Characteristics of Cyclone Development in the Arctic and Their Hydrologic Impacts

本研究将增进我们对北方高纬度地区热带外气旋的发展和衰减及其水文影响的了解。这项研究将集中在两个关键区域：1）北大西洋北方，特别是冰岛低地周围地区以及格陵兰海和巴伦支海的边缘冰区;第一个区域是北大西洋气旋路径的终点，对进入北极海盆的热量和水分输送以及海冰覆盖的环流，特别是通过弗拉姆海峡的海冰通量有一级影响。这种冰通量的变化对海洋的温盐环流有潜在的强烈影响。过去的研究表明，该地区的气旋变化与北极涛动/北大西洋涛动（AO/NAO）的相位密切相关，但相对较少关注当地发展过程的作用。冬季期间，该地区的天气活动似乎受到格陵兰东南部背风面涡度生成和沿着海冰边缘斜压性增强的强烈影响。我们的假设是：（1）这种局地发展过程对调节弗拉姆海峡的冰通量是重要的;（2）这些局地发展过程的强度与AO/NAO正/负位相相关的一般天气环境的差异有关。夏季的特点是沿欧亚大陆东北部沿着发展出明显的斜压区。据解释，这是由寒冷的北冰洋和无雪陆地之间的强烈差异加热引起的。欧亚大陆东北部斜压区的发展伴随着同一地区频繁的气旋生成，在该地区，夏季月份的年降水量福尔斯特别大。欧亚大陆东北部产生的气旋经常迁移到北冰洋中部。该假说认为，气旋生成极大值可以通过海岸斜压性和地形发展过程之间的相互作用来解释。第二个假设是，在该地区形成的气旋显着影响风驱动的海冰环流在北冰洋中部，是夏季最大的降水在北冰洋中部和沿海地区的主要驱动程序，这些研究将使用从美国国家环境保护中心（NCEP）和ERA-40再分析系统，沿着与生成的数据集的大气场套件。这些包括气旋活动，锋面位置和强度，以及Q矢量场的六小时时间序列。还将利用每日卫星得出的海冰运动和集中情况以及陆地和北冰洋每日降水量。

ABSTRACTOPP-0240984SerrezeBarryThis study will improve our understanding of the development and decay of extra-tropical cyclones in northern high latitudes and their hydrologic impacts. The study will focus on two key regions: 1) the northern North Atlantic, in particular the area around the Icelandic Low and the marginal ice zones of the Greenland and Barents seas; and 2) a domain comprising northeast Eurasia extending to the central Arctic Ocean.The first region, representing the terminus of the North Atlantic cyclone track, has first order impacts on heat and moisture transports into the Arctic basin and the circulation of the sea ice cover, in particular, the flux of sea ice through Fram Strait. Variability in this ice flux has potentially strong influences on the ocean's thermohaline circulation. Past studies have shown that cyclone variability in this region is closely tied to the phase of the Arctic Oscillation /North Atlantic Oscillation (AO/NAO), but relatively little attention has been paid to the role of local development processes. Synoptic activity in this region during the winter season appears to be strongly influenced by vorticity production in the lee of southeast Greenland and enhanced baroclinicity along the sea ice margins. The hypothesis is that, 1) such local development processes are important in modulating the Fram Strait ice flux; and 2) the intensity of these local development processes is associated with differences in the general synoptic environment associated with the positive/negative phases of the AO/NAO.Studies for the second domain will focus on summer. Summer is characterized by development of a pronounced baroclinic region along the shores of northeast Eurasia. It is interpreted to arise from strong differential heating between the cold Arctic Ocean and snow free land. Development of the baroclinic region over northeast Eurasia is attended by frequent cyclogenesis in the same region where a particularly large fraction of annual precipitation falls during the summer months. Cyclones generated over northeast Eurasia often migrate into the central Arctic Ocean. The hypothesis is that the cyclogenesis maximum can be explained through interactions between coastal baroclinicity and orographic development processes. A second hypothesis is that cyclones forming in this region significantly impact on the wind driven sea ice circulation in the central Arctic Ocean and are primary drivers of the summer maximum in precipitation over the central Arctic Ocean and coastal zone.These studies will use the suite of atmospheric fields from the National Center for Environmental Protection (NCEP) and ERA-40 reanalysis systems, along with generated data sets. These include six hourly time series of cyclone activity, frontal location and intensity, and Q vector fields. Use will also be made of daily satellite derived fields of sea ice motion and concentration together with daily precipitation over both land and the Arctic Ocean.