Collaborative Research: The Effect of Near-Equatorial Islands on Climate

该项目将研究近赤道岛屿对气候的影响。将进行一系列实验，首先使用一个简单的、没有旋转影响的二维模式，然后使用麻省理工学院大气环流模式(MIT-GCM)来检查岛屿对降雨分布、所产生的风场的影响，从而对大尺度环流的影响。利用MIT-GCM进行的实验将使用简化的几何形状，其中包括对海洋环流的宽度可以忽略不计的障碍，但不包括对大气环流的障碍，以及热带岛屿的不同数量、分布、横向尺寸和海拔，以寻求这些岛屿范围测量与大气和海洋响应之间的尺度关系。目标有两个：首先，建造海洋大陆的岛屿的增长是否已经足够改变了大气环流，从而改变了赤道太平洋的海面温度分布，从一个永久的类似厄尔尼诺的状态，变成了目前平均的弱拉尼娜状态？第二，能否为岛屿对热带降水和上升的影响推导出参数，从而允许GCM包括太小而无法在这样的全球模式中解决的岛屿的影响？更广泛的影响是高的：如果岛屿确实在气候中发挥主要作用，这项研究将产生有助于将小岛屿的影响包括在模型模拟中的参数。此外，这项工作还将支持一名研究生。。

This project will examine the effect of near-equatorial islands on climate. A series of experiments, first with a simple, two-dimensional model without the effects of rotation, and then with the Massachusetts Institute of Technology General Circulation Model (MIT-GCM) will be carried out to examine the effects of islands on the distribution of rainfall, the resulting wind field, and hence on large-scale circulation. Experiments with the MIT-GCM will be carried out with simplified geometries that include barriers of negligible width to ocean circulation, but not atmospheric, circulation and with different numbers, distributions, lateral dimensions, and elevations of tropical islands in order to seek scaling relationships between these measures of island extent and the response of the atmosphere and ocean. The goals are two-fold: First, could the growth of islands to build the Maritime Continent have altered atmospheric circulation sufficiently to change the sea-surface temperature distribution in the equatorial Pacific from one resembling a permanent El Niño-like state to its present mean weak La Niña-like state? Second, can parameterizations be derived for the effects of islands on tropical precipitation and ascent that allow GCMs to include the effects of islands that are too small to be resolved in such global models? The broader impacts are high: if islands do play a major role in climate, this study will yield parameterizations that will be useful for including the effects of small islands in model simulations. In addition this work will support a graduate student. .