Space Weather: Intensity and Asymmetry of the Storm-Time Ring Current: Quantification and Prediction

空间天气：风暴时间环流的强度和不对称性：量化和预测

• 批准号: 0318173
• 负责人: Shinichi Ohtani
• 金额: $ 27.06万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0318173&HistoricalAwards=false
• 关键词: Space; Weather; Intensity; Asymmetry; Storm

The development and decay of magnetic storms has traditionally been addressed in terms of the Dst magnetic index. Although the Dst index is traditionally thought of as a measure of the intensity of the ring current, electric currents on the magnetopause and in the Earth's magnetotail make significant contributions. Using the Dst index thus leads to inaccuracies in estimates of the intensity of the ring current as well as inaccuracies in the timing of the development and decay of the ring current. In addition, the Dst index does not provide any information about the local-time distribution of the ring current. This project will utilize data from the IMAGE/HENA instrument along with magnetometer data (1) to develop a new index that accurately reflects the intensity of the ring current, (2) to address the predictability of the new index by examining the characteristics of its response to solar wind conditions, (3) to quantify the asymmetry of the ring current by parameterizing the local-time distribution of the ring current, and (4) to examine the ring current in terms of the Asy-H and Sym-H indices and relate that to the development of magnetic substorms. The new index will provide a more useful measure of the dynamical features of the ring current and the progression of magnetic storms.

磁暴的发展和衰减传统上是用Dst磁指数来描述的。虽然Dst指数传统上被认为是测量环电流强度的指标，但磁层顶和地球磁尾上的电流也起着重要作用。因此，使用Dst指数会导致环电流强度的估计不准确，以及环电流发展和衰减的时间不准确。此外，Dst指数不能提供环电流本地时间分布的任何信息。该项目将利用IMAGE/HENA仪器的数据和磁力计数据(1)开发一个准确反映环电流强度的新指数，(2)通过检查其对太阳风条件的响应特征来解决新指数的可预测性问题，(3)通过参数化环电流的局部时间分布来量化环电流的不对称性。(4)用sy- h和Sym-H指数考察环电流，并将其与磁暴的发展联系起来。新的指数将提供一个更有用的测量环电流的动态特征和磁暴的进展。