Mechanisms for the Regulation of Minimum Mid-tropospheric and Surface Temperatures at High Latitudes

将研究一种可能在冬季调节北极地区对流层中层和地面气温的机制。对观测到的对流层中部北极温度的调节假设如下：北极的冬季空气与开阔的海洋反复接触，这使得变暖通过潮湿的对流从表面向上至少通过对流层中部迅速发生;当这些温暖的空气柱在冰雪覆盖的表面上移动时，它们从底部向上冷却，然而，这个过程发生得如此缓慢，以至于它调节了SAT。最终的结果是，在北极冬季，由于辐射平衡过程，对流层中层的变暖将导致近地层的变暖。 研究人员将（1）在每天4次的国家环境预测中心再分析中对500 mb温度场进行详细的观测分析，以在空间上跟踪个体变暖和变冷模式，以及（2）使用低分辨率大气环流模型（行星模拟器）并提高高纬度SST几度以检验提出的假设。智力优点：这项工作的完成将为调节北极冬季地表和对流层中层气温的机制提供新的见解。 更广泛的影响：这项研究将增加我们对冬季北极地表和对流层中层气温调节过程的了解。它有可能改善这些过程在大气环流模式中的表现。它还为研究助理提供学习经验和培训。

A mechanism that may regulate both mid-tropospheric and surface air temperatures (SATs) in the Arctic region during the winter season will be examined. Regulation of observed mid-tropospheric arctic temperatures is hypothesized as follows: winter air in the Arctic has repeated contact with open ocean which allows warming to occur quickly through moist convection from the surface upward through at least the mid troposphere; and as these warmed air columns move over snow and ice covered surfaces, they cool from the bottom upwards, however, this process happens so slowly that it regulates SATs. The end result is that a warmer mid-troposphere will result in a warmer near surface layer during Arctic winter because of radiative equilibrium processes. The PIs will (1) perform a detailed observational analysis of the 500mb temperature field in the 4 x daily National Centers for Environmental Prediction reanalysis to track individual warming and cooling patterns spatially, and (2) use a low resolution General Circulation Model (planet simulator) and increase high latitude SSTs by several degree to examine the hypotheses proposed. Intellectual merit: Completion of this work will offer new insights into the mechanism that regulates the Arctic wintertime surface and mid-troposphere air temperatures. Broader impacts: The research will increase our understanding of the processes involved in the regulation of the wintertime Arctic surface and mid-troposphere air temperature. It has a potential to improve these processes' representation in general circulation models. It also provides learning experiences and training for a research assistant.