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

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衡量环电流强度的指标，但磁层顶和地球磁尾的电流也有重要贡献。 因此，使用Dst指数会导致环电流强度估计的不准确性以及环电流发展和衰减时间的不准确性。 此外，Dst指数不提供任何关于环电流的本地时间分布的信息。 该项目将利用IMAGE/HENA仪器的数据以及磁强计数据，（1）制定一个准确反映环电流强度的新指数，（2）通过检查新指数对太阳风条件的反应特点，解决新指数的可预测性问题，（3）通过确定环电流当地时间分布的参数，量化环电流的不对称性，（4）用Asy-H和Sym-H指数研究环电流，并将其与磁亚暴的发展联系起来。 新的指数将提供一个更有用的测量环电流的动力学特征和磁暴的进展。

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.