A Study of Frontal-Scale Air-Sea Interaction along the Gulf Stream Extension Using a High-Resolution Coupled Regional Climate Model

墨西哥湾流延伸区(GSE)已被确定为温带外地区的一个关键位置，在那里，海洋表面温度的变化可能会引起相当大的大气变化，从而增加了中纬度海气相互作用的有趣可能性。首席调查员计划在大西洋区域进行非常高分辨率的耦合区域气候模式模拟，在GSE上方的嵌套子区域使用高达3公里的水平网格分辨率。在这些分辨率下，大气对流和海洋涡旋的重要方面得到了明确的解决，并可以直接研究沿墨西哥湾流的锋面尺度的海洋-大气相互作用。PIS将审查以下科学问题：(1)气候模式偏差在多大程度上会影响北大西洋区域气候变异性的模拟和预测？(2)墨西哥湾流的强热锋是否会影响大西洋风暴路径？如果是这样的话，天气尺度的大气变率如何与海洋相互作用，大气和海洋之间在小空间尺度上的反馈机制是什么？(3)墨西哥湾流对大西洋经向翻转环流(AMOC)变化的响应能否产生重大的大气响应？如果是这样的话，是什么动力过程导致了这种反应？这项活动的更广泛影响是巨大的：这项研究将增进我们对预测全球气候变化对大西洋区域的影响的不确定性的理解，这对该区域各国具有重要的社会和经济后果。

The Gulf Stream Extension (GSE) region has been identified as a key location in the extratropics where sea surface temperature variability may induce considerable atmospheric variability, raising the intriguing possibility of significant midlatitude air-sea interaction. The Principal Investigators (PIs) plan to carry out very high-resolution coupled regional climate model simulations in the Atlantic domain, using horizontal grid resolution as fine as 3 km in nested sub-regions over the GSE. At these resolutions, important aspects of atmospheric convection and oceanic eddies are explicitly resolved and frontal-scale ocean-atmosphere interaction along the Gulf Stream can be directly examined. The PIs will examine the following scientific questions: (i) To what extent can climate model biases in the GSE region affect simulations and predictions of regional climate variability in the North Atlantic? (ii) Can the strong thermal front of the Gulf Stream affect the Atlantic storm tracks? If so, how does synoptic-scale atmospheric variability interact with the ocean and what are the feedback mechanisms between the atmosphere and ocean at small spatial scales? (iii) Can shifts in the Gulf Stream in response to changes in the Atlantic Meridional Overturning Circulation (AMOC) changes produce a significant atmospheric response? If so, what are the dynamical processes responsible for such a response? The broader impacts of this activity are substantial: the research will enhance our understanding of the uncertainties in projecting the impact of global climate change on the Atlantic region, which has important social and economic consequences for countries in the region.