MIPAS provides global ozone distributions from the lower stratosphere to the lower thermosphere

The spectral measurements of MIPAS in the middle (MA) and upper atmosphere (UA) mode and the noctilucent cloud (NLC) mode provided observations of ozone that cover the lower stratosphere (20 km) up to the lower thermosphere (105 km), continuously from January 2007 to April 2012. The figure shows the time series of derived ozone mixing ratios for daytime (left) and nighttime (right) in the tropics (top) and the Northern polar regions (bottom). The white stripes are periods when there is no nighttime and daytime condition, respectively, over the pole. The retrieved ozone data provide all expected features like the strong diurnal variation above about 55 km, seasonal and semi-annual variations, the tertiary ozone maximum in polar regions during winter around 70 km, and a solar signature in phase with the solar cycle around 90 km during day in the tropics.

The retrieval of ozone above the stratopause requires the modelling of non-LTE effects in the population of the v₁ and v₃ molecular states during the radiative transfer calculations. The populations are updated in each iteration step of the retrieval. The only quantity necessary for the radiative transfer modelling but not available from the measurements themselves is the concentration of atomic hydrogen (nighttime only) that is provided by merged profiles from the NRLMSISE-00 and the SD-WACCM model.

For more information see: https://doi.org/10.5194/amt-11-2187-2018