Effects of the number of stations and time resolution on Dst derivation
- 作者：Jr. ; Odim Mendes ; Aracy Mendes da Costa ; Fern ; o Celso Perin Bertoni
- 关键词：Earth's magnetosphere ; Sun– ; Earth coupling ; Geomagnetic storm ; none ; color ; black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6VHB-4KSSWKG-1&_mathId=mml118&_user=10&_cdi=6062&_rdoc=8&_acct=C000050221&
- 刊名：Journal of Atmospheric and Solar-Terrestrial Physics
- 出版年：2006
- 期刊代码：41_13646826
- 类别：ear
- 出版时间：December 2006
- 卷：68
- 期：18
- 页码：2127-2137
- 文件大小：396 K
摘要
For at least 30 years now it has been well known that the VHB-4KSSWKG-1&_mathId=mml106&_user=10&_cdi=6062&_rdoc=8&_acct=C000050221&_version=1&_userid=10&md5=cf5a0b60835301ef68b9a4d3de6615ae" title="Click to view the MathML source">Dst index can be modelled using the solar wind as input. Since then, many attempts have been made to improve the predictability of Dst using different approaches. These attempts are useful, for instance, to understand which features of the solar wind–magnetosphere interactions are most important in producing magnetospheric activity and how the Dst index would improve the space weather forecast. The Dst index is by far the most reliable and simple indication that a magnetic storm is in progress. In this work, the effect of using more than four magnetic stations and shorter time intervals than the hourly averages used in Sugiura's procedures is evaluated. The discussion is based on the results presented by Burton in 1975 and Feldstein in 1984 considering 4 or 12 magnetic stations and time averages of 2.5 min for a magnetic disturbed period that occurred from February 7–28, 1967, including two geomagnetic storms. The analysis has shown that the global representation of a magnetic storm by the standard Dst (Sugiura) is well preserved either using 4, 6, 12 magnetic stations or using 1 h, 2.5 min 1 min averages. A brief review of the current understanding of Dst has been included to support the discussions. The analysis performed has shown that a more refined Dst index (time and number of stations>4) would be useful to investigate the intrinsic processes and the different current systems involved in the ring current development during magnetic storms; the standard Dst, as it is conceived, is quite adequate to monitor geomagnetic storms and identify their overall features; concerning the magnetic stations normally considered, the inclusion of higher magnetic latitude stations (>35) may underestimate the observed Dst.