Strong Warming Over the Antarctic Peninsula During Combined Atmospheric River and Foehn Events: Contribution of Shortwave Radiation and Turbulence
Strong Warming Over the Antarctic Peninsula During Combined Atmospheric River and Foehn Events: Contribution of Shortwave Radiation and Turbulence
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DOI：
10.1029/2022jd038138
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发表时间：
2023-08
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影响因子：
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通讯作者：
Xun Zou;P. Rowe;I. Gorodetskaya;D. Bromwich;M. Lazzara;Raúl R. Cordero;Zhenhai Zhang;B. Kawzenuk;J. Cordeira;J. Wille;F. Ralph;L. Bai
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作者：
Xun Zou;P. Rowe;I. Gorodetskaya;D. Bromwich;M. Lazzara;Raúl R. Cordero;Zhenhai Zhang;B. Kawzenuk;J. Cordeira;J. Wille;F. Ralph;L. Bai
南极半岛（AP）最近经历了更频繁和强烈的表面融化，危及冰架的稳定性，最终导致冰的损失。引发地表融化的关键现象包括大气河流（ARs）和背风；ARs和风的综合影响导致2018年12月AP的地表温和变暖，并在2022年2月打破了创纪录的地表融化。针对2022年更强烈的情况，本研究利用先进模式配置的高分辨率极地WRF模拟、南极地形参考高程模式和观测到的地表反照率，以更好地了解ar和fehn之间的关系及其对地表变暖的影响。在2022年的事件中，由于强烈的AR （AR3）入侵，弱的低层阻塞和逆风侧的强地形降水导致潜热释放，从而导致更类似于深风的事件。在背风面，感热通量在夜间是主要的驱动因素，而在白天，感热通量则是由静止地形重力波引起的次要驱动因素。在白天，特别是在AR/ feehn事件高峰之后，向下的短波辐射通过云层清除而增强，并主导了地面融化。然而，由于AP复杂的地形，ar可以通过间隙流将额外的水分输送到背风面，从而使吹风事件复杂化。在2022年的增温高峰期，背风面云层的形成阻碍了短波向下辐射，而略微增加了长波向下辐射。
The Antarctica Peninsula (AP) has experienced more frequent and intense surface melting recently, jeopardizing the stability of ice shelves and ultimately leading to ice loss. Among the key phenomena that can initiate surface melting are atmospheric rivers (ARs) and leeside foehn; the combined impact of ARs and foehn led to moderate surface warming over the AP in December 2018 and record‐breaking surface melting in February 2022. Focusing on the more intense 2022 case, this study uses high‐resolution Polar WRF simulations with advanced model configurations, Reference Elevation Model of Antarctica topography, and observed surface albedo to better understand the relationship between ARs and foehn and their impacts on surface warming. With an intense AR (AR3) intrusion during the 2022 event, weak low‐level blocking and heavy orographic precipitation on the upwind side resulted in latent heat release, which led to a more deep‐foehn like case. On the leeside, sensible heat flux associated with the foehn magnitude was the major driver during the night and the secondary contributor during the day due to a stationary orographic gravity wave. Downward shortwave radiation was enhanced via cloud clearance and dominated surface melting during the daytime, especially after the peak of the AR/foehn events. However, due to the complex terrain of the AP, ARs can complicate the foehn event by transporting extra moisture to the leeside via gap flows. During the peak of the 2022 foehn warming, cloud formation on the leeside hampered the downward shortwave radiation and slightly increased the downward longwave radiation.