DART: Empowering Geoscience with Improved Ensemble Data Assimilation

The Data Assimilation Research Testbed (DART) is a community facility for ensemble data assimilation developed and maintained by the National Center for Atmospheric Research (NCAR). DART has undergone many changes and improvements since last years' transition to GitHub, including a new URL: https://dart.ucar.edu.

A substantial investment in human capital and computer resources was used to create a high-quality 80 member atmospheric reanalysis at 1degree resolution for 2011 through 2019 which is publicly and freely available on the NCAR Research Data Archive (https://rda.ucar.edu/datasets/ds345.0/). This dataset also provides forcing files for land and ocean ensemble experiments.

DART now uses the Radiative Transfer for TOVS (RTTOV) radiative transfer model as the forward operator for all-sky visible, infrared, and microwave computations. If the model has the required variables, all features of v12.3 are available, including cloud and aerosol scattering and principal component calculations. The code also supports directly specifying scattering properties. The ability to support radiance observations has motivated new forward operators for useful constituents and new observation converters.

Several models and/or their scripting support have been updated for use with the Manhattan version of DART and their current versions. These include the Global Ionosphere Thermosphere Model (GITM), the cubed-sphere spectral element dynamical core for the Community Atmosphere Model (CAM), the global and regional configurations of the atmospheric Model for Prediction Across Scales (MPAS), the Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem), WRF-Hydro, the Community Land Model (CLM), and the Parallel Ocean Program (POP).

There are new observation converters and new or updated documentation to support these changes, including an updated WRF-DART tutorial and Issues and Wikis on GitHub. There is an improved testing facility to ensure good software practices and code portability. This poster will present an overview of the many updates and features available for this updated DART.