The Organization of Tropical Rainfall

热带降雨的组织

基本信息

批准号：
NE/I021012/1
负责人：
Christopher Holloway
金额：
$ 34.17万
依托单位：
University of Reading
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FI021012%2F1
关键词：
Organization Tropical Rainfall

项目摘要

Tropical cloud systems and rainfall help drive the global circulation of the atmosphere, transferring heat from near the Earth's surface upward for many kilometres. These convective systems can be found in groups of many different sizes, from isolated showers and thunderstorms to equatorial waves to tropical cyclones to the Madden-Julian Oscillation (MJO), an eastward-propagating weather system composed of superclusters of convection several thousand kilometres across which dominates tropical weather variability on weekly to monthly time scales. Global numerical weather forecast and climate models still do not adequately simulate these organized storm clusters and, as a result, have too little (or incorrect) variability of tropical rainfall. Improvement of the representation of organized tropical convection, and therefore the accuracy of weather forecasts, would greatly improve the lives of billions of people who rely on rainfall for agriculture in the tropics and subtropics; better forecasts of strong storms and flooding would also save countless lives and reduce property damage. Furthermore, these processes may change in the future as the climate changes due to human activities, so an improvement of the ability of global models to simulate organized convection will lead to better predictions of possible climate change scenarios over the whole globe. Global weather and climate models divide the Earth into grid boxes about 100 km across. These boxes are too large to directly simulate the motions responsible for small-scale rainstorms, instead estimating total rainfall based on average conditions in the box. This simplified rain estimation, necessary because of limited computer resources, ignores the interaction of isolated rain showers with each other and regional weather conditions. An exciting new research area is the study of organized convection in high-resolution idealized models. These models, with constant sea surface temperatures and constant sunlight, can now be run on domains several thousand kilometres across and with grid boxes of only a few kilometres long, allowing convection to be represented explicitly. These models are beginning to provide insight into processes that lead to spontaneous growth of convective clusters which can ultimately grow to a single large cluster accounting for all of the rainfall in the domain. These processes act over a wide range of spatial scales which are not fully resolved in global models. However, the processes which lead to organized convection in idealized models are still not well understood, and it is not known whether they are also important for organizing tropical convection in nature. This fellowship will exploit a large archive of high-resolution model runs, forecast analyses, and observations from satellites to make more direct comparisons between idealized cases and observed phenomena. Ultimately, this endeavour has the potential to lead to improvements in the way that global models, especially the UK Met Office Unified Model, simulate tropical rainfall and with it global weather and climate. This fellowship will benefit from being undertaken at the Department of Meteorology at the University of Reading, a world-leading centre for atmospheric science. Close ties with the Met Office ensure that this research will be interactive with ongoing efforts to improve the simulation of convection and tropical weather and climate in the Unified Model. In addition, there will be collaborations with other scientists approaching similar problems using different models, which will allow for exploration of possible model differences.

热带云系统和降雨有助于推动大气的全球循环，从地球表面附近转移热量数公里。这些对流系统可以在许多不同尺寸的群体中找到，从孤立的淋浴和雷暴到赤道波到热带气旋到热带气旋，再到Madden-Julian振荡（MJO），这是一个由向对流的向对流的向对流的向对流组成的，由对流的超级公里组成几千公里，在该对流中，几千公里在每周的每周一次的热带天气变异性占据了热带天气可变性。全球数值天气预报和气候模型仍然没有充分模拟这些有组织的风暴群，因此，热带降雨的变化太少（或不正确）。改善有组织的热带对流的代表，因此天气预报的准确性将大大改善数十亿人的生活，这些人依靠降雨来改善热带和亚热带地区的农业；更好地预测强风暴和洪水还可以节省无数生命并减少财产损失。此外，随着人类活动的气候变化，这些过程可能会在未来发生变化，因此，全球模型模拟有组织对流的能力的提高将更好地预测整个世界上可能的气候变化情景。全球天气和气候模型将地球分为大约100公里的网格箱。这些盒子太大，无法直接模拟导致小规模暴雨的动作，而是根据盒子中的平均条件估算总降雨量。由于计算机资源有限，这种简化的降雨估计是必要的，忽略了隔离的雨水阵雨和区域天气状况的相互作用。一个令人兴奋的新研究领域是对高分辨率理想模型中有组织的对流的研究。这些模型持续的海面温度和恒定的阳光，现在可以在几千公里的域上运行，网格盒仅长几公里，可以明确表示对流。这些模型开始洞悉导致对流群集自发增长的过程，这些过程最终可以生长到一个大型集群中，这占该域中所有降雨量。这些过程在全球模型中未完全解决的各种空间尺度上起作用。但是，导致理想化模型中有组织对流的过程仍未得到充分理解，并且尚不清楚它们对于在自然界中组织热带对流是否也很重要。该奖学金将利用大量高分辨率模型运行，预测分析和观察结果的大量档案，以在理想化的情况和观察到的现象之间进行更直接的比较。最终，这项工作有可能导致全球模型，尤其是英国大都会办公室统一模型，模拟热带降雨以及全球天气和气候的方式改善。该奖学金将受益于在世界领先的大气科学中心雷丁大学气象学系进行的。与大都会办公室的密切联系确保这项研究将与统一模型中的对流和热带天气和气候的仿真持续互动。此外，将与其他科学家进行合作，使用不同的模型处理类似的问题，这将允许探索可能的模型差异。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Transient Aggregation of Convection: Observed Behavior and Underlying Processes

对流的瞬态聚集：观察到的行为和潜在过程

DOI：
10.1175/jcli-d-19-0933.1
发表时间：
2021
期刊：
Journal of Climate
影响因子：
4.9
作者：
Masunaga Hirohiko;Holloway Christopher E.;Kanamori Hironari;Bony Sandrine;Stein Thorwald H. M.
通讯作者：
Stein Thorwald H. M.

Observed Relationships between Cloud Vertical Structure and Convective Aggregation over Tropical Ocean