TY - JOUR
T1 - Diurnal cycle of the dust instantaneous direct radiative forcing over the Arabian Peninsula
AU - Osipov, Sergey
AU - Stenchikov, Georgiy L.
AU - Brindley, H.
AU - Banks, J.
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2015/8/27
Y1 - 2015/8/27
N2 - In this study we attempted to better quantify radiative effects of dust over the Arabian Peninsula and their dependence on input parameters. For this purpose we have developed a stand-alone column radiation transport model coupled with the Mie, T-matrix and geometric optics calculations and driven by reanalysis meteorological fields and atmospheric composition. Numerical experiments were carried out for a wide range of aerosol optical depths, including extreme values developed during the dust storm on 18–20 March 2012. Comprehensive ground-based observations and satellite retrievals were used to estimate aerosol optical properties, validate calculations and carry out radiation closure. The broadband surface albedo, fluxes at the bottom and top of the atmosphere as well as instantaneous dust radiative forcing were estimated both from the model and observations. Diurnal cycle of the shortwave instantaneous dust direct radiative forcing was studied for a range of aerosol and surface characteristics representative of the Arabian Peninsula. Mechanisms and parameters responsible for diurnal variability of the radiative forcing were evaluated. We found that intrinsic variability of the surface albedo and its dependence on atmospheric conditions, along with anisotropic aerosol scattering, are mostly responsible for diurnal effects.
AB - In this study we attempted to better quantify radiative effects of dust over the Arabian Peninsula and their dependence on input parameters. For this purpose we have developed a stand-alone column radiation transport model coupled with the Mie, T-matrix and geometric optics calculations and driven by reanalysis meteorological fields and atmospheric composition. Numerical experiments were carried out for a wide range of aerosol optical depths, including extreme values developed during the dust storm on 18–20 March 2012. Comprehensive ground-based observations and satellite retrievals were used to estimate aerosol optical properties, validate calculations and carry out radiation closure. The broadband surface albedo, fluxes at the bottom and top of the atmosphere as well as instantaneous dust radiative forcing were estimated both from the model and observations. Diurnal cycle of the shortwave instantaneous dust direct radiative forcing was studied for a range of aerosol and surface characteristics representative of the Arabian Peninsula. Mechanisms and parameters responsible for diurnal variability of the radiative forcing were evaluated. We found that intrinsic variability of the surface albedo and its dependence on atmospheric conditions, along with anisotropic aerosol scattering, are mostly responsible for diurnal effects.
UR - http://hdl.handle.net/10754/577019
UR - http://www.atmos-chem-phys.net/15/9537/2015/
UR - http://www.scopus.com/inward/record.url?scp=84940469712&partnerID=8YFLogxK
U2 - 10.5194/acp-15-9537-2015
DO - 10.5194/acp-15-9537-2015
M3 - Article
SN - 1680-7324
VL - 15
SP - 9537
EP - 9553
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 16
ER -