TY - JOUR

T1 - Dynamics of polar boundary of the auroral oval derived from the IMAGE satellite data

AU - Lukianova, R.

AU - Kozlovsky, A.

PY - 2013/5/6

Y1 - 2013/5/6

N2 - Based on a new database on positions of the auroral oval boundaries including measurements made by the IMAGE satellite in 2000-2002 with correct determination of the glow boundaries, statistical estimations of the latitudinal position of the polar cap boundary (PCB) are obtained depending on the IMF By and Bz, and the PCB evolution during a magnetic storm is analyzed. At zero IMF in the noon (midnight) sector, PCB is located approximately at 80° (76°) CGMLat. The PCB displacement along the noon-midnight meridian is controlled by the IMF Bz, and in the noon (midnight) sector it is equal to 0. 45° (0.15°) CGMLat when Bz changes by 1 nT. The PCB displacement along the dawn-dusk meridian depends on the IMF By, and it equals 0. 1° CGMLat when By changes by 1 nT. Accordingly, the north polar cap as a whole is shifted to the dawn (dusk) side at By > 0 (By<0). After northward turn of the IMF during the storm's recovery phase, the PCB on the dayside is shifted to the north practically without time delay. The night boundary requires 25 h or more in order to be shifted to the pole to a latitude corresponding to Bz > 0.

AB - Based on a new database on positions of the auroral oval boundaries including measurements made by the IMAGE satellite in 2000-2002 with correct determination of the glow boundaries, statistical estimations of the latitudinal position of the polar cap boundary (PCB) are obtained depending on the IMF By and Bz, and the PCB evolution during a magnetic storm is analyzed. At zero IMF in the noon (midnight) sector, PCB is located approximately at 80° (76°) CGMLat. The PCB displacement along the noon-midnight meridian is controlled by the IMF Bz, and in the noon (midnight) sector it is equal to 0. 45° (0.15°) CGMLat when Bz changes by 1 nT. The PCB displacement along the dawn-dusk meridian depends on the IMF By, and it equals 0. 1° CGMLat when By changes by 1 nT. Accordingly, the north polar cap as a whole is shifted to the dawn (dusk) side at By > 0 (By<0). After northward turn of the IMF during the storm's recovery phase, the PCB on the dayside is shifted to the north practically without time delay. The night boundary requires 25 h or more in order to be shifted to the pole to a latitude corresponding to Bz > 0.

UR - http://www.scopus.com/inward/record.url?scp=84876947562&partnerID=8YFLogxK

U2 - 10.1134/S0010952513010061

DO - 10.1134/S0010952513010061

M3 - Article

AN - SCOPUS:84876947562

VL - 51

SP - 46

EP - 53

JO - Cosmic Research

JF - Cosmic Research

SN - 0010-9525

IS - 1

ER -