Retrieval of Temperature, Trace Species and Aerosols From the High Resolution Dynamics Limb Sounder (HIRDLS).
Abstract
The retrieval algorithms developed for the High Resolution Dynamics Limb Sounder (HIRDLS) will be presented. The non-linear inversion technique is based on the Rodgers optimal estimation method (maximum a posteriori). An objective function, consisting of the sum of the cost function (departure of radiance measurements from forward model) and penalty function (departure of retrieved state from the a priori) is minimized using a modified Marquardt-Levenberg algorithm which combines the inverse Hessian and steepest descent approaches and uses a simplified trust-region scheme to control the step-size at each iteration. The diagnostic information obtained from the retrieval allows quantification of the effects of the a priori state on the retrieved state and decomposition of the various sources of error so that the effect of each on the retrieved state can be appreciated. A 3D 12-h global-mode set of simulated HIRDLS radiances were generated using atmospheric data fields at 20 minute intervals from the NCAR MOZART3 model which allows the effects of line of sight gradients and diurnally varying species on the retrieval to be investigated.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.A21C0988L
- Keywords:
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- 0305 Aerosols and particles (0345;
- 4801);
- 0340 Middle atmosphere: composition and chemistry;
- 0394 Instruments and techniques;
- 3260 Inverse theory