Improving the Understanding and Modeling of Land Processes in the Community Climate System Model (CCSM4.0)

陆地过程在地球系统中起着关键作用，其处理对气候系统建模至关重要。该项目的总体目标是改进新版社区气候系统模式（CCSM4.0）对土地过程的理解和建模，该模式的土地成分是社区土地模式（CLM4.0）。在国家科学基金会的支持下，研究人员在解决与陆地-大气-海洋界面过程有关的各种跨学科问题方面取得了重大进展，如在CLM4.0中实施了与陆地过程的五个不同方面有关的改进的参数化，在欧洲中期天气预报中心（ECMWF）实施了他们的海洋皮肤温度方案，以及在国家环境预测中心（NCEP）区域和全球预测模型中测试和实施他们关于动量和热量的陆地表面粗糙度长度的新公式。该项目将通过广泛的现场和卫星数据分析、过程研究和全球建模来解决四个问题：a) CCSM4.0的地表能量/水/碳循环和动态植被的现实程度如何？b) CNDV（动态植被下的碳氮循环）如何影响CLM4.0的能量/水/碳循环，如何进一步改善其处理？c)地下水如何影响CLM4.0中的其他陆地过程，如何进一步改善其处理？d)如何利用从这些努力中获得的见解来更好地理解CCSM4.0对陆地过程的未来气候预测中的不确定性？建议工作的更广泛影响包括：a)提高对能源/水/碳循环的理解，改进两个重要过程（即地下水和动态植被的碳氮循环）的处理，培训学生，并将研究成果纳入教学；B)为跨学科研究升级和维护计算机集群；c)通过同行评议的出版物、在会议和研讨会上的演讲、网页和向公众演讲广泛传播结果。

Land processes play a key role in the earth system, and their treatment is crucial for climate system modeling. The overall goal of this project is to improve the understanding and modeling of land processes in the new version of the Community Climate System Model (CCSM4.0) whose land component is the Community Land Model (CLM4.0). The investigators build on their significant progress under prior NSF support in addressing various interdisciplinary issues related to the land-atmosphere-ocean interface processes, as evidenced by the implementation in CLM4.0 of their improved parameterizations related to five different aspects of land processes, the implementation in the European Centre for Medium-Range Weather Forecasts (ECMWF) of their ocean skin temperature scheme, and the testing and implementation of their new formulations of land surface roughness lengths for momentum and heat in the National Centers for Environmental Prediction (NCEP) regional and global forecasting models.This project will address four questions through extensive in situ and satellite data analysis, process studies, and global modeling: a) How realistic are the land surface energy/water/carbon cycles and dynamic vegetation from CCSM4.0? b) How does CNDV (carbon and nitrogen cycling with dynamic vegetation) affect the energy/water/carbon cycles in CLM4.0 and how can its treatment be further improved? c) How does groundwater affect other land processes in CLM4.0 and how can its treatment be further improved? and d) How to use the insights gained from these efforts to better understand the uncertainties in the future climate projections of land processes from CCSM4.0?The broader impacts of the proposed work include: a) improving the understanding of energy/water/carbon cycles, improving the treatment of two important processes (i.e., groundwater and dynamic vegetation with carbon and nitrogen cycling), training students, and incorporating research results in teaching; b) upgrading and maintaining a computer cluster for interdisciplinary research; and c) broadly disseminating results through peer-reviewed publications, presentations at conferences and workshops, web page, and lectures to the general public.