During a geomagnetic storm, the energy deposition from magnetosphere to thermosphere through Joule heating leads to variations in the total mass density of thermosphere. In this study, measurements obtained from the Challenging Minisatellite Payload and Gravity Recovery and Climate Experiment satellites between 2002 and 2008 are used to study the response of thermospheric density during geomagnetic storms of different magnitudes inferred from the Dst index. Based on the height‐integrated Joule heating with data derived from the Defense Meteorological Satellite Program spacecraft, we statistically analyze 265 geomagnetic storm cases to study the characteristics of Joule heating distribution and its influence on thermospheric density. The results show that between thermospheric density and Joule heating during weak and moderate geomagnetic storms, the time lag is only about 0–2 hr, while the same for intense storms is 3–5 hr. This indicates that the time lag is positively correlated with the intensity of geomagnetic storms. Besides, it is found that the peak duration of Joule heating increases for more intense geomagnetic storms.

中文翻译：

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不同大小地磁暴期间焦耳热和热圈响应的统计分析

在地磁风暴期间，通过焦耳加热从磁层到热层的能量沉积会导致热层的总质量密度发生变化。在这项研究中，从2002年至2008年从具有挑战性的微型卫星有效载荷和重力恢复及气候实验卫星获得的测量值用于研究根据Dst指数推断出的不同强度地磁暴期间热层密度的响应。基于从国防气象卫星计划航天器获得的高度积分焦耳热，我们统计分析了265个地磁风暴案例，以研究焦耳热分布的特征及其对热层密度的影响。结果表明，在弱磁和中等地磁暴期间，热圈密度与焦耳热之间，时间滞后仅为0–2小时，而强风暴的滞后时间为3–5小时。这表明时间滞后与地磁风暴的强度呈正相关。此外，发现焦耳加热的峰值持续时间随着更强烈的地磁风暴而增加。