Collaborative Research: Processes and Patterns in The North American Monsoon Macrosystem

这个项目的重点是研究地球气候系统中控制北美季风系统的空间覆盖范围和年际变化的过程，北美季风系统支持从墨西哥中部到美国西南部的生态和人类系统。这项研究将使用先进的计算机模型，将天气预报与与地面植物相关的生物过程结合起来，以确定高度变化的季风降雨如何控制入侵草（包括欺骗草和牛皮草）的传播，以及这些入侵草的传播如何反过来影响季节性天气模式和季风系统本身。其他方面包括对西南部树木年轮的分析，这将揭示季风的规模和分布的历史模式，也可以用来验证模型的预测。该研究还将探讨低海拔干燥草原和高海拔森林在野火周期方面的比较。夏季降雨可能会影响火灾从草原向森林的蔓延，这项研究将有助于解释这种联系是如何受到季风降雨变化的影响的。最后，将努力扩大对控制季风降雨的因素的理解，将气候的自然周期包括在内，例如与2至7年的厄尔尼诺周期和太平洋年代际振荡有关的周期，这两者都影响太平洋的表面温度。这是对该地区季风降雨与生态系统之间耦合的最终原因的探索。例如，一个主要目标将是探索确定季风系统空间范围的气候和生态力量的性质，以及确定其规模和长期变化的海洋过程和循环。这个大型综合项目的参与者包括来自美国和墨西哥的生态学家和气候科学家。这个项目将在几个方面对科学和社会产生更广泛的影响。培养博士后6人，研究生7人。通过树木年轮研究实验室将创建一个“发现研究员”项目，该项目将雇用六名学校教师，其中包括一些来自纳瓦霍族的教师，他们将参与组装西南地区的树木年轮档案。将建立一个进程，开发一个新的区域陆地表面计算机模型，该模型将由国家大气研究中心管理，并广泛提供使用。将开始与墨西哥的双边合作，其中包括每年与科学家和研究生进行长期访问。最后，将创建一个展示，描述夏季季风与美洲原住民群体和当代社会的相关性；它将被安置在图森的生物圈2号中心展出，该中心每年接待约75000名游客。

This project focuses on studying the processes in the earth's climate system that control the spatial coverage and year-to-year variation in the North American Monsoon System, which supports ecological and human systems from central Mexico through the southwestern United States. The study will use advanced computer models that combine weather forecasting with biological processes associated with the plants on the ground to determine how the highly variable monsoon rains control the spread of invasive grasses, including cheat grass and buffel grass, and the how the spread of these invasive grasses may, in turn, influence seasonal weather patterns and the monsoon system itself. Other aspects include the analysis of tree rings from across the southwest that will reveal historical patterns in the magnitude and distribution of the monsoons and also can be used to validate model predictions. The study will also explore how low elevation dry grasslands and high elevation forests compare with regard to cycles of wildfires. Summer rains are likely to influence the spread of fires from grasslands to forests and this study will help explain how this connection is influenced by variability in the monsoon rains. Finally, an effort will made to extend understanding of what controls monsoon rains to include natural cycles in climate, such as those associated with the two-to-seven year El Nino cycle and the Pacific Decadal Oscillation, both of which affect surface temperatures of the Pacific Ocean. This is a search for the ultimate causes of the coupling between monsoon rains and the ecological systems in the region. For example, a main objective will be to explore the nature of the climate and ecological forces that define the spatial extent of the monsoon system, and the ocean processes and cycles that define its magnitude and long-term variation. The participants in this large and integrated project include ecologists and climate scientists working together, from both the U.S. and Mexico.This project will have broader impacts to science and society in several ways. Six post-doctoral students and seven graduate students will be trained. A Discovery Fellows program will be created through the Laboratory of Tree Ring Research that will hire six school teachers, including some from the Navajo Nation, who will be involved in assembling a tree ring archive for the southwest. A process will be established to develop a new regional land surface computer model that will be administered by the National Center for Atmospheric Research and made widely available for use. A bi-national collaboration with Mexico will be started that will include extended visits each year with scientists and graduate students. Finally, a display will be created that describes the relevance of summer monsoons to Native American groups and contemporary societies; it will be housed and shown at the Biosphere 2 Center in Tucson, which hosts about 75,000 visitors each year.