Volcano Erebus as the Key Factor of Enhancement of the Antarctic Ozone Hole
E. S. SAVELYEVA, V. V. ZUEV and N. E. ZUEVA
Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch of the Russian Academy of Sciences, Pr. Akademicheskiy 10/3, Tomsk 634055 (Russia)
Keywords: Antarctic ozone hole, circumpolar eddy, polar stratospheric clouds, volcano Erebus, degassing, chlorine cycle
Abstract
Estimation of the amount of stratospheric hydrogen chloride HCl necessary for the formation of the spring ozone hole was carried out during the period of its existence above McMurdo station in 1992 on the basis of the maximal concentration of ClO in lower Antarctic stratosphere. The height of gas plume emitted by the Antarctic volcano Erebus during active degassing was calculated, as well as the trajectories of further cyclonal elevation of these emissions inside high cyclones to the height of more than 18 km, obtained using the NOAA HYSPLIT model. It is demonstrated that the fraction of volcanic emissions reaching the height of the stratosphere averaged per year is 41.5 %. It is established that the amount of volcanogenic HCl entering the Antarctic stratosphere every year is sufficient for the formation of the ozone hole of modern scale. It is shown that anomalous enhancement of the activity of Erebus in early 1980es became the key factor for the substantial increase of the Antarctic ozone anomaly. A decrease of the size of the spring ozone hole above Antarctica is possible only in the case of sharp decrease or complete termination of the activity of this volcano.
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