Surface Energy Budgets at Arctic Terrestrial Sites: Quantifying Energy and Momentum Fluxes and their Associated Physical Processes

该项目将在位于加拿大、阿拉斯加和西伯利亚的北冰洋周围的几个北极环境变化研究（ECOC）气候观测站对调制地表辐射、湍流和传导通量的过程进行诊断分析，以调查地表能量收支（SEB）的年度周期及其与大气和地表过程的耦合。如有必要，将增加现有的观测结果，以完成SEB测量套件。现有数据或将获得数据，以侧重于以下科学问题：（一）北极陆地站点的SEB受哪些过程的支配？地形或海岸线等局部效应发挥什么作用？局部空间SEB异质性有多大？影响SEB的物理过程在不同地点之间有何不同？这些SEB气候学如何与SHEBA站点或格陵兰代表的海冰状况进行比较？哪些SEB术语可能会受到气候变化的影响，以及如何影响？(ii)经典的莫宁-奥布霍夫相似性（MOS）和非MOS过程对北极陆地站点热量和动量通量的相对贡献是什么？现有的散装算法的表面湍流通量的模型适用于北极网站或新的开发是必要的？(iii)哪些SEB项决定土壤温度和活动层深度？是什么机制导致了这些术语的可变性？每个地点积雪的年周期如何影响SEB，从而影响温度状况？这些陆地站点的关键过程将与其他研究人员在北极海冰和格陵兰岛上所做的研究进行比较。这些协调一致的观测和分析提供了对北极大气-土壤相互作用过程的了解，这是罕见的，将引起包括遥感和建模界在内的广大科学界的兴趣。由此产生的数据和分析将可能成为未来各种学科模型研究的关键数据来源。从物理上了解永冻层能量通量的调节，应有助于更好地了解气候变化情景中温室气体释放过程的潜力。该项目利用了与北极地区（美国，加拿大和俄罗斯）调查人员的机构间和国际合作，并将通过与CIRES教育和推广小组的合作关系，为北极气候系统的教育做出贡献，从而促进教师发展和课堂实施新的气候主题。

This project will perform diagnostic analyses of the processes modulating the surface radiative, turbulent, and conductive fluxes at several Study of Environmental Arctic Change (SEARCH) climate observatories located around the Arctic Ocean in Canada, Alaska, and Siberia to investigate the annual cycle of the surface energy budget (SEB) and its coupling to atmospheric and surface processes. Where necessary, existing observations will be augmented to complete the suite of SEB measurements. Data exist or will be obtained to focus on the following scientific questions: (i) What processes govern the SEB at Arctic terrestrial sites? What role do local effects such as terrain or coastlines play? How large is the local spatial SEB heterogeneity? How do the physical processes affecting the SEB differ among the various sites? How do these SEB climatologies compare with a sea-ice regime as represented by the SHEBA site, or with that of Greenland? Which SEB terms might be impacted by climate change and how? (ii) What is the relative contribution from classical Monin-Obukhov similarity (MOS) and non-MOS processes to heat and momentum fluxes at Arctic terrestrial sites? Are existing bulk algorithms for surface turbulent fluxes in models applicable at Arctic sites or is the development of new ones necessary? (iii) Which SEB terms determine the soil temperatures and the active layer depth? What mechanisms force variability in those terms? How does the annual cycle of snow cover at each site influence the SEB and thus temperature regimes?Comparisons of key processes at these terrestrial sites will be made to those done by other researchers over Arctic sea ice and on Greenland. These coordinated observations and analyses, which provide process understanding of atmospheric-soil interactions in the Arctic, are rare and will be of interest to a broad spectrum of the scientific community, including the remote sensing and modeling communities. The resulting data and analyses will likely be key data sources for future model studies in a variety of disciplines. Physical understanding of the modulation of energy fluxes to permafrost should provide enhanced understanding of the potential for the greenhouse gas release process in climate-change scenarios. The project takes advantage of interagency and international collaborations with investigators located around the Arctic (USA, Canada, and Russia) and will contribute to education on Arctic climate systems through partnership with the CIRES Education and Outreach group, leading to teacher development and classroom implementation of new climate topics.