ice world.
9.  This is a cool temperate world.
10. Low temperatures and high escape velocities may have caused this large planet to retain much of its primitive hydrogen atmosphere.
11.  The planet has a nearly continuous cloud cover, which helps depress day temperatures and elevate/moderate night temperatures.
12.  The planets light cloud cover allows for large day and night temperature fluctuations.
13.  This is a water world.
14.  Continents may not exit; islands may provide the only dry land mass.
15.  This large world has three times the water producing mass of Earth, but only 10% more surface area for the water to cover.
16.  The planet has large polar ice caps, whose formation subsequently increases the surface area of dry land.
17.  Small continents and large islands are probably the main land masses.
18.  This rather large planet has two times the water producing mass of Earth, but only 42% more surface area of dry land.
19.  Forest like vegetation may be the most important land crop.
20.  Grass like vegetation may be the most important land crop.
21.  Desert like vegetation may be the most important land crop.
22.  Tropical type forests may be the most important land crop.
23.  Ice caps are present in the planets polar regions.
24.  Permafrost caps exist in the planets polar region.
25.  The planet has large hot, arid deserts in continental rain shadows.
26.  The sense of smell may be more acute than on Earth.
27.  The sense of smell may be less acute than on Earth.
28.  Communication may not be as sound dependant as on Earth.
29.  Communication may be more sound dependant than on Earth.
30.  Communication mat be by sonar using bat like high frequency echo location.
31.  Low temperatures allow for the formation of very complex molecules.
32.  High temperatures threaten complex molecules.
33.  Cool temperatures result in slower chemical reactions and perhaps longer life spans.
34.  Warm temperatures result in faster chemical reactions and perhaps shorter life spans.
35.  The planets rapid rate of rotation helps reduce day to night temperature differences.
36.  The planets slow rate of rotation increases the day to night temperature difference.
37.  Many life forms on this planet would be described as ‘long and spindly’.
38.  Many life forms on this planet would be described as ‘short and squat’.
39.  Animal life has developed an efficient means of getting rid of internal heat at a high rate.
40.  Animal life has developed an efficient means of generating and storing internal energy at a high rate.
41.  The minimum weight for an intelligent Being with a highly developed brain is 40 to 50 pounds (this seemingly critical lower mass would have different      weights on the various planetary models).
42.  The APST is too hot for permanent polar ice caps. With low axial inclination polar regions would have moderate temperatures, but low illumination.

Star-Planet Energy Relationship Table
In the table, Star-Planet Energy Relationships Table, immediately below, each model planet’s mass and the parameters leading to the average surface temperature are compared to provide the resulting associated: % cloud cover, solar constant and albedo; this information will be useful in filling in the templates that follow in Chapter 10.

Star-Planet Energy Relationship Table

.

Table of Planet Surface Conditions
The Table of Planet Surface Conditions, large sideways chart below, was derived from combinations of the physical parameters existing on our model planets. On the table, you’ll find planetary mass rows listed along left margin. Reading from left to right along each row, you will intersect with columns of various environmental characteristics and potentials associated with that chosen mass (planet size).

For example, let’s examine a 2.0 Earth mass planet: Reading across the table, the conditions we would expect to encounter on that world would be a:
•  L  (large) potential for wind generating energy,
•  M  (medium) expectancy for wide use of buried organics for fuel, i.e.  petroleum/coal,
•  S  (small) expectancy that solar power will provide much energy.

Further along that same row we find the planet has the addition probable characteristics (among others):
•  G  (great/much) volcanism, as compared to Earth,
•  S  (small) mountain height,
•  and, a 150 pound man on Earth would weigh 204 pounds there.

Continuing to read across the row titled, 2.0 Earth mass,but now looking at the far right side of the table,  we find that with;
•  A 0ºC (-32 º F) APST, the planet would have M (medium) or average (somewhat similar) humidity as found on Earth.
•  At 45ºC (113ºF ) APST, the average humidity would be considered VH (very high)  compared with the Earth average.

The Relative Humidity  sub-table (far lower right) was derived from the considerations that:
a) A graded land-water ratio exists on the study planets and that the water coverage to area dry land ratio increases with the mass of the planet.
b) The greater the mass of the planet, the greater the atmospheric density.
c) As the APST increases, the average  planetary humidity increases. On two planets with the same APST: The smaller planet, with a thin, light atmosphere and relatively small bodies of water, will have lower humidity than a large planet with its heavier, denser atmosphere and large bodies of water.

Comparing the various data in the Table of Planet Surface Conditions, you can see that Man could potentially do quite well on some of the model planets, but would be under considerable biological stress under others; examples can be seen below, from an examination of several variables in the following small table, which was extracted from Environments Table IV.

Condition Selected
Conditions
Man’s weight Humidity Atmospheric
Oxygen
1. 1.0 Earth,
APST 59ºF
150 lbs. Medium Medium
2. 0.5 Earth,
APST 32ºF
103 lbs. Very dry Weak / little
3. 2.0 Earth,
APST 113ºF
204 lbs. Very high Much / great

.
Condition 1:  An Earth like planet, used for comparing Conditions 1 & 2 below.
Condition 2: The planet’s lower gravity results in a human colonist weighing less than on Earth. Man is therefore more mobile, physical activity is less taxing and he requires less oxygen; however,  there is less oxygen available in the thinner atmosphere. The planets habitable equatorial region has temperatures in the 41ºF to 45ºF range. Cool temperatures and low humidity would result in outdoor work conditions similar to those encountered during the Fall season in Earth’s mid latitudes.
Condition 3:  The planet’s higher gravity results in the Human colonists effectively carrying an additional 54 pound body weight. High gravity, high humidity and quite warm temperatures would create an environment more difficult for Man to settle. The planet’s habitable temperature zone basically extends from 50º to 70º latitude and carries a rapidly decreasing temperature across the latitudes, from 99ºF to 41ºF across this band. On the positive side, there is a large amount of atmospheric oxygen which would assist in labor and increase the efficiency of converting organics into electricity, etc. The planet would be more ideally suited to a short (about 4 feet tall) and slender intelligent being. This species expansion would probably require specialized adoptions to rid their body of heat. If the planet orbited a F class star, we might expect to find the alien with darker skin pigmentation, particularly in lower latitudes. Warm blooded animal life on such a planet may not have developed heavy fur coats as are found on Earth mammals.

Table of Planet Surface Conditions

.

This study can be used:
1.  To understand star-planet-biological relationships
2.  Determine general planetary environments
3.  Assist in the study of Humans and human technological adaptively under a variety of habitable extraterrestrial conditions.
4.  Back track an intelligent alien, that is, given a description of the intelligent alien’s form you will be able to derive a general model of his home planet, thereby narrowing the range of a) detected habitable star-planet configurations we know of, to date, b) or other Main Sequence stars, from which he came.

See also:
a) The Visual Exoplanet Catalog: < http://exoplanet.hanno-rein.de/complete.php&gt;
b)  The continuously updated list of known multi planetary systems at, <http://en.wikipedia.org/wiki/List_of_multiplanetary_systems>
c) The extra Solar Planets catalog at, <http://exoplanet.eu/catalog.php&gt;

Continued in Chapter 10: Templates

Leave a comment

Filed under __0. SRAPO: Introduction, __Chapter 9: Data Compilation

Chapter 8: Into A New World

Biotic Zones
We began this study with a set of basic rules for the development of intelligent tool using life – as we know it. We said conditions must allow for,
a)  the availability of liquid water, b) the planet would need to have an average surface temperature between 0º and 60ºC, the freezing point of water and the temperature at which protien is denatured, and c) the  planet’s mass should fall within the range of 0.25 and 3x Earth’s mass.
We went on to determine cloud cover, albedo and the associated range of solar constants.
We learned how to calculate the planet’s orbital radius, it’s day and year length.
We considered the intelligent alien’s morphology, it’s height, body build and general need for protective skin pigmentation.
We determined what class of main sequence stars could support a life giving ecosphere and learned how long these stars would remain stable for life to develop.
Now it time for our mind’s eye to float down and settle on these alien worlds.
As a child awakening in a new world, we’ll begin to tie together the things we learned from, a) conditions on mother Earth, b) our understanding of bio-organic chemistry, astronomy, atmospheric physics, etc.
Using the SRAPO construct, we’ll now begin to draw and label images for what we may expect to theoretically find on a given alien planet.
.
Within complexity lies basic uniformity and structure is related to function. Structural shifts occur within the matrix of complexity, but the matrix remains uniform in function. Mr Larry

The patterns of temperature, precipitation and atmospheric circulation carve out the basic land environments on Earth; we can expect these factors to play equally important, roles on other worlds.
.
As we go through our early years of schooling, we learn to associate terms like, ‘equatorial wet forest’ with an area that is hot, wet and jungle like. We call the Sahara, Gobi and Mohave deserts-‘deserts’. Our language can tend to limit our understanding of alien worlds, because we tend to classify environments with a name associated with a mental picture of that environment.
When we are creating planetary models, we need to associate environments with wholistic patterns, combining average planetary surface temperature, atmospheric circulation, illumination levels across the latitudes and biological adaptation. We need to think of an environment as a  process and biological adaptions as shifts with in the matrix of interplay between the given planetary and solar parameters.

