Premium
Segmentation of SED by Boundary Flows Associated With Westward Drifting Partial Ring current
Author(s) -
Wang Zihan,
Zou Shasha,
Coppeans Thomas,
Ren Jiaen,
Ridley Aaron,
Gombosi Tamas
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl084041
Subject(s) - geophysics , interplanetary magnetic field , physics , plume , convection , magnetosphere , boundary layer , ring current , geology , mechanics , atmospheric sciences , magnetic field , solar wind , meteorology , quantum mechanics
The segmentation mechanism of polar cap patches is agreed to be related to temporal changes of interplanetary magnetic field or transient reconnection. In this letter, using Global Ionosphere Thermosphere Model driven by two‐way coupled Block‐Adaptive‐Tree‐Solarwind‐Roe‐Upwind‐Scheme and Rice Convection Model, a new segmentation mechanism is proposed. This mechanism works as follows: A strong boundary flow between the Region 1 and Region 2 field‐aligned currents develops, while a shielding process develops in the inner magnetosphere. As the partial ring current drifts westward, the peak of the boundary flow also moves westward. This strong boundary flow raises the ion temperature through enhanced frictional heating, enhances the chemical recombination reaction rate, and reduces the electron density. When this boundary flow crosses the storm‐enhanced density (SED) plume, the plume will be segmented into patches. No external interplanetary magnetic field variations or transient reconnections are required in this mechanism.