Total Ozone Content Trend during the Last Decade over Western Indian Tropical Station i.e. Udaipur

This study focuses on multi-year change in Total Ozone Content (TOC) values measured simultaneously by ground based instrument, i.e., MICROTOPS-II sun photometer and space based TOMS satellite experiment during the last decade, i.e., the period from 2002 to 2009 in the outskirts of the semi-arid and semi-urban tropical region of Udaipur (24.6°N, 74°E;580 m asl), India. The negative declining trend in TOC value has been detected about 2 DU/decade by using Linear Regression Analysis (LRA) of the monthly averaged TOC levels. The LRA presents the best statistically significant percentage level (p) of greater than 99%. From the comparison of present result with the observations reported over mid, high and polar latitude sites, long-term TOC variability from tropical site is found to be the lowest, followed by their intermediate range from 10 to 30 DU/ decade over mid latitude sites and the highest range from 30 to 50 DU/decade over high to polar latitude. In order to establish the possible linking of reduction in TOC level per decade with other stratospheric dynamic parameters and atmospheric UV aerosols parameter, inter-annual change in average monthly TOC level has shown a strong correlation coefficient (r) of the order of 0.73 (p > 99.9990) with the stratospheric temperature, followed by its observed lower r value of 0.25 (p = 99%) for stratospheric zonal wind and then a significant correlation (r = 0.17;p = 95%) for AI 300 nm (Aerosols Index 300 nm) parameter. The variation of monthly mean meridional wind component does not illustrate a statistically significant correlation (r = 0.13;p < 80%) with their respective multi-year change in mean monthly TOC values. The consequence of such reduction of TOC per decade may be identified as the result of expected enhancement in incident ground UV-radiation level. At the same time, the harmful influence of increasing the UV level seems to be counteracted and reduced with the evidence of observed higher level of AI at 300 nm as high as 3 in the summer months over selected tropical environmental site.

Numerical Experiment of Combined Infrared and Ultraviolet Radiation Remote Sensing to Determine the Profile and Total Content of Atmospheric Ozone

A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of the infrared channels is 0.01 cm-1, less than Lorentz half-width at the earth's surface, rather than the present width, because these channels can obtain information about variations in the ozone profile below the profile main-peak. The numerical experiments show that the method has a satisfactory precision in determining total ozone content, just about I percent error, and vertical distribution from the earth to 65 km space. In addition, some semi-analysis functions lor calculating backscattered ultraviolet and a relaxation equation are described in this paper.

Water Content Effect on Oxides Yield in Gas and Liquid Phase Using DBD Arrays in Mist Spray

Electric discharge in and in contact with water can accompany ultraviolet（UV）radiation and electron impact, which can generate a large number of active species such as hydroxyl radicals（OH）, oxygen radical（O）, ozone（O_3） and hydrogen peroxide（H_2O_2）. In this paper, a nonthermal plasma processing system was established by means of dielectric barrier discharge（DBD）arrays in water mist spray. The relationship between droplet size and water content was examined,and the effects of the concentrations of oxides in both treated water and gas were investigated under different water content and discharge time. The relative intensity of UV spectra from DBD in water mist was a function of water content. The concentrations of both O_3 and nitrogen dioxide（NO_2） in DBD room decreased with increasing water content. Moreover, the concentrations of H_2O_2, O_3 and nitrogen oxides（NOx） in treated water decreased with increasing water content,and all the ones enhanced after discharge. The experimental results were further analyzed by chemical reaction equations and commented by physical principles as much as possible. At last,the water containing phenol was tested in this system for the concentration from 100 mg/L to9.8 mg/L in a period of 35 min.