Spatial and Temporal Variability of Total Column Ozone over the Indian Subcontinent: A Study Based on Nimbus-7 TOMS Satellite

Abstract

How to cite this paper: Madhu, V. (2014) Spatial and Temporal Variability of Total Column Ozone over the Indian Subcontinent: A Study Based on Nimbus-7 TOMS Satellite. Atmospheric and Climate Sciences, 4, 884-898. http://dx. AbstractThe distribution and variability of ozone is very important to the atmospheric thermal structures, and it can exert their greater influence on climate. Present study is based on Nimbus-7 TOMS overpass column ozone for a period of 14 years (1979-1992) over twelve selected Indian stations from south to north latitude and it explores the spatial and temporal variability of Total Column Ozone (TCO). For this investigation an advanced statistical methods such as Factor Analysis and Morlet wavelet transform are employed. Total column ozone variability over these stations is grouped into two clusters (Eigen value greater than 1) by the Multivariate Factor analysis. It is found that the Group I stations shows the same nature of variability mainly due the first factor as the primarily loading and whereas as the Group II stations shows the same nature of variability due to second factor as the primary loading. The correlation value of TCO decreases from 0.9 to 0.32 as we move from south to north stations (lower latitude to higher latitude). The total column ozone over tropical stations is maximum during monsoon season with peak in the month of June and that for the higher latitude stations is during the pre-monsoon season. Annual average of TCO for tropical stations is about 265 DU and that for subtropical stations is about 280 DU and a difference of 15 DU is noted in the annual average of TCO between tropical and subtropical stations. A large reduction in TCO is noted over the Indian subcontinent in the year 1985, the same year in which the ozone hole over Antarctica was discovered. It is also found that two prominent oscillations are present in total column ozone one with a periodicity of 16 to18 months and other with 28 to 32 months (QBO periodicity) apart from the annual oscillations. These oscillations are found to be significant at above 95% level of confidence when tested with Power Spectrum method. Tropical TCO shows high concentration during the westerly phase and low concentration during the easterly phase of the equatorial stratospheric quasi-biennial oscillation.

Madden Julian Oscillations in Total Column Ozone, Air Temperature and Surface Pressure Measured over Cochin during Summer Monsoon 2015

“…From October onwards there was sudden decline in TCO anomaly to −15 DU within a gap of two months (October-November) from the annual mean. From earlier studies it is observed that total ozone variability is high over tropical Indian monsoon region especially the stations close to the proximity of equator [30]. The above results are true when compared with the 35 year climatology of ECMWF reanalysis of TCO [36].…”

Temporal Distribution of Total Column Ozone over Cochin—A Study Based on <i>in Situ</i> Measurements and ECMWF Reanalysis

“…The Quasi-Biennial oscillation (QBO) is the phenomenon in which tropical winds in the lower stratosphere switch from easterly to westerly within a period of two years. Thus the QBO plays a dominant role in the inter-annual variability of tropical lower stratospheric temperature, which is directly linked with ozone concentration and distribution [5]- [8]. The distribution of tracer gas such as ozone [5], meteorological parameter such as rainfall amount [7] and frequency of tropical cyclones are also linked with the phases of Quasi-Biennial oscillations (QBO).…”

“…Most of the studies were based on mid and high latitude regions. Long-term variability of atmospheric ozone and regional variation of tropical total column ozone over Indian stations are reported by many authors [5] [20]- [26]. From 1970, observations show that the amount of total ozone on earth's atmosphere is decreasing due to the catalytic destruction of ozone by atomic halogens.…”

ECMWF Atmospheric Profiles in Maroua, Cameroon: Analysis and Overview of the Simulation of Downward Global Solar Radiation

“…These variations are usual and were similar to those in N'djamena (12.12 • N, 14.92 • E), a neighboring area, where, although the high insolation dry period appears to be favorable for an abundant ozone production, the contrary occurs for the TCO variation, which is driven by wind dynamics over West Africa [48]. The same type of evolution is also observed in tropical Indian regions (latitudes <20 • N), where TCO concentration raise and the peak has been related to the monsoon occurrence [49].…”