By definition, a desert is a region left unoccupied; waste, barren; it is also an arid region lacking the moisture to support much vegetation. Our perceptions of a ‘desert’ relate to the later narrow description, yet in a broader context we can define other deserts, as;
•  Aquatic Nutrient Desert:  Where there is a lack of available nutrients; such conditions exist on Earth’s ocean surface, beyond the continental shelf.
•  Cold Desert:  The continent of Antarctica.
•  Arid Desert:  The arid Gobi, Sahara, Kalahari, Rub Al Kahali, Mohave deserts, etc.
•  Heat Desert:  As located on some of our warmer planetary models; heat is the biologically limiting factor.
•  Illumination Desert: Located near 90º latitude on very warm, low axial inclination planets. Perpetual, extremely low levels of illumination are biologically limiting factors, unless nutriens feed into the illumination desert from biologically active areas.
.
The pattern in which each of Earth’s biological communities have developed was influenced by temperature, precipitation, atmospheric composition and circulation, axial inclination, planetary mass, stellar spectral class, the existence of other orbiting bodies (‘moon’, binary star system), etc. If we shift the values of any of these variables on  Earth, there would be a direct impact on the morphology, size and distribution of our biological community, changing them away from what we hyave considered the norm. The norm that we find on extraterrestrial worlds will have developed under their own interplay of planet-star conditions. Intelligent, tool using creatures may seem quite different from what we’re accoustomed to at first glance, but only because they developed from their own unique mix of conditions. They are products from within the same matrix of physical proscesses, just shifted from what is found and called ‘normal’ on Earth. The greater the shift with in the matrix, the more uniusual they will seem, at first.

Equatorial Wet Forest
On worlds with low to medium axial inclination and moderate APST, we can expect to find wet forests in equatorial regions. This zone will have an average temperature 5ºC to 15ºC (9ºF to 27ºF) above the APST and a precipitation rate 50% greater than the planetary average. When compared with the planet’s polar region, the equatorial wet forest will have a greater variation between day and night temperatures, but would remain nearly constant, or only gradually changing on a day to day seasonal basis. Since precipitation would be relatively plentiful, the plant community would have to compete primarily for  sunlight, as a result, some of the tallest plants on the planet would be growing here. If an aerial canopy develops, we could expect a wide variety of shade tolerant plants on the forest floor. The equatorial wet forests moist conditions would be ideal for bacterial and insect life, which would function to bring about the organic decomposition of plant and animal organic material.

Arid Desert Zone
In the high pressure zones above and below the Equatorial Wet Forest exist discontinuous belts of relative arid Desert. The extent  of the Arid Desert across the planet’s land mass will depend on the planetary mass, APST and axial inclination. On our model worlds, any area receiving about 10 inches or less of annual rainfall may be considered an arid desert. Keep in mind that ‘annual’ refers to Earth’s 365 day year. If the model planet has a Sidereal Period twice Earth’s and day length remained the same) the arid desert would only receive half as much precipitation.

Arid Deserts on Earth occupy 14% of the terrestrial environment. They characteristically have a temperature range of 4ºC to 32ºC (39ºF to 89ºF) with an average of 23ºC (73ºF). The Arid desert has a hot, dry climate and is found to register the planets hottest surface temperatures. Plant life which has adapted to the dry, hot climate display biological adoptions for water collection and retention. On the hottest planets,  many desert plants may display reverse phototropism; an hour after the sunrises, the plant may close its leaves, only to reopen them an hour or so before sunset. Succulent plants would have either a small leaf or no leaf at all, with photosynthesis occurring through the plant stem, as in the Barrel cactus and Saguaro cactus. The bulk of the trunk in these plant’s are composed of water storage cells; while the volume of the shoot is large, the surface area is small. This results in a large storage area for the areas biologically limiting factor, water, and a relatively small area from which they can lose their precious liquid reserves.

Non succulent plants will be modified with leathery leaves, thick cuticle layers on the outer surfaces of their leaves, they may have the ability to fold and curl, also leaves will likely be small. An example of a plant displaying many of these characteristics is the Creosote bush found commonly in the US southwestern arid desert.

In arid deserts, both succulent and non succulent plant species would have extensive root systems for water collection and potentially as locations for water storage.

Chemical inhibitors may also be used to maintain territory. This would result visually, in a more or less even spacing of the plants across the desert.

Other plants which have adapted to the Arid Desert might undergo their entire life cycle in that brief period when moisture was available. These ‘annuals’, with their fast growing shoots would die after the end of the moist season, leaving their seeds and/or a viable root system to lie dormant until the next moist period.

Animal life in the Arid Desert would tend to be either the small burrowing variety or larger, but thin. Due to the extreme temperatures, large animal life would have small body volume to large surface area ratios.

In these climatic conditions, both plant and animal life will have made specialized adoptions to reduce water loss; these adoptions may be biological or by technique or both.

Prairie & Grasslands
The condition of a temperate climate coupled with erratic and limited rainfall can extend grassland communities from the equator to near the polar region. On Earth, the grasslands have an annual precipitation rate that falls between 25%  (10 inches) and 75% (30 inches) of the planets average. These areas are typified by small short lived plants, mainly annual and perennial herbs, relatively little rain, good fertile soil and numerous large herbivores.

In temperate regions on alien worlds which receive similar precipitation, we might expect to find similar types of biological adoptions. We might also expect to find such regions under agricultural use as fields or pasture amongst intelligent species.

While the plants and animal living in these zone will certainly look exotic, we will understand from their distribution and general adaptations to the limiting factors in the environment that they fill the same or similar roles in the ecology of the communities in which they live.
.
Cool Forest
The temperate forest regions of Earth’s mid latitudes are extremely complex in their makeup and adoptions to temperature and moisture availability. Across broad regions of our own planet, the cool temperate forest experience temperatures ranging from -34ºC to 27ºC (-29ºF to 81ºF) with an average of 3ºC (37ºF) and precipitation rates of 10 to 60 inches per year.

The ability of a plant to survive freezing temperatures is called ‘frost resistance’, this ability varies widely among different species and is normally seasonal.

On cool and mild APST planets with low rates of axial inclination, frost resistant species would be found primarily in the mid to higher latitudes. As we encounter increased rates of axial inclination, frost resistance would tend to migrate closer to the equator. On planets with a very high  degree of axial inclination and mild temperatures, we would  find most plant species specialized with both frost resistance and heat tolerance. On such worlds, we might find plants going through a growing cycle where their cells are partially filled with an electrolyte during the winter, forming a biological antifreeze. As winter gives way to spring and spring to summer, the electrolyte might gel into a paste, reducing water loss. Then as the climate cooled, the paste would dissolve back into antifreeze.

Ice Caps, Tundra and Snow Fields
On many of our model worlds, we should expect to find the existence of ice caps. On the cooler worlds we will find thicker ice caps in the polar regions, with snow fields extending in various coverage down to mid latitudes. Cooler planets with a low degree of axial inclination will have permanent ice caps. Warmer planets, with a high degree of axial inclination, will have ice sheets and snow fields that migrate with the season, similar to winter snow across northern latitudes on Earth. On planets with a high degree of axial inclination the plant and animal life with have a high degree of cold and heat tolerance, species migration may be an important part of many large animal life forms and hibernation a retreat from the cold for most of the smaller less mobile creatures.

Ice caps are bordered by Tundra in terrestrial environments. As we move up through the APST range, we could find the Tundra and Ice Caps at progressively higher latitudes. Eventually the ice cap is replaced by diminished snow fields. As the APST approaches 60ºC, the Snow fields melt away and are replaced by a low illumination environment.

If we compared two planets of the same mass and axial inclination, the planet with the higher APST would have the smallest ice cap. If we compared two planets of same mass and APST, the planet with the smallest axial inclination would have the largest permanent snow fields.

On warm planets with moderate to high axial inclination, the ice cap may completely disappear during that hemisphere’s summer. The activity of the biotic community on alien worlds will be similar to that on Earth as each season is experienced. The hemisphere entering Spring, a time of increases sunlight and warmth,  will come out of winter dormancy and experience growth.

In the hemisphere entering Fall, the biotic community will be gearing down for the approaching Winter. The plants will winterizes, the animals will migrate, build up energy reserves, prepare for hibernation and/or utilize other adaptive mechanisms.

On planets with approximately a 30ºC APST, we may find the absence of true ice caps. In their place may exist the relatively more temperate permafrost fields with perennially frozen ground or nearly permanent frost.

