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Prestebakke – regional background station

Foto: Claludia Hak

The monitoring station Prestebakke is a so-called regional background station that measures tropospheric ozone – ozone near the ground. The station lies 25 km south-southeast of Halden and east of Iddefjorden in Østfold County. The location is particularly well suited for detecting peak ozone episodes caused by long-range transport of air pollution from the continent to south-eastern Norway.

Most of us think of ozone as the stuff up in the stratosphere that protects us from harmful UV radiation from the sun.

Tropospheric ozone

But tropospheric ozone, which is present near the earth’s surface, doesn’t protect us. It is a poisonous gas formed when carbon monoxide (CO), nitrogen oxides (NOx) and volatile organic compounds (VOC) react with each other in the presence of sunlight and heat.

This means that tropospheric ozone is essentially a summer problem in Norway.

High levels of tropospheric ozone can harm vegetation, reduce crop yields, and have negative on our health. Ozone harms plant cells after entering through the stomata (openings) in their leaves. Tropospheric ozone can cause breakdown of exposed surfaces, and is considered a short-lived greenhouse gas. Exposure to tropospheric ozone can result in substantial economic losses for agriculture, especially in southern Europe.

Moreover, tropospheric ozone can be detrimental to human health, impairing respiratory function and exacerbating illnesses of the respiratory tract. Fortunately, ozone levels are rarely high enough to threaten life and health here in Norway.

NILU has monitored ozone at Prestebakke since November 1985. The station was originally set up as part of the acid rain surveillance programme, and previously measured several components of air. Ozone data from Prestebakke are also used in the Swedish surveillance programme.

National Reference Laboratory for Ozone and Air

The Norwegian Metrology Service has appointed NILU to be the National Reference Laboratory for Ozone. This means that NILU represents Norway’s top competence in the measurement of ozone. In addition, NILU is the National Reference Laboratory for Air (NRL).
Consequently, at Prestebakke – and all other measuring stations in Norway – the instruments are operated, and the data are quality-controlled according to stringent protocols. These ensure that the ozone instruments function well, with minimal downtime.

Aktuelle rapporter basert på data fra bl.a. Prestebakke

Overvåkningsrapporten «Monitoring of long-range transported air pollutants in Norway. Annual Report 2018”: https://www.miljodirektoratet.no/globalassets/publikasjoner/m1395/m1395.pdf