Some determinations of atmospheric absorption by measurement of solar radiation from aircraft and at the surface

Measurements, on aircraft and at the ground, of the downward and upward fluxes of solar radiation and illumination in cloudless conditions are compared with computed values and with each other. The indirect estimates of absorption from surface observations are in agreement with the more direct aircraft measurements. As in previous work, measured absorption and upward scatter is considerably in excess of that computed ‐ excess by about a factor of two at heights up to 20,000 ft. The discrepancy is attributed to suspended matter.