Climate Question

[snrdg082102]

Hello Malenfant,

Martin Heidemann, pomphisandpristine@t-online.de, posed this post on JTAS, could you help him out:

Both G:Space and GT:FI give climate levels. I have two problems:

"Earthlike" is the term for 295 - 302 °K. But AFAIK the average surface temperature of Earth is somewhere around 288°K.

The climate levels have different ranges, between 5°K and 12°K. Some rules talk about changing temperatures in levels, for example for day/night and summer/winter cycles. As long as I stay within the given bands, okay. But what if this gets me off the charts into Torrid or Frigid ? What is two levels colder than Frigid ?

As it´s the colder bands which cover 11°K or 12°K, and the hotter which cover 5°K or 6°K, I am contemplating a house rule to change the
bands as follows:

Frigid all levels below 239
Frozen 240-249
Very Cold 250-259
Cold 260-269
Chilly 270-279
Cool 280-289
Earthlike 290-299
Warm 300-309
Tropical 310-314
Hot 315-319
Very Hot 320-324
Torrid all levels 325+

Additional levels below 239 would be 10°K per level, additional levels above 325 would be 5°K per level.

"Earthlike" is still a bit too warm, but I wanted to stay close to the numbers in the books and have more standardized temperature bands.

Any comments ? Is there something to the official ranges which I overlooked and makes this a bad idea ?

 

[Straybow]

I think, first of all, that temps cited are daytime highs averaged over all latitudes and adjusted to sea level value. The dayside average would include areas in local dawn/dusk and give a lower reading. The planetary adjusted average (probably the 288°K you mentioned) would be lowered by the night side readings, and a gross average would be lowered by any regions significantly above sea level (or whatever datum applies to the planet).

 

[Malenfant]

Hi Tom,

Oh, I'd forgotten about that in all the hullaballoo of the past few days...

I'd pointed out the fact that "earthlike" in FI wasn't actually earthlike at all earlier on delphi - IIRC Jon said that he was aware of it and had in fact deliberately set things up that way to be compatible with GURPS Space.

The temperature rules in FI are IMO a little bit lacking in places though (not terribly so, but enough to make me scratch m y head a bit). First there's the obvious non linear division of the temperature bands that Martin noticed. Then there's the fact that the greenhouse effect formula falls apart for greenhouse worlds like Venus (the multiplier goes through the roof for those). It does say that greenhouse worlds should be assumed to be very hot, but the temperature formula is clearly tailored for more earthlike worlds. I also suspect that cloud cover should be related to the greenhouse effect, so that if you have to have a more reflective (higher albedo/cloudier) world which ought to make things cooler there, the greenhouse effect will be correspondingly higher - which would warm things up again. I'm also not sure that the day/night effects are realistic - there should be some atmospheric density factor in there too. And of course, it doesn't tell you how to figure out the temperature in multiple systems.

Most of these things I'm qualitatively aware of, but don't have hard numbers to throw out at people yet.


But to stop rambling and actually answer the question, I don't really see anything wrong with what Martin's suggested. It does make things a little more consistent.

Tom, can you see if you can get Martin to come over here if he wants to pick my brain (or anyone else's, for that matter) on this sort of thing?

 

[snrdg082102]

Evening Malenfant,

Thank-you for posting an answer to Martin's question. In this case I sent Martin your comments via email. I'll try to get more people over here to ask you questions or do what I did with Martin's question.

Originally posted by Malenfant:
Hi Tom,

Oh, I'd forgotten about that in all the hullaballoo of the past few days...

I'd pointed out the fact that "earthlike" in FI wasn't actually earthlike at all earlier on delphi - IIRC Jon said that he was aware of it and had in fact deliberately set things up that way to be compatible with GURPS Space.

The temperature rules in FI are IMO a little bit lacking in places though (not terribly so, but enough to make me scratch m y head a bit). First there's the obvious non linear division of the temperature bands that Martin noticed. Then there's the fact that the greenhouse effect formula falls apart for greenhouse worlds like Venus (the multiplier goes through the roof for those). It does say that greenhouse worlds should be assumed to be very hot, but the temperature formula is clearly tailored for more earthlike worlds. I also suspect that cloud cover should be related to the greenhouse effect, so that if you have to have a more reflective (higher albedo/cloudier) world which ought to make things cooler there, the greenhouse effect will be correspondingly higher - which would warm things up again. I'm also not sure that the day/night effects are realistic - there should be some atmospheric density factor in there too. And of course, it doesn't tell you how to figure out the temperature in multiple systems.

Most of these things I'm qualitatively aware of, but don't have hard numbers to throw out at people yet.


But to stop rambling and actually answer the question, I don't really see anything wrong with what Martin's suggested. It does make things a little more consistent.

Tom, can you see if you can get Martin to come over here if he wants to pick my brain (or anyone else's, for that matter) on this sort of thing?

 

[Malenfant]

Originally posted by Thomas Rux:
[QB] Evening Malenfant,

Thank-you for posting an answer to Martin's question. In this case I sent Martin your comments via email. I'll try to get more people over here to ask you questions or do what I did with Martin's question.

Thanks Tom - I guess I should have emailed him my reply too in hindsight. I'd rather people came over here to track me down though in future.

 

[snrdg082102]

Evening Malenfant,

I understand and I shall refrain from posting similar questions from the JTAS boards. My apologies for not asking before I did my deed.

Originally posted by Malenfant:
</font><blockquote>quote:</font><hr />Originally posted by Thomas Rux:
[QB] Evening Malenfant,

Thank-you for posting an answer to Martin's question. In this case I sent Martin your comments via email. I'll try to get more people over here to ask you questions or do what I did with Martin's question.

Thanks Tom - I guess I should have emailed him my reply too in hindsight. I'd rather people came over here to track me down though in future. </font>[/QUOTE]

 

[Straybow]

Eh? Whahappen on JTAS boards??

 

[Drakon]

In a different game, Runequest (or more exactly the Runequest supplement "Questworld") they divided climate up into 9 zones. Based on temperature and precipitation. I will look it up if anyone is interested.

 

[Malenfant]

The Blue Planet RPG divides Poseidon into many different biomes, which is a nifty idea. I'd love to see a single planet given that much detail in Traveller

.

 

[mike wightman]

Originally posted by Straybow:
Eh? Whahappen on JTAS boards??

Their loss is our gain

 

[Straybow]

Si, señor