2022 Workshop: GC: Poynting Flux

White paper Link:

https://docs.google.com/document/d/1Tpd536JHHUUwkSHlAGSrG231rlxgzYt_9lW…

At high latitudes, electromagnetic energy from the Solar wind and magnetosphere flows into the upper atmosphere through the ionosphere (e.g. Gary et al., 1994). This is quantified in terms of Poynting flux. During active magnetic periods, this energy source can be larger than Solar radiation (Luhr and Liu, 2006) and is certainly harder to characterize at all times. The Poynting flux is transformed into thermal or kinetic energy through particle acceleration in the magnetosphere and Joule/frictional heating in the upper atmosphere (e.g. Thayer and Semeter, 2004). Despite the obvious importance of this energy source to the coupled Ionosphere-Thermosphere-Mesosphere (ITM) system, an accurate global picture of the Poynting flux at relevant spatio-temporal scales remains elusive. Current models of the ITM typically still rely on empirical models based on historic datasets (e.g. Heelis et al., 1982; Weimer, 2005) to estimate this forcing. Recent major advances in modeling from the ground up to 600-km (e.g. WACCM-X, WAM, GAIA) and, separately, from the Solar wind down to the ionosphere (e.g. GAMERA, BATS-R-US) essentially meet here.

The science question driving this Grand Challenge is: What is the electromagnetic energy input into the Earth’s atmosphere? This topic is aligned with the strategic thrusts outlined in the CEDAR strategic vision. It explores an exchange of energy between all of the space-atmosphere-interaction region (SAIR), it merges many geoscience datasets and models, and it synthesizes knowledge from several disciplines of the solar-terrestrial sciences. Therefore, this Grand Challenge is expected to have a major impact on a large segment of the CEDAR research community.