Initial Implementation of Space Weather Data Assimilation Capabilities in the JEDI System

The Joint Effort for Data assimilation Integration (JEDI) data assimilation system is a model agnostic data assimilation software that is the product of a coordinated effort by the Joint Center for Satellite Data Assimilation (JCSDA) and its partner organizations: NASA, NOAA, US Navy and Air Force, and the UK Met Office. It is developed with the goal of rapid adaptation and integration of new and emerging sensors and data types. To that end, the JEDI software is designed with reusability in mind, so that new models and techniques can be implemented with ease and minimal repeated code. JEDI has developed unified forward operators (UFO) and these have been previously applied mostly for neutral atmospheric data assimilation.

This work introduces the first effort to introduce space weather data assimilation capabilities into the JEDI system, taking advantage of what has been developed in JEDI UFO. Observations from two instruments are considered in this work, ionosondes and space-based radio occultation (RO). Both measure electron density. Ionosondes are profile measurements of electron density produced by a ground based high frequency radio transmitter. RO measures the total electron density along the path of the GPS signal through the atmosphere. The background of the electron density for JEDI is provided by the Python implementation of the International Reference Ionosphere (PyIRI). It is a climatological model that was developed at the U.S. Naval Research Laboratory (NRL) in order to run the widely used, climatological International Reference Ionosphere (IRI) model at significantly reduced computational cost. Converters will be developed to store the data in the Interface for Observation Data Access (IODA) format used by JEDI. We will then develop the forward operators necessary to transform the PyIRI model data to observation space by leveraging existing JEDI forward operators. Ionosonde forward operators will be based on those established for radiosonde observations and ionospheric RO measurements will utilize the strategies developed for the neutral atmosphere. Future work will include the utilization of this newly developed framework for observations in a JEDI based pseudo-cycling assimilation system.