Frost caps require an annual temperature of about -3ºC (26ºF) or less in order to exist; however, the temperature range over the entire area may run from -36ºC to 4ºC (-32ºF to 39ºF). Precipitation in these regions is under 15 inches per year. Climatic conditions in the permafrost zone is are cold and dry, with long winters and cool summers.
[Illustration at right: Ice Cap & Snow Field expansion on a cool planet with varying degrees of axial inclination.]

On any world with a permafrost region either covering the poles or circumventing the icecap, an explorer would find large expanses of flat land and rounded hilly terrain, where the effects of freezing and thawing would have reduced rocks to small particles. The soils of these regions would be poorly drained and poorly aerated on planets with low axial inclination and just the opposite planets with high axial inclination.

Remember, if the planet were orbiting a relatively cool G9 or K0 spectral class star, it’s orbit would be near the star, providing a short year. If the planet orbited a much hotter, F24 or F4 star, its orbit would fall further from the star giving it a year perhaps twice as long as our own, hence a ‘quarter year’ of about 6 months- plenty of time for small plants to go through their life cycle, or even a couple of generations.

Permafrost environments are typically a low energy areas offering little year around food to the larger animals. Most of the animal life consists of small burrowing types with insulated feet and various seasonal visitors. I suspect that small animals would inhabit permafrost regions on planets orbiting cool stars. Larger migrating species would be more important on planets orbiting hotter stars, where the growing season is longer, where a larger deposit of biomass has accumulated and where the season length would allow the larger species to migrate.

Small (short height) plant life would only have a few months, depending on the planets sidereal period (length of year) to carry out their life cycle before
reduced temperatures would bring about dormancy.

Planetary Bio-Zones, Plant Growth & Limiting Factors 

On all of our model worlds, we could expect to encounter a mix of the following environments: cold, warm or hot arid deserts, rivers, marsh land, fresh water lakes, bays, hills, meadows and plains. We would expect to find a vast assortment of analogous physical surface structures, i.e., rock, sand, gravel, humus with partially decayed organic material, cliffs, etc. We would see common atmospheric phenomena, the parent sun in the sky, stars visible at night, fog, rain, snow, wind, clouds, storms-all with great variation in quantity, frequency and  intensity as the stellar and planetary parameters were varied.

The biological community whose evolutionary histories track back through a particular environment, will display adoptions peculiar to that environment. It’s also reasonable to believe that similar environments on different alien worlds will tend to carry life forms who share somewhat similar morphological and very general behavioral patterns.

Atmospheric Circulation & Biotic Zone Diagram
The following Illustration: Atmospheric Circulation and Biotic Zones provides a general view of the effects of precipitation and atmospheric circulation.

This planet’s biotic communities exist somewhat in bands that tend to change with latitude. Earth type vegetation has been symbolically drawn along the planets curvature in an attempt to trigger a conceptualization of the processes that occur in each biotic zone. While studying this illustration, keep in mind that:
•  As the mass of the planet increases, gravity increases, resulting in generally shorter, more squat looking plants and animals. Also, the land to water ratio decreases-leading to less dry land and more water on the larger planet.
•  If the APST were increased, the biotic zones would migrate toward the poles. Conversely, decreasing the APST would cause ice caps, tundra and snow fields to expand toward the equator pushing all other biotic zones before them. With a very low APST, the wet tropical forest might simply disappear, giving rise      to an equatorial temperate forest.
•  Biotic zones and land-to-water ratios expand or contract as we adjust the various parameters examined in this study.

Biotic Zone diagram

In relation to the Biotic Zone diagram, also see below, the Relative Precipitation-Solar Radiation-Vegetation diagram and the  Latitude – Temperature Tables.

Relative Precipitation-Solar Radiation-Vegetation diagram

Latitude – Temperature Table

High latitudes Mid latitudes Low Latitudes
Temperature may  constrain life. Combination (local   climate) Precipitation constrains life
High annual   temperature variation. Temperature   variations greater inland than coastal. Low annual   temperature variation.
 Low daily temperature variation. High daily   temperature variation.
Low storm activity. Storm rates increase over land, decrease over sea. High storm activity.


Spring: Land heats up fast developing low pressure areas, sea develops a high pressure system.
Fall: Water remains warmer and develops a low pressure system, high pressure developers over land.
Planets with low to moderate axial inclination (little tilt) will generally provide increasingly lower temperature, stable temperature bands as one moves from the equator toward the poles.

Planets with a moderate degree of axial inclination will experience pronounced seasons as the year progresses. During the summer, that hemisphere tilted toward its sun will experience seasonably higher temperatures. A half of their year later, when the previously warmer hemisphere is tilted away from its sun, it will experience seasonably low temperatures. These seasonal temperatures create an overall average temperature for each latitude and region.

On a planet with no axial inclination, each latitude would still have a narrow annual average temperature between it’s ‘summer highs and winter lows’, this derives from the probability that the planet’s orbit is not a perfect circle about the parent star, a condition similar to Earths orbit. The extremes for all latitudes, on either side of the average, would be eliminated by the lack of axial inclination.
On Earth, the average annual temperature for a given latitude is that temperature the latitude would have if Earth had a 0º, instead of 23-1/2º axial inclination.

Shown in the Biotic Zone Table below, are the annual average planetary surface temperatures for each latitude. Since we have eliminated the temperature variation by using ‘average temperatures’, we can in effect say that if these temperatures were maintained throughout the year, that the planet has no axial inclination.

Lets now say that on any planet where there is no axial inclination, the temperatures vary with latitude just as they would on a Earth with no axial inclination. If this is so, we can compare temperatures with latitude for planets displaying all the APST used in this study. We should  remember that the resultant temperature models provide:
•  The annual average temperature for each latitude on a planet with 0º axial inclination, or,
•  the annual average temperature for each latitude as derived from the overall seasonal variations on those planets with axial inclination.

In the Biotic Zone Table, compare temperatures (in degrees Fahrenheit and Centigrade) with latitude for each of our planetary models.
Earth equivalent biotic zones have been colored into the chart showing the migration of  plant life related to APST.
The temperatures given in the table were calculated as follows:

Example #1: 140ºF (hot planet’s APST) – 68ºF (Earth’s APST) = 72ºF difference (on hotter planet)
Therefore, 72ºF hotter (in general) + 81ºF at Earth 0º latitude (equator) = 153º F at 0º latitude (equator) on hot ASPT planet.

Example #2:  68ºF (Earth’s APST) – 32ºF (cold planet’s APST) =  -36ºF cooler difference (on cooler planet).
Therefore,  -36ºF cooler (in general) + (-4ºF on Earth at 70º latitude) = -40ºF at 70º latitude on the cold planet.

Look across the top of the Biotic Zone Table to locate 113ºF, then read down the column to find the approximate surface temperature at a given latitude. On a planet with an APST of 113ºF, the equatorial temperature would be about 126ºF, at 60º latitude it would be a warm 80ºF  and a cool 41ºF at 70º latitude.

Drawn to overlay the preceding table are the color coded, approximate temperature and latitude boundaries, of the various biotic communities found on Earth. I’ve extended the APST range an additional 15ºC on either side of the conditions used in this study to demonstrate the serious deterioration of the planets habitability, see double blue and double red verticle lines toward either side of the chart.
In the column at far right, Earth’s APST (average planetary syrface temperature) and general biotic conditions per latitude have been included for comparison.
Note that the biotic community we are accustomed to on Earth, would be seen to shift toward the planets equator with a reduction in the average planetray surfave temperature; conversely, the biotic zones would shift toward the poles with an increase in APST.

In order to better understand the migration of biotic zones and the general climate of our model planets, I’ve included the illustrations below showing and equatorial and polar view for each 15ºC change in APST within the SRAPO filter parameters. An Earth model has been included for comparative reference.

Model illustrations on the left, provide an equatorial view of the planet with latitudes shown on the extreme left and temperatures on the right.
The models on the right, are shown in a polar view. The numbers entered above the pole are latitude and number below are the average temperatures for the given latitude.

ILLUSTRATION: APST, LATITUDE and ENVIRONMENT MODELS.

Environmental Limiting Factors & The Plant Community
The planetary models we looked immediately above, have no axial inclination, we were determining the average temperature for a latitude;  the length of the day to night cycle made no contribution. The parent star will rise and set in the same locations daily. Each day at local noon, the sun will have risen to it’s highest point in the morning sky and will begin its move lower in the afternoon sky. The elevation the sun rises to above the horizon al local noon will depend on ones latitude on the planetary surface.

On a planet with no axial inclination and 0ºC APST, plants in the equatorial zone, below 25º latitude, would be exposed to nearly perpendicular sunlight at local noon.

On planets with0 to 30ºC APST, most of the plant communities exist below 60º latitude. In these locations, the noon sunlight comes from a position relatively high in the sky. This results in the tropical and cool forest developing ‘ vertical light gathering stratification’. Hence we would find fungi located in the lower strata, rising above the fungi would be the shade lovers, then the shade tolerant and finally a canopy of sun seekers.

