Large-scale precipitation estimates using satellite data; Application to the Indian Monsoon

Abstract

Thirty months of continuous low resolution statellite measurements of albedo and emitted longwave radiation are used to study precipitation associated with the Indian Monsoon. Combined with rainfall data for the Indian subcontinent, the satellite data are employed to develop a precipitation intensity index. It is postulated that such an index must first adequately depict the extreme monsoon rainfall regime before it can be applied to the study of rainfall over other regions, especially those devoid of conventional precipitation measurements.Three monsoons are studied to develop the index: the 1963 monsoon, the strong 1964 monsoon and the very weak 1965 monsoon. The apparently successful quantitative measure of monsoon intensity by use of the precipitation intensity index was checked using independent data for the same region in i966 and 1969. With the aid of the index the time history of the 1964 and 1965 monsoons are examined showing how the intense cloudiness of the 1964 monsoon lingered for a number of months apparently reducing surface heating significantly preceeding the weak 1965 monsoon. This two-parameter, bi-spectral remote sensing method using satellite data can be tested for other regions using currently available satellite measurements.

Seasonal oceanic precipitation frequencies from Nimbus 5 microwave data

“…Satellite data offer much better resolution, but Until the launch of Cosmos 243 in 1968 and Nimbus 5 in 1972, all satellite data were from the visible or infrared portions of the electromagnetic spectrum in which precipitation cannot be observed directly because of the opacity of clouds. (See Martin and Scherer [1973] and Dittberner and Vonder Haar [1973] for a review of precipitation estimation techniques using visible and infrared satellite data.) Several authors have shown the usefulness of microwave imagery from the Nimbus 5 electrically scanning microwave radiometer (ESMR) in depicting oceanic precipitation zones [Theon, 1973;Sabatini and Merritt, 1973;Allison et al, 1974a, b;Wilheit et al, 1976].…”

Precipitation Measurement and the Advancement Toward Global Observations

“…Another algorithm includes the bispectral approach, which are discussed in the studies conducted by Tsonis and Isaac (1985), Lovejoy and Austin (1979a,b), and Dittberner and Vonder Haar (1973). In this technique, cold/bright and warm/dark cloud radiances are cross‐analyzed in order to determine the probability of precipitation.…”