Ozone Hole Watch
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Ozone Hole Meteorology: 2006 Temperature

Tables-based version .

The depth and area of the Antarctic ozone hole are governed by the temperature of the stratosphere and the amount of sunlight reaching the south polar region. Temperatures that are cold enough can form polar stratospheric clouds (PSCs). PSCs are an important component in the destruction of ozone molecules. PSCs can be formed when temperatures fall below a given threshold for each type of PSC. The formation temperature is dependent on concentrations of nitric acid and water vapor, and the potential temperature of the air. PSCs can be formed from sulfate aerosols, nitric acid trihydrate (NAT), or ice.

Comparison to all years

The following figures show the daily progression through the ozone hole season, comparing the current year to the climatology of all other years.

2006, 50 hPa, Minimum Temperature The 50-hPa minimum Antarctic temperature is determined for latitudes south of 50°S.
  • Minumum Temperature …
  • 2006, 60°–90°, 50 hPa Temperature 60°–90°S Temperature … The 50-hPa temperature averaged around the polar cap for latitudes south of 60°S. This is a good measure of the overall temperature in the polar vortex.
  • 2006, 55°–75°, 50 hPa Temperature 55°–75°S Temperature … The 50-hPa temperature averaged for 55°S to 75°S. This is a good measure of the temperature in the polar vortex boundary region.
  • 2006, 460 K, PSC NAT Area PSC NAT Area Area of PSCs formed from nitric acid trihydrate (NAT). We assume a fixed profile of nitric acid, with a value of 4.54 ppt on the 460 K potential temperature surface, and a fixed concentration of water at 5.0 ppm. We interpolate temperatures to potential temperature surfaces and then find the area of temperatures less than the condensation temperature for each surface.
  • 2006, 460 K, PSC NAT Volume PSC NAT Volume To calculate the volume, we first calculate areas and then integrate the areas over the range of input levels. Instead of using fixed theta levels, we calculate an average value of theta over each pressure level from 60°S to 90°S.
  • 2006, 460 K, PSC Ice Area PSC Ice Area Area of PSCs formed from ice. We assume a fixed profile of nitric acid, with a value of 4.54 ppt on the 460 K potential temperature surface, and a fixed concentration of water at 5.0 ppm. We interpolate temperatures to potential temperature surfaces and then find the area of temperatures less than the condensation temperature for each surface.
  • 2006, 460 K, PSC Ice Volume PSC Ice Volume To calculate the volume, we first calculate areas and then integrate the areas over the range of input levels. Instead of using fixed theta levels, we calculate an average value of theta over each pressure level from 60°S to 90°S.

-- click on a link for a PDF figure --

Detailed descriptions of the plots are available. The Code 613.3 web page has many other meteorological statistics.