SI2-SSI: Lightweight Infrastructure for Land Atmosphere Coupling (LILAC): A Tool for Easy Integration of the Community Land Model into Multiple Modeling Systems

地球上的每个人都生活在地面上，因此大气和陆地表面之间的相互作用是气候系统的一个至关重要的部分，了解这些相互作用对于天气预测，农业和城市水资源管理非常重要。地球系统模型（Earth System Models，简称ESM）是一个复杂的软件系统，代表复杂的自然系统。它们是诊断、理解和预测大气、海洋和陆地生态系统相互作用和变化的重要工具。该项目将开发一个新的软件系统，用于耦合地球系统模型的陆地和大气部分，特别是用于世界上使用最广泛的气候模型：社区地球系统模型。新系统将能够模拟地面附近的气候，包括植被土地和空气之间的热量、水和碳的交换，以及水流和土壤湿度。作为CESM的一个官方支持的组成部分，它将被世界各地成千上万的科学家和学生使用。与其前身不同，新系统将能够以高分辨率模拟小区域，用于重要应用和测试。该项目还将支持计算机科学研究生以及帮助开发和测试软件的学者和科学家。PI将通过一系列研讨会和网络研讨会以及专业协会和出版物吸引全球软件开发人员和用户社区。PI认识到妇女和少数民族在计算机科学和大气科学方面的长期代表性不足。为了解决这个问题，他们将为来自代表性不足群体（URG）的中学生举办计算机科学夏令营，并与K-12教师的现有气候课程，K-12学校的科学推广以及PI运营的非常成功的REU网站密切合作。该项目将大大提高现有最广泛使用的气候模型的可用性。全球数百名开发人员和数千名用户将受益于该模型更大的灵活性和用例。社区陆地模型将与更广泛的大气代码相结合，用于天气预报、空气质量应用和气候预测，以提高世界各地人民的生活质量。 社区地球系统模型CESM）是一个独特的开放式ESM，拥有全球数百名开发人员和数千名用户的分布式社区。与其他ESM相比，CESM是“气候模型中的Linux”。“CESM的陆地部分，即社区土地模型（CLM），有自己充满活力和多样化的用户和开发社区，支持建立一个特别全面的陆地系统模型。它包括一系列丰富的过程，使人们能够研究自然陆地生态系统和人类管理的土地影响气候和天气以及受气候和天气影响的物理、生物和化学过程。CESM只能在全球范围内运行，但人们普遍有兴趣将CLM与其他高分辨率大气模型相结合，以研究存在于小空间尺度和大空间尺度之间的具有挑战性的科学问题。然而，这项研究的一个障碍是，CLM不能很容易地耦合到替代大气模型。CLM耦合接口仅支持与CESM耦合基础设施（CPL 7）的通信，这对大气组件如何与CLM通信提出了严格的要求。一个关键的要求是大气模型在耦合发生之前完成一个完整的时间步长。这一要求需要对许多大气模型进行重大重构，以使它们通过CPL 7耦合到CLM。此外，构建和配置CLM的工具目前很难在CESM环境之外使用。由于所有这些原因，CLM从未以可持续的方式与替代大气模型相结合。科罗拉多州立大学（CSU）与国家大气研究中心（NCAR）合作，提出开发一个轻型基础设施的土地-大气耦合（LILAC），将显着简化耦合CLM替代大气模型。LILAC耦合器和相关的CLM工具链的精简和简化建议将使用原型高分辨率大气模型CSU SAM云解析模型进行开发和测试，并将扩展用于任何目标大气模型。LILAC和相关工具的开发将使许多团体能够将CLM与其大气模型相结合，并在新的最先进的CLM模型版本可用时快速更新。这将开辟陆地-大气研究的新途径，可以利用CLM的地球物理和地球化学能力与高分辨率大气模型的优势。它将能够研究各种尺度上的陆地-大气相互作用，从塔和飞机数据的分辨率模拟到云分辨率模拟，以研究小尺度陆地特征，如山坡，山谷，湖泊，河流，城市地区和农场合谋改变地面气候和大气边界层特征，土地覆盖和土地利用变化对天气和气候影响的规模模拟。该项目得到了计算机信息科学与工程局高级网络基础设施办公室和极地计划办公室以及大气和地球空间科学司的支持&。地球科学理事会。

Everyone on Earth lives on the ground, so interactions between the atmosphere and the land surface are a critically important part of the climate system and understanding these interactions is important for weather prediction, agriculture, and urban water management. Earth System Models (ESMs) are complex software systems representing complex natural systems. They are critical tools for diagnosing, understanding, and predicting interactions and change in the atmosphere, oceans, and land ecosystems. This project will develop a new software system for coupling the land and atmosphere components of Earth System models, specifically for the most widely-used climate model in the world: the Community Earth System Model (CESM). The new system will be capable of simulating climates near the ground including exchanges of heat, water ,and carbon between vegetated land and the air as well as streamflow and soil moisture. As an officially-supported component of CESM, it will be used by thousands of scientists and students around the world. Unlike its predecessor, the new system will be able to simulate small areas at high resolution for important applications and testing. The project will also support a computer science graduate student as well as academics and scientists who will help develop and test the software. The PIs will engage a global community of software developers and users through a series of workshops and webinars as well as through professional societies and publications. The PIs recognize the chronic under-representation of women and ethnic minorities in both Computer Science and Atmospheric Science. To address this, they will host a computer science summer camp for middle school students from underrepresented groups (URGs), and close collaboration with existing climate courses for K-12 teachers, science outreach in K-12 schools, and a highly successful REU-Site operated by the PI. This project will dramatically improve the usability of the most widely-used