On 0º axial inclination planets, with 45ºC to 60ºC APST, the  majority of the plant community exists above 45º latitude. Under these  conditions, the tropical and cool forest would tend to develop ‘horizontal light gathering stratification’. On the equatorial side of the forests reaching deeper and deeper into the hotter zones, plants would decrease in size or biomass, attempting to adapt to extreme temperatures. On the polar side of the forests, plant life would again decrease in size or biomass, but this time light would be the limiting factor.

The following, illustration, Relative Plant Size and Biomass Per Unit Area, uses APST, latitude and various biological limiting factors to assist in developing a feeling for plant height and /or biomass per unit area, for various latitudes across a planet’s surface.

Also, remembered that gravity affects height, so that the largest or tallest plants on a 3.0 Earth mass planet will be considerably shorter than the tallest plants on a 1.0  or 0.5 Earth mass planet—that is, if all parameters are equal except planetary mass.

The  0ºC APST’ model in the  illustration shows short plants growing at around 30º latitude, this planets tundra zone. This biologically limiting, cold environment, rapidly gives way to a cool forest which extends from about 25º ‘north (and south’) latitude to the equator. With the sun passing nearly over the habitable equatorial zone, we would expect to find the plant communities of the cool temperature forest well developed into vertical light gathering strata.
.
Illustration: Relative Plant Size and Biomass Per Unit Area

The 60ºC APST (140ºF average planetary surface temperature) model has short, ‘shade loving’ plants in the biologically limiting, dimly lit, twilight like polar region. With a decrease in latitude and subsequent increase in elevation of the mid day sun, the cool temperature forests develop a fierce competition for light. Around 60º latitude, the damp. Warm and fairly well illuminated conditions produce a tropical type forest canopy which carries the tallest plants on the planet. Below 60º latitude, increasing temperatures tend to overcome moisture availability where upon plant size or biomass per unit area must be reduced to thwart starvation.
Approaching 30º latitude, the high pressure system creates arid conditions. This area is not only arid, but extremely hot, with air temperatures 10ºF above that required to destroy protein. From about 30º latitude and down to the equator, temperatures tend to become the biologically limiting factor. (Note: For comparison, its recommended that we turn adjust the water temperature in our home hot water tank from 140ºF to about 120ºF to reduce the chance of being scalded).

On a planet with a large mass, i.e. 2.0 to 3.0 Earth mass, the dry land area is quite small compared with the area covered by water, therefore, at 60ºC APST, a dry land area located at 30º latitude would not be arid, it would be for us, an environment of extreme heat and severe humidity. On such a world, at 30º latitude, our bodies would feel like they were in a 140ºF sauna. We wouldn’t feel comfortable until we relocated to 70º latitude where 70ºF air temperatures would be found; equivalent to being above our ‘Arctic Circle’, in Finland, Alaska, northern Russia, northern Canada, Greenland.

Continued in Chapter 9: Data Correlation

Leave a comment

Filed under SRAPO (Stellar Radii and Planetary Orbits), __Chapter 8: Into A New World

Chapter 6: Stellar Parameters

 Stars are originally formed from local condensations of interstellar gas and debris.
As the dust cloud contracts, it forms a relatively dense opaque sphere which is not yet hot enough for the occurrence of thermonuclear reactions.
The protostar continues to contract under its own increasing gravitation and begins to convert gravitational potential energy into heat and light. As time passes, the protostar continues to contract while its surface temperature increases. At a critical temperature, the atoms and ions within the interior of the star have begun moving fast enough to exert a balancing pressure against the weight of the overlying material. At this time, contraction ceases and a condition of near equilibrium begins.

The Main Sequence
Once the young star has reached equilibrium, it’s luminosity and surface temperature remain stable for a very long time. Stars having achieved this long-term stability are  said to be ‘Main Sequence stars’.

Please study the following, Hertzprung-Russel Diagram. As you look at the narrow sequence of stars that run across the H-R Diagram, from the upper left to the lower right, note that stellar luminosity and surface temperatures decrease incrementally between spectral class O through spectral class M.
As you move from upper left to lower right in the the diagram, the Main Sequence stars become cooler and less bright.
Its difficult to show in the diagram, but the color of the stars change as they become cooler, with the hottest stars being blueish, then white hot , then cooling to white-yellow, yellow, yellow-orange, orangish and finally, to small reddish stars.
On a clear night when you’ve been outdoorslooking at the stars, did you notice that some twinkle bluish, some white and some twinkle reddish? The color you saw is related to the star’s temperature and its stable period.

Residence on the Main Sequence
A star’s initial mass determines it’s length of stability, hence residence on the Main Sequence. See Table: Stellar Parameters below; and compare Mass (where p, our Sun, =1 for comparison) with a Stable Period (in billions of years) for the various stellar classes.

A large, hot, luminous star like a spectral class F2, uses its fuel rapidly, becoming unstable after maybe 3.47 billion years. A  smaller, cool, dimmer star, like the G9 spectral class uses its fuel much more slowly, giving it a stable period of 9.3 billion years. Other examples of this are;
•  A star of Spectral class B0 has a mass roughly 17 times that of our Sun, a surface temperature of about 20,000K and  a Luminosity 30,000  times greater than the Sun. This class of Main Sequence star radiates a very large amount of light and heat into space. Quickly using up its hydrogen fuel, it provides only an 8 million year period of stable energy output.
•  Stars of Spectral Class K0 have a Mass of only 0.74 and a Luminosity 0.28 of our Sun and a Surface Temperature of 4685K.      The K0 class of stars radiates relatively small amount of light and heat into space; slowly burning  their hydrogen fuel, they have a 28 billion year stable period of residence on the Main Sequence.

Lets assume that a star must remain stable for 3-1/2 billion years before intelligent, tool using life develops in its ecosphere. This assumption means that evolution occurred there considerably faster than it has on Earth; a process that could be accelerated by other stellar or planetary surface conditions.

A star of Spectral Class F2 has a 3.47 billion year residence on the Main Sequence, it is here that we will draw the upper limit for stellar luminosity and surface temperatures.

Table: Stellar Parameters

.

Table: Tidal Retardation and Stellar Spectral Class

Spectral   Class

<   G6

G7

G8

G9

APST   restrictions –
if any.

All habitable APSTs may exist through G6 class stars. 45ºC  to 60ºC max. APST for G7 class stars. Only 45ºC and lower APST for G8  stars. 30ºC and lower for G9 class stars.
Spectral   Class K0 K1 K2   >

APST   restrictions –
if any.

Only 15ºC and lower for K0 stars. Around   0ºC APST only for K1 stars. There is tidal retardation over the entire habitable APST range.

APST= The average planetary surface temperatures used in this study, ranging from oºC to 60ºC.

Between G7 and K1, only those planets with progressively cooler APST can be considered for this study. We will draw the lower habitable limit of stellar luminosity and surface temperature at spectral class K1.

Planetary models with average surface temperatures between 0°C and 60ºC can only exist in orbit around stars of spectral class,
F2 (upper limit), due to it sshort 3.47 billion year stable period and K1, below which the planet’s rotation is stopped.

Computing Sidereal Period and Orbital Radius
Early in this study, we learned that by starting with a planet’s average planetary surface temperature (APST), we could trace our way up through the atmosphere, adding on the Albedo energy losses, etc. and finally end up with the planet’s Solar Constant  at the top of the atmosphere.
We can now choose a Main Sequence star between Spectral Class F2 and K1, and by using the planet’s Solar Constant, determine the planet’s Sidereal Period (year length) and Orbital Radius (distance from star).
Please note that the Orbital Radius, Spectral Class and related Sidereal Period, are conditions which help create the Solar Constant on a model planet.

In the next graph, Computing Sidereal Period and Orbital Radius, I have eliminated the computations so that one need only read the graph in order to determine a planet’s sidereal period and orbital radius.

Let’s read through the graph once to see how it works:
Suppose that your planetary model has a Solar Constant of 1.5 Earth’s and that you wish to place this model in orbit around a F2 Spectral Class star:
Step 1.  Locate the 1.5 Earth equivalent Solar Constant on the bottom of the graph and read up until you intersect with the F4 Spectral Class curve.

