Dependence of plasmaspheric hiss on solar wind parameters and geomagnetic activity and modeling of its global distribution

作者：Kim Kyung Chan^*; Lee Dae Young; Shprits Yuri

来源：JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2015, 120(2): 1153-1167.

DOI：10.1002/2014JA020687

• plasmaspheric hiss
• radiation belts
• empirical modeling
• geomagnetic storms
• artificial neural network

Accurate knowledge of the global distribution of plasmaspheric hiss is essential for the radiation belt modeling because it provides a direct link to understanding the radiation belt loss in the slot region. In this paper, we study the dependence of hiss activity on solar wind parameters and geomagnetic activity indices using Time History of Events and Macroscale Interactions during Substorms hiss measurements made from 1 July 2008 to 30 June 2012 based on a correlation analysis. We find that hiss amplitudes are well correlated with the preceding solar wind speed V-SW, interplanetary magnetic field (IMF) B-Z, and interplanetary electric field (IEF) E-Y with delay times of 5-6h for V-SW and 3-4h for IMF B-Z and IEF E-Y, while the best correlation with the geomagnetic indices, AE, Kp, and SYM-H, occurs at a delay time of 2-3h for AE and SYM-H and 3-4h for Kp. Of the solar wind parameters, the dawn-to-dusk component of IEF E-Y yields the best correlation with the variation of hiss wave. More interestingly, the global distribution of hiss waves shows a significant dependence on the V-SW and IMF B-Z: the most intense hiss region tends to occur at prenoon sector for a more southward IMF B-Z, while the tendency is opposite with increasing V-SW. This implies different origins of hiss activity. Also, we employ an artificial neural network technique to develop models of the global distribution of hiss amplitudes based on the solar wind parameters and geomagnetic indices. The solely solar wind parameter-based model generally results in a higher correlation between the measured and modeled hiss amplitudes than any other models based on the geomagnetic indices. Finally, we use the solar wind parameter-based model to investigate hiss activity during storm events by distinguishing between coronal mass ejection-driven storms and corotating interaction region-driven storms. The result shows that in spite of the differences in the behavior of solar wind parameters between the two storm groups, the different types of storms lead to the similar evolution of hiss waves in overall appearance even though the detailed behavior of hiss activations are different.

• 出版日期2015-2
• 单位MIT