Open AccessOnset, withdrawal and intra-seasonal variation of northeast monsoon over coastal Tamil Nadu, 1901-2000
Author(s) -
Y. E. A. Raj
Publication year - 2003
Publication title -
mausam
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.243
H-Index - 12
ISSN - 0252-9416
DOI - 10.54302/mausam.v54i3.1551
Subject(s) - tamil , monsoon , climatology , geography , seasonality , period (music) , physical geography , environmental science , oceanography , geology , biology , ecology , philosophy , linguistics , physics , acoustics
The onset and withdrawal dates of northeast monsoon over coastal Tamil Nadu have been objectively determined for the ten year period 1991-2000. The statistics of onset and withdrawal dates for the 100 year 20th century period 1901-2000 have been presented and discussed. It has been shown by employing techniques such as harmonic/spectral analysis and cross lag correlation over 100 year rainfall data, that the daily rainfall of coastal Tamil Nadu during September-February displays a prominent 40-days periodicity and that rainfall anomalies move from south to north taking nearly 2 days to traverse between Pamban and Chennai separated latitudinally by nearly 400 km. In 70% of the years the onset and withdrawal process of northeast monsoon gets excited by the 40-day periodicity.