Graph: Computing Sidereal Period and Orbital Radius

Step 2. From this intersection, read directly to the graph’s left margin and read the planet’s Orbital Radius, which in this example is 1.25 AU (25% further from the F4 star than we are from the Sun).
Step 3. Using a ruler or other straight edge, read from the 1.25 AU across the chart to the far right, until you intersect the curve on the Sidereal Period graph.
Step 4. From this intersection, drop a line straight down to the bottom of the graph and read the planets sidereal period (length of year relative to Earth), which in this case is 1.4 Earth years.
.
[Note, if you have turned to the graph above, Computing Sidereal Period and Orbital Radius, from the graph, Determining Solar Constants in Chapter 2, you will need to convert the ‘actual Solar Constant’ from cal/cm2 min into the ‘solar constant in Earth equivalents’ (where Earths normal =1) , by dividing the model planet’s Solar Constant by 1.97 cal/cm2 min. Usethe equation below, otherwise use the previous steps to determine  Sidereal Period and Orbital Radius.)
Conversion factor, if needed:  (2.95 cal/cm2 min)/ (1.97 cal/ cm2 min)= 1.5 as used in the example above.   ]

If you wish to do the calculations on your own, the equations are provided below,

R = /(L/Se)  and  R3= P2

R  = Orbital radius in Astronomical   Units (AU)
L  = Luminosity of the star relative to that of the Sun, so that  Š =1
Se= The model planets Solar Constant relative to Earth, so that  Ê = 1
P  = Sidereal Period, relative to Earth, so that Ê = 1

To convert orbital Radius from AU to miles, multiply

R (miles) = R(AU) * 93,000,000 miles/AU

 

Converting 24 Hour Earth Days to Alien Planet Days
In the previous example, we found that a planet with a Solar Constant of 1.5 (relative to the Sun), orbiting  a F4 Spectral Class star has a Sidereal Period 1.4 times as long as Earths, so that,

1.4 (sidereal period) * 365 days per Earth year = 511 Earth days per year for this particular model planet

During our discussion of planetary rotation in Chapter 2, we found that a planet’s mass is related to it’s rate of Rotation. See Table: Planetary Parameters, row ‘Rate of Rotation’, Chapter 2.  Note that a planet of 2.0 Earth mass has a 14.4 hour rate of rotation; it’s day is 9.6 hours shorter than our  24 hour day length on Earth.

The preceding equation gives the planet’s year length (Sidereal Period) in terms of Earth days. It is important to convert from Earth length days to alien planet length days, in order to gain a clearer perspective of the interaction between life forms and their duration of exposure to heat, cold, light, ultraviolet radiation, etc.

Consider the following examples;
•  If an American service worker spends 1-1/2 hours per day commuting to and from work, has a 1 hour lunch and 2 each 15      minute work breaks, he has spent 3 hours or 12.5% of an Earth standard 24 hour day, basically idle. If an alien worker living  on a 2.0 Earth mass planet with a 14.4 hour day, spent as much time commuting, eating lunch and on work break, those 3 hours we took would account for 20.6% of his ‘day’.
•  On a hot, arid desert, temperatures climb rapidly during the first hour after sunrise and begin to decline an hour before sunset.
On Earth, a desert inhabitant would have about a 10 hour exposure to extreme heat; however, a desert inhabitant on our model 2.0 Earth mass  planet, with its faster rate of rotation, would only have about a 5-1/4 hour exposure to extreme heat.
•  Survival, in a habitat  hostile to unadapted life forms, depends on the degree and length of exposure to the life limiting elements.

Converting from the number of ‘Earth Days per year’ to the number of ‘Alien Planet Days per ‘year’

Equation: Pa = (Pe*365 days*24 hours)/N

Pa = Sidereal Period in Alien days
Pe = Sidereal Period relative to Earth (where  Ê = 1)
N = Rate of rotation for the model ‘alien’ planet,  in hours.

From our previous example:
How many Alien days are there on a 2.0 Earth mass model planet which is orbiting a F4 star and having a 1.4 (w=1) Sidereal Period? Using the previous equation:

Pa = (1.4*365 days*24 hours)/14.5 hours

Pa = 845 Alien days is the length of  this model planet’s year
This model planet has a year length of 845 days, while each day is 14.5 hours long.
.

Stellar Rotation
It’s currently felt that stars which are accompanied by a planetary system, have transferred most of their angular momentum to the planets.
In our own solar system, only 0.1% of the mass, but 98% of the angular momentum is tied up in the planets.
If the planets did not exist, the Sun would rotate once on its axis every 12 hours, instead of once every 25 days as it does.

When considering Main Sequence stars, there is a large decrease in the rotation rates between spectral classes O through spectral class A; however, the rate of rotation remains fairly constant between spectral classes F through S, this is thought to be the result of these cooler stars having transmitted their angular momentum to planetary systems in their domain.

 Table of Observed Stellar Rotation Rates

Planetary Systems
The space environment, around potentially habitable stars systems spectral class F – S, is likely to contain many of the same planetary orbiting bodies as are found in our Solar System. The general mass range of these bodies may include:  one or two stars, super planets, rocky planets, planetary satellites (moons), asteroids and comets; our system contains all these bodies except a super planet.

Alien intelligence may find their solar system containing a different numerical mix of orbiting masses, but if they ever develop a technical phase they would deduce the same laws regarding nature as we have.

Whether you have a 24 hour day and 365 day year, a G2 class star, 1.0 Earth mass planet with cool temperatures, or a 14.5 hour day and 845 day year, F4class  star, 2.0 Earth mass planet with warm temperatures is immaterial. The laws of physics and chemistry are the same on both and all planets.
Water will freeze or evaporate under similar conditions of temperature and pressure. Carbon will form with oxygen to make carbon dioxide, rain will soak into the soil and excess will run off in rivulets seeking to accumulate in lower areas, ie lakes or seas.
The poles on planet’s with low axial inclination will be much cooler than the equatorial regions.
Life will develop to make use of and extract stored energy in the environment.
During much of the planets habitable period there will be a Darwinian explosion in the number of life forms, representing greater diversity with occassional environmentally imposed fluctuations. Later, as the parent star becomes less stable, there will follow a several million year Post Darwinian collapse, extant life will become simpler in a habitat less capable of supporting life.

Continued in Chapter 7: Morphology of Intelligent Life

Leave a comment

Filed under SRAPO (Stellar Radii and Planetary Orbits), __Chapter 6: Stellar Parameters

Chapter 5: Atmospheric Retention

At the beginning of this study, we  set the upper and lower limits for our planetary models at 0.25 and 3.0 Earth masses. The lower limit denoted a small planet which was in  the process of losing its water. The upper mass was the largest planet capable of losing its reducing atmosphere and still retain a potentially habitable average planetary surface temperature. Let now look at how these parameters were derived.

Exosphere Temperature
The outer most region of a planet’s atmosphere is called it’s ‘exosphere’. It is from the exosphere that molecules of atmospheric gasses, i.e.,, hydrogen, helium, water molecules, nitrogen and oxygen escape into space.

There are three basic factors at work in the exosphere which result in the loss of atmospheric gasses, these are:

  1. The planet’s gravity. Gravity is related to mass in such a way that the smaller a planet’s mass, the weaker its gravity. The weaker the gravity, the easier it is for a gas molecule to reach the planets escape velocity and become lost from the atmosphere. Compare the Planetary Mass, Gravity and Escape Velocities listed in the  previous, Table: Planetary Parameters Table, .
  2. The molecular weight of the gas is important: water  (H20) has a molecular weight of 18 and can escape from the atmosphere much more easily than oxygen (O2), which has a molecular weight of 32.
  3. The exosphere temperature: A cool exosphere temperature provides less of the energy required for gasses to escape.

Below is the method I used to determine a formula for calculating exosphere temperatures.

 Table: Comparative Cloud Cover & Exosphere Temperatures

Planet Exosphere Temperature ºK APSTºK Cloud Cover% Exosphere Temp/APST
Venus ~ 2500 ~ 426 100 5.8
Earth ~ 1650 ~ 293 ~ 47 5.6
Mars ~ 1200 ~ 223 ~ 10 5.4

From the table above, I divided each planet’s exosphere temperature by it’s APST providing the results listed in right most column, ‘Exosphere Temp/APST’. The average of these numbers, 5.6, was used as a rough constant, that when multiplied by the APST (ºK) of any of our planetary models, should give a close to actual exosphere temperature (ºK).

In order to calculate exosphere temperatures, first convert degrees Centigrade or degrees Fahrenheit into degrees Kelvin, then multiply your result by the constant, 5.6.

CONVERSIONS:

From Centigrade to Kelvin: APST ºC + 273 = APST ºK

From Fahrenheit to Kelvin: [(APST ºF – 32) * 5/9] + 273 = APST ºK

 Exosphere Temperature (K) = APST (K) * 5.6

By inserting each of our theoretical APST into the preceding equation we find the range of possible exosphere temperatures, seen below in the Table: Average Exosphere Temperature Range.

Table: Average Exosphere Temperature range

APST (ºC) 0 15 30 45 60
Exosphere Temperature (ºK) 1528 1613 1696 1780 1864

.

Determining Atmospheric Gas Retention
In order to determine what gasses would be retained in the atmosphere for about 5-1/2 billion years, it was necessary to compute the Mean Square Root Molecular Velocity of an unknown gas. See Equation #1 below. Then using Equation #2, the molecular weight of the gas was found.

