Delineation of air temperature based models for estimation of global solar radiation

Abstract

Data on global solar radiation is an essential input variable to many crop models from the process oriented crop models at field scale, to the land surface based ecological models at regional scale and the global circulation models. Here an attempt has been made to delineate four temperature based relations proposed by Bristow and Campbell (1984), Hargreaves (1985), Richardson ( 1985) and Goodin et al., (1999) for their relevance to the actually measured. Daily data on measured solar radiation, maximum and minimum air temperatures at Patancheru location is collected for the period 1st Jan 2009 to 1st April 2011. Models performance has been evaluated using mean bias error, mean absolute percentage error, root mean square error and D-index of agreement. The comparative analysis revealed that among the four models Bristow-Campbell model estimated solar radiation comparatively with less errors and the estimated radiation values were most close to the measured values.

Keywords

• Bristow-Campbell
• Hargreaves
• Richardson
• Goodin et al.,
• Extra terrestrial radiation