Exceptional Air Mass Transport and Dynamical Drivers of an Extreme Wintertime Arctic Warm Event
Exceptional Air Mass Transport and Dynamical Drivers of an Extreme Wintertime Arctic Warm Event
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DOI：
10.1002/2017gl075841
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发表时间：
2017-12-16
影响因子：
5.2
通讯作者：
Wernli, Heini
中科院分区：
文献类型：
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作者：
Binder, Hanin;Boettcher, Maxi;Wernli, Heini
在2015/2016年之交，北极的最高表面温度达到创纪录的高值，超过了熔点，导致北极海冰范围在寒冷季节中期大幅减少。在这里，我们表明，使用拉格朗日方法，非常不同的气流的组合促成了这一事件：（i）温暖的低层空气的副热带起源，（ii）最初寒冷的低层空气的极地起源加热的表面通量，和（iii）强烈下降的空气加热绝热压缩。这些暖气流的极向输送是沿着一系列气旋和准静止反气旋之间的强烈低空急流进行的。这一复杂的三维结构使得这一输送得以实现，这得益于持续上升到反气旋上部的温暖传送带。这项研究强调了多重传输过程和瞬态天气尺度动力学的综合作用，建立一个极端的北极变暖事件。
At the turn of the years 2015/2016, maximum surface temperature in the Arctic reached record-high values, exceeding the melting point, which led to a strong reduction of the Arctic sea ice extent in the middle of the cold season. Here we show, using a Lagrangian method, that a combination of very different airstreams contributed to this event: (i) warm low-level air of subtropical origin, (ii) initially cold low-level air of polar origin heated by surface fluxes, and (iii) strongly descending air heated by adiabatic compression. The poleward transport of these warm airstreams occurred along an intense low-level jet between a series of cyclones and a quasi-stationary anticyclone. The complex 3-D configuration that enabled this transport was facilitated by continuous warm conveyor belt ascent into the upper part of the anticyclone. This study emphasizes the combined role of multiple transport processes and transient synoptic-scale dynamics for establishing an extreme Arctic warm event.