Equation #1 Equation #2
c = Ve/R M = 3rt/c²
c =  Mean square root molecular velocity
M =  Molecular weight of the gas
Ve =  Velocity of escape
r =  Constant: (8.314*10^7 erg/C mol)
R =  Retention factor
t =  Exosphere temperature C

.
The Atmospheric Component Retention Table, seen below, shows what gasses are being retained or lost from the planet’s atmosphere. The separate, vertical red lines labeled, “Low Exo Temp” and “High Exo Temp” are the outside boundaries for the average exosphere temperatures previously determined, therefore encompass the 0ºC to 60ºC APST range used in this study.

The horizontal blue line labeled H2O (with a molecular weight of 18) is the upper limit for retaining water vapor in the atmosphere.

Where the  sloped, brown planetary lines remain below the molecular weight of 18, conditions favor the retention of water vapor, above 18 and the water will eventually lose its water. A 0.5 Earth mass planet (1/2 Earth mass) can be seen slowly losing its water at higher APSTs. The 0.25 Earth mass planet (1/4 Earth mass) is losing its water , therefore becoming more and more arid, across the habitable temperature range.

At lower APST, a 5.5 billion year old, 0.25 Earth mass planet may still have considerable water tied up in ice in mid to high latitudes. Life on these worlds may be very active along the seasonally melting permafrost regions. At higher temperatures there will be less water on the planet’s surface, because of the lack of substantial or any, ice caps.

Volcanism, geysers, etc., may be important in maintaining habitable zones. In any case, there will still be considerable water tied up chemically across the face of the planet. Please note that Mars with only 40% our hypothetical 0.25 Earth mass planet (1/10 Earth mass) is thought to have polar accumulations of frozen water and frozen CO2  (carbon dioxide). [Written in the 1980s – lfp]

We should view the small 0.25 Earth mass planet as a planet that is slowly drying up. It did not have much water to begin with (relatively speaking) and after 5-1/2 billion years it has considerably less. We should also realize that our calculations have been aimed at a 5-1/2 billion  year residency of potentially loseable gasses. If the planet were, lets say, 3-1/2 billion years old, there would be more water available. A large asteroid or comet strike every billion years or so would bring about more volcanic activity and release meaningful quantities of H2O (water) from the planet’s crust, being favorable for the creation of life, yet a hazard to existent life.

All of the planets in this study can be seen to have retained oxygen in their atmosphere. (molecular weight 32). Note, however, that the large, 3.0 Earth mass, planet has barely lost its primal atmosphere envelope of hydrogen.

Continued in Chapter 6: Stellar Parameters

1 Comment

Filed under SRAPO (Stellar Radii and Planetary Orbits), __Chapter 5: Atmospheric Retention

Chapter 4: Atmospheric Circulation

The next variable we’ll consider in determining the general climate on a model planet, is it’s atmospheric circulation system.

The surface wind systems with their distribution of atmospherically absorbed solar energy and powers of precipitation and evaporation, are immensely important in creating climate and determining basic direction in which biological adaptations must be made.

At the beginning of this section, I should point out that my use of the terms, ‘tropic’ and ‘subtropic’ are not meant to suggest jungle or climatic conditions similar to those found on Earth, but as geographic locations and ‘conditions relative’ to the given average planetary surface temperature.

The tropic region is that area extending about 20º latitude on either side of the point perpendicular to the planet’s parent star, for most of the models, this is above or somewhat near the equator.

The average temperature of tropic (usually, but not always equatorial) regions on the planet models used herein, extend between 41ºF and 151ºF, depending on the selected model.

The sub tropic region, is an area about 25º latitude above and below the point perpendicular to the planet’s sun. Let’s consider the basic planetary climatic zones, seen in the illustration below.

The tropical, subtropical, temperate and frost zones on our model planets may be nearly stationary and relatively tranquil, as in Figure A; or they may move up and down across the latitudes with specific seasons, seen in Figure B; or they may move across longitudes with sweeping change, as in Figure C.

Air movement
Air close to the ground in the tropic zone absorbs ‘relatively’ large amounts of heat. As this occurs, the capacity of the air to hold moisture increases and the warm mass of air begins to rise in the atmosphere. The rising air is replaced by cooler air as it moves onto progressively cooler regions.  As the warm air cools, it looses it’s ability to carry moisture, where upon the excess moisture is lost through precipitation.

The cooling air mass continues to move away from the tropic zone toward those areas which receive a lesser amount of seasonal sunlight/ As the air moves, it further cools and begins to sink.

In order to gain a background understanding of atmospheric circulation we’ll now discuss only those planetary models with relatively low angles of axial inclination.

Around 35º latitude, the relatively cool and drier air finally reaches the ground and creates a general band of high pressure; from this point, the now cooler air begins to move back toward the tropic zone.

Cool air does not carry much moisture, so as the cool air mass moves from about 35º latitude to 20º latitude, it will be crossing relatively arid terrain. Since these latitudes still receive about 80% of the sunlight available in the tropics, this zone will be relatively hot, as well as dry. This portion of the atmospheric circulation system can be seen in the associated illustration, Tropic and Sub tropic Zone Circulation.

On the whole, the circulation system of the tropic and sub tropic zones will be quite large and fairly steady, except on worlds with high axial inclination,

Biologically, conditions in the tropic zone depend on temperatures and the availability of water.

On planets with low axial inclination and low to mid range APST (about 0ºC-30ºC), I suspect we would find something between temperate and steamy tropical forests as temperatures were elevated. Between an APST of 45ºC and extending up toward 60ºC, I believe the tropical forest would break down to be replaced by simpler plant communities with smaller individuals. Under these conditions, hot temperatures become a limiting factor in much the same way as cold temperatures limit growth in Earth’s tundra.

Around 50º to 60º latitude, on either side of the central tropic zone, there is a low pressure area. This region is cooler than the tropic low since it receives only about one half the solar energy. Being cooler, this mid latitude area is less humid and receives less precipitation.

The asterisks at 1.0 in the above graph, Relative Precipitation and Latitude axis, indicates the average precipitation level for the model world. Once the average precipitation and evaporation rate has been calculated a good model can be made for precipitation.

The following precipitation table was computed using data from the table in Chapter 3: Climatic Factors, Table: Data for Computing precipitation and Evaporation Rates used in either the associated equation or the BASIC computer program.

Table:  Average Inches of Precipitation and Evaporation for Planets with the given Mass and APST

Planetary Mass   Ê = 1
   APST ↓ 0.25 0.5 1.0 1.5 2.0 3.0
APST ºC 0ºC 55.1 50.4 41.7 35.2 29.5 18.2
15ºC 56.5 49.6 41.2 34.6 28.6 15.9
30ºC 55.8 49.6 40.6 33.6 27.4 13.0
45ºC 55.2 48.7 40.8 31.9 25.0 7.8
60ºC 55.0 48.4 38.9 30.4 19.2 5.2

In order to see if the preceding table had relevancy, I also ran calculations for Earth, where the averages are fairly well known, see following table:

Table: Average Inches of PPT & Evaporation on an Earth Mass Planet with 24 Hr Rate of Rotation

APST ºC 0 15 30 45 60
Inches Precipitation 41.7 42.07 40.6 38.9

Earth, with al 20ºC APST, has an actual  average annual precipitation rate of 40 inches.  The theoretical (calculated) Earth mass planet with 20ºC APST and 24 hour rate of rotation  has 41.6 inches of precipitation, a 4% difference between the actual and theoretical. Graph the above table (using the Chapter 3- Table: Cosine of planetary latitudes)

Although the theoretical precipitation rate works out well for an Earth type planet, meaningful equation results seem to degenerate as we approach the much smaller 0.25 Ê mass or the larger 3.0 Ê mass planets.

On the 0.25 Earth mass planet: At 0ºC to 15ºC there is a fairly small habitable zone which may indeed receive the theoretical amount of precipitation; however, most of what water exists on the planet will be locked up as ice in higher latitudes. Also, because there is a small water to land ratio, there is a very large area which will be arid-cool arid and cold arid.

In the 30ºC to 60ºC range, we’d find the higher latitude ice and frost caps either gone or greatly diminished. This would not lead to larger bodies of liquid water. The 0.25 Earth mass planet is a planet losing its moisture. The surface gravity is such that at higher temperatures, water molecules in the atmosphere simply drift out into space, resulting in a planet that is slowly drying. Therefore, in the higher APST range, I would suspect the precipitation and evaporation figures to break down. Several billion year old planets of this small size and high temperature would have relatively dry atmospheres.

On the large 3.0 Earth mass planets there maybe only small land masses, perhaps only island chains as opposed to ‘continents’. Warm moist ocean air might not move out onto large cool land masses.

At 0ºC to 15ºC, there would exist in the north and south latitudes, very large ice caps. Under cooler conditions the oceans would have reduced depth and the island land masses may have expanded to form small continents. This scenario would tend to increase the precipitation level for those areas, above the data given in the Precipitation and Evaporation table.

