TY - JOUR
T1 - Dayside open field line region boundary at high altitudes
AU - Fennell, J. F.
AU - Roeder, J. L.
AU - Friedel, R.
AU - Grande, M.
AU - Spence, H. E.
N1 - Funding Information:
Acknowledgments We acknowledge the members of the instrument teams who labored long and hard to produce the high quality Polar instruments. We also thank R. Lepping and K. Ogilvie for providing the WIND data. The effott at Aerospace was supported in part under NASA grant NAGS-30368, the work at Boston University was supported in part by Aerospace subcontract 46-OtXJtKl260, the effort at Max Planck lmtitut fuer Aemnomie was supported by contracts SOOC89131 and 56OC95022, and the work at Rutherford Appleton Laboratories was supported by the UK Particle Physics and Astronomy Research Council.
Copyright:
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.
PY - 1999
Y1 - 1999
N2 - The Polar satellite with its high apogee and high latitude orbit offers a unique opportunity to chart the dayside open/closed field line boundary (OCB). The data from energetic particle and plasma measurements are examined to obtain the position of the OCB for a range of IMF and magnetic disturbance conditions. The Polar observations were taken within two hours of local noon in the spring and fall 1996 and spring 1997. These data were examined for evidence of IMF and solar wind control of the OCB. Some evidence of control was observed in the Polar data. However, the OCB position was found to depend more strongly on the magnetic activity levels than on IMF B(Z) and solar wind pressure, for example. Examination of the invariant (Λ) and magnetic (λ) latitude of OCB for B(Z) < 1 gave better results than using the whole data set. For B(Z) < 1 the OCB Λ ~ 78.9 + 0.38 B(Z) and examination of the VB(Z) dependence gave Λ ~ 78.9 + 1.023 VB(Z). The comparison with K(P) gave Λ ~ 80.2 - 0.88 K(P). These dependencies are similar to those previously observed for the auroral zone boundaries.
AB - The Polar satellite with its high apogee and high latitude orbit offers a unique opportunity to chart the dayside open/closed field line boundary (OCB). The data from energetic particle and plasma measurements are examined to obtain the position of the OCB for a range of IMF and magnetic disturbance conditions. The Polar observations were taken within two hours of local noon in the spring and fall 1996 and spring 1997. These data were examined for evidence of IMF and solar wind control of the OCB. Some evidence of control was observed in the Polar data. However, the OCB position was found to depend more strongly on the magnetic activity levels than on IMF B(Z) and solar wind pressure, for example. Examination of the invariant (Λ) and magnetic (λ) latitude of OCB for B(Z) < 1 gave better results than using the whole data set. For B(Z) < 1 the OCB Λ ~ 78.9 + 0.38 B(Z) and examination of the VB(Z) dependence gave Λ ~ 78.9 + 1.023 VB(Z). The comparison with K(P) gave Λ ~ 80.2 - 0.88 K(P). These dependencies are similar to those previously observed for the auroral zone boundaries.
UR - http://www.scopus.com/inward/record.url?scp=0032771352&partnerID=8YFLogxK
U2 - 10.1016/S1464-1917(98)00019-1
DO - 10.1016/S1464-1917(98)00019-1
M3 - Article
AN - SCOPUS:0032771352
SN - 1464-1917
VL - 24
SP - 129
EP - 133
JO - Physics and Chemistry of the Earth, Part C: Solar, Terrestrial and Planetary Science
JF - Physics and Chemistry of the Earth, Part C: Solar, Terrestrial and Planetary Science
IS - 1-3
ER -