Abstract

We discuss the reasons for the extreme compression of the magnetosphere during the storm on February 27, 2023, when the magnetopause crossed the geostationary orbit. At the same time, aurora was observed at middle latitudes. The global parameters of magnetospheric current systems were calculated from data on the parameters of the interplanetary medium and geomagnetic indices characterizing the evolution of the ring current and the westward auroral electrojet, using a paraboloid model of the magnetosphere. We have calculated the contributions of various current systems to the observed value of the \({{D}_{{st}}}\) index. The contribution of the tail current sheet is comparable with the contribution of the ring current for this storm. The calculated modelled field is compared with the data of the GOES-16, 18 magnetometers; the results are in good agreement with observations.

中文翻译：

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2023 年 2 月 27 日磁暴期间的磁层和极光椭圆动力学

摘要

我们讨论了 2023 年 2 月 27 日磁层顶穿过地球静止轨道时的风暴期间磁层极度压缩的原因。与此同时，中纬度地区观测到极光。利用磁层抛物面模型，根据行星际介质参数和表征环流和西向极光电喷流演化的地磁指数数据，计算了磁层电流系统的全局参数。我们计算了当前各种系统对\({{D}_{{st}}}\)指数观测值的贡献。对于这次风暴，尾电流片的贡献与环电流的贡献相当。将计算出的模型场与GOES-16、18磁力计的数据进行比较；结果与观察结果非常吻合。