Solar and thermal radiation flux measurements over the east coast of Australia

Aircraft measurements show that the albedo of much of the east coast of Australia may be described in terms of only two curves of albedo versus solar elevation (A vs. θ), those of eucalypt forest and dry grassland. The theoretical albedo of white-capping sea to isotropic sky radiation (derived from an experimental A vs. θ curve) is found to be about 5 to 6%, which is nearly the same as the equivalent value for smooth sea. A significant relation between upward long-wave flux F and short-wave albedo A just above trade wind cumulus was obtained for midwinter conditions over the ocean east of Cairns where the temperature of the sea surface was 24°C. Profiles of the components of short- and long-wave flux through uniform decks of trade wind strato-cumulus are presented. The effective emissivities of these decks were in the range 0.85 (a 180 m-thick deck) to 0.94 (a 560 m-thick deck), much lower than the values normally accepted for strato-cumulus.