NG33A-1859
Lognormal Assimilation of Water Vapor in a WRF-GSI Cycled System
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Anton Kliewer1, Steven J Fletcher2, Andrew S Jones2 and John Michael Forsythe1, (1)Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, United States, (2)Colorado State University, Cooperative Institute for Research in the Atmosphere, Fort Collins, CO, United States
Abstract:
Recent publications have shown the viability of both detecting a lognormally-distributed signal for water vapor mixing ratio and the improved quality of satellite retrievals in a 1DVAR mixed lognormal-Gaussian assimilation scheme over a Gaussian-only system. This mixed scheme is incorporated into the Gridpoint Statistical Interpolation (GSI) assimilation scheme with the goal of improving forecasts from the Weather Research and Forecasting (WRF) Model in a cycled system. Results are presented of the impact of treating water vapor as a lognormal random variable. Included in the analysis are: 1) the evolution of Tropical Storm Chris from 2006, and 2) an analysis of a “Pineapple Express” water vapor event from 2005 where a lognormal signal has been previously detected.
