Long-term ozone trend and its effect on night airglow intensity of Li 6708 Å at Ahmedabad (23°N, 72.5°E), India and Halley Bay (76°S, 27°W), British Antarctic Service Station

Abstract

A critical analysis has been made of the long-term yearly and seasonal variations of ozone concentration at Ahmedabad (23°N, 72.5°E), India and Halley Bay (76°S, 27°W), a British Antarctic Service Station. The effect of O 3 depletion on night airglow emission of Li 6708 Å line at Ahmedabad and Halley Bay has been studied. Calculations based on chemical kinetics show that the airglow intensity of Li 6708 Å line has also been affected due to the depletion of O 3 concentration. The nature of yearly variation and seasonal variation of intensity of Li 6708 Å line for the above two stations have been shown and compared. It has been shown that the rate of decrease of intensity of Li 6708 Å line was comparatively higher at Halley Bay due to dramatic decrease of Antarctic O 3 concentration.

Contribution of some ozone depleting substances (ODS) and greenhouse gases (GHGs) on total column ozone growth at Srinagar (34°N, 74.8°E), India

“…The variation of ozone concentration represented by figure 1 clearly depicts an increasing trend in total ozone column over Srinagar by 6.98 DU per year for the above period, whereas, Jana and Nandi (2005, 2006band 2006c, Jana et al (2008Jana et al ( , 2010 Randeniya et al (2002) also reported that halogen loading of the atmosphere has peaked and stratospheric ozone levels are expected to recover to pre-1980 levels in this century. Figure 2 represents the little scattered decline of total mid-latitude ozone with increase in concentrations of CFC-11, CH 3 Br, CCl 4 , CH 3 CCl 3 , CFC-113 and WMO minor and vice versa with different rates.…”

Yearly variation and annual cycle of total column ozone over New Delhi (29°N, 77°E), India and Halley Bay (76°S, 27°W), British Antarctic Survey Station and its effect on night airglow intensity of OH(8, 3) for the period 1979–2005

“…Total column ozone densities of different stations have been obtained from the website http://jwocky. gsfc.nasa.gov (Jana et al 2010a(Jana et al , 2010b. Monthly mean ozone densities have been calculated from daily average value of ozone in DU for the stations, namely, New Delhi and Halley Bay.…”

Long-Term Changes in Night Time Airglow Emission at 557.7 nm over Mid Latitude Japanese Station i.e., Kiso (35.79oN, 137.63oE)

“…In these perspectives of long-term trends, Jana & Nandi [16][17][18][19] and Jana et al [3,20], have performed the analysis specifically based on computed long-term night airglow intensity at 589.3 nm at some of Indian stations and reported the close association of long-term change in MLT Airglow intensities with depletion of long-term trend in ozone. Similarly Vyas & Saraswat [21] on the basis of observed data of Na-D airglow of the present study site i.e., Kiso (Japan) reported a declining longterm trend in ozone value and mesospheric temperature or ozone depletion and mesospheric cooling phenomena.…”