Understanding the Balance of Dayside and Nightside Reconnection Contributions to the Cross Polar Cap Potential During Solar Wind Disturbances
Abstract
This study focused on the investigation of how solar wind energy is deposited into the magnetosphere-ionosphere system during sudden enhancements of solar wind dynamic pressure (Psw), using the coupled OpenGGCM-CTIM 3D global magnetosphere ionosphere thermosphere model. Three unique events of solar wind pressure enhancements that occurred during negative, near-zero, and positive IMF Bz were simulated. Then, the behavior of the dayside and nightside reconnection rates were examined, and their respective contributions to Cross Polar Cap Potential (CPCP), a proxy of ionospheric plasma convection strength, were quantified. The modeled CPCP increased after a Psw enhancement in all three cases, which agrees well with observations from the Defense Meteorological Satellite Program (DMSP) spacecraft and predictions from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) technique. In the OpenGGCM-CTIM model, dayside reconnection increased within 9-13 minutes of the pressure impact, while nightside reconnection intensified about 13-25 minutes after the pressure increase. As the strong Psw compresses the dayside magnetosheath and, subsequently, the magnetotail, their magnetic fields intensify and activate stronger anti-parallel reconnection on the dayside magnetopause first and near the central plasma sheet second. For southward IMF, dayside reconnection contributes to the CPCP enhancement two to four times more than nightside reconnection. For northward IMF, the dayside contribution weakens, and nightside reconnection contributes more to the CPCP enhancement. It was found that high-latitude magnetopause reconnection during northward IMF produced sunward ionospheric plasma convection, which decreases the typical dawn-to-dusk ionosphere electric field. This results in a weaker dayside reconnection contribution to the CPCP during northward IMF.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 2014
- Accession Number
- ADA602458
Entities
People
- Christos G. Christodoulou
Organizations
- University of New Mexico