Increasing trends of tropospheric ozone and NO₂ at the prominent hot spots along the coastal belt of the Arabian Sea in Indian Subcontinent

Tropospheric ozone is one of the key species in the atmosphere and it plays a vital role in the air quality, atmospheric chemistry, and climate change over a region. Ozone production in the troposphere is a result of photolysis of NO₂ which is emitted from the enhanced anthropogenic and industrial activities. The photo-dissociation of NO₂ in the presence of other trace gases and solar radiation yields the production of tropospheric ozone and this process in the troposphere has gained wide attention in recent years. Thus the variation of tropospheric NO₂ and ozone concentration over a region provides an account of the air quality and efficiency in imparting global warming. In this paper we report the fIrst continuous record of tropospheric ozone and NO₂ along the major hotspots in Indian coastal belt of the Arabian Sea. The data were retrieved from TOMS and SCIAMACHY satellite sensors during period from 2005 to 2009 and from 2003 to 2009 respectively. Since these locations are close the sea, the air quality analysis is quite important to study the influence of marine environment that signifIcantly changes the air quality. From our analysis, it is found that ozone and NO₂ concentrations at these locations have been experienced an elevated trend. The average magnitudes of increase in the concentrations of NO₂ and Ozone at these locations are different due to the geography, industrial activities and the transport of these species. A maximum increase in NO₂ and ozone are found to be at Goa (15.8 percent/year) and at Trivandrum (8.8 percent/year) which is mainly accounted due to the variation in boundary layer height and transportation of these gases.