Addressing the Grand Challenge of regional sea level change prediction

海平面变化是温室气体排放造成的气候变化的最广为人知和潜在的严重后果之一。它涉及公众和决策者，因为它对沿海和低洼地区的人口和生态系统产生不利影响。这种影响预计在未来几个世纪内还会增加。海水在一个被称为热膨胀的过程中随着温度的升高而膨胀。由于进入海洋的热量的变化而引起的热膨胀是预计在21世纪海平面上升的最大因素。区域海平面还受到降水、蒸发和海洋上风的变化的影响，因为这些变化沿着加热，影响海洋密度和海流。在气候变暖的情况下，冰川和冰盖的收缩是导致全球和区域海平面变化的另一个重要因素，但这是一个不同的科学问题，我们不打算在这里直接讨论。计算机气候模型对海平面变化的预测不一致。这意味着我们无法对地球仪的平均海平面上升做出精确的预测。此外，虽然所有模型都预测，一些区域的增长将高于平均水平，而另一些区域的增长将低于平均水平，但它们对这些地理模式并不一致。不确定性的很大一部分与各种模型对热、水和风的影响变化的不同反应有关。它们的表现不同，因为在它们的公式中作出了不同的假设，反映出缺乏精确的知识，本项目旨在通过使用新技术详细分析海洋模式如何对特定输入作出反应，并通过与理论和观测进行比较，来研究这些不确定性。因此，我们的目的是缩小预测的范围。任何此类减排都可能带来巨大的社会和经济效益;例如，需要就可能持续数十年、耗资数十亿英镑的沿海基础设施做出规划决策。

Sea level change is one of the most widely known and potentially serious consequences of climate change due to emissions of greenhouse gases. It concerns both the public and policymakers, because of its adverse impact on the populations and ecosystems of coastal and low-lying areas. This impact is expected to increase for centuries to come.Sea water expands as it warms in a process known as thermal expansion. Thermal expansion due to changes in the amount of heat entering the ocean is the largest contributor to sea level rise projected for the 21st century. Regional sea level is also affected by changes in precipitation, evaporation and winds over the ocean because, along with heating, these affect ocean density and currents. The contraction of glaciers and ice sheets expected in a warming climate is another important contributor to projected global and regional sea level change, but it is a different scientific subject which we do not propose to address directly here.Computer climate models disagree in their projections of sea level change. This means that we are not able to make precise predictions of sea level rise on average over the globe. Moreover, while all models predict that some regions will experience a larger rise than average and others a smaller rise than average, they do not agree on these geographical patterns. A large part of the uncertainty is related to the different behaviour of the various models in response to the changing effects of heat, water and winds. They behave differently because different assumptions have been made in their formulations, reflecting a lack of precise knowledge.This project aims to study these uncertainties, by detailed analysis, using new techniques, of how the ocean models respond to particular inputs, and by comparison with theory and observations. Our aim is thus to reduce the range of the projections. Any such reduction is potentially of large societal and economic benefit; for example, planning decisions need to be made concerning coastal infrastructure that may last for decades and cost billions of pounds.