8 August, 1998

Saturday, August 8th, 1998

Ozonesonde Data Evaluation from the South Pole:

This data was collected on August , 1998 and then was e-mailed to Bryan for conversion and analysis. The graph shoes both, the temperature and ozone profile. Note the difference to the Boulder data discussed yesterday. There are some differences:

* The tropopause is lower (colder air such as in the Antarctic is more compressed ) and more difficult to identify from the temperature profile compared to the Boulder data.

* Within the first kilometer at the surface there is a temperature-inversion. This is when the temperature in the troposphere increases first with height before it decreases as it usually does in the troposphere. This phenomena is parcticularly pronounced during the dark months in the Antarctic. It is due to the fact that 6 months out of the year there is no sun light in the Antarctic, consequently there is no radiation heating the surface any further. The surface air molecules getting in contact with the surface are getting cooler, because they give off heat to the cooler surface layer that they contact . Therefore they are cooler than usual, hence, the lower temperature at the beginning of the profile before reaching the usual temperature. (Temperature inversion can also happen during the night in Boulder.)

* This temperature inversion becomes usually less pronounced

during the Antarctic spring and summer. The temperature profile then looks different at the South Pole. So does the ozone profile. Since the mid 80s every time during the Antarctic spring the depletion of the ozone starts.

We will follow the depletion of the Antarctic ozone which starts in September. We will provide data and discuss more of it before my leave for the Antarctic. I will be there in January/February and will report more about the South Pole research on site. So, stay tuned....!!