Collaborative Research: Parameterization of the Land-Surface Thermal and Moisture Heterogeneities

这项研究试图创建新的基本知识和计算机模型表示法，用于在陆地存在较大热量和湿度差异的地区进行大气模拟。研究人员将首先在犹他州西部沙漠的Playa上使用变革性的测量技术进行高分辨率的野外实验，那里的地形特征是相对均匀的粗糙表面，表面温度和土壤水分在空间和时间上都存在差异。这项野外试验的结果将被用来：(1)调查地表温度和湿度波动的时间/空间结构和(2)建立新的关系或修正来解释地表温度和湿度的差异。这项研究试图解决在更细的尺度上表示大气表层(ASL)中的不均匀所面临的挑战，因为空间平均不能提供均匀的场。野外数据将在犹他州普拉亚地区收集，该地区的地形相对平坦，大概粗糙度均匀；但温度和土壤湿度变化不定。这项研究的目标是使用在弱层结下收集的现场数据进行100米(M)分辨率的模拟，以开发新的大涡模拟(LES)参数化；预计改进20%。正在测试的主要假设是，即使在平坦的地形上，温度和湿度变化的空间结构也将在详细的通量测量中反映出来。结果将在大涡模拟和中尺度模式中进行检验。初步实验将在裸露、干燥的土壤条件下进行。更广泛的影响包括与公众的宣传和教育活动；以及改进数值天气预报模式的模式参数化的可能性。

This study seeks to create new fundamental knowledge and computer model representations for atmospheric simulations in regions where the land presents large thermal and moisture differences. The investigators will first conduct a high-resolution field experiment using transformative measurement techniques over the playa in Utah's West Desert, where the terrain is characterized by a relatively uniform rough surface with differences in both space and time of surface temperature and soil-moisture. Results from this field experiment will be used to: (1) investigate the time/space structure of the surface temperature and moisture fluctuations and (2) formulate new relationships or corrections that account for the differences in surface temperature and moisture.The research seeks to address the challenges in representing heterogeneities in the Atmospheric Surface Layer (ASL) at finer scales where spatial averaging cannot be used to provide homogeneous fields. Field data will be collected over the Utah Playa, an area with relatively flat terrain and, presumably, uniform roughness; but variable temperature and soil moisture. The goal of this study is to run simulations at 100-meter (m) resolution using field data collected under weak stratification to develop new Large Eddy Simulation (LES) parameterizations; with anticipated improvements of 20%. The main hypothesis being tested is that the spatial structure of temperature and moisture variations will be represented in the detailed flux measurements, even over flat terrain. Results will be tested in both LES and mesoscale models. Initial experiments will be conducted for bare, dry soil conditions. The broader impacts include outreach and education activities with the public; as well as the potential to improve model parameterizations for numerical weather prediction models.