Lidar Observations of Polar Mesospheric Clouds at South Pole: Diurnal Variations
نویسندگان
چکیده
Polar mesospheric clouds (PMCs) were observed by a ground-based Fe Boltzmann temperature lidar for 65 h on 17-19 and 24-26 January 2000 above the geographic South Pole. The mean PMC backscatter ratio, volume backscatter coetficient, total backscatter coetficient, layer centroid altitude, and layer rms width are 53.5, 2.9x10 -9 m-Xsr -x, 4.3x10 -6 sr -x, 85.37 km, and 0.78 km, respectively. Strong semidiurnal and diurnal oscillations were observed in the PMC backscatter ratio, volume backscatter coetficient, total backscatter coetficient, and centroid altitude. The oscillations are all maximum around 0630 and 1900 UT. The variations appear to be linked to vertical advection of the PMC scattering layers by a persistent oscillation in the vertical wind velocity. Scattering is strongest when the PMCs are highest which suggests that the colder temperatures at higher altitudes near the mesopause facilitate the formation of larger PMC particles.
منابع مشابه
Lidar studies of interannual, seasonal, and diurnal variations of polar mesospheric clouds at the South Pole
[1] Polar mesospheric clouds (PMC) were observed by an Fe Boltzmann temperature lidar at the South Pole in the 1999–2000 and 2000–2001 austral summer seasons. We report the study of interannual, seasonal, and diurnal variations of PMC using more than 430 h of PMC data. The most significant differences between the two seasons are that in the 2000– 2001 season, the PMC mean total backscatter coef...
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