Snow accumulation and its moisture origin over Dome Argus, Antarctica
Snow accumulation and its moisture origin over Dome Argus, Antarctica
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DOI：
10.1007/s00382-012-1398-9
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发表时间：
2013-02
期刊：
影响因子：
4.6
通讯作者：
Yetang Wang;H. Sodemann;S. Hou;V. Masson‐Delmotte;J. Jouzel;H. Pang
中科院分区：
文献类型：
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作者：
Yetang Wang;H. Sodemann;S. Hou;V. Masson‐Delmotte;J. Jouzel;H. Pang
南极洲Dome Argus附近积雪的空间和时间变异性进行了评估，使用新的雪坑和桩测量数据与现有的雪坑，冰芯和自动气象站的记录。积雪积累率在过去的七个世纪中表现出很大的年际变化，但稳定的几十年的水平。Dome Argus 50 km范围内积雪的空间变化相对较小，这可能是由于地形平坦。这些累积观测与ECMWF再分析（ERA-40和ERA-中期）的比较表明，ECMWF再分析捕捉到了季节性变化，但低估了Dome Argus的总体积雪量约50%。在Dome Argus降水的水分来源检查的拉格朗日水分源诊断的手段，根据跟踪特定的湿度变化沿着空气包裹轨迹，为2000-2004年期间使用业务ECMWF分析数据。Dome Argus主要接收来自中纬度（46 ± 4°S）南印度洋的水汽，季节性纬向偏移约6°。与其他中东部南极深冰芯站点（如Dome F、Dome C、Bostok和EPICA Dronning Maud Land）相比，Dome Argus具有更偏南的水分来源，可能是由于地形对水分传输路径的影响。这些结果具有重要的意义，未来冰核在Dome Argus的解释。
The spatial and temporal variability of snow accumulation near Dome Argus, Antarctica, is assessed using new snow pit and stake measurement data together with existing snow pit, ice core and automatic weather station records. Snow accumulation rate shows large inter-annual variations, but stable multi-decadal levels over the last seven centuries. Spatial variations in snow accumulation within the space of 50 km of Dome Argus are relatively small, probably thanks to the smooth topography. A comparison of theses accumulation observations with ECMWF reanalyses (ERA-40 and ERA-Interim) suggests ECMWF reanalysis captures the seasonal variations, but underestimates the overall snow accumulation at Dome Argus by ~50 %. The moisture sources for precipitation over Dome Argus are examined by means of a Lagrangian moisture source diagnostic, based on the tracing of specific humidity changes along air parcel trajectories, for the period 2000–2004 using operational ECMWF analysis data. Dome Argus mainly receives moisture from the mid-latitude (46 ± 4°S) South Indian Ocean, with a seasonal latitudinal shift of about 6°. Compared to other central East Antarctic deep ice core sites such as Dome F, Dome C, Vostok, and EPICA Dronning Maud Land, Dome Argus has a more southerly moisture origin, probably due to topographic influences on the moisture transport paths. These results have important implications for the interpretation of future ice cores at Dome Argus.