Capturing global magnetospheric dynamics using the location of region 1 currents

Details Capturing global magnetospheric dynamics using the location of region 1 currents Capturing global magnetospheric dynamics using the location of region 1 currents

Dec 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufmsm51d..06c&link_type=abstract

American Geophysical Union, Fall Meeting 2011, abstract #SM51D-06

Physics

[2721] Magnetospheric Physics / Field-Aligned Currents And Current Systems, [2740] Magnetospheric Physics / Magnetospheric Configuration And Dynamics, [2784] Magnetospheric Physics / Solar Wind/Magnetosphere Interactions, [2794] Magnetospheric Physics / Instruments And Techniques

Scientific paper

Using radial current densities provided by the AMPERE project we employ a fi[|#12#|]tting scheme to identify the location of the maximum Region 1 (R1) current at all magnetic local times (the R1 oval). We investigate the change in size of the R1 oval in response to auroral activations. The radius of the R1 oval is seen to undergo a cyclic variation which matches the substorm cycle; during the growth phase the radius increases until a substorm is triggered and subsequently the oval contracts. We interpret these observations in the framework of the expanding-contracting polar cap paradigm: dayside reconnection adds open magnetic flux to the polar cap during the growth phase, which pushes the open-closed fi[|#12#|]eld line boundary (OCB) and the R1 oval equatorward. Tail reconnection during the substorm expansion phase destroys open flux, causing the polar cap to contract and as a result the OCB and the R1 oval move poleward. In a second case study we show that during enhanced ring current intensity the R1 oval can grow to larger sizes than during periods of weak ring current. These observations are consistent with the previous suggestion that a larger ring current stabilizes the magnetospheric tail, hence allowing the magnetosphere to accumulate more magnetic flux before becoming unstable to substorms. We also compare the magnetic flux enclosed by the R1 oval in the Northern hemisphere with the flux in the Southern hemisphere. Although the R1 oval does not always co-locate with the OCB, our analysis shows that the R1 oval accurately captures the dynamics of the OCB movement and is hence of signi[|#12#|]cant value while trying to understand solar wind-magnetosphere-ionosphere coupling.

Affiliated with

Also associated with

No associations

Rating

Capturing global magnetospheric dynamics using the location of region 1 currents does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Capturing global magnetospheric dynamics using the location of region 1 currents, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capturing global magnetospheric dynamics using the location of region 1 currents will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1891640