Análise do decaimento da coluna total de ozônio sobre a América do Sul

Abstract

Ozone (O3) is less than 1% of Earth's atmospheric gases. However it is essential for life on Earth because it absorbs ultraviolet radiation of the UV-B type, which is detrimental to the health of living beings. The tropical region is the biggest producer of stratospheric ozone; however, due to the Brewer-Dobson circulation there is a depletion of ozone total column in this region, which may extend to higher latitudes. In 1985 a great depletion was identified in the ozone content in the Antarctic atmosphere, where air masses with low ozone concentration may detach the Antarctic vortex and migrate to lower latitudes, especially in austral spring. These are the so-called side effects of the Antarctic ozone hole. This work has the main objective to analyze the decay of total ozone over South America (20°N and 60°S; 30°W and 80°W), through monthly averages and thresholds of ozone total column data from the OMI sensor (daily average and 1°x1° spatial resolution). From the monthly average and thresholds, can be observed the greatest meridional variability in total column ozone during the months near the spring and less variability during the months of near fall, between the polar and middle latitude. On quantification of days below the threshold of decay events are observed total ozone column over the region near Antarctica, where the months between September and February had more days below the threshold. The months of May, July and December showed a higher number of days below the threshold between latitudes 20 ° S and 40 ° S, on the continental area, especially in May, on the north-central Argentina. The analysis of potential vorticity indicated 06 cases of tropical origin of the air mass (February, March, June, July, August and September), and 06 with polar origin (January, April, May, October, November and December), and July is the month with the highest depletion compared to the monthly average. Almost all months had their decays total column O3 associated with the presence of anticyclones, with the exception of January and May, when the fall occurred shortly after the passage of the frontal system, still having cloudy and December, with the frontal system over point to decay.