Publication Date:
2020-12-18
Description:
This study is based on ground-based measurements of downward surface shortwave irradiance (SW), columnar water vapour (wv), and aerosol optical depth (s) obtained at Thule Air Base (Greenland) in 2007–2010,
together with MODIS observations of the surface shortwave albedo (A). Radiative transfer model calculations are used
in combination with measurements to separate the radiative effect of A (∆SWA), wv (DSWwv), and aerosols (∆SWs) in modulating SW in cloud-free conditions. The shortwave
radiation at the surface is mainly affected by water vapour absorption, which produces a reduction of SW as low as -100 Wm-2 (-18%). The seasonal change of A produces an increase of SW by up to +25 Wm-2 (+4.5%). The
annual mean radiative effect is estimated to be -(21–22) Wm-2 for wv, and +(2–3) Wm-2 for A. An increase by +0.065 cm in the annual mean wv, to which corresponds an absolute increase in ∆SWwv by 0.93 Wm-2 (4.3%), has been observed to occur between 2007 and 2010.
In the same period, the annual mean A has decreased by -0.027, with a corresponding decrease in ∆SWA by 0.41 Wm-2 (-14.9%). Atmospheric aerosols produce a reduction of SW as low as -32 Wm-2 (-6.7%). The
instantaneous aerosol radiative forcing (RFs) reaches values of -28 Wm-2 and shows a strong dependency on surface albedo. The derived radiative forcing efficiency (FEs) for solar zenith angles between 55 and 70 is estimated to be (-120.6 ± 4.3) for 0.1〈A〈0.2, and (-41.2 ± 1.6) Wm-2 for 0.5〈A〈0.6.
Description:
Published
Description:
953-969
Description:
1.10. TTC - Telerilevamento
Description:
3.7. Dinamica del clima e dell'oceano
Description:
JCR Journal
Description:
restricted
Keywords:
Arctic radiative balance
;
Surface albedo
;
Atmospheric aerosols
;
Water vapour
;
Direct radiative forcing
;
Arctic amplification
;
01. Atmosphere::01.01. Atmosphere::01.01.02. Climate
;
01. Atmosphere::01.01. Atmosphere::01.01.05. Radiation
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
