Ecoclimate Teleconnections: Effects of a Shifting Intertropical Convergence Zone (ITCZ)

该项目的目标是量化生态系统-气候或生态气候遥相关对远离原始强迫的地区的影响，并确定与这些地区生态系统结构、功能和生产力变化相关的反馈。先前的研究表明，中纬度森林覆盖的增加可以提高北半球的温度，并有能力改变热带环流和与热带辐合带（ITCZ）相关的降水位置。这种由生态系统驱动的远程连接通过大气环流将彼此相距遥远的陆地区域的生产力联系起来。通过与全球尺度环流模型和生态系统动力学模型的离线耦合方法，将量化与植被覆盖变化相关的反馈的一级影响。具体地说，将量化中纬度树木覆盖对热带综合试验区位置的影响，并评估由此引起的热带森林生产力和结构的变化。还将研究热带森林结构的任何变化对全球气候系统的影响。该项目将解决以下科学问题：中纬度树木覆盖的大规模变化是否会通过大气遥相关破坏世界其他地区的生态系统稳定？这些生态气候遥相关是如何通过大气传播的？中纬度树木覆盖的多少变化才会影响热带地区的森林？提高对生态系统-气候相互作用的认识具有实质性的更广泛的影响。

The goals of this project are to quantify the impact of ecosystem-climate, or ecoclimate, teleconnections on regions remote to the original forcing and to identify feedbacks associated with the change in ecosystem structure, function, and productivity in those locations. Prior work has shown that an increase in mid latitude forest cover can raise northern hemisphere temperature and has the ability to shift the general circulation of the tropics and the location of precipitation associated with the intertropical convergence zone (ITCZ). This ecosystem-driven teleconnection links productivity in land regions remote to one another through the circulation of the atmosphere. Through an offline-coupling approach with both a global-scale circulation model and a model of ecosystem dynamics, the first order impact of feedbacks associated with changes in vegetation cover will be quantified. In particular the impact of mid latitude tree cover on the location of the ITCZ will be quantified and the resulting change in tropical forest productivity and structure will be assessed. The impact of any changes in tropical forest structure back onto the global climate system will also be examined. The scientific questions that will be addressed in this project are the following: Can large-scale changes in mid latitude tree cover destabilize ecosystems in other parts of the world through atmospheric teleconnections? How are these ecoclimate teleconnections communicated through the atmosphere? How much change in mid latitude tree cover is needed to impact forests in the tropics? Improved understanding of ecosystem-climate interactions has substantial broader impacts.