Arctic Climate Change and its Mid-latitude Impacts

北极气候正在迅速变化，海冰正在加速融化。自1979年以来，常年海冰覆盖面积减少了近一半。延续这一趋势，2011年夏季海冰损失接近历史记录。过去5年是现代记录中9月份海冰数量最少的5年。海冰的这种不可阻挡的退缩可能对全球气候系统产生深远的影响。迫切需要对未来北极海冰状况进行科学预测，以便为政策决策提供信息。该项目的目的是提高我们对北极气候变化及其对北半球中纬度地区（包括英国）天气和气候的影响的认识，以及对控制这些相互作用的物理过程的认识。这一目标将通过对观测结果的补充分析和最先进的气候模式实验来实现。北极海冰的变化会影响其上方的大气，并可能导致气候模式的大规模变化，从而将北极的变化“传达”给遥远的地区。2009/10年和2010/11年英国异常寒冷的冬天提供了一个很好的例子，说明北极和英国的气候是如何联系在一起的。在这些冬季，不寻常的大规模天气模式导致北极地区异常温暖，而英国则持续低温，大雪和冻雨。这些灾害导致交通、能源供应和电力传输中断以及农业受损；所有这些都要付出巨大的经济代价。在这些破纪录的冬季之前，夏季和秋季北极海冰覆盖面积减少。虽然许多研究提出了两者之间可能存在的联系，但能够解释这种联系的物理过程仍不清楚。此外，目前还不清楚未来预计的海冰减少将如何影响英国的天气和气候。这项研究将使用气候模型来深入了解这些关键问题。在模型设置中，可以以可控的方式操纵海冰覆盖，以揭示它如何以及通过什么过程影响更广泛的气候系统。这项研究的目的是提供一个更好的了解当地和远程气候对海冰条件变化的响应，以及控制这些响应的机制。它将揭示最近的冬季是相对孤立和随机的事件，还是北极冰盖减少的结果。提高我们对影响气候系统对北极海冰损失反应的因素的理解和建模，将提高我们预测、减缓和适应未来气候变化的能力，从而提高可能造成的潜在环境、社会经济和政治影响的能力。这项研究将由埃克塞特大学与英国气象局哈德利中心和美国国家大气研究中心合作进行。它补充和扩展了英国nerc资助的为期5年的北极科学密集计划。

The Arctic climate is changing fast and its sea ice is melting at an increasing rate. Since 1979, perennial sea ice cover has shrunk by nearly half. Continuing this trend, 2011 witnessed near record losses of summer sea ice. The last five years have had the five lowest amounts of September sea ice in the modern record. This inexorable retreat of sea ice may have far reaching repercussions for the global climate system. There is an urgent need for scientific projections of future Arctic sea ice conditions to inform policy decisions. The aim of this project is to improve our understanding of Arctic climate change and its impacts on weather and climate in the northern hemisphere mid-latitudes (including the United Kingdom), and of the physical processes that govern these interactions. This objective will be achieved through complementary analyses of observations and state-of-the-art climate model experiments.Changes in the Arctic sea ice impact the atmosphere above it, and can cause large-scale shifts in weather patterns that "communicate" Arctic change to distant regions. The abnormally cold UK winters of 2009/10 and 2010/11 provide good examples of how the climates of the Arctic and the United Kingdom are connected. In these winters, unusual large-scale weather patterns led to exceptionally warm conditions in the Arctic whereas in the UK there were persistent cold temperatures, heavy snowfall and freezing rain. These resulted in disruptions to transport, energy supply and power transmission, and agricultural damage; all with significant economic costs. These record-breaking winters were preceded by reductions in summer and autumn Arctic sea ice cover. Whilst a number of studies have proposed possible connections between these, the physical processes that could explain such a connection remain unclear. Furthermore, it is unclear how future projected sea ice loss will effect the UK weather and climate. This research will use climate models to gain insight into these critical issues. In a model setting, the sea ice cover can be manipulated in a controlled manner to reveal how and by what processes it effects the wider climate system. This research aims to provide an improved understanding of the local and remote climate responses to changing sea ice conditions, and the mechanisms that govern these responses. It will shed light on whether the recent winters are relatively isolated and random events, or instead are a consequence of the dwindling Arctic ice cover. Improving our understanding and modeling of the factors affecting the climate system response to Arctic sea ice loss will improve our ability to anticipate, mitigate and adapt to future climate change, and hence the potential environmental, socio-economic and political impacts that may result.The research will be undertaken at the University of Exeter, in partnership with the UK Meteorological Office Hadley Centre and the US National Center for Atmospheric Research. It complements and extends upon a NERC-funded 5-year intensive programme of Arctic Science within the UK.