In addition to astronomical considerations, meteorological conditions are also important factors. Guo, a senior engineer of xichang satellite launch center Meteorological Bureau, pointed out that 65438+ 10 is the "golden season" for Xichang to launch satellites.
Xichang, with high altitude, low latitude and sparse population, is an ideal geographical location for launching satellites. However, among several satellite launch centers in China, the meteorological conditions are the most complicated. Located at the eastern foot of the Qinghai-Tibet Plateau, in the undulating zone of the transition from Yunnan-Guizhou Plateau to Sichuan Basin, and facing the Bay of Bengal in the southwest, the meteorological system affecting the weather in the site is complex. Moreover, the site is located at the edge of the southwest minefield, one of the three strong thunderstorm areas in China, and there are many thunderstorm convective weather, which has a great impact on the launch mission.
"Launching rockets and satellites has strict requirements on meteorological conditions." Guo, who has been engaged in meteorological forecasting for space launch for more than 20 years, listed in detail several meteorological conditions that Chang 'e flight must meet: during the whole launch period, that is, within 4-8 hours, no precipitation exceeding 1 mm, that is, more than light rain; During the period from refueling to rocket launch, there shall be no lightning activity within 30 kilometers around the site; The ground wind force cannot be greater than 14m/s, that is, it must be lower than level 5.
Guo said, "After entering 5438+ 10 in June, the unfavorable factors affecting the meteorology in the launch site gradually decreased and the meteorological conditions tended to be stable."
Xichang satellite launch center Meteorological Bureau made statistics on the meteorological data from 1974 to 2006, and made special research on precipitation, thunderstorm and lightning, high-altitude wind, etc. The results show that the average monthly precipitation in 65438+ 10 is 70.8 mm, and the average precipitation days are 17.9 days, accounting for 57.8% of the total days. The average number of thunderstorm days is 3. 1 day, accounting for 10. 1% of the total days. The average wind speed is 0.8m/s, with a maximum of 1.4m/s and a minimum of 0.3m/s; The average wind speed in the upper air is 32m/s, with a maximum of 42m/s and a minimum of 23m/s. ..
"These meteorological features have created favorable conditions for the successful launch of satellites, which is why Xichang launched satellites at this time." Guo said:
In addition, xichang satellite launch center has established the first relatively complete lightning early warning system in China, which can improve the accuracy of short-term rainy season forecast and comprehensive lightning forecast in the launch site to over 95%.