In the 30ºC to 60ºC APST range, we would find the ice caps diminishing to frost caps and finally entirely absent. As the APST increases, the atmosphere would become more and more saturated with moisture. Instead of true precipitation, we may find states of continual condensation occurring on terrestrial objects, especially at night and in latitudes experiencing change of season. Humidity would be extreme.

Wind deflection
Because all of the planet models rotate on their axis, we can expect wind systems to be deflected at various latitudes on either side of the tropic zone. The basic global air circulation for models, with a low to mid range axial inclination may be illustrated as follows.

As we study the Basic Global Circulation model above and recall the concepts derived from Tropic and Sub tropic Zone Circulation, illustration, page 21 and Relative Precipitation and Latitude graph, page 21, we are able to predict some interesting bits of information about continental climates.

Looking at the Subtropical Highs, we see the winds have a tendency to move from east to west as they return to the low pressure area in the tropic zone. This moving air mass is relatively cool and dry, and as previously mentioned, the area of the planet’s surface crossed will tend to be warm and arid, relative to the APST and the average planetary precipitation rate. The biotic community, which extends across these bands of high pressure depend on the APST, so that on worlds with an

APST  0ºC: The planet may carry cold/dry adaptive, coniferous forest type vegetation

APST  30ºC: Zone may be a hot desert.

APST 60ºC: Plant life is sparse and terrestrial animal life nocturnally active.

Local Climates
At any latitude, where high mountain ranges are situated perpendicular to the prevailing winds, we could expect higher moisture on the windward side and more arid conditions on the lee side.

On planetary models with some degree of axial inclination, that hemisphere undergoing Spring would have its land masses heating up faster than the oceans. This results in a low pressure system developing over the land and a high pressure system developing over the adjacent ocean. Conversely, in the Fall, the land would cool faster than the ocean and the high and low pressure systems would be reversed.

Water has a greater capacity to hold heat than does soil. Therefore the temperature variation between land and ocean would remain more stable in  the equatorial region that at higher latitudes on worlds with much free surface water.

Inland areas of continents have a far greater annual variation in temperature than coastal areas of the same latitude.

The planet’s surface temperature range
Planets with small axial inclinations have small variations in seasonal temperatures. As the axial inclination increases, the total range of temperatures for each latitude expands.

Model planet A, at left, has  0º axial inclination. An observer at 0º latitude would note his Sun rises to a point directly overhead every day and that the average temperatures through out the year is, let’s say, 81ºF.

Model B has a 15º axial inclination. An observer at 15º N will note that the sun is directly overhead at noon during the summer and that his summer average  temperature is perhaps 81ºF. Half a year later, the Sun has apparently moved to a point 15º below the equator and is now 30º lower in the sky to our observer. Recording his average Winter temperature of 70ºF, the observer notes that there is a 11ºF difference between his Summer and Winter temperatures averages.

Model C has a 45º axial inclination. This time, our observer is located at 45º N latitude. He notices the sun directly over head at noon and a temperature of 81ºF during the summer. Half a year later, the Sun has moved to a point 45º below the equator and is now 90º lower in the sky to the observer. At noon during the winter, the Sun will rise to a point where it just peeks over the southern horizon and the average temperature will be about -25ºF,

For the sake of comparison and to develop a better understanding of axial inclination and the subsequent temperature range, see the following table:

Table: Approximate Change in Temperature Range  (from the concept explanation above)

     AXIAL    INCLINATION SUMMER      ºF WINTER   ºF TEMPERATURE RANGE ºF
        0º     81      81        0
       15º     81      70        11
       45º     81     -25       106
For a planet of 1.0 Earth mass and 20ºC APST (Earth like); the axial inclination has been varied in the table to show simplified temperature effects. Our imaginary observer is located at a latitude above the equator which is equal to the planets axial inclination. For any given location on a planet, the greater the axial inclination, the greater the temperature range for that location and therefore, the greater the variation in its seasonal climate.
The chart shows, the greater the axial inclination, the more pronounced are the ‘seasons’ of the year.
.

Thunderstorms
All the planets whose mass and APST fall within the parameters of this study will have thunderstorms, with possible exception of the 0.25 Earth mass planet. The ingredients necessary for thunderstorm development are unstable warm air and humidity. These conditions exist in at least some latitudes on all the other, larger habitable planets. About the only area that would not be at least occasionally affected by thunderstorm activity would be the ice caps and other extensive desert (arid) regions

Continued in Chapter 5: Atmospheric Retention

Leave a comment

Filed under SRAPO (Stellar Radii and Planetary Orbits), __Chapter 4: Atmospheric Circulation

Chapter 3: Climatic Factors

Attempting to determine the basic climatic conditions for our model planets, we will take into account several major variables. We will attempt to treat some of these variables in order to develop an insight into general planetary climatology. You should keep in mind that the approach taken in the survey is a combination of intuition and empiricism and that even current attempts to calculate mean annual temperatures for Earth (mid to late 1960s) have not been highly successful.

Axial Inclination
Axial inclination refers to the number of degrees which a planet’s equator is tilted from its orbital plane.

Since all of the planets in our Solar System display axial inclination, we may theorize that whatever the process leading to its development here, perhaps exists universally. However, since the process isn’t understood, we’ll consider various degrees of axial inclination to develop an understanding of their general effect on a planet’s surface temperature.

Axial inclination, near 0º
On a planet with 0º or near 0º axial inclination, the temperature, precipitation rate and length of day would not vary appreciably in any one spot throughout the year, assuming a nearly circular orbit. circular.Because the planet has no tilt, there  would be no seasonal change as the year progresses. At any point on the planet’s surface, the  prevailing conditions in January would be the same as  in July. Low latitudes, near the equator, would experience the planets perpetual summer temperatures. High latitudes, nearer the poles would exist in a relative condition of winter with low illumination. On either side of the equatorial summer zone, there would exist temperatures we may classify as relatively spring like. The next zone would be fall like, with temperatures declining as one approached the high latitude winter zone.

Proceeding from the equator toward either pole, you would almost imperceptibly move across the planet’s surface temperature gradients, from relatively hot, to relatively cold.

Many plant species on Earth require a certain number of days with frost, a particular number of hours sunlight or some other abiotic factor to trigger seasonal growth. On worlds with 0º or very low axial inclination, plant life would have made other adaptations to the essentially non varying climate at their latitude. We might expect more sensitive biological triggers and a greater number of species which were perennials and fewer annuals.

Axial inclination approaching 90º
Worlds with axial inclinations approaching 90º would experience some really exciting seasonal climatic variation.

As the planet orbited its parent star, it would alternately have one of its poles bathed in summer sunlight for a quarter year, have a quarter in semi dark winter. Between the long hot polar summer cold winter cycles, the lower latitudes would gradually shift into a regular day and night cycle. The day and night cycle on this model would be complex, with the polar regions growing tropically warm in their seasonal summer and declining to Arctic cold in their seasonal winter.

Note from the preceding diagram that , the planets south polar region is experiencing summer. A few months later having orbited to position B, the polar regions are now located at a point approximately 90º from the sun, therefore are experiencing conditions similar to those at Earth’s poles. Note also that in position A, the “spring and fall” moderate temperature zones on the illuminated side of the hemisphere do not experience night. In these locations, the sun would simply circle in the sky. But it would not set As the planet orbits to position B, the spring  and fall temperature zones acquire a day and night cycle.

To a person standing on the illuminated hemisphere in planetary position A, the sun would appear to circle in the sky, but as the weeks passed, the apparent circle would spiral closer to the horizon. At some point midway between points A and B, the sun would dip below the horizon for a period of sunset, then it rise again. Approaching position B, the sun would set and nights would become longer. At position B, the sun would rise on one side of the horizon and set on the other, visually similar to what we experience.

As the planet orbited toward position C, the sun would  be seen to rise lower and lower in the sky, the days would shorten and temperatures. At position C, an observer at the south pole would be in several months of cold darkness. Southern latitudes would be in s state of extended twilight. Northern latitudes would be basking under extended periods of continuous daylight. At the same time, the north polar region would be baking in a summer season under overhead tropical sunlight.

Note that between location A and C, the poles experiencing summer and winter have reversed.

If this planet had an APST of 68ºF (20ºC) then a large percentage of the planet’s surface would experience a temperature range from between 81ºF to -25ºF. I would more or less expect tundra type terrain and vegetation on either side of the equator and vegetation specialized for hot and cold temperatures in higher latitudes.

Should such a planet exist in the ecosphere of a F class star, it would have a long year and therefore longer seasons for growth, before dormancy. Migration might play a major influence amongst larger life forms. If the planet orbited a relatively small cool class K star the year would be short and the growing season reduced.

Intermediate axial inclinations
Climatic factors arising on planets with intermediate axial inclination would vary according to the level of inclination. Planets with axial inclinations of 10º-15º will have milder seasonal temperature variations than planets with larger inclinations.

