The Influence of the Amundsen-Bellingshausen Seas Low on the Climate of West Antarctica and Its Representation in Coupled Climate Model Simulations
The Influence of the Amundsen-Bellingshausen Seas Low on the Climate of West Antarctica and Its Representation in Coupled Climate Model Simulations
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DOI：
10.1175/jcli-d-12-00813.1
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发表时间：
2013-09-01
影响因子：
4.9
通讯作者：
Phillips, Tony
中科院分区：
文献类型：
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作者：
Hosking, J. Scott;Orr, Andrew;Phillips, Tony
与早期的研究相反，作者通过去除背景区域平均海平面压力（MSLP），根据其相对（而不是实际）中心压力描述了南大洋南太平洋部分上空存在的气候深层低压系统，称为阿蒙森-别林斯高晋海低压（ABSL）。这样做可以消除整个ABSL扇区大范围变化的影响（例如，由于南部环模），从而可以更清楚地了解ABSL变化及其对南极洲西部区域气候的影响。利用ECMWF中期再分析(ERA-Interim)场，1979年至2011年期间ABSL相对中心压力的年周期显示出冬季(夏季)的最小值(最大值)，这与早期基于实际中心压力的研究存在很大差异，这表明存在半年振荡。 ABSL 纵向位置的年周期对背景压力不敏感，并且表明它在夏季和冬季之间从大约 250 度东移到大约 220 度东经，这与早期的研究一致。作者通过量化其对关键气象参数的影响，证明了ABSL的变化，特别是其纵向位置，在控制西南极洲和周围海洋的表面气候方面发挥着重要作用。对使用历史强迫运行的 17 个 CMIP5 气候模型中的 ABSL 年周期进行的检查表明，大多数模型都存在明显的偏差，特别是在纵向位置方面，并且相应地对西南极气候的代表性较差。
In contrast to earlier studies, the authors describe the climatological deep low pressure system that exists over the South Pacific sector of the Southern Ocean, referred to as the Amundsen-Bellingshausen Seas low (ABSL), in terms of its relative (rather than actual) central pressure by removing the background area-averaged mean sea level pressure (MSLP). Doing so removes much of the influence of large-scale variability across the ABSL sector region (e.g., due to the southern annular mode), allowing a clearer understanding of ABSL variability and its effect on the regional climate of West Antarctica. Using ECMWF Interim Re-Analysis (ERA-Interim) fields, the annual cycle of the relative central pressure of the ABSL for the period from 1979 to 2011 shows a minimum (maximum) during winter (summer), differing considerably from the earlier studies based on actual central pressure, which suggests a semiannual oscillation. The annual cycle of the longitudinal position of the ABSL is insensitive to the background pressure, and shows it shifting westward from approximate to 250 degrees to approximate to 220 degrees E between summer and winter, in agreement with earlier studies. The authors demonstrate that ABSL variability, and in particular its longitudinal position, play an important role in controlling the surface climate of West Antarctica and the surrounding ocean by quantifying its influence on key meteorological parameters. Examination of the ABSL annual cycle in 17 CMIP5 climate models run with historical forcing shows that the majority of them have definite biases, especially in terms of longitudinal position, and a correspondingly poor representation of West Antarctic climate.