Collaborative Research: NSWP--Improvement and Real-time Updating of the International Reference Ionosphere with the Contribution of Auroral Electrons

合作研究：NSWP--极光电子贡献的国际参考电离层的改进和实时更新

• 批准号: 0819440
• 负责人: Dieter Bilitza
• 金额: $ 11.35万
• 依托单位: George Mason University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-11-01 至 2013-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0819440&HistoricalAwards=false
• 关键词: Collaborative; Research; NSWP; Improvement; Real

The project has two main objectives: (1) Improve the International Reference Ionosphere (IRI) model by including the contributions from precipitating electrons to the model; this will result in better specification of the auroral E region in the model; and (2) Develop, implement, test, and validate an auroral boundary and/or Kp driven ability for nowcasting and forecasting of the polar E-region ionosphere. The IRI is an empirical model which is one of the most widely used by the upper atmosphere community to simulate the ionosphere for given conditions. However, its representation of the auroral region has been known to be somewhat compromised due to a lack of information on and observations for the polar region. One of the processes not well parameterized is that due to precipitating electrons, one of the major drivers of space weather in the ionosphere and thermosphere. The precipitation not only creates extra ionization in the high latitude ionosphere which leads to absorption and disturbances in radio communication, but also enhances the Joule heating which alters the thermospheric convection and composition. The altered thermospheric convection brings composition changes induced by Joule heating from high latitudes down to middle and low latitudes, even to the opposite hemisphere, and can cause global ionospheric disturbances. The precipitating electrons will be specified in the new IRI model by using a new Kp-dependent global auroral model that was developed with FUV image data obtained by the GUVI instrument on the TIMED satellite. The auroral model provides the global distribution of mean energy and energy flux of precipitating electrons. With these, one can then determine two key auroral E-layer parameters: the peak E-layer density (NmE) and the E layer height (hmE). The new NmE and hmE values will provide the data base for modifying the IRI E-region model to include the contribution from precipitating electrons. The FUV-based global auroral model will also enable better representation of the real time auroral oval conditions by providing information on the boundaries of the auroral oval and the location of the peak electron energy fluxes in different magnetic local time sectors. These will be represented as a statistical model for inclusion in the IRI. The auroral E-layer representation and the auroral boundaries in the improved IRI will be validated with electron density profile data from incoherent scatter radars such as Sondrestrom, EISCAT, and NSF's new Poker Flat Incoherent Scatter Radar, and with precipitating electron data from the DMSP F13-F17 particle detectors.

该项目有两个主要目标：(1)改进国际参考电离层（IRI）模型，纳入沉淀电子对模型的贡献；这将使模型更好地描述极光E区；(2)开发、实施、测试和验证极光边界和/或Kp驱动的能力，用于极地e区电离层的临近预报和预报。IRI是一种经验模式，是高层大气界在给定条件下模拟电离层最广泛使用的经验模式之一。然而，由于缺乏关于极地地区的资料和观测，已知其对极光区域的描述在一定程度上受到了损害。其中一个没有很好地参数化的过程是由于电子的沉淀，这是电离层和热层空间天气的主要驱动因素之一。降水不仅在高纬度电离层产生额外的电离，导致无线电通信的吸收和干扰，而且还增强了焦耳加热，改变了热层对流和成分。热层对流的改变使焦耳加热引起的成分变化从高纬度下降到中低纬度，甚至到另一个半球，并可引起全球电离层扰动。沉淀电子将在新的IRI模型中指定，使用新的依赖于kp的全球极光模型，该模型是根据TIMED卫星上GUVI仪器获得的FUV图像数据开发的。极光模式提供了沉降电子的平均能量和能量通量的全球分布。有了这些，人们就可以确定两个关键的极光E层参数：峰值E层密度（NmE）和E层高度（hmE）。新的NmE和hmE值将为修改IRI e -区域模型提供数据基础，以包括沉淀电子的贡献。基于fuv的全球极光模型还将通过提供关于极光椭圆的边界和不同磁地方时扇区中峰值电子能量通量的位置的信息，更好地表示实时极光椭圆条件。这些将作为统计模型表示，以便纳入IRI。改进后的IRI中的极光e层表示和极光边界将通过来自Sondrestrom、EISCAT和NSF新一代Poker平面非相干散射雷达的电子密度剖面数据以及DMSP F13-F17粒子探测器的沉淀电子数据进行验证。