Those of us living in the mid latitudes on Earth (my 1980-2005 home is roughly on 45º33’ north latitude) can attest to the seasonal climatological effects of Earths 23½º axial inclination.

A mid latitude location on a planet with an APST of 20ºC and a 40º-60º axial inclination would be subjected to a steamy tropical summer and a frigid Arctic winter. On small to mid size planets with moderate inclinations, plant life would have developed highly protective tissues against the relative cold and heat. Desiccation and starvation  would be major biological problems.

Warm vs. Cold-bloodedness
Axial inclination and APST are two very important variables in broadly determining whether intelligent life on our model planets are warm or cold-blooded.

Basically, the difference between being ‘cold blooded’ or ‘warm blooded’ is that the former life forms are dependant on external temperatures while the latter have developed mechanisms to maintain internal temperatures under a wide range of external temperatures.

Persistent wide variability, periodic extreme oscillations and ‘cold’ or ‘hot’ are conditions conductive to the development of warm ‘bloodedness’. On the contrary, mild and seasonal temperature changes in a warm climate (not hot) are favorable to cold ‘bloodedness’.

It takes more biological equipment to be warm-blooded than cold-blooded; however, the extra activity gained in a hostile environment, apparently make the investment worthwhile.

I’ve worked out the following graphic to demonstrate the gross conditions where I believe we might find the development either cold or warm-blooded life forms.

In the upper portion of the graph, hot temperatures tend to be a limiting factor for cold-blooded dominant life forms. Low and to the left, it is general cold that limits cold-blooded expansion and-or probabilities. Looking up and to the right, we see that warm ‘bloodedness’ is favored as the  planets axial inclination rises, since this increases the summer high and drops the winter low temperature average for each latitude.

Although warm-blooded dominant life forms could exist on all the planetary models represented in the graph, cold blooded dominant life would probably be found on planets whose general climatic scheme was delineated by the green hashed area.

Planetary energy balance
In order to determine evaporation rates, we need to start with the total available solar radiation, make the necessary subtraction for albedo, etc. and thereby find the planets working energy balance.

We’ll start at the top of the planet’s atmosphere with the solar constant, a ‘constant’ because it varies little over a long period of time.

Coming down through the atmosphere, the first quantity of energy we subtract from the solar constant is the albedo, this amount is reflected back into space by atmospheric reflection (from the cloud cover). The remaining energy  is almost entirely used to heat the planet’s surface and to circulate the atmosphere.

Since atmospheric surface pressure is related to atmospheric density, the ratio between percent energy absorbed by our atmosphere and the surface pressure were used to determine the percent energy absorbed by the atmospheres of our model planets.

In the following table, the percent energy absorbed from the incoming radiation by the atmosphere is shown related to the corresponding planets mass.

Mass of planet ,  Ê = 1 0.25 .50 1.0 1.5 2.0 3.0
Percent energy absorbed 7 12 17 20 22 25

Having  reduced the solar constant by subtracting out the albedo and the energy absorbed by the atmosphere, what we have left is the radiant energy actually reaching the planet’s surface. Of this energy, some is lost as long wave radiation and some is reflected. When water or ground moisture is available, nearly all the remaining energy is used in evaporation.

Computing precipitation and evaporation
It’s been calculated that the average evaporation and precipitation rate for Earth is 100 cm (40 inches) per year. However, this is merely an average, because there is a sizeable difference in this rate over land and sea. The oceans have a precipitation rate close to 111 cm. (44 inches) and an evaporation rate of 120 cm (48 in), with the difference being returned to the oceans by river flow.

On land, the average precipitation rate is 71 cm (28 inches) per year with about 24 cm (10 inches) lost by river discharge.

The average evaporation rate for land is misleading because it takes into account a large portion of the land surface which contributes little to the figure, for example, tundra, icecaps, deserts and mountains. When these areas are taken into account, we find that the balance of the land receives about 100 cm (40 in) per year, the global average.

On a global scale, total evaporation equals total precipitation, or “what goes up must come down”. The following equation may be used to calculate precipitation or evaporation rates for our model planets:

Average annual Planetary Precipitation (cm) = [(1-(A+a)) *(0.29d)* (0.4E((/R3*8760)/Z)]/H

Conversions: The precipitation rate in cm/2.5 = the precipitation rate in inches.

Factors used in the Precipitation computation See the required data in Table: Data for computing precipitation and evaporation rates, below.

A   = Percent energy absorbed by the planet’s atmosphere.
a   = Percent albedo loss, See below, Table: Data for computing precipitation and evaporation rates.
d   = Planetary rate of rotation in minutes.
E   = See Determining Solar Constants (read in cal/cm² min), Chapter 2.
R   = See Orbital Radius, See Chapter 2.
H   = Latent Heat of vaporization.
Z   = See Planetary Rate of Rotation (in hours).

The following Table: Data for Computing Precipitation and Evaporation Rates, provides the data required to calculate average precipitation and evaporation for the model planets:

Table : Data for computing precipitation and evaporation rates

M Mass  w = 1 0.25 0.50 1.0 1.5 2.0 3.0    
A1 % Energy absorbed by the Planets Atmosphere 0.07 0.12 0.17 0.20 0.22 0.25 0.31 0.34
A2 % Albedo loss 0ºC 0.20 0.22 0.30 0.36 0.42 0.54    
15ºC 0.22 0.26 0.33 0.39 0.45 0.57    
30ºC 0.26 0.30 0.36 0.42 0.48 0.61    
45ºC 0.30 0.33 0.38 0.46 .052 0.61 = x  
60ºC 0.33 0.36 0.42 0.49 0.59 0.61   = x
D Rate of Rotation (minutes) 1380 1200 1020 900 870 780    
Z Rate of Rotation (hours) 23 20 17 15 14.5 13    
E Solar Constant(cal/cm² min) 0ºC 1.34 1.4 1.58 1.7 1.88 2.36    
15ºC 1.58 1.62 1.82 2.0 2.22 2.4    
30ºC 1.8 1.9 2.08 2.3 2.6 2.8    
45ºC 2.06 2.16 2.38 2.72 3.0 3.3    
60ºC 2.34 2.48 2.7 3.08 3.48 3.92    
H Latent Heat of Vaporization of Water (cal/gm) 0ºC 595    
15ºC 588    
30ºC 580    
45ºC 571    
60ºC 563    

Left column labels M, A, A2, etc. are computer variable names used in the following computer program.

x = Seen at right in the table show the percent energy absorbed at 100% cloud cover, the last two 61% albedo loss only.

Using data from, Table: Data for Computing Precipitation and Evaporation Rates, you may compute the average precipitation and evaporation rates with the following B.A.S.I.C. language program.

Line Number Northstar B.A.S.I.C.
10 REM   CALCULATE INCHES PRECIPITATION FOR PLANETS
20 !CHRS$(11)
30 INPUT   “Mass of planet ?”, M
40 INPUT   “APST ?”, W
50 INPUT   “% Energy absorbed by atmosphere ?”, A1
60 INPUT   “% albedo loss ?”, A2
70 INPUT   “Rate of Rotation  (in minutes) ?”, D
80 INPUT   “Planets Solar Constant ?”, E
90 INPUT   “Rate of rotation (in hours) ?”, Z
100 INPUT   “Latent Heat of Vaporization (water) ?”, H
110 REM   L=SPECTORAL CLASS-G0-STAR LUMINOSITY
120 L=1.04
130 REM   CALCULATE ORBITAL RADIUS RELATIVE TO EARTH
140 E1=E/1.97
150 R1+L/E1
160 R2=SQRT(R1)
170 R3=R2*R2*R2
180 REM   R4=RELATIVE SIDEREAL PERIOD
190 R4=SQRT(R3)
200 REM   PRECIPITATION EQUATION IN CENTIMETERS PPT.
210 P1=[1-(A1+A2)]*(0.29*D)*[0.4*E(R4*8760/Z)]/H
220 REM   CONVERT CENTIMETERS PPT TO INCHES PPT
230 P2=P1/2.5
240 !   ”MASS PLANET”, M
250 !   “APST”, W
260 !   “INCHES PPT”, P2
270 INPUT   “Do calculations again ? Y or N”, Q$
280 IF   Q$=”Y” THEN 20, ELSE 290
290 END

If you multiply the planet’s average precipitation or evaporation rate by the cosine of the planet’s latitude you’ll be able to roughly determine the precipitation or evaporation for the chosen latitude.

Table: Cosine of planetary latitudes

Latitude 10º 20º 30º 40º 50º 60º 70º 80º 90º
Cosine 1.0 0.984 0.939 0.866 0.766 0.642 0.500 0.342 0.173 0

The preceding method of determining precipitation rates over the planet’s surface will be modified in the next chapter.

Continued in Chapter 4: Atmospheric Circulation

Leave a comment

Filed under SRAPO (Stellar Radii and Planetary Orbits), __Chapter 3: Climatic Factors