NSWP: Space Weather of the Thermosphere from CHAMP and GRACE Accelerometer Measurements

该项目旨在描述热层在大范围的空间和时间尺度上的变化特征。它将利用CHAMP和GRACE卫星的卫星观测来获得2002年至2008年的总质量密度和交叉轨道风。这些航天器数据特别有用，因为沿着从极点延伸到极点的卫星轨道几乎连续地以优于80公里的分辨率获得观测。该数据库将通过网络提供给研究界，提供从太阳活动周期最大值到太阳活动极小值的空间天气的全面视图。然后，这些数据集将用于各种其他调查。其中之一将描述和解释全球磁暴对热层密度、风和外逸层温度的响应，作为经度、当地时间和季节的函数。将进行类似的研究，以阐明密度、风和外逸层温度对不同太阳活动水平的局地时间响应；这项研究包括调查源自低层大气的潮汐相对于由太阳EUV吸收在原位强迫的潮汐分量的相对贡献。该数据集还将用于研究最近在电离层观测到的各种区域现象，如赤道电离异常、午夜最高温度和波4经度结构；这些特征可以对它们的季节、太阳周期和磁活动依赖的全局视图进行检查。CHAMP卫星计划于2009年重新进入大气层，有可能利用在此期间获得的数据来推算垂直风。该项目将为航空航天工程和空间气象科学的研究生提供跨学科的培训机会，并将有助于满足国家在培训未来工程师和科学家方面的需求，同时解决与社会相关的问题，如轨道阻力预测和电离层对通信的影响。它还将使研究小组能够参与欧空局GOCE任务，这将进一步促进国际合作。空间天气的好处包括开发改进的经验密度和风模型，验证和测试第一性原理模型，利用DMSP卫星的同步轨道平面数据进行离子中性耦合研究；并利用CNOFS卫星的数据进行协调研究。

This project aims to characterize the variability of the thermosphere over a wide range of spatial and temporal scales. It will accomplish this by utilizing satellite observations from the CHAMP and GRACE satellites to derive total mass densities and cross-track winds from 2002 through 2008. These spacecraft data are particularly useful since observations are obtained almost continuously with better than 80-km resolution along the satellite track which extends from pole to pole. The database will be provided to the research community via the web, yielding a comprehensive view of space weather from solar cycle maximum through solar minimum. These datasets will then be used in a variety of other investigations. One of these will delineate and interpret the global magnetic storm response of the thermospheric densities, winds, and exospheric temperatures as a function of longitude, local time, and season. A similar study will be performed to elucidate the local time response of the density, winds, and exospheric temperatures for different levels of solar activity; this study includes an investigation of the relative contributions of the tides originating in the lower atmosphere relative to the tidal components forced in situ by solar EUV absorption. The dataset will also be used to investigate a variety of regional phenomena such as the equatorial ionization anomaly, the midnight temperature maximum, and wave 4 longitude structures recently observed in the ionosphere; these features can be examined for the global view of their seasonal, solar cycle, and magnetic activity dependences. The CHAMP satellite is scheduled to re-enter the atmosphere in 2009 and it may be possible to use data obtained during this period to derive vertical winds. The project will provide a cross-disciplinary training opportunity for graduate students in aerospace engineering and in space weather science and will help meet national needs in terms of training future engineers and scientists while addressing problems relevant to society such as orbital drag prediction and ionospheric effects on communication. It will also enable the research team to participate in the ESA mission GOCE which will further international collaborations. The space weather benefits include development of improved empirical density and wind models, validation and testing of first-principles models, conducting ion-neutral coupling studies using coincident orbital plane data from the DMSP satellites; and coordinated studies with data from the CNOFS satellite.