München 2019 – scientific programme
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UP: Fachverband Umweltphysik
UP 3: Planetary atmospheres (joint session EP/UP)
UP 3.4: Talk
Tuesday, March 19, 2019, 17:15–17:30, HS 22
Solar heating rates derived from SCIAMACHY observations of the O2 dayglow — •Miriam Sinnhuber1, Stefan Bender2, Thomas Reddmann1, and Amirmahdi Zarboo1 — 1Karlsruhe Institute of Technology, Karlsruhe, Germany — 2University of Trondheim, Trondheim, Norway
Solar heating by ozone absorption in the UV spectral range is an important contributor to radiative heating of the terrestrial stratosphere and mesosphere. At altitudes above about 60 km, the efficiency of the heating is reduced as part of the absorbed energy is transferred to excited species – O2(1Σ), O2(1Δ) – and lost by emission.
We use observations of the O2(1Σ) and O2(1Δ) dayglow in the mesosphere and lower thermosphere observed by SCIAMACHY on ENVISAT from 2008-2012 to derive ozone densities and the efficiency of the ozone solar heating. The heating efficiency decreases from 1 around 60 km to less than 0.6 at the mesopause depending on latitude and time of year. Resulting ozone heating rates vary from more than 10 K/day in the lower mesosphere to less than 1 K/day around 80 km, with a secondary maximum of up to 5 K/day around 90 km in the region of the second ozone maximum.