PLANETARY-SCALE CHARACTERISTICS OF MONTHLY MEAN LONG-WAVE RADIATION AND ALBEDO AND SOME YEAR-TO-YEAR VARIATIONS

Abstract

Global patterns of monthly averages of outgoing long-wave radiation and albedo as derived from TIROS IV radiometer data for the period February?May 1962 are examined relative to each other and with respect to monthly mean mid-tropospheric flow patterns. It is found that long-wave radiation and albedo are inversely correlated on a broad scale, particularly over ocean and non-desert regions. Both quantities show broadscale relationships to the planetary flow patterns over the Northern Hemisphere, particularly the strength and location of features of the wave patterns and the westerlies. Comparisons of long-wave radiation patterns for the same months of two different years, using data from both TIROS IV and VII, show differences averaging about 5 percent and ranging up to about 30 percent of the monthly averaged values. Over the Northern Hemisphere these radiation differences are related to mid-tropospheric circulation differences. Over the equatorial regions and the Southern Hemisphere, where mid-tropospheric circulations are poorly known, the radiation differences serve as indicators of sizable differences in circulation in the two years. Some of the radiation difference patterns are aligned in a series of zonal bands extending over about 60°?90° of longitude and between middle latitudes of both hemispheres; these suggest interactions between large-scale circulations in the two hemispheres.