MétéoSuisse - Sounding

Ozone soundings at Payerne

Since 1968, the altitude distribution of ozone is measured three times per week above Payerne in conjunction with the aerological soundings.

At Payerne, the ozonesondes are launched with aerological balloons capable of reaching an altitude of ~ 35 km. In situ ozone measurements are recorded during the balloon ascent. The ozonesonde consists in a small pump injecting outside air in a bubbler containing a few ccm of a dilute potassium iodide (KI) solution. Chemical reaction of the solution with the ozone contained in the air produce an electrical current proportional to the ozone concentration.

Two types of ozonesondes are shown on the picture deside: the BM (Brewer-Mast) on the left and the ECC (Electrochemical Concentration Cell) on the right. The size of both instruments is about 10 cm. These sondes are packed in a styrofoam box to isolate the sonde from the low temperature of the stratosphere during the ascent. The BM is the operational ozonesonde at Payerne since 1968 up to present time.

Two types of ozonesondes: the BM (Brewer-Mast) on the left and the ECC (Electrochemical Concentration Cell) on the right. The size of both instruments is about 10 cm. The BM has been the operational ozonesonde at Payerne from 1968 up to 2002. The ECC sondes are the instruments presently used to measure the ozone profiles.

Seasonal mean ozone profiles for Payerne soundings for year 2004.

The altitude distribution of ozone is represented for the different seasons of the year 2004. The maximum of ozone is situated between 20 to 23 km depending on the season and it is more pronounced in the first half of the year. Two examples of individual ozone profile are shown with their original altitude resolution. It appears that the structure of the ozone distribution is layered with large changes over small altitude differences. The profile from 26.11.2004 corresponds to the smallest amount of ozone recorded in 2004 (239DU) while the 27.02.2004 profile corresponds to the largest ozone amount (423 DU).

Ozone profiles by sounding