CLM3和SHAW模式在青藏高原中部NMQ站的模拟研究

利用那曲地区NMQ站2010年11月1日至2011年7月26日的观测资料作为通用陆面过程模式CLM3.0和水热耦合模式SHAW的大气强迫, 在青藏高原中部季节冻土区进行了单点模拟研究.在参照观测资料的基础上, 对两个陆面模式的模拟结果对比发现: SHAW模式和CLM3.0模式模拟的向上短波辐射和向下长波辐射值基本相近或重合, 但两个模式均未考虑新雪存在对向上短波辐射的影响, 以及青藏高原日冻融循环过程中潜热释放对向上长波辐射的影响.此外, SHAW模式和CLM3.0模式均能模拟各层土壤温度的逐日变化, 均是上层土壤的模拟效果较下层好; 相比SHAW模式, CLM3.0各层土壤温度的模拟值更接近于实测值.对土壤含水量的模拟而言, 60 cm以上(包括60 cm)SHAW模式和CLM3.0模式各有其优缺点, 60 cm以下SHAW模式的模拟结果要好于CLM3.0, 尤其是土壤冻结和消融时段的模拟结果.

Simulation Studies of CLM3 and SHAW at NMQ Station on the Central Tibetan Plateau

Observation data at NMQ Station was used as the atmospheric forcing data of the general land surface processes model (Community Land Model, CLM3.0) and Simultaneous Heat and Water (SHAW). Single point simulation studies were carried out for the seasonal frozen soil regions of the central Tibetan Plateau. Comparing the observed and simulated values from the two land surface processes models, it is found that simulation values of upward shortwave and upward long wave radiations from SHAW model are similar to those from CLM3.0. However, both models have not considered the effects of upward shortwave radiation from new snow and of upward long wave radiation due to latent heat release in daily freeze-thaw cycle. In addition, the daily variation of ground temperature has been well simulated by the SHAW model and CLM3.0 mode, but for the upper layers is better than for the lower layers. As compared with SHAW mode, the simulation value from CLM3.0 is closer to the measured value. For simulating soil water content, as the depth lees than 60 cm (including 60 cm), SHAW model and CLM3.0 mode all have their advantages and disadvantages, but as the depth more than 60 cm, the SHAW model is better than CLM3.0, especially for the process of soil freeze-thaw.