Sandhu, JK; Rae, IJ; Freeman, MP; Gkioulidou, M; Forsyth, C; Reeves, GD; Murphy, KR; Sandhu, JK; Rae, IJ; Freeman, MP; Gkioulidou, M; Forsyth, C; Reeves, GD; Murphy, KR; Walach, M; - view fewer (2019) Substorm‐Ring Current Coupling: A Comparison of Isolated and Compound Substorms. Journal of Geophysical Research: Space Physics , 124 (8) pp. 6776-6791. 10.1029/2019ja026766.

Preview

Text Sandhu_2019JA026766.pdf - Published Version Download (2MB) | Preview

Abstract

Substorms are a highly variable process, which can occur as an isolated event or as part of a sequence of multiple substorms (compound substorms). In this study we identify how the low‐energy population of the ring current and subsequent energization varies for isolated substorms compared to the first substorm of a compound event. Using observations of H^{+} and O^{+} ions (1 eV to 50 keV) from the Helium Oxygen Proton Electron instrument onboard Van Allen Probe A, we determine the energy content of the ring current in L‐MLT space. We observe that the ring current energy content is significantly enhanced during compound substorms as compared to isolated substorms by ∼20–30%. Furthermore, we observe a significantly larger magnitude of energization (by ∼40–50%) following the onset of compound substorms relative to isolated substorms. Analysis suggests that the differences predominantly arise due to a sustained enhancement in dayside driving associated with compound substorms compared to isolated substorms. The strong solar wind driving prior to onset results in important differences in the time history of the magnetosphere, generating significantly different ring current conditions and responses to substorms. The observations reveal information about the substorm injected population and the transport of the plasma in the inner magnetosphere.

Download activity - last month

Export as JSONXMLCSV

Download activity - last 12 months

Export as CSVXMLJSON

Downloads by country - last 12 months

Export as JSONXMLCSV

Archive Staff Only

View Item