Nocturnal temperature structure in the mesopause region over the Arecibo Observatory (18.35°N, 66.75°W): Seasonal variations
Nocturnal temperature structure in the mesopause region over the Arecibo Observatory (18.35°N, 66.75°W): Seasonal variations
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DOI：
10.1029/2006jd008220
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发表时间：
2007-07
影响因子：
--
通讯作者：
J. Friedman;X. Chu
中科院分区：
文献类型：
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作者：
J. Friedman;X. Chu
[1] 我们通过 2003 年 12 月至 2006 年 9 月期间 106 个晚上的钾多普勒激光雷达观测，展示了波多黎各阿雷西博天文台（北纬 18.35°，西经 66.75°）上方中层顶区域（80-105 公里）夜间温度结构的平均季节性气候。这是第一个完整的热带地区中层顶气候学。 latitude 展示了几个独特的功能。与高纬度地区相比，阿雷西博夜间的中层逆温层要弱得多。季节性大逆温发生在夏季，但在一年中的其余时间几乎不存在。阿雷西博气候显示出三级中层顶：夏季高海拔（约100公里）、深秋和冬季中海拔（约96公里）和早春低海拔（约91公里）。中层顶在至日时寒冷（夏季~171 K，冬季~176 K），春分前后温暖，特别是深秋接近 195 K，而春季中层顶温度接近 185 K。阿雷西博约 100 公里的低层热层在达到最冷温度时显示从春季到夏季温度下降，这与所有中纬度地区观测到的温度上升相反 地点。在阿雷西博大部分 MLT 海拔范围内，季节性温度的半年变化幅度与年变化幅度一样大。这些观察到的季节性变化似乎与半年振荡有关，这是一种主要的热带现象。这份报告提供了极少数关于较低热层温度半年振荡的观测结果之一。
[1] We present the mean seasonal climatology of the nocturnal temperature structure in the mesopause region (80–105 km) above the Arecibo Observatory, Puerto Rico (18.35°N, 66.75°W) from 106 nights of potassium Doppler lidar observations between December 2003 and September 2006. This first complete range-resolved mesopause climatology for a tropical latitude exhibits several unique features. Compared to higher latitude sites, mesospheric temperature inversion layers in the nocturnal means are much weaker at Arecibo. Seasonally large inversions occur in summer but are almost non-existent during the rest of the year. The Arecibo climatology shows a three-level mesopause: a high altitude in summer (∼100 km), a medium altitude in late autumn and winter (∼96 km), and a low altitude in early spring (∼91 km). The mesopause is cold in the solstices (∼171 K in summer, ∼176 K in winter) and warm around equinoxes, particularly late autumn when it is near 195 K, while the spring mesopause temperature is close to 185 K. The lower thermosphere around 100 km at Arecibo shows a decreasing temperature from spring to summer when it reaches its coldest temperature, which is contrary to the increasing temperature observed at all midlatitude locations. Semiannual variations in the seasonal temperature have amplitudes as large as the annual variations through most of the MLT altitude range at Arecibo. These observed seasonal variations appear to be associated with the semi-annual oscillation, a predominantly tropical phenomenon. This report provides one of the very few observations of the semi-annual oscillation in lower thermosphere temperature.