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）通过纳入沉淀电子对模型的贡献来改进国际参考电离层（IRI）模型；这将导致模型中极光 E 区域的更好规范； (2) 开发、实施、测试和验证极光边界和/或 Kp 驱动的极地 E 区电离层临近预报和预报能力。 IRI 是一种经验模型，是高层大气界最广泛使用的模型之一，用于模拟给定条件下的电离层。 然而，由于缺乏对极地地区的信息和观测，其对极光地区的代表性在某种程度上受到了影响。 尚未很好参数化的过程之一是由于电子沉淀而导致的，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中产生额外的电离，导致无线电通信的吸收和干扰，而且还增强了焦耳加热，从而改变了热层对流和成分。热层对流的改变带来了焦耳热引起的成分变化，从高纬度到中低纬度，甚至到相反的半球，并可能引起全球电离层扰动。 沉淀电子将通过使用新的 Kp 相关全球极光模型在新的 IRI 模型中指定，该模型是根据 TIMED 卫星上的 GUVI 仪器获得的 FUV 图像数据开发的。 极光模型提供了沉淀电子的平均能量和能量通量的全球分布。 有了这些，我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 区域模型提供数据库，以包含沉淀电子的贡献。 基于FUV的全球极光模型还将通过提供有关极光椭圆形边界和不同磁本地时间扇区中峰值电子能量通量位置的信息，更好地表示实时极光椭圆形条件。 这些将被表示为包含在 IRI 中的统计模型。 改进的 IRI 中的极光 E 层表示和极光边界将通过来自非相干散射雷达（例如 Sondrestrom、EISCAT 和 NSF 的新型 Poker Flat 不相干散射雷达）的电子密度剖面数据以及来自 DMSP F13 的沉淀电子数据进行验证-F17粒子探测器。