Testing theories of baroclinic adjustment in the laboratory and in simple atmospheric models

在实验室和简单大气模型中测试斜压调节理论

基本信息

批准号：
1617727
负责人：
金额：
--
依托单位：
University of Oxford
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-1617727
关键词：
Testing theories baroclinic adjustment laboratory

项目摘要

The state of the Earth's climate can be viewed as resulting from a delicate balance between radiative forcing processes and the dynamical response of the system as it seeks to transport heat across the planet. Recent research has tended to focus on quantifying the radiative forcing processes and their associated uncertainties, and various factors (including those human-induced) leading to changes in the climate. But radiative forcing primarily constrains the energy throughput of the climate system and only indirectly influences key climate variables such as the mean surface temperature. Climate variables are also strongly affected by how efficiently heat is redistributed across the planet by dynamical processes in the atmosphere and oceans. These are intrinsically nonlinear, and are affected by internal feedbacks that are still not well understood. This leaves open such fundamental questions as: what determines the mean lapse rate in the extra-tropical atmosphere, and what determines the thermal contrast in the atmosphere between equator and poles or continents and oceans?In this project, therefore, we will study the relevant dynamical processes in numerical model simulations, based on the Met Office ENDGame dynamical core, (a) in a configuration representing a novel laboratory analogue of the mid-latitude climate system in a real fluid under carefully controlled conditions (currently being investigated experimentally in Prof. Read's group in Oxford), and (b) in simplified global atmospheric models subject to idealized radiative and boundary forcing. Numerical model simulations will be carried out and (for (a)) compared with detailed measurements of the flow and thermal structure in the Oxford experiments. This will enable us to determine the efficiency of heat transfer linking convective and baroclinic regions in order to determine how transport efficiency scales with key parameters and how the flow itself determines the mean static stability. We will also be able to assess the conditions under which fully developed turbulent energy cascades emerge or may be suppressed. This will then be investigated (in (b)) over a range of atmospheric conditions, resolutions and convective parameterizations in the full ENDGame model with idealized forcing.

地球气候状态可以视为是由于辐射强迫过程与系统试图在整个地球上运输热量时的动态响应之间的微妙平衡所致。最近的研究倾向于专注于量化辐射强迫过程及其相关的不确定性，以及导致气候变化的各种因素（包括人类诱导的因素）。但是辐射强迫主要限制气候系统的能量吞吐量，仅间接影响关键气候变量，例如平均表面温度。气候变量还受到大气和海洋中动态过程在整个地球上重新分布的有效性重新分布的强烈影响。这些是本质上非线性的，并且受到仍然不太了解的内部反馈的影响。这留下了开放的基本问题：什么决定了在流动气氛中的平均失误率，什么决定了赤道与电线杆或大陆或大陆和海洋之间大气中的热对比度？在仔细控制的条件下（目前正在牛津大学的Read教授组中进行实验研究）和（b）在简化的全球大气模型中受到理想化的辐射和边界强迫的研究。与牛津实验中的流量和热结构的详细测量相比，将进行数值模型模拟，并（对于（a））。这将使我们能够确定连接对流和斜压区域的传热效率，以确定如何使用关键参数的运输效率尺度以及流动本身如何确定平均静态稳定性。我们还将能够评估完全开发的湍流能量级联反应或可能被抑制的条件。然后，将在全面的最终游戏模型中使用理想化的强迫措施中的一系列大气条件，决议和对流参数化进行研究（在（b）中）。