Ran Limei, Pleim Jonathan, Song Conghe, Band Larry, Walker John T, Binkowski Francis S
United States Environmental Protection Agency, Research Triangle Park, North Carolina, USA.
Institute for the Environment, University of North Carolina at Chapel Hill, North Carolina, USA.
J Geophys Res Atmos. 2017 Feb 16;122(3):1930-1952. doi: 10.1002/2016JD025583.
A coupled photosynthesis-stomatal conductance model with single layer sunlit and shaded leaf canopy scaling is developed for the Pleim-Xiu land surface model (LSM) option in the meteorology and air quality modeling system - WRF/CMAQ (Weather Research and Forecast model and Community Multiscale Air Quality model). The photosynthesis-based model for the PX LSM (PX PSN) is implemented and evaluated in a diagnostic box model that has evapotranspiration and ozone deposition components taken directly from WRF/CMAQ. We evaluate PX PSN for latent heat (LH) estimation at four FLUXNET sites with different vegetation types and landscape characteristics and at one FLUXNET site with ozone flux measurements against the simple Jarvis approach used in the current PX LSM. Overall, the PX PSN simulates LH as well as the PX Jarvis approach. The PX PSN, however, shows distinct advantages over the PX Jarvis approach on grassland that likely results from its treatment of C and C plants for CO assimilation estimation. Simulations using Moderate Resolution Imaging Spectroradiometer (MODIS) LAI rather than LAI observations assess how the model would perform with the grid averaged data available in the Eulerian grid model (WRF/CMAQ). While MODIS LAI generally follows the seasonality of the observed LAI, it cannot capture the extreme highs and lows of the site measurements. MODIS LAI estimates degrade model performance at all sites but one site having old and tall trees. Ozone deposition velocity and ozone flux along with LH are simulated especially well by PX PSN as compared to significant PX Jarvis overestimation.
针对气象与空气质量建模系统-WRF/CMAQ（天气研究与预报模型及社区多尺度空气质量模型）中的Pleim-Xiu陆面模型（LSM）选项，开发了一种具有单层光照和阴影叶冠尺度的耦合光合作用-气孔导度模型。基于光合作用的PX LSM模型（PX PSN）在一个诊断箱模型中实现并进行评估，该诊断箱模型的蒸散和臭氧沉降组件直接取自WRF/CMAQ。我们在四个具有不同植被类型和景观特征的FLUXNET站点以及一个有臭氧通量测量值的FLUXNET站点，针对潜热（LH）估计对PX PSN进行评估，并与当前PX LSM中使用的简单Jarvis方法进行对比。总体而言，PX PSN对LH的模拟效果与PX Jarvis方法相当。然而，PX PSN在草地方面相较于PX Jarvis方法具有明显优势，这可能源于其在估算CO同化时对C3和C4植物的处理方式。使用中分辨率成像光谱仪（MODIS）叶面积指数（LAI）而非LAI观测值进行的模拟，评估了该模型在欧拉网格模型（WRF/CMAQ）中可用的网格平均数据情况下的表现。虽然MODIS LAI通常遵循观测到的LAI的季节性变化，但它无法捕捉到站点测量值的极端高低值。除了一个有古老高大树木的站点外，MODIS LAI估计值在所有站点都会降低模型性能。与PX Jarvis的显著高估相比，PX PSN对臭氧沉降速度、臭氧通量以及LH的模拟效果特别好。
