Premium
Statistics of the mid‐altitude cusp observed by Polar
Author(s) -
Rae I. J.,
Lester M.,
Davies J. A.,
Milan S. E.,
Fenrich F. R.,
Fritz T. A.,
Scudder J. D.
Publication year - 2002
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 - 10.1029/2001gl013371
Subject(s) - interplanetary magnetic field , polar , cusp (singularity) , magnetic reconnection , geophysics , latitude , field line , ionosphere , physics , geology , solar wind , geodesy , plasma , astronomy , geometry , mathematics , quantum mechanics
The Polar GGS space mission has allowed the northern hemispheric polar cusp region to be probed in a variety of ways to further our understanding and knowledge of the processes that occur within this region. The discovery of pulsed, energy‐dispersed ion injections on newly‐opened field lines (Pulsed Particle Signatures, or PPSs), the magnetospheric plasma signatures of transient reconnection, is one such advancement in our knowledge. Utilising a ∼22 months subset of Polar's mission, we perform a statistical study of the dayside traversals of the cusp region by the spacecraft to determine the extent and location of PPSs as well as the prevailing Interplanetary Magnetic Field (IMF) conditions under which they occur. In this paper we report upon the broad extent of these signatures in latitude and local time regardless of IMF orientation, and show that PPSs occur under both southward and northward IMF conditions in high percentages, although favouring southward directed IMF. These results are discussed in terms of previous statistical studies of reconnection signatures, and in terms of lobe and low latitude reconnection.