The CGS science investigation focuses on the importance of mesoscale processes in enabling the full range of couplings, forcings and cross-scale interactions in stormtime geospace. The following three science themes, along with the corresponding science questions within them, comprise the breadth of CGS science.
A more detailed description of this theme can be found below. The science question we address here are:
How is plasma and electromagnetic energy transported through the plasma sheet to the ring current at different spatiotemporal scales?
How do plasma sheet dynamics at different spatiotemporal scales control energy deposition and momentum transfer from the magnetosphere to the ionosphere-thermosphere, and what are the corresponding global geospace impacts?
Polar cap density structures, such as tongues of ionization and patches, that present a major space weather hazard due to their detrimental effect on communications. They also present a major scientific and modeling challenge as part of the global plasma circulation process involving the ionosphere, the plasmasphere and the inner magnetosphere, sometimes referred to as the geospace plume (Foster et al., 2020). The science questions we pursue under this theme are:
How do high-latitude energy deposition and momentum transfer engender mass circulation throughout the ionosphere-thermosphere at different spatiotemporal scales?
What are the global impacts of mass circulation throughout geospace and its origins in mesoscale ionospheric structure and dynamics?
Atmospheric gravity waves exert forcing on and precondition the ionosphere and thermosphere (Qian and Yue, 2017), and thus can affect their responses to geospace storms. At the same time, storm-time effects in the ionosphere-thermosphere system introduce changes in the circulation and may affect the breaking and deposition of energy and momentum by gravity waves and tides. Thus it is important to investigate the change of global mean flow and lower atmosphere waves, and their interaction during storms and of the physical mechanisms that determine this interaction (Hagan et al., 2015; Pedatella, 2016). The science questions within this theme are:
How does the interplay between magnetosphere and lower atmosphere forcing regulate the formation and evolution of equatorial plasma bubbles?
How do lower atmosphere waves change during storms and how significant are their effects on geospace responses to storms through preconditioning?