权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Fundamental Mechanisms of Arctic Summer-time Cyclone Growth and Sea-ice Interaction

北极夏季气旋增长和海冰相互作用的基本机制

基本信息

批准号：
2435642
负责人：
金额：
--
依托单位：
University of Reading
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2020
资助国家：
英国
起止时间：
2020 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2435642
关键词：
Fundamental Mechanisms Arctic Summer time

项目摘要

As the climate has warmed in response to increasing greenhouse gases, the September minimum in Arctic sea-ice extent has decreased dramatically and the drift speed of summer Arctic pack ice has increased, attributed tothinner ice. At the same time, human activity has expanded within the Arctic, with more residents and visitorsmaking use of the reduced sea ice extent for shipping and offshore operations in summer. This has drivendemand for forecasts of weather, ocean and sea-ice state across the Arctic on timescales needed to makedecisions, typically ranging from hours to weeks. As we move to the "new Arctic", where the marginal ice zoneis projected to dominate the summer Arctic Ocean, we anticipate that surface drag will increase due to the icefloe edges and this may enhance surface interactions with Arctic weather systems. Unfortunately, currentforecast skill is more variable in the Arctic than the northern mid-latitudes. The new frontier in prediction is tomodel this coupled system with fidelity and skill. However, improvements in Arctic weather system prediction have yet to be realized because understanding of the physical processes is incomplete.Arctic cyclones are the dominant type of hazardous weather system affecting the Arctic environment in summerand can also have critical impacts on sea-ice movement. The aim of the project will be to isolate the mechanisms that distinguish Arctic cyclones from the much studied mid-latitude cyclones and to determine whether these mechanisms render them less predictable, or whether the coupling with the dynamic sea ice surface beneath is responsible for the lower forecast skill. Different approaches will then be investigated to see if prediction can be improved.The project brings together modelling and theoretical approaches to cyclone dynamics and coupling with sea-ice. We will use novel approaches to interrogate forecast models as they run and determine the mechanisms through which the surface properties alter cyclone growth. The primary tool will be the state-of-the-art ECMWF global atmospheric model with and without coupling to a sea ice model. The PhD project will evolve in 3 stages: 1) analysis of operational ECMWF forecasts archived with physical process tendencies for the extended YOPP period (3 years), 2) experiments using the comprehensive ECMWF model but in simplified configurations to examine sensitivity of cyclone development to varying environment and 3) re-forecasts in real cases varying the coupling with the sea ice through changes in the coupling physics and sea ice model itself.The project will be based in the Department of Meteorology, University of Reading and partnerwith the ECMWF and University of Oklahoma. The ECMWF global coupled earth system model (IFS) will beused for new experiments with support from ECMWF to run the model and use of ECMWF supercomputingresources. This will entail occasions working at the ECMWF.In addition to the computer modelling, the project could involve a combination of the development of theory(building on existing theory for mid-latitude cyclones) and use of new observations, depending on your skill setand strengths and the direction you chose to take the project. You will receive masters-level training in thedynamics and physics of the atmosphere, global numerical modelling, as well as the ECWMF course onNumerical Weather Prediction.The project links in with the THINICE international project which plans an aircraft experiment in summer 2021aiming to observe Arctic cyclones and the evolving sea ice state below. The studentship funding will involve aresearch placement at the University of Oklahoma (USA), with the THINICE project team and their Arctic andAntarctic Research Group. You will have the opportunity to join the flight planning mission team in the Arctic to conduct the aircraft experiment.

由于温室气体的增加导致气候变暖，9月份北极海冰范围的最小值急剧下降，夏季北极浮冰的漂移速度加快，这是由于冰层变薄。与此同时，北极地区的人类活动也在扩大，越来越多的居民和游客在夏季利用海冰面积减少进行航运和近海作业。这推动了对整个北极地区天气、海洋和海冰状况的预测需求，这些预测需要在做出决策所需的时间尺度上进行，通常从几小时到几周不等。当我们移动到“新北极”时，边缘冰带预计将主导夏季北冰洋，我们预计由于浮冰边缘，地表阻力将增加，这可能会增强地表与北极天气系统的相互作用。不幸的是，目前的预报技术在北极比在北部中纬度地区变化更大。预测的新前沿是用保真度和技巧对这种耦合系统建模。然而，由于对物理过程的了解尚不完整，北极天气系统预报的改进尚未实现。北极气旋是夏季影响北极环境的主要危险天气系统类型，也可能对海冰运动产生关键影响。该项目的目的是将区分北极气旋与已被广泛研究的中纬度气旋的机制分离出来，并确定是这些机制使它们难以预测，还是与下方动态海冰表面的耦合导致了较低的预测能力。然后将研究不同的方法，看看是否可以改进预测。该项目将气旋动力学和与海冰耦合的建模和理论方法结合在一起。我们将使用新颖的方法来询问预报模型，因为他们运行和确定的机制，通过表面性质改变气旋的增长。主要工具将是最先进的ECMWF全球大气模型，无论是否与海冰模型耦合。博士项目将分3个阶段进行：1)分析扩展的YOPP期间（3年）的物理过程趋势存档的ECMWF业务预报；2)使用综合ECMWF模型进行简化配置的实验，以检查气旋发展对不同环境的敏感性；3)通过耦合物理和海冰模型本身的变化，在实际情况下改变与海冰的耦合。该项目将以雷丁大学气象系为基础，并与ECMWF和俄克拉荷马大学合作。ECMWF全球耦合地球系统模型（IFS）将在ECMWF的支持下用于新的实验，以运行该模型并使用ECMWF超级计算资源。这将需要在ECMWF工作。除了计算机建模之外，该项目还可以结合理论的发展（建立在现有中纬度气旋理论的基础上）和新观测的使用，这取决于你的技能和优势以及你选择的项目方向。您将获得大气动力学和物理、全球数值模拟以及ECWMF数值天气预报课程的硕士水平培训。该项目与THINICE国际项目相关联，该项目计划在2021年夏季进行一次飞机实验，旨在观察北极气旋和下面不断变化的海冰状态。奖学金资金将包括在俄克拉何马大学（美国）与THINICE项目团队及其北极和南极研究小组进行研究安排。您将有机会加入飞行计划任务小组在北极进行飞机实验。