CEDAR: Modeling Metastable Helium Emissions in the Terrestrial Thermosphere

这项合作研究，由计算物理公司提出。和西南研究所，将进行模拟研究的规模和空间变化的高层大气的1083气辉发射。 该项目将在调查员以前两年的探索性工作的基础上进行。 研究人员将包括经验和分析描述的光电子通量衰减后，通过等离子体的共轭光电子通量的迭代计算。 它们还将生成各种地球物理条件下氦分布和由此产生的1083 nm和388.9 nm发射强度的综合地图（纬度与当地时间），以揭示气辉发射对各种输入的敏感性，并支持对他人获得的1083 nm和388.9 nm数据的分析和解释。 在第二年，他们将评估用于遥感热层温度和运动的谱线轮廓特征。 氦是上层热层动力学的示踪剂，因此测得的线中心位移可以提供上层热层大气环流模型的独特检验。 然而，由于1083号卫星的排放峰值高度在400公里以上，观测到的位移将不会构成直接的风速测量，而是反映出由密度和温度的纬向和经向梯度以及风型所决定的横向（弹道）通量的大小。

This collaborative research, proposed by Computational Physics, Inc. and Southwest Research Institute, will carry out modeling studies of the magnitude of and spatial variation in the upper atmosphere's 1083 airglow emission. The project will build upon the investigator's previous exploratory work in a two-year effort. The investigators will include empirical and analytic descriptions of the attenuation of photoelectron fluxes upon passage through the plasmasphere in the iterative calculation for conjugate photoelectron fluxes. They will also generate comprehensive maps (latitude vs. local time) of helium distributions and resulting 1083 nm and 388.9 nm emission intensities under a variety of geophysical conditions, both for revealing the sensitivities of the airglow emissions to various inputs and for supporting the analysis and interpretation of 1083 nm and 388.9 nm data obtained by others. In the second year, they will assess line profile features for remote sensing of thermospheric temperatures and motions. Helium is a tracer of upper thermospheric dynamics, so that measured line center displacements may offer a unique test of general circulation models of the upper thermosphere. However, since the 1083 emission peak altitude is above 400 km, observed displacements will not constitute a direct wind speed measurement, but rather will reflect the magnitude of lateral (ballistic) fluxes governed by latitudinal and longitudinal gradients in density and temperature as well as by wind patterns.