Valley floor climate observations from the McMurdo dry valleys, Antarctica, 1986-2000
Valley floor climate observations from the McMurdo dry valleys, Antarctica, 1986-2000
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DOI：
10.1029/2001jd002045
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发表时间：
2002-12-21
影响因子：
4.4
通讯作者：
Lyons, WB
中科院分区：
文献类型：
--
作者：
Doran, PT;McKay, CP;Lyons, WB
利用南极东部麦克默多干旱河谷7个谷底自动气象站1986 - 2000年的气候观测资料，分析了该地区的气候特征。年平均温度范围为-14.8 ℃至-30.0 ℃，取决于测量地点和测量时间。年平均相对湿度通常在海岸附近最高。年平均风速随着接近极地高原而增加。站点之间的平均年太阳通量和PAR的变化是由于每个站点的曝光和随时间的变化可能与云量的变化。在非夏季月份，强烈的下降风在某些地点频繁，而在其他地点则不频繁，由于风的变暖效应，造成年平均温度的巨大变化。下降风暴露似乎在很大程度上受到该地区较冷空气的控制，这些空气聚集在低点，并保持温暖的低密度下降气流。下降风的强烈影响使得仅根据地理位置（海拔和离海岸的距离）预测相对年平均温度是不可能的。在夏季的几个月里，向岸风占主导地位，当它们穿过山谷时会变得温暖，从而产生了一个很强的线性关系（r（2）=0.992），即潜在温度随着离海岸的距离（0.09 ℃ km（-1））而增加。与年平均温度相比，夏季温度适合于模型预测，并用于构建一个统计模型，用于预测未监测站点的夏季干谷温度。
Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from -14.8degreesC to -30.0degreesC, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r(2)=0.992) of increasing potential temperature with distance from the coast (0.09degreesC km(-1)). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites.