Title:Cloudy radiance assimilation with cloud control variables

Author: Byoung-Joo Jung (National Center for Atmospheric Research)
Thomas Auligné (National Center for Atmospheric Research)
Gael Descombes (National Center for Atmospheric Research)

In this study, cloudy radiance assimilation is tried with 15 km WRF model and GSI system. For this, together with standard control variables (CVs), cloud CVs (cloud water and cloud ice) are augmented. Background error statistics for cloud CVs is estimated with NMC method. The horizontal length scales for cloud CVs are much smaller than the other CVs.To keep the possible cloudy radiance observations, we relaxed the firstguess check criteria and skipped the cloud screening process for infra red (IR) sounder. Rather than Gaussian, huber norm is used to represent the error distribution of all-sky (clear and cloudy) radiance observation. In the initial tests with AMSU-A and AIRS, reasonable convergence was shown and more discussion will be given at the presentation.

GMAO Head: Steven Pawson Global Modeling and Assimilation Office NASA Goddard Space Flight Center

Curator: Nikki Privé Last Updated: Feb 9 2015