PostDoctoral Research Fellowship

博士后研究奖学金

• 批准号: 1204019
• 负责人: Sonya Lyatsky
• 金额: $ 13.47万
• 依托单位: Lyatskaya Inna V
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1204019&HistoricalAwards=false
• 关键词: PostDoctoral; Research; Fellowship

This award is to (1) develop a numerical model of Interhemispherical Field-Aligned Currents (IHCs) flowing between polar ionospheres in two hemispheres, (2) examine expected effects of these currents on geomagnetic activity, ionosphere, and upper atmosphere in the polar regions in both hemispheres, and (3) compare the modeling results with experimental data. The IHCs flow between the Northern and Southern high-latitude ionospheres exists predominantly due to differences in the ionospheric conductivity of the respective polar regions. Due to the Earth's orientation, the northern summer (southern winter) these interhemispherical currents can be very strong and comparable in magnitude with the total field-aligned currents (FACs) flowing in and out of the respective hemispheres at the specific Universal Time (UT) intervals. While crossing an equatorial plane, the IHCs do not change their direction; and as a result, they may increase the total FACs strength in one hemisphere, but decrease it in the opposite hemisphere. This can lead to the strong asymmetry in the total FACs system, as well as to specific geomagnetic and ionospheric disturbances in the two polar regions. The research will bring better understanding of interhemispherical asymmetry in the FACs system, northern and southern auroras, and ionospheric disturbances and UT variations in geomagnetic activity. The proposed model of interhemispherical currents would also be an important component of the set of Space Weather models, improving space weather forecasts of geomagnetic and ionospheric disturbances over two hemispheres and their potential effects on the low-orbiting spacecraft.

该奖项的目的是（1）开发在两个半球的极地电离层之间流动的半球间场向电流（IHC）的数值模型，（2）检查这些电流对两个半球极地地区地磁活动，电离层和高层大气的预期影响，以及（3）将模拟结果与实验数据进行比较。北方和南方高纬度电离层之间的IHC流主要是由于各自极地地区电离层电导率的差异而存在的。由于地球的方位，在北方夏季（南方冬季），这些半球间电流可能非常强，并且在幅度上与在特定世界时（UT）间隔流入和流出相应半球的总场向电流（FACs）相当。当穿过赤道平面时，IHC不改变它们的方向;因此，它们可能增加一个半球的总FACs强度，但减少另一个半球的总FACs强度。这可能导致整个FAC系统的强烈不对称性，以及两个极地地区的特定地磁和电离层扰动。这项研究将使人们更好地了解FAC系统中的半球间不对称性、北方和南方极光、电离层扰动和地磁活动中的UT变化。拟议的半球间电流模型也将是整套空间气象模型的一个重要组成部分，改进对两个半球的地磁和电离层扰动及其对低轨道航天器的潜在影响的空间气象预报。