NG33A-1858
Gaussian and Mixed Lognormal-Gaussian 1DVAR Satellite Retrievals for Water Vapor and Temperature in the West Pacific
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Steven J Fletcher1, Anton Kliewer2, Andrew S Jones1 and John Michael Forsythe2, (1)Colorado State University, Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, United States, (2)Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, United States
Abstract:
A mixed lognormal-Gaussian distribution data assimilation scheme is implemented in the CIRA 1-Dimensional Optimal Estimator (C1DOE) 1DVAR retrieval system to model the background errors associated with temperature as Gaussian and those with respect to mixing ratio as lognormal. The new mixed distribution is compared against the traditional Gaussian configuration and a logarithmic transformation for the water vapor mixing ratio for Advanced Microwave Sounding Unit (AMSU) observations from the month of September 2005 over the west Pacific where a lognormal signal for moisture had previously been detected. How the mixed distribution scheme outperforms the Gaussian and transform systems is presented in the form of a reduction of the final innovation in AMSU-A and –B water vapor and temperature channels.
