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Total ozone trends over low latitude Indian stations
Author(s) -
Kundu Namita,
Jain Meena
Publication year - 1993
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/93gl03306
Subject(s) - total ozone mapping spectrometer , equator , latitude , environmental science , climatology , atmospheric sciences , trend analysis , longitude , ozone , meteorology , geography , mathematics , geology , statistics , ozone layer , geodesy
The network of Dobson spectrometers in India have been measuring total ozone over several stations for the last three decades. Measurements over three stations Srinagar, Delhi and Kodaikanal are considered for trend analysis and its latitudinal variation. The data series extends over the period 1965–91 except for Srinagar where data is vailable only upto 1988. A statistical model having terms for different variabilities such as linear trend, six monthly, seasonal and biennial oscillations, as well as, long term solar variability is used. Since the data base is the monthly average ozone value, short term noise is eliminated. As the calculated and observed ozone data agree with each other the linear trend could be obtained from the model. The trend near the equator, though small, is positive, decreasing to negative values at higher latitudes. The analysis of 11 years TOMS data by other workers does not show the positive trend in the equatorial region. The trend of Dobson data near 30°N latitude is less negative than that obtained from TOMS data and agrees better with the theoretical model.