If the earth's rotation was to slow....

[Eelpie]

If the earth was to rotate over say a period of 25 hours what would the impact be on night time and daytime temperatures? Would the relationship be linear, eg a 2 hour increase in rotation time would increase peak day time temperature on average by twice as much as a 1 hour increase?

[MattyT]

One would have thought there would be a linear relationship, but then again I suppose it would depend on all the other variables that are dependent on roational speed of the Earth such as Atmospheric dynaimics or the Geomagnetic field. Would be interesting to see if anyone has any thoughts on this!

[lemur]

I think that as dawn breaks, warming air rises and lowers barometric pressure slightly causing night-air to blow toward the rising sun. If the Earth turned slower, I would think this effect would be more pronounced since the dawning region would heat more in a closer vicinity to the still shaded region. I.e. fast rotation would mean more even heating and cooling so slow(er) rotation would mean more polarized heating and cooling, I think. A slower-turning rotisserie oven allows its contents to roast longer at any given moment than one set to turn fast, right? Heat builds up more and radiates away less on the sunny side of a planet, no? Thus longer night would mean colder morning temperatures and longer days would mean more daytime warming, I think.

Edited May 8, 2011 by lemur

[OSHMUNNIES]

fast rotation would mean more even heating and cooling so slow(er) rotation would mean more polarized heating and cooling

 

I agree with Lemur...take that concept to the extreme: If the earth's rotation was synchronous with its orbit about the sun such that one side (say North and south America) was exposed to sunlight at all times, and the other side (i.e. most of Europe, Africa, Asia) were in total darkness at all times, there would obviously be relatively extreme temperature differences between the two faces.

 

Conversely, let's say that days were only a minute long. Not only would solar radiation be more constant at any given point (with respect to the faces of the earth exposed or not exposed to the sun, assuming the same sort of temperature variance at the poles that already occurs), temperatures on opposing faces would have less time to polarize, and atmospheric convection would attenuate.

Edited May 11, 2011 by OSHMUNNIES