Integrating the Sun-Earth System for the Operational Environment: A study of the 3–5 April 2010 geomagnetic storm

The Naval Research Laboratory is developing the Integrated Sun-Earth System for the Operational Environment (ISES-OE), an interdisciplinary physics-based space weather model development and validation program. The goal of ISES-OE is to improve our quantitative understanding of the space environment that can disrupt or degrade operational communications and navigation systems. The ultimate goal is to improve our ability to forecast space weather. The core ISES-OE model consists of SAMI3, NRL's state-of-the-art ionosphere model. SAMI3 has been coupled with NRL's Lyons-Fedder-Mobarry (LFM) magnetosphere model to properly specify the ionospheric boundary conditions. Also underway is the integration of a general circulation model of the thermosphere into SAMI3. To drive the coupled models, ISES-OE utilizes models of solar EUV spectrum variations based the TIMED/SEE measurements. The ambient solar wind is specified by both the Wang-Sheeley and HAF+3DMHD model, and the CME impacts by a suite of NRL instruments on LASCO and STEREO, semi-empirical NRL CME propagation models, HAF+3DMHD and from L1 monitoring.

The first significant solar event of solar cycle 24 occurred on 3-5 April 2010. A coronal mass ejection (CME), directed toward Earth, occurred on 3 April and led to a moderate geomagnetic storm (Kp=7) on 5 April that received wide publicity due to its suspected impact on the Intelsat Galaxy 15 communications satellite. We use the ISES models to follow this solar event from the surface of the sun to the Earth's ionosphere in order to demonstrate the current ability of ISES-OE to specify the geospace environment and its response to solar forcing. The model results from SAMI3/LFM are compared with a number of ground- and space-based observations including total electron content (TEC) measurements from JASON-1, GPS-derived TEC maps, and ionospheric and thermospheric densities constructed from UV remote sensing observations from RAIDS and SSULI.