news@cit-vax.Caltech.Edu (Usenet netnews) (01/08/87)
Organization : California Instititute of Technology Keywords: Hadley cell clouds rain forests From: myers@hobiecat.Caltech.Edu (Bob Myers) Path: hobiecat!myers In article <282@sri-arpa.ARPA> TSOMMER%IRLEARN.BITNET@WISCVM.WISC.EDU writes: >(This is not necessarily a physics question but here goes ) Followup to sci.misc. >Does anyone know if the climatic effect of loss of most of the Earth's >equatorial rain forest has been calculated or even studied ? I ask >this question as I have heard it said that at the present rate, only 15 % >approximately of it will remain in 15 years. Since a large amount of cloud >covers these regions The reason the rain forests are disappearing is because of human created deforestation, not lack of cloud cover. Nor is there any clear direct relationship between the cloud cover and the rain forest. (I don't see how cutting down trees directly affects the clouds in the area.) >and helps cool the planet in these regions (i.e. there >would be a higher net heating if they were not there, ) and thus if they >were destroyed would this affect cloud cover and hence the "Hadley Cells" ? >(The Hadley cells are the currents of air circulating from the equatorial >regions to the tropics of both hemispheres and back again ) The equatorial cloud cover is caused by the Hadley cell circulation. The air is rises at the equator, and the water vapor condenses out into clouds. I don't want to go into the thermo, but it does. Similarly, the downflow of the Hadley cell circulation in the subtropics is very dry (most of the world's major deserts are in this area). > If these air currents were upset even regionally, then I assume they may >affect ocean surface currents. And since the "El Nino" phenomena is related >to oceanic temperature changes etc etc, could this then provide for >instabilities in the weather/climate on a larger scale ? Certainly. El Nino is intimately related to changes in the equatorial winds. It's not clear what causes what, though. ---------------------------------------------------------------- Bob Myers myers@hobiecat.Caltech.Edu