A Real-Time Model of the Seasonal Temperature of Lunar Polar Region and Data Validation

A small tilt in the spin axis of the moon over the ecliptic plane causes seasonal incidence variation of solar illumination and, especially, causes significant temperature difference at the polar region. In this article, following the position of the subsolar point, the real-time model of solar illumination incidence over the moon polar region is developed. Based on this model with solving the 1-D heat conduction equation, the seasonal temperature of the lunar surface is obtained and is in agreement with the Diviner infrared (IR) data. Meanwhile, using the fluctuation-dissipation theorem and the Wentzel–Kramers–Brillouin (WKB) approach for lunar regolith media, the seasonal microwave (MW) brightness temperature (TB) is also obtained and validated by Chang’e-2 (CE-2) 37-GHz TB data. These data also show that the lunar surface temperature and the MW TB even in the permanent shaded region (PSR) undergo seasonal variation as well. It might be due to the seasonal thermal radiation on the topographic PSR coming from the sunlit crater walls caused by seasonal temperature variation. The Diviner IR data show that the highest temperature in the Hermite-A crater at the north polar PSR can reach 109 K in summer.