A Study on Influence of A Index and Southwest Monsoon Over Northeast Monsoon Using Back Propagation Neural Network

Tamil Nadu is the sub – division of the Indian union which receives most of the rainfall during North East monsoon season than South West monsoon. The North East monsoon rainfall over Tamil Nadu depends on several factors such as solar variability (aa index), southern oscillation index, ElNino, Outgoing long wave radiation, Tropical Easterly jet, Quasibinneal Oscillation and South West monsoon etc. The aa index is a measure of the disturbance level of Earth's magnetic field based on magnetometer observations at two, nearly antipodal, stations in Australia and England. The objective of the paper is to find the relationship between aa index and SouthWest monsoon and the North East monsoon. A correlation analysis between the South West and the North East rainfall series revealed that the South West monsoon rainfall is negatively correlated (−0.03400397) with that of the North East monsoon rainfall. Similarly, the correlation analysis between the aa index and the North East rainfall series revealed that the aa index is negatively correlated (−0.272399) with that of the North East monsoon rainfall. Using Back Propagation Neural Network method North East monsoon can be predicted.