Ozone trend, Antarctica

Ozone loss over the Arctic has been less dramatic than that over the Antarctic, mainly because the different distribution of land and sea in the Northern Hemisphere allows for only a weak vortex over the Arctic. There is more mixing of air with that from lower latitudes and temperatures do not become low enough for routine formation of polar stratospheric clouds. In years when the Arctic has been cold enough for cloud formation similar ozone destruction has been observed, but for less prolonged periods than over Antarctica. Trends in ozone over the rest of the globe have been small compared to those of the Antarctic, or even Arctic, and are quantified in section 2.4.1. 

Fig. 16-3 Illustration of the linked behavior of radiatively important trace species concentrations over different time-scales. (a, b, c) Concentrations of methane, nss-SOj , and CO2 over the past 160 000 years found in ice cores from Vostok, Antarctica (temperature deduced from 02 also shown), (d, e, f) Secular trends in nitrous oxide, methane, and CO2 over the past 300 years, (g, h, i, j, k) Changes in October stratospheric ozone column burden over Antarctica, and chloroflourocarbon, methane, sulfate, and nitrate from south Greenland ice, and carbon dioxide concentrations over the past 30 years. Figures adapted from (a) Chappellaz et al. (1990) with the permission of Macmillan Magazines Ltd. (b) Legrand et al. (1988) with the permission of Macmillan Magazines Ltd. (c) Bamola et al. (1987) with the permission of Macmillan Magazines Ltd. ...

---