A framework for space weather data assimilation: Aether and the Data Assimilation Research Testbed

Historically, space weather observing platforms consisted primarily of isolated large facilities. Newer instruments consist of distributed arrays of lower powered instruments, such as the Global Positioning System Total Electron Content network, coherent-scatter high-frequency radars (e.g. SuperDARN), all-sky imagers, Fabry-Perot Interferometers, and ionosondes. As part of the Space Weather with Quantified Uncertainties program sponsored by the National Aeronautics and Space Administration (NASA) and the United States National Science Foundation (NSF), the Aether model of the Earth's upper atmosphere is designed to account for gaps in available data and improve upon current model and software limitations. Aether is developed by a team spanning academia (the University of Michigan), civil service (NASA Goddard), the military (Naval Research Laboratory) and Federally Funded Research and Development Centers (NSF National Center for Atmospheric Research). Aether's interface to the Data Assimilation Research Testbed (DART) allows for the assimilation of total election content and electron density profiles from Global Navigation Satellite System observations, O/N2 & TDISK from Global-scale Observations of the Limb and Disk (GOLD) observations, wind velocity from Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) observations, temperature from the Aura Microwave Limb Sounder observations and temperature from Sounding of the Atmosphere using Broadband Emission Radiometry (SABRE) observations. An overview of the current system's capabilities is presented and DART's general capabilities for assimilation of upper atmospheric observations is described.