climate model in existence. Hundreds of developers and thousands of users around the world will benefit from the far greater flexibility and use cases for this model. The Community Land Model will be coupled to a much greater range of atmospheric codes for weather prediction, air quality applications, and climate projections that enhance the quality of life for people everywhere. The Community Earth System Model CESM) is a uniquely open ESM with a distributed community of hundreds of developers and thousands of users around the world. Compared to other ESMs, CESM is the "Linux of climate models." The land component of CESM, the Community Land Model (CLM), has its own vibrant and diverse user and development community, which has supported the construction of a particularly comprehensive terrestrial system model. It includes a rich array of processes that enable examination of the physical, biological, and chemical processes by which natural terrestrial ecosystems and human-managed land affect and are affected by climate and weather. CESM can only be run globally, but there is widespread interest in coupling CLM to alternative high-resolution atmosphere models to study the challenging scientific problems that exist at the interface between small and large spatial scales. A barrier to this research, however, is that CLM cannot readily be coupled to alternative atmosphere models. The CLM coupling interface only supports communication with the CESM coupling infrastructure (CPL7), which imposes strict requirements on how an atmospheric component can communicate with CLM. One key requirement is for the atmosphere model to complete a full time step before coupling can occur. This requirement necessitates significant refactoring of many atmospheric models in order for them to couple to CLM via CPL7. In addition, the tools to build and configure CLM are currently difficult to use outside of the CESM context. For all of these reasons, CLM has never been coupled to alternative atmospheric models in a sustainable fashion. Colorado State University (CSU), in partnership with the National Center for Atmospheric Research (NCAR), proposes to develop a Lightweight Infrastructure for Land-Atmosphere Coupling (LILAC) that will significantly simplify the coupling of CLM to alternative atmospheric models. The LILAC coupler and the associated proposed streamlining and simplification of the CLM tool chain will be developed and tested with a prototype high-resolution atmosphere model, the CSU SAM Cloud Resolving Model, and will be extended for use with any arbitrary Target Atmosphere Model. The development of LILAC and associated tools will enable numerous groups to couple CLM to their atmospheric models, and to quickly update to new state-of-the-art CLM model versions as they become available. This will open up new avenues of land-atmosphere research that can exploit the combined biogeophysical and biogeochemical capabilities of CLM with the strengths of high-resolution atmosphere models. It will enable research into land-atmosphere interactions across a variety of scales, ranging from turbulence-resolving simulations of tower and aircraft data to cloud-resolving simulations to study how small-scale land features such as hillslopes, valleys, lakes, rivers, urban areas and farms conspire to alter surface climate and atmospheric boundary layer characteristics to continental-scale simulations of the impact of land cover and land use change on weather and climate.This project is supported by the Office of Advanced Cyberinfrastructure in the Directorate for Computer & Information Science and Engineering and the Office of Polar Programs and Division of Atmospheric and Geospace Science in the Directorate for Geosciences.