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

该项目将对位于加拿大、阿拉斯加和西伯利亚北冰洋周围的几个环境北极变化研究（SEARCH）气候观测站的地表辐射、湍流和传导通量调制过程进行诊断分析，以调查地表能量收支（SEB）的年循环及其与大气和地表过程的耦合。必要时，将扩大现有的观测，以完成SEB的一整套测量。现有的或将获得的数据集中于下列科学问题：(i)什么过程支配北极陆地站点的SEB ？地形或海岸线等局部影响起什么作用？局部空间SEB异质性有多大？不同地点影响SEB的物理过程有何不同？这些SEB气候学与示巴站点所代表的海冰状况或格陵兰岛的气候状况相比如何？哪些SEB条款可能受到气候变化的影响，以及如何受到影响？（二）经典莫宁-奥布霍夫相似过程和非莫宁-奥布霍夫相似过程对北极陆地站点的热量通量和动量通量的相对贡献是什么？现有模型中地表湍流通量的整体算法是否适用于北极地区，还是需要开发新的算法？（iii）哪些SEB项决定土壤温度和活动层深度？在这些术语中，是什么机制导致了可变性？每个地点积雪的年循环如何影响SEB，从而影响温度状况？将把这些陆地地点的关键过程与其他研究人员在北极海冰和格陵兰岛所做的过程进行比较。这些协调的观测和分析提供了对北极大气-土壤相互作用过程的理解，这是罕见的，将引起科学界广泛的兴趣，包括遥感和建模界。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。对永久冻土能量通量调节的物理认识应有助于加强对气候变化情景下温室气体释放过程的潜力的认识。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教育和外展小组的合作，为北极气候系统教育做出贡献，从而促进教师发展和课堂上新气候主题的实施。

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.