The magnetosphere‐ionosphere (MI) coupling is crucial in modeling the thermosphere‐ionosphere (TI) response to geomagnetic activity. In general circulation models (GCMs) the MI coupling is typically realized by specifying the ion convection and auroral particle precipitation patterns from for example, empirical or assimilative models. Assimilative models, such as the Assimilative Mapping of Ionospheric Electrodynamics, have the advantage that the ion convection and auroral particle precipitation patterns are mutually consistent and based on available observations. However, assimilating a large set of diverse data requires expert knowledge and is time consuming. Empirical models, on the other hand, are convenient to use, but do not capture all the observed spatial and temporal variations. With the availability of Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) data, there is an opportunity for employing field‐aligned currents (FAC) in GCMs to represent the MI coupling. In this study, we will introduce a new method which enables us to use observed FAC in GCMs and solve for the interhemispherically asymmetric electric potential distribution. We compare Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM) simulations of a geomagnetic storm period using the new approach and two other often‐used methods for specifying MI coupling based on empirical and assimilative high latitude electric potentials. The comparison shows general similarities of the TI storm time response and improved temporal variability of the new method compared to using empirical models, but results also illustrate substantial differences due to our uncertain knowledge about the MI coupling process.

中文翻译：

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通过TIEGCM模拟的规定场对准电流进行磁层-电离层耦合

磁层-电离层（MI）耦合对于模拟热层-电离层（TI）对地磁活动的响应至关重要。在一般循环模型（GCM）中，MI耦合通常通过指定离子对流和极光颗粒沉淀模式（例如，经验模型或同化模型）来实现。同化模型（例如电离层电动力学的同化映射）具有以下优势：离子对流和极光颗粒沉淀模式相互一致，并且基于可用的观察结果。但是，吸收大量不同的数据需要专业知识，并且很耗时。另一方面，经验模型易于使用，但不能捕获所有观察到的空间和时间变化。有了主动磁层和行星电动力学响应实验（AMPERE）数据，就有机会在GCM中采用场对准电流（FAC）来表示MI耦合。在这项研究中，我们将介绍一种新方法，该方法使我们能够在GCM中使用观测到的FAC并解决半球形不对称电位分布。我们使用新方法和另外两种基于经验和同化高纬度电势指定MI耦合的常用方法，比较了地磁风暴周期的热层-电离层-电动力学通用循环模型（TIEGCM）模拟。比较结果显示，与使用经验模型相比，TI风暴时间响应具有总体相似性，并且新方法的时间变异性有所提高，