Investigation of diurnal land-atmosphere interactions in snow-dominated mountainous terrain

山区在水文方面具有重要意义，因为据估计，世界上六分之一以上的人口的大部分水资源来自含有季节性融雪的盆地。事实上，在许多半干旱地区，城市和农业地区几乎完全依赖该地区山区的融雪径流。 尽管它们很重要，但这些复杂地形的地区通常使用区域气候模式（RCMs）模拟得很差。提高对复杂地形下陆-气相互作用的认识是改进区域气候模型在山区的预测的关键一步。本项目的主要目标是研究复杂地形下陆-气相互作用，重点是雪起重要作用的地区。该项目将利用2002-2003年在科罗拉多北方进行的冷地过程实地实验（CLPX）的大量数据来解决科学问题。拟议的研究将使用分层的方法来调查雪过程和耦合的陆-气相互作用在一系列的自然地理特征。这种方法将允许不仅在形貌中而且在表面状态（例如，雪，雪），辐射通量和湍流通量，以及它们对三维边界层流动和云形成的影响。将在以下领域处理若干科学问题：对过程的理解（雪和耦合的陆-气过程）、空间变异性（作为自然地理学的一个功能）及其如何影响陆-气相互作用、地表状态/通量的不确定性以及这种不确定性如何在耦合系统内传播。这项工作将推动有关山区地形过程的知识发展，并与许多相关学科交叉联系，包括积雪水文学、山区气象学、边界层过程和计算流体动力学。该项目更广泛的影响源于了解陆地的重要性山区地形中的大气相互作用，以便改进大尺度气候模型中状态和通量的预测，用于近期预报和气候变化分析。据推测，在这个项目中获得的洞察力将最终证明是有用的，以改善亚网格尺度参数化在大规模模型在山区地形，这将是有用的，在研究界的广泛群体。

Mountain regions are hydrologically important given the estimate that over one-sixth of the world's population derive the majority of their water resources from basins containing seasonal snowmelt. In fact, in many semi-arid regions, urban and agricultural areas rely almost exclusively on snowmelt runoff from regional mountainous areas. Despite their importance, these regions of complex terrain are often poorly simulated using regional climate models (RCMs). Improvement in understanding land-atmosphere interactions in complex terrain is a key step toward improving the predictions of RCMs in montane regions.The primary objective of this project is to study land-atmosphere interactions in complex terrain with an emphasis on those areas where snow plays a significant role. The project will address science questions using the wealth of data from the Cold Land Processes Field Experiment (CLPX) site that took place in northern Colorado (2002-2003). The proposed research will use a hierarchical approach to investigate snow process and coupled land-atmosphere interactions across a range of physiographic characteristics. Such an approach will allow for explicit representation of surface heterogeneity in not only topography, but in surface states (e.g., snow, albedo), radiative fluxes, and turbulent fluxes, as well as their impacts on 3D boundary layer flow and cloud formation. Several science questions will be addressed in the areas of process understanding (both snow and coupled land-atmosphere processes), spatial variability (as a function of physiography) and how it impacts land-atmosphere interactions, and uncertainty in surface states/fluxes and how this uncertainty propagates within the coupled system. This work will move the state of knowledge regarding processes in mountainous terrain forward with cross-connections to many related disciplines including snow hydrology, mountain meteorology, boundary-layer processes, and computational fluid dynamics.The broader impacts of this project derive from the importance of understanding land-atmosphere interactions in mountainous terrain in order to yield improved predictions of states and fluxes in large-scale climate models, both for near-term forecasts and climate change analysis. It is hypothesized that the insight gained in this project will ultimately prove useful for improving sub-grid scale parameterizations in large-scale models in mountainous terrain, which would be useful to a broad group in the research community.