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

将研究一种可能调节北极地区冬季对流层中层和地表气温的机制。观测到的北极对流层中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，这使得从表面向上至少穿过对流层中的潮湿对流迅速变暖；当这些暖气柱在冰雪覆盖的表面上移动时，它们会从底部向上冷却，然而，这个过程发生得非常缓慢，以至于它会调节sat。最终结果是，由于辐射平衡过程，对流层中变暖将导致北极冬季近地表变暖。ppi将(1)在国家环境预测再分析中心每天4次对500mb温度场进行详细的观测分析，以跟踪空间上的个别增温和降温模式；(2)使用低分辨率大气环流模式（行星模拟器）并将高纬度海温增加几度来检验所提出的假设。学术价值：这项工作的完成将为北极冬季地表和对流层中空气温度的调节机制提供新的见解。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气温调节过程的理解。它有可能改善这些过程在一般循环模型中的表示。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.