Premium
Aerosol direct radiative effect of smoke over clouds over the southeast Atlantic Ocean from 2006 to 2009
Author(s) -
Graaf M.,
Bellouin N.,
Tilstra L. G.,
Haywood J.,
Stammes P.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl061103
Subject(s) - aerosol , sciamachy , angstrom exponent , environmental science , atmospheric sciences , radiative transfer , climatology , climate model , satellite , moderate resolution imaging spectroradiometer , meteorology , climate change , geology , physics , oceanography , troposphere , quantum mechanics , astronomy
Abstract The aerosol direct radiative effect (DRE) of African smoke was analyzed in cloud scenes over the southeast Atlantic Ocean, using Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite observations and Hadley Centre Global Environmental Model version 2 (HadGEM2) climate model simulations. The observed mean DRE was about 30–35 W m −2 in August and September 2006–2009. In some years, short episodes of high‐aerosol DRE can be observed, due to high‐aerosol loadings, while in other years the loadings are lower but more prolonged. Climate models that use evenly distributed monthly averaged emission fields will not reproduce these high‐aerosol loadings. Furthermore, the simulated monthly mean aerosol DRE in HadGEM2 is only about 6 W m −2 in August. The difference with SCIAMACHY mean observations can be partly explained by an underestimation of the aerosol absorption Ångström exponent in the ultraviolet. However, the subsequent increase of aerosol DRE simulation by about 20% is not enough to explain the observed discrepancy between simulations and observations.