Retrieval of Lower Thermospheric Temperatures from O2 A Band Emission: The MIGHTI Experiment on ICON
Retrieval of Lower Thermospheric Temperatures from O2 A Band Emission: The MIGHTI Experiment on ICON
复制标题
从 O2 A 波段发射反演较低热层温度：ICON 上的 MIGHTI 实验
作者：
M. Stevens;C. Englert;J. Harlander;S. England;K. Marr;C. Brown;T. Immel
迈克尔逊全球高分辨率热层成像干涉仪（might）是一项卫星实验，计划于2018年在美国宇航局的电离层连接探测器（ICON）上发射。MIGHTI旨在测量水平中性风和陆地热层的中性温度。温度将通过对低热层边缘的分子氧大气带（A带）成像来推断。MIGHTI将使用离散波长通道测量A波段的光谱形状，从波段的旋转包络线推断环境温度。在这里，我们基于仪器的已建特性和典型白天和夜间条件下A波段的预期发射速率剖面，给出了模拟温度检索。我们发现，对于球对称大气，白天在90 ~ 105 km之间的测量精度为1 K，而夜间则从90 km处的1 K增加到105 km处的3 K。我们还发现，对于相同的高度，精度为2 K至11 K。预期的MIGHTI温度精度在ICON任务的测量要求之内。
The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) is a satellite experiment scheduled to launch on NASA’s Ionospheric Connection Explorer (ICON) in 2018. MIGHTI is designed to measure horizontal neutral winds and neutral temperatures in the terrestrial thermosphere. Temperatures will be inferred by imaging the molecular oxygen Atmospheric band (A band) on the limb in the lower thermosphere. MIGHTI will measure the spectral shape of the A band using discrete wavelength channels to infer the ambient temperature from the rotational envelope of the band. Here we present simulated temperature retrievals based on the as-built characteristics of the instrument and the expected emission rate profile of the A band for typical daytime and nighttime conditions. We find that for a spherically symmetric atmosphere, the measurement precision is 1 K between 90–105 km during the daytime whereas during the nighttime it increases from 1 K at 90 km to 3 K at 105 km. We also find that the accuracy is 2 K to 11 K for the same altitudes. The expected MIGHTI temperature precision is within the measurement requirements for the ICON mission.