Abstract
In order to make clear the difference between the earth’s radiation budget over land and over sea, three components of the budget measured by the wide field of view sensors aboard NIMBUS 7 were analyzed for the period during November 1978 to October 1979.
In each of the absorbed solar radiation and the emitted terrestrial radiation, it is confirmed that the zonal average over sea is about 40 W/m2 larger than over land covering the latitudinal range of 40 degrees around the solar declination. It is interpreted because the clear sky albedo over sea is about half of that over land and also the cloud amount over sea is about 13% less than that over land in the equatorial zone.
In the absorbed solar radiation, it is found that in summer the zonal average over sea is about 15 W/m2 smaller than that over land covering the latitudinal range of 30 degrees centered 60N or 60S. It is estimated because in the latitude of summer the cloud amount over sea is so larger than over land as to cancel the clear sky albedo effect though clear sky albedo over sea is about half of that over land.
In the emitted terrestrial radiation, it is also found that the minimum zone of it associated with ITCZ is lower over land than over sea, and the maximum zones of it associated with the subtropical high pressure zones are larger over land than over sea. This strangely means that the direct circulation over land looks like more active than over sea in the equatorial zone.
