Developing a Coupled Land-Atmosphere Data Assimilation for UFS With JEDI: Evaluation With Near-Surface Weather Forecasting

In this study, we developed a coupled land-atmosphere data assimilation capability with the Joint Effort for Data Assimilation Integration (JEDI) system using the Unified Forecast System (UFS) and Noah-MP land surface model. We conducted ensemble forecasting experiments with various land surface perturbations and evaluated the effectiveness of different perturbation methods on short- and medium-range weather forecasts using the UFS model. We also examined the cross-covariances between land and atmosphere. The effectiveness of horizontal and vertical localization schemes were also evaluated. The Soil Moisture Active Passive (SMAP) satellite-derived soil moisture observations and near-surface atmospheric data (2-m temperature, humidity, and 10-m wind) are simultaneously assimilated into a coupled land-atmosphere data assimilation configuration. The impacts of the coupled data assimilation on the short- and medium-range weather forecasts, especially the prediction of near-surface atmospheric conditions with the UFS model, are examined.