Assimilation of Near Space Ozone Data from SABER and MLS Observations into the Whole Atmosphere Community Climate Model and Data Assimilation Research Test-Bed

This research adds interface programs to the near space data assimilation and forecasting systemWACCM+DART (Whole Atmosphere Community Climate Model, Data Assimilation Research Test-Bed) for assimilation of SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) and MLS (Microwave Limb Sounder) ozone data, and performs SABER and MLS ozone data assimilation experiments to simulate a SSW (stratosphere sudden warming) event during February 2016. The following main conclusions are reached. Firstly, the ozone analysis produced by SABER and MLS ozone volume concentrations data assimilation can well represent the sudden variation of stratospheric ozone profile above the north polar area during SSW, which shows good agreement with ERA5 (Fifth Generation of ECMWF Reanalyses) data in describing characteristics of ozone changes. The verification of 6-hour ozone forecast based on SABER and MLS observations shows that the improvement of 6-hour ozone forecast and analysis through assimilating SABER and MLS ozone volume concentrations data is obviously reflected in the stratosphere above the high latitudes in the Southern Hemisphere, the upper-middle stratosphere, and lower mesosphere above the middle and high latitudes in the Northern Hemisphere. The forecast verification based on ERA5 reanalysis suggests that the advantages of assimilation are more significant in high-latitude areas in the Northern Hemisphere, where the quality of ozone analysis in the middle and upper stratosphere and the lower mesosphere is improved and analysis errors of temperature in the upper stratosphere and the lower mesosphere and zonal winds in the lower mesosphere are reduced. The verification of 0-10-d ozone forecast based on MLS ozone observations shows that adding SABER and MLS ozone volume concentrations data assimilation to the WACCM+DART can better improve 0-5-d ozone forecasting results of the WACCM in the lower stratosphere and lower mesosphere compared to the control experiment.