An OSSE study using the GFDL ensemble coupled data assimilation system: Biased twin experiment for deep Argo array

Thursday, 18 December 2014
You-Soon Chang1, Shaoqing Zhang2, Anthony Rosati3, Gabriel Andres Vecchi2 and Xiaosong Yang3, (1)Kongju National University, Gongju, South Korea, (2)Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States, (3)University Corporation for Atmospheric Research, Boulder, CO, United States
A "biased" twin experiment of coupled data assimilation with two CGCMs is designed to address two questions: 1) given atmospheric and oceanic observations and a biased numerical climate system, how to obtain balanced climate estimation? 2) Within the steady and coherent climate estimation framework, what is the impact of deep ocean Argo profiles? Based on the modern Argo observing system and artificial extension to the full depth, "observations" drawn from one CGCM are assimilated into the other. Our results show that the simultaneous atmospheric and oceanic constraints play a significant role for preventing the deep ocean drift. Within the bias magnitude in the twin experiment, the Argo extension to the full depth does not significantly improve the quality of climate estimation. More studies based on different assimilation models with improved spatial and temporal scales of the deep Argo array are demanding for further understanding the impact of deep Argo array.