Lagrangian Detection of Moisture Sources for the Southern Patagonia Icefield (1979–2017)
Lagrangian Detection of Moisture Sources for the Southern Patagonia Icefield (1979–2017)
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DOI：
10.3389/feart.2018.00219
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发表时间：
2018-11
影响因子：
2.9
通讯作者：
Lukas Langhamer;T. Sauter;G. Mayr
中科院分区：
文献类型：
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作者：
Lukas Langhamer;T. Sauter;G. Mayr
南巴塔哥尼亚冰原的水分来源和水分向其输送的方式尚未完全了解。这些数量对冰原、邻近湖泊和附近植被的稳定同位素组成有很大的影响，很难从观测中量化。明确确定的水分来源有助于解释稳定同位素组成的异常，并有助于从冰原和附近的古气候记录。本文采用拉格朗日水汽源法探测冰原的水汽源。运动学18天后向轨迹计算使用了欧洲中期天气预报中心（ERA-Interim）1979年1月至2017年1月的再分析数据。主要水汽源地位于80 ~ 160 ° W、30 ~ 60 ° S的南太平洋。副热带的持续反气旋和盛行西风带对湿空气的平流是主要的流型。大部分的湿气不到10天就到达了冰原。大多数的轨迹起源于行星边界层以上，但进入太平洋边界层，到达前2天达到最大的吸湿。在最后一天，轨道上升，因为他们遇到地形。水汽来源的位置受季节、南极涛动、厄尔尼诺南方涛动和月降水量的影响，这可以用西风带的位置和强度的变化来解释。
The origin of moisture for the Southern Patagonia Icefield and the transport of moisture towards it are not yet fully understood. These quantities have a large impact on the stable isotope composition of the icefield, adjacent lakes and nearby vegetation, and is hard to quantify from observations. Clearly identified moisture sources help to interpret anomalies in the stable isotope compositions and contribute to paleoclimatological records from the icefield and the close surrounding. This study detects the moisture sources of the icefield with a Lagrangian moisture source method. The kinematic 18-day backward trajectory calculations use reanalysis data from the European Centre for Medium-Range Weather Forecasts (ERA-Interim) from January 1979 to January 2017. The dominant moisture sources are found in the South Pacific Ocean from 80◦ W to 160◦ W and 30◦S to 60◦ S. A persistent anticyclone in the subtropics and advection of moist air by the prevailing westerlies are the principal flow patterns. Most of the moisture travels less than 10 days to reach the icefield. The majority of the trajectories originate from above the planetary boundary layer but enter the Pacific boundary layer to reach the maximum moisture uptake 2 days before arrival. During the last day trajectories rise as they encounter topography. The location of the moisture sources are influenced by seasons, Antarctic Oscillation, El-Nino Southern Oscillation, and the amount of monthly precipitation, which can be explained by variations in the location and strength of the westerly wind belt.”