Climate forcing and response to idealized changes in surface latent and sensible heat

Ban-Weiss, George A and Bala, Govindasamy and Cao, Long and Pongratz, Julia and Caldeira, Ken (2011) Climate forcing and response to idealized changes in surface latent and sensible heat. In: Environmental Research Letters, 6 (3).

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Abstract

Land use and land cover changes affect the partitioning of latent and sensible heat, which impacts the broader climate system. Increased latent heat flux to the atmosphere has a local cooling influence known as `evaporative cooling', but this energy will be released back to the atmosphere wherever the water condenses. However, the extent to which local evaporative cooling provides a global cooling influence has not been well characterized. Here, we perform a highly idealized set of climate model simulations aimed at understanding the effects that changes in the balance between surface sensible and latent heating have on the global climate system. We find that globally adding a uniform 1 W m(-2) source of latent heat flux along with a uniform 1 W m(-2) sink of sensible heat leads to a decrease in global mean surface air temperature of 0.54 +/- 0.04 K. This occurs largely as a consequence of planetary albedo increases associated with an increase in low elevation cloudiness caused by increased evaporation. Thus, our model results indicate that, on average, when latent heating replaces sensible heating, global, and not merely local, surface temperatures decrease.

Item Type:	Journal Article
Publication:	Environmental Research Letters
Publisher:	IOP Publishing ltd
Additional Information:	Copyright of this article belongs to IOP Publishing ltd.
Keywords:	climate change;latent heat;evapotranspiration;Bowen ratio; evaporative cooling
Department/Centre:	Division of Mechanical Sciences > Divecha Centre for Climate Change Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	25 Oct 2011 09:49
Last Modified:	25 Oct 2011 09:49
URI:	http://eprints.iisc.ac.in/id/eprint/41667

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