Improving Neutral Density Predictions Using Exospheric Temperatures Calculated on a Geodesic, Polyhedral Grid
Improving Neutral Density Predictions Using Exospheric Temperatures Calculated on a Geodesic, Polyhedral Grid
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DOI：
10.1029/2019sw002355
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发表时间：
2020-01
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影响因子：
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通讯作者：
D. Weimer;P. Mehta;W. Tobiska;E. Doornbos;M. Mlynczak;D. Drob;J. Emmert
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文献类型：
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作者：
D. Weimer;P. Mehta;W. Tobiska;E. Doornbos;M. Mlynczak;D. Drob;J. Emmert
已经开发了一种新的外层温度模型，目的是以更高的空间和时间精度预测全球值。根据这些温度，通过使用海军研究实验室质谱仪和非相干散射雷达扩展(NRLMSISE-00)模型，可以计算出热层中的中性密度。外圈温度模型是根据几颗卫星上的中性密度测量得出的。这些数据根据位置被分类到测地线网格上的三角形单元中。利用最小误差拟合法推导出每个网格单元的预测方程。使用日期、时间、太阳辐射和一氧化氮排放等参数对模型方程的几个版本进行了测试，这些参数是通过使用热层电离层中间层能量和动力学(TIMED)卫星上的宽带发射辐射测量仪(SABER)探测大气而测量的。在使用太阳风速度和行星际磁场的经验模型中，增加了流入极区的总坡印亭通量，提高了精度。有了这样的输入，该模型就可以生成全球的外圈温度地图。这些地图显示了极地区域的变化，由于磁极的每日旋转，极地区域受到一天中的时间的强烈调制。为方便起见，新模型缩写为EXTEMPLAR(多面体网格上的离层温度)。从EXTEMPLAR-NRLMSISE-00模型计算的中性密度与实测值相比，得到了非常好的结果。
A new model of exospheric temperatures has been developed, with the objective of predicting global values with greater spatial and temporal accuracy. From these temperatures, the neutral densities in the thermosphere can be calculated, through use of the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended (NRLMSISE‐00) model. The exospheric temperature model is derived from measurements of the neutral densities on several satellites. These data were sorted into triangular cells on a geodesic grid, based on location. Prediction equations are derived for each grid cell using least error fits. Several versions of the model equations have been tested, using parameters such as the date, time, solar radiation, and nitric oxide emissions, as measured with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. Accuracy is improved with the addition of the total Poynting flux flowing into the polar regions, from an empirical model that uses the solar wind velocity and interplanetary magnetic field. Given such inputs, the model can produce global maps of the exospheric temperature. These maps show variations in the polar regions that are strongly modulated by the time of day, due to the daily rotation of the magnetic poles. For convenience the new model is referred to with the acronym EXTEMPLAR (EXospheric TEMperatures on a PoLyhedrAl gRid). Neutral densities computed from the EXTEMPLAR‐NRLMSISE‐00 models combined are found to produce very good results when compared with measured values.