The Role of Tropical Asian Landcover Disturbance in Altering Large-scale Circulations: Interaction with El Nino Southern Oscillation (ENSO) and the Asian Summer Monsoon

最近的几篇论文记录了气候模型模拟中热带土地覆盖变化引起的大气环流变化。拟议的研究重点是通过各种大气环流模式模拟，阐明土地覆盖变化在改变全球环流机制中的作用，以及土地覆盖变化的影响与包括厄尔尼诺南方振荡(ENSO)和亚洲夏季风在内的其他可变性模式之间的相互作用。主要假设如下：1)热带和东南亚的历史土地覆盖变化引起了与ENSO交替阶段相似的大小环流变化。通过影响热带辐散环流，这些变化具有全球影响。2)热带土地覆被变化引起热带环流的转移，从而导致厄尔尼诺现象的增强，而拉尼娜现象的影响。3)由于土地覆被变化引起的环流变化与由于ENSO引起的环流变化是非线性相互作用的。4)热带土地覆盖变化引起的环流变化可能是厄尔尼诺现象与印度夏季风反相关减弱的原因之一。PIS将通过集合大气环流模式模拟和观测分析来检验这些假设，这些环流变化是由于热带土地覆盖变化、由于厄尔尼诺类海温异常造成的环流变化以及由于这两种影响的综合影响而引起的环流变化。更广泛的影响：这项研究大大增加了以前关于土地覆盖变化影响的研究，并解决了两个大的、突出的问题(智力价值)，在促进跨学科研究和社会影响方面具有更广泛的影响，包括预测区域季风变化和表达预期的二氧化碳导致的全球变暖。该项目得到气候可变性和可预测性计划(CLIVAR)的支持。

Several recent papers have documented atmospheric circulation changes resulting from changing tropical land cover in climate model simulations. The proposed research focuses on elucidating the role of land cover changes in changing global circulation regimes and the interactions between the effects of land cover change and other modes of variability including El Nino southern oscillation (ENSO) and the Asian summer monsoon through a variety of general circulation model simulations. The PIs address the following main hypotheses:1) Historical land cover changes in the tropics and in Southeast Asia, in particular, cause similar magnitude circulation changes as seen in the alternating phases of ENSO. By affecting the tropical divergent circulation, these changes have global reach. 2) Tropical land cover changes cause shifts in tropical circulations which would tend to enhance the El Nino phase of ENSO at the expense of La Nina.3) Circulation changes due to land cover change and those due to ENSO interact non-linearly.4) Circulation changes due to tropical land cover changes may have a role in explaining the observed decreased anticorrelation between El Nino and the Indian summer monsoon. The PIs will examine these hypotheses with ensemble general circulation model simulations and observational analysis of circulation changes due to tropical land cover changes; changes due to El Nino-like SST anomalies and circulation changes due to a combination of both effects. Broader Impacts: This research adds significantly to previous studies of the effect of land cover change and addresses two large, outstanding questions (intellectual merit) with broader impacts in promoting interdisciplinary research, and societal implications including the prediction of regional monsoon variability and the expression of expected CO2 induced global warming.This project is supported under the Climate Variability and Predictability Program (CLIVAR).