Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-23T03:35:53.576Z Has data issue: false hasContentIssue false

The accuracy of downward short- and long-wave radiation at the earth's surface calculated using simple models

Published online by Cambridge University Press:  29 March 2004

J. W. Finch
Affiliation:
Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB, UK Email: [email protected]
M. J. Best
Affiliation:
The Met. Office, London Road, Bracknell, Berks, RG12 2SZ, UK
Get access

Abstract

Estimates of the downward global solar and long-wave radiations are commonly made using simple models. We have tested the estimates produced by a number of these simple models against the values predicted by the radiative transfer model used in a climate model in order to determine their suitability for global applications. For clear sky, two simple models were comparable, but under cloudy conditions a combination of a clear-sky model based on the Angstrom-Prescott equation (which deals with the downwelling solar radiation) with a cloud transmissivity utilising total cloud fraction proved best. The lowest root mean square errors were 27 W m−2 for clear-sky global solar radiation and 90 W m−2 for cloudy conditions. For downward long-wave radiation in clear-sky conditions, the model of Garratt (1992) performed best with a root mean square error of 24 W m−2. However, in cloudy conditions the model of Idso & Jackson (1969) performed best with a root mean square error of 22 W m−2, and, as it performs nearly as well as that of Garratt (1992) in clear-sky conditions, it is probably the best choice.

Type
Research Article
Copyright
© 2004 Royal Meteorological Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)