The Ranges Of Subauroral Geomagnetic Field Elements

Abstract

This study investigated the variation of the ranges of the geomagnetic field elements H, D, Z at seasonal and yearly levels. The relationship of the geomagnetic field ranges with the solar cycle is also examined. The seasonal variation of ranges on quiet condition is in accord with the Sq seasonal variation at low latitudes. On quiet condition, the range in j season dominates over d- and e- seasons in all elements. On disturbed condition, ranges of H and Z maximize in e-season. An anomaly in seasonal response of range at high solar activity is observed on disturbed condition. Generally, the seasonal range in the D component for all the years as well as in H and Z components - apart from the anomaly - maintain the order e>j>d of seasonal variation which is in agreement with the popular equinoctial maximum observed in geomagnetic activity. Linear sunspot-range relationship exists during both quiet and disturbed conditions. The e-season is the season with the minimum Wolf number M and sunspot-range correlation coefficient on disturbed condition. The range of H is linearly proportional to the range of Z during quiet and disturbed conditions. During disturbed condition, the d-season range of Z is greater than range of H. The solar cycle influence the geomagnetic field at the subauroral region must be directional.

Key words: sunspot number, Wolf number, geomagnetic field elements, subauroral, ranges.

Nig. J. of Pure & Appl. Physics Vol.3 2004: 52-63