中国科学院地球化学研究所机构知识库

We used the bolometric brightness temperatures (T_Bol) derived from the Lunar Reconnaissance Orbiters Diviner Lunar Radiometer (Diviner) as an upper boundary condition in our thermal model. We then calculated temperature profiles at any local time based on our improved thermal model at low to middle latitudes (70° N/S). Based on the temperature profiles, we modeled the midnight brightness temperature at 19.35 (T_B19) and 37 GHz (T_B37). Comparing to the Chang'E‐1 and Chang'E‐2 (CE‐1/2) observations, we found that CE‐1 showed a better data quality than that of CE‐2, especially for the T_B37 data. Assuming that the issue with the CE‐2 data is caused by heat contamination of the cold‐reference antennas, we performed an empirical normalization of the CE‐2 microwave radiometer data near midnight following the approach of Hu et al. (2017). The results show that T_B difference (modeled values minus modified T_B) for 19.35 GHz is less than 3.40 K for ∼80% of the pixels. At 37 GHz, ∼67% of the pixels have T_B difference less than 2.88 K. Additionally, we identified some areas of low microwave temperature in our modified T_B maps. These low‐T_B features can be characterized by two types: (1) low T_B spots at fresh craters with high rock abundance and bright rays and (2) high‐Ti lunar mare surfaces with a low content of rock fragments. Investigating these low‐T_B regions with the modified T_B data can reveal more information about subsurface thermal regime and properties and help us better understand the evolution of regolith on the Moon.