Premium
Magnetospheric Flux Throughput in the Dungey Cycle: Identification of Convection State During 2010
Author(s) -
Milan Stephen E.,
Carter Jennifer A.,
Sangha Harneet,
Bower Gemma E.,
Anderson Brian J.
Publication year - 2021
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2020ja028437
Subject(s) - substorm , magnetosphere , geophysics , physics , solar wind , convection , electrojet , interplanetary magnetic field , ionospheric dynamo region , earth's magnetic field , flux (metallurgy) , geomagnetic storm , context (archaeology) , convection cell , atmospheric sciences , magnetic field , mechanics , geology , combined forced and natural convection , natural convection , chemistry , paleontology , organic chemistry , quantum mechanics
We quantify the contributions of different convection states to the magnetic flux throughput of the magnetosphere during 2010. To do this we provide a continuous classification of convection state for the duration of 2010 based upon observations of the solar wind and interplanetary magnetic field, geomagnetic indices, and field‐aligned currents measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Convection states are defined as (1) quiet, (2) weak activity, substorm (3) growth, (4) expansion and (5) recovery phases, (6) substorm driven phase (when relatively steady magnetospheric convection occurs), (7) recovery bays (when recovery phase is accompanied by a negative excursion of the AL electrojet index), and (8) periods of multiple intensifications (storm‐time periods when continuous short‐period AL activity occur). The magnetosphere is quiet for 46% of the time, when very little convection takes place. The majority of convection occurs during growth and driven phases (21% and 38%, respectively, of open magnetic flux accumulation by dayside reconnection). We discuss these results in the context of the expanding/contracting polar cap model of convection, and describe a framework within which isolated substorms and disturbances during periods of more continuous solar wind‐magnetosphere driving can be understood.