A Comparison of Conjugate Auroral Electojet Indices

共轭极光电喷射指数的比较

• 批准号: 1043621
• 负责人: James Weygand
• 金额: $ 21.13万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1043621&HistoricalAwards=false
• 关键词: Comparison; Conjugate; Auroral; Electojet; Indices

The auroral electrojet index (AE) is used as an indicator of geomagnetic activity at high latitudes representing the strength of auroral electrojet currents in the Northern polar ionosphere. A similar AE index for the Southern hemisphere is not available due to lack of complete coverage the Southern auroral zone (half of which extends over the ocean) with continuous magnetometer observations. While in general global auroral phenomena are expected to be conjugate, differences have been observed in the conjugate observations from the ground and from the Earth's satellites. These differences indicate a need for an equivalent Southern auroral geomagnetic activity index. The goal of this award is to create the Southern AE (SAE) index that would accurately reflect auroral activity in that hemisphere. With this index, it would be possible to investigate the similarities and the cause of differences between the SAE and "standard" AE index from the Northern hemisphere. It would also make it possible to identify when the SAE does not provide a reliable calculation of the Southern hemisphere activity, and to determine when it is statistically beneficial to consider the SAE index in addition to the standard AE while analyzing geospace data from the Northern and Southern polar regions. The study will address these questions by creating the SAE index and its "near-conjugate" NAE index from collected Antarctic magnetometer data, and will analyze variations in the cross-correlation of these indices and their differences as a function of geomagnetic activity, season, Universal Time, Magnetic Local Time, and interplanetary magnetic field and solar wind plasma parameters. The broader impact resulting from the proposed effort is in its importance to the worldwide geospace scientific community that currently uses only the standard AE index in a variety of geospace models as necessary input.

极光电喷流指数（AE）被用作高纬度地磁活动的指标，代表北方极地电离层极光电喷流的强度。由于连续磁力计观测无法完全覆盖南半球极光区（其中一半延伸到海洋），因此无法获得南半球类似的AE指数。虽然一般认为全球极光现象是共轭的，但在地面和地球卫星的共轭观测中观察到了差异。这些差异表明需要一个等效的南极极光地磁活动指数。该奖项的目标是创建南方AE（SAE）指数，以准确反映该半球的极光活动。使用该指数，可以研究北方半球SAE和“标准”AE指数之间的相似性和差异原因。它还可以确定SAE何时不能提供南半球活动的可靠计算，并确定在分析来自北方和南极地区的地球空间数据时，除了标准AE之外，何时考虑SAE指数在统计上是有益的。该研究将通过从收集的南极磁力计数据创建SAE指数及其“近共轭”NAE指数来解决这些问题，并将分析这些指数的互相关变化及其差异，这些指数是地磁活动、季节、世界时、磁地方时以及行星际磁场和太阳风等离子体参数的函数。拟议工作产生的更广泛影响在于其对全世界地球空间科学界的重要性，目前在各种地球空间模型中仅使用标准AE指数作为必要的投入。