24 Observed 850 hPa westerly wind trends over the Southern Ocean during 1979-2011 exhibit 25 strong regional and seasonal asymmetries. On an annual basis, trends in the Pacific Sector 26 (40°S-60°S; 70°W-160°W) are significant and three times larger than zonal-mean trends related 27 to the increase in the Southern Annular Mode (SAM). Seasonally, the SAM-related trend is 28 significant in austra...

The ozone layer in the stratosphere absorbs a large part of the harmful UV-radiation coming from the sun. In the natural situation ozone is continuously being formed and destroyed. However, a number of man-made chemicals that contain fluorine, bromine and chlorine groups, called Ozone Depleting Substances (ODS), can greatly increase the rate of destruction, leading to a reduction in the thickne...

An assimilated data base of total column ozone measurements from satellites has been used to generate a set of indicators describing attributes of the Antarctic ozone hole for the period 1979 to 2003, including (i) daily measures of the area over Antarctica where ozone levels are below 150 DU, below 220 DU, more than 30% below 1979 to 1981 norms, and more than 50% below 1979 to 1981 norms, (ii)...

environmental degradation all over the world is one of the three major concerns of the human being. depletion of fresh water sources on earth, ozone layer depletion, soil degradation, intensive farming, climate change and temperature increase, biodiversity loss, population increase, poverty, pollution, extinction of rare species, biological extinction and endangered species are the main environ...

Ozone column amounts obtained by the total ozone mapping spectrometer (TOMS) in the southern polar region are analyzed during late austral winter and spring (days 240-300) for 1980-1991 using area-mapping techniques and area-weighted vortex averages. The vortex here is defined using the -50 PVU (1 PVU = 1.0 x 10(-6) K kg-1 m2 s-1) contour on the 500 K isentropic surface. The principal results...

Abstract In contrast to the general stratospheric ozone recovery following international agreements, recent observations show an ongoing net depletion in tropical lower stratosphere (LS). This is thought be driven by dynamical transport accelerated global warming, while chemical processes have been considered unimportant. Here we use a chemistry–climate model demonstrate that halogenated ozone-...

We use a chemistry-climate model and new estimates of smoke produced by fires in contemporary cities to calculate the impact on stratospheric ozone of a regional nuclear war between developing nuclear states involving 100 Hiroshima-size bombs exploded in cities in the northern subtropics. We find column ozone losses in excess of 20% globally, 25-45% at midlatitudes, and 50-70% at northern high ...

7 Observations show an increase in maximum precipitation extremes and a decrease in 8 maximum temperature extremes over southeastern South America (SESA) in the second 9 half of the 20th century. The Community Earth System Model (CESM) Large Ensemble 10 (LE) experiments are able to successfully reproduce the observed trends of extreme precip11 itation and temperature over SESA. Careful analysis...