Ozone profile retrieval from backscattered ultraviolet radiances: The inverse problem solved by regularization

Authors

  • Otto P. Hasekamp,

  • Jochen Landgraf


Abstract

A new algorithm is presented for the retrieval of ozone profiles from backscattered ultraviolet radiation, as measured by the Global Ozone Monitoring Experiment (GOME). It is the first algorithm for ozone profile retrieval from this type of measurement that does not depend on climatological information about the ozone profile. For the inversion, Phillips-Tikhonov regularization is used in combination with the L curve criterion for choosing the regularization parameter. This inversion technique allows one to retrieve a maximal possible information amount from the measurement, while at the same time the influence of the measurement noise on the retrieved profile is minimized. In this paper, we show the suitability of this method for ozone profile retrieval from GOME radiance measurements. The average vertical resolution of the retrieved profiles varies between 8 and 10 km. The GOME ozone profiles are validated with 163 ozonesonde profiles spread over seven stations. The root-mean-square differences between the sonde and GOME ozone profiles are generally 5–10% in the stratosphere. Differences in the mean profile are in the range 1–7% in the stratosphere.

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