An Improved Estimation of SuperDARN Heppner-Maynard Boundaries Using AMPERE Data
An Improved Estimation of SuperDARN Heppner-Maynard Boundaries Using AMPERE Data
复制标题
使用 AMPERE 数据改进 SuperDARN Heppner-Maynard 边界估计
DOI：
10.1029/2019ja027218
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Fogg A
中科院分区：
文献类型：
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作者：
Fogg A
超级双极光雷达网（SuperDARN）电离层对流图是研究太阳风-磁层-电离层相互作用的有力工具。SuperDARN数据具有很高的时间（约分钟）和空间（约45公里）分辨率，这意味着对流可以在精细的时间尺度上进行映射，比模式中的大尺度变化更详细。赫普纳-梅纳德边界（HMB）定义了对流区域的低纬极限，它的识别是标准SuperDARN对流映射技术的重要组成部分。然而，这一边界的纬度的估计取决于电离层散射的可用性。因此，它容易受到非物理变化的影响，因为不同纬度和当地时间区域的散射区域出现和消失，通常是由于传播条件的变化。在本文中，HMB与来自主动磁层和行星电动力学响应实验（AMPERE）的独立场对准电流数据集进行了比较。在北方半球，在太阳活动最小值和最大值时，HMB与AMPERE区域1和区域2场向电流之间的边界之间存在线性趋势。使用这种趋势和AMPERE电流数据集来预测的纬度位置的HMB被发现，以提高对流映射的SuperDARN测量的解释。
Super Dual Auroral Radar Network (SuperDARN) ionospheric convection maps are a powerful tool for the study of solar wind‐magnetosphere‐ionosphere interactions. SuperDARN data have high temporal (approximately minutes) and spatial (∼45 km) resolution, meaning that the convection can be mapped on fine time scales that show more detail than the large‐scale changes in the pattern. The Heppner‐Maynard boundary (HMB) defines the low‐latitude limit of the convection region, and its identification is an essential component of the standard SuperDARN convection mapping technique. However, the estimation of the latitude of this boundary is dependent on ionospheric scatter availability. Consequentially it is susceptible to nonphysical variations as areas of scatter in different latitude and local time regions appear and disappear, often due to changing propagation conditions. In this paper, the HMB is compared to an independent field‐aligned current data set from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). A linear trend is found between the HMB and the boundary between the AMPERE Region 1 and Region 2 field‐aligned currents in the Northern Hemisphere, at both solar minimum and solar maximum. The use of this trend and the AMPERE current data set to predict the latitude position of the HMB is found to improve the interpretation of the SuperDARN measurements in convection mapping.