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Margit Dyrland has worked on observations of temperature and airglow
changes in upper atmosphere/mesosphere trying to find a key to weather and
climate variability. Combination of several methods was used and she has
found relationships between various climate elements, fully described in her
PhD thesis.
Airglow is a light seen in the upper reaches of
the Earth’s atmosphere. When high-energy radiation from the Sun collides
with molecules in the ionosphere, the molecules release energy in the form
of light.
The knowledge about climate variables and their
dynamics in the upper atmosphere and mesosphere are both important for
climate on the Earth's surface and they can influence it too. Search for
changes in mesopause temperature through observations of airglow by
combination of ground-based measurements with satellite observations
delivered unique results.
Firstly, it was possible to derive the temperature of
menopause from measurements of airglow intensity changes. The temperature
was derived for a period of 25 years - when the airglow observations were
made. Secondly, it was showed that the altitude, intensity and temperature
of airglow variations are linked to direction of meridional winds (derived
from meteor activity). Northward winds lead to higher temperatures in the
mesopause and increased intensity of airglow. For southward winds the
opposite is true.
Direct link between the meridional winds and the
altitude of the hydroxyl layer (airglow) has never been observed before.
Source:
Weather and climate 90 km above Svalbard (UNIS/UiT press release)
Contact: Margit E. Dyrland, UNIS (margitd@unis.no)
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