Open AccessFive years of shortwave radiation budget measurements at a continental land site in southeastern Australia
Author(s) -
Prata A. J.,
Grant I. F.,
Cechet R. P.,
Rutter G. F.
Publication year - 1998
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/98jd02349
Subject(s) - shortwave radiation , shortwave , albedo (alchemy) , environmental science , downwelling , upwelling , earth's energy budget , satellite , climatology , atmospheric sciences , remote sensing , geology , radiative transfer , radiation , oceanography , art , physics , quantum mechanics , aerospace engineering , performance art , engineering , art history
A new data set of near‐continuous, high‐quality measurements of the components of the land surface radiation budget (SRB) at a uniform site in Australia is described. Its intended uses include the validation of SRB parameters predicted by general circulation models (GCMs), the validation of SRB parameters remotely sensed by satellites, and the study of surface processes. The site at Uardry (145.30°E, 34.39°S) near the town of Hay is the first in Australia's Continental Integrated Ground‐truth Site Network. It is located in extremely flat and homogeneous natural terrain, with grassland cover that is characteristic of much of the Australian continent, beneath an atmosphere that is characterized by low amounts of water vapor and aerosol. The measurements include the downwelling and upwelling shortwave flux densities. The upwelling measurements are made at several points across the site in order to sample the variability on a scale of 1 km, which is approximately the resolution of many current and planned satellite‐based sensors. The paper describes the shortwave component of the data set, shows some internal quality checks, presents some statistical summaries, and makes comparisons with the albedos used in GCMs. It then discusses features of the temporal variation of the albedos derived from the data set in terms of their impact on the remote sensing of land albedo. In particular, significant morning‐afternoon asymmetry is present in the diurnal variation on some days, and changes of 20% in albedo occur over a few days. Both of these characteristics violate common assumptions of algorithms used to retrieve land reflective properties from satellite measurements. Consideration of their effect is merited.