CICERO - Center for International Climate Research

Schematic diagram of the energy fluxes and fast and slow precipiation changes (ΔP) processes.

Frame 1: At the top of the atmosphere, in the atmosphere and at the surface the energy budget is nearly in balance on a global scale. Changes in the atmospheric radiative cooling (ΔQ) can be caused by changes in absorption of shortwave radiation (SW) or changes in absorption/emission of longwave radiation (LW) or both. LH=LΔP is latent heat and SH is sensible heat.

Frame 2: An external driver of climate change alters the radiative fluxes at the top of the atmosphere and this may alter the atmospheric absorption.

Frame 3: The instantaneous change through radiation may further alter the atmospheric temperature, water vapor and clouds, through rapid adjustments. These rapid adjustments may lead to decrease or increase in clouds and water vapor and can vary through the atmosphere. The instantaneous radiative perturbation and rapid adjustments changes precipitation on a fast time scale (days to few years).

Frame 4: Climate feedback processes through changes in the surface temperature further alter the atmospheric absorption which 29 occurs on a long time scales (decades). Net radiative fluxes at the top of the atmosphere is given as F, water vapor as WV, temperature as T, and latent heat of vaporization L. In Frames 2 to 4, blue indicates the unperturbed state, orange represents the rapid adjustments and red represents the effect of both fast and slow adjustments.


PDRMIP: A Precipitation Driver and Response Model Intercomparison Project, Protocol and preliminary results

G. Myhre, P. M. Forster, B. H. Samset, Ø. Hodnebrog, J. Sillmann, S. G. Aalbergsjø, T. Andrews, O. Boucher, G. Faluvegi, D. Fläschner, T. Iversen, M. Kasoar, V. Kharin, A. Kirkevåg, J.-F. Lamarque, D. Olivié, T. Richardson, D. Shindell, K. P. Shine, Camilla W. Stjern, T. Takemura, A. Voulgarakis, F. Zwiers

Bull. Amer. Meteor. Soc., doi: 10.1175/BAMS-D-16-0019.1, 2016