Na lidar measurements of atom meteor trails with an integration period of 3.2 s were conducted at Wuhan (30.5°N, 114.4°E), China. A total of 125 Na meteor trail events were registered from 166 hours (16 nigh...Na lidar measurements of atom meteor trails with an integration period of 3.2 s were conducted at Wuhan (30.5°N, 114.4°E), China. A total of 125 Na meteor trail events were registered from 166 hours (16 nights) of lidar data. These Na trails show peak densities ranging from 4040 to 39170 cm?3 with a mean of 16430 cm?3, while their occurrence altitudes vary from 77.2 to 111.6 km with a distribution centroid at 92.6 km. The upper edge of the Na trail altitude distribution resembles that of the altitude profile of the simultaneously observed mean Na layer. In particular, the trail altitude histogram maximum occurs around the mean Na layer peak. This is consistent with early lidar observations of K and Fe trails, which shows that meteoroids entering the atmosphere tend to yield more atom meteor trails detectable by ground-based lidars around the peak of the regular metal layers than elsewhere. It was found that the formation of the Nas layers was usually accompanied by a bunch of Na meteor trails, and that they occurred near the altitude of the Nas layer peak.展开更多
基金supported by the Na-tional Natural Science Foundation of China (40674085 and 40731055)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT0643)
文摘Na lidar measurements of atom meteor trails with an integration period of 3.2 s were conducted at Wuhan (30.5°N, 114.4°E), China. A total of 125 Na meteor trail events were registered from 166 hours (16 nights) of lidar data. These Na trails show peak densities ranging from 4040 to 39170 cm?3 with a mean of 16430 cm?3, while their occurrence altitudes vary from 77.2 to 111.6 km with a distribution centroid at 92.6 km. The upper edge of the Na trail altitude distribution resembles that of the altitude profile of the simultaneously observed mean Na layer. In particular, the trail altitude histogram maximum occurs around the mean Na layer peak. This is consistent with early lidar observations of K and Fe trails, which shows that meteoroids entering the atmosphere tend to yield more atom meteor trails detectable by ground-based lidars around the peak of the regular metal layers than elsewhere. It was found that the formation of the Nas layers was usually accompanied by a bunch of Na meteor trails, and that they occurred near the altitude of the Nas layer peak.
