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Experimental Investigations of Total Ozone Content and Surface Ozone Concentration During SHEBA |
International Arctic Research Center, University of Alaska Fairbanks,
Arctic and Antarctic Research Institute, St. Petersburg, Russia,
Arctic and Antarctic Research Institute, St. Petersburg, Russia
The observations of total ozone content (TOC) and surface ozone concentration (SOC) had been executed in Sheba ice camp during April 5 - May 31, 1998 year. The TOC measurements had been made every two hours for sun heights above 80 onboard the "Des Groseilliers" with Russian standard filter ozonometer. This device measured and compared direct or scattered from zenith solar radiation in narrow spectral ranges 300 nm and 320 nm. A relative error of the total ozone measurements is not more than 3-5% for sun height above 100 and bellow 8% for sun heights less than 100.
The surface ozone concentration measurements were organized in Met Hat, in 300 meters from the ship. SOC was measured continuously by means of the ozone analyzer based on the effect of heterogeneous hemiluminescence due to exothermic reaction of ozone with special compound. The ozone analyzer had been calibrated before and after expedition in the Russian State Institute of Metrology. The relative accuracy of device is 15%, detection limit -1 mkg/m3 and resolution time - 2 minutes.
The results of TOC measurements show reasonable agreement with existing data of satellite and surface measurements for the region under study. Same time its give possibility to reveal strong decrease of total ozone content during April 20 - May 6, from 460 Du to 360 Du, coincided with strong proton flare on the Sun and corresponding growth of geomagnetic activity level. The comparison with air temperature from Sheba soundings shows that same days the air temperature on heights 19.5-20 km decreased from -450 to -500°C. Possible mechanisms for explanation of mini ozone holes formation are proposed.
The data of SOC measurements during SHEBA confirmed the existence of known event of total surface ozone depletion in the polar spring. Almost continuos run of measurements had shown strong temporal variability of SOC in first weeks of April, its fall bellow the analyzer detection limit in the last week of April and first weeks of May and gradual recovering of surface ozone in second half of May with some diurnal variability. The observed instantaneous and averaged values of surface ozone concentration during experiment were more than twice smaller obtained at Barrow and Resolute, and relatively close to data of ice camps T-3 and SWAN (Hopper et al, 1994).
