Journal
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
Volume 9, Issue 7, Pages 2468-2482Publisher
AMER GEOPHYSICAL UNION
DOI: 10.1002/2017MS001116
Keywords
-
Categories
Funding
- DOE [SC0006841]
- NSF [AGS-1417659]
- Directorate For Geosciences
- Div Atmospheric & Geospace Sciences [1417659] Funding Source: National Science Foundation
Ask authors/readers for more resources
In energetic equilibrium, the atmosphere's net radiative divergence (R) is balanced by sensible (S) and latent (L) heat fluxes, i.e., R + S + L = 0. Radiative forcing from increasing CO2 reduces R, and the surface warming following an increase in CO2 is largely due to the reduction in atmospheric energy demand in S and L, with only a smaller surface radiative budget perturbation. With an idealized General Circulation Model, we show that the fast atmospheric adjustment at fixed surface temperature produces the required decrease in the sum of S and L through changes in the near-surface temperature and specific humidity. In layers near the surface, the reduced radiative cooling forces a temperature increase that leads to a negative Planck radiative feedback and, because of the reduced surface-atmosphere temperature difference, also to a reduction in sensible heat flux. In the free troposphere, the reduced radiative cooling leads to a weakening of the tropospheric circulation. Consequently, there is a decrease in the water flux exported from the layers near the surface, and as such in precipitation. By mass conservation, the near-surface specific humidity increases and surface evaporation decreases until it balances the reduced export flux. Other processes can amplify or dampen the responses in S and L and change the partitioning between these two fluxes, but by themselves do not ensure R + S + L = 0.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available