Trends and Periodicities of Rainfall Over India
نویسنده
چکیده
Trends and periodicities in the annual rainfall of India were studied using data for 48 stations having record lengths of over 70 yr. Increasing or decreasing rainfall tendencies were found over large continuous areas in India. These trends, however, are not significant over all the stations in the areas but only at a few places distributed a t random. Wherever a trend is significant, i t has persistance or a periodicity of more than 40 yr. Quasibiennial oscillation (&BO) is exhibited a t several stations in the areas of increasing or decreasing trend. Similarly, the 11-yr cycle (solar cycle) is also exhibited in both areas. The &BO and the solar cycle are both present a t only three stations, however. This casts a serious doubt on whether or not there is any physical relation between the &BO and the solar cycle, a t least for rainfall. '
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