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

该项目将在加拿大、阿拉斯加和西伯利亚的北冰洋周围的几个环境北极变化(SEARCH)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)的年度循环及其与大气和地面过程的耦合。如有必要，将扩大现有观测值以完成SEB测量套件。现有或将获得的数据集中在以下科学问题上：(1)管理北极陆地站点的SEB的过程是什么？地形或海岸线等局部影响起到什么作用？局部空间SEB异质性有多大？影响SEB的物理过程在不同站点之间有何不同？这些SEB气候与Sheba站点所代表的海冰系统或格陵兰岛的海冰系统相比如何？哪些SEB术语可能会受到气候变化的影响？如何影响？(2)经典的Monin-Obukhov相似(MOS)过程和非MOS过程对北极陆地站点的热量和动量通量的相对贡献是什么？模式中地表湍流通量的现有整体算法是否适用于北极地区，或者是否有必要开发新的算法？(3)哪些SEB术语决定了土壤温度和活跃层深度？在这些术语中，是什么机制推动了可变性？每个站点的年积雪周期如何影响SEB，从而影响温度机制？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过程进行比较。这些协调一致的观测和分析提供了对北极大气-土壤相互作用的过程了解，这是罕见的，将引起包括遥感和模型界在内的广泛科学界的兴趣。由此产生的数据和分析很可能成为各种学科未来模型研究的关键数据来源。对多年冻土能量通量调制的实际了解应有助于更好地了解气候变化情景下温室气体排放过程的潜力。该项目利用与北极地区(美国、加拿大和俄罗斯)研究人员的机构间和国际合作，并将通过与CIRES教育和外联小组的伙伴关系，促进北极气候系统的教育，导致教师发展和新气候主题的课堂实施。

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.