不同湖泊模式对青藏高原典型湖泊适用性对比研究

Comparative Study on Applicability of Different Lake Models to Typical Lakes in Qinghai-Tibetan Plateau

一维湖泊模式是青藏高原湖泊研究的主要手段之一,但不同湖泊模式在青藏高原适用性及其差异依然不够明确。利用MODIS地表温度数据、青藏高原鄂陵湖站点观测的气象数据、湖温及湖面能量数据,驱动、评估和对比了目前应用最为广泛的两个一维湖泊模式Freshwater Lake Model(FLake)和Community Land Model version 4.5(CLM4.5)中耦合的湖泊模块在青藏高原典型湖泊的适用性。结果表明:FLake和CLM模式均能较好的对湖泊热力状况进行模拟,CLM模式对于湖表面温度和湖泊内部不同深度的温度模拟优于Flake模式,净辐射和能量的累积也是CLM模式的模拟值更接近观测值。造成Flake模式模拟偏差更大的原因与模式中计算感热、潜热的摩擦速度有关,观测的摩擦速度均值为0.22 m·s-1,CLM模式中的摩擦速度与观测值接近,为Flake模式的1.5倍,将CLM模式中的摩擦速度替换到Flake模式中后模拟结果有明显的改善。

The one-dimensional lake model is one of the main means of lake research in the Qinghai-Tibetan Plateau,but the applicability and differences of different lake models in the Qinghai-Tibetan Plateau are still not clear enough.This paper uses the MODIS Surface Temperature data and observations of lake temperature and lake energy observed at the Ngoring in the Tibetan Plateau to drive,evaluate and compare two most widely used one-dimensional lake model:Freshwater Lake Model(FLake)and Community Land Surface model version 4.5(CLM4.5)coupled lake module,applicability of typical lake in the Tibetan Plateau.The results show that both FLake and CLM can better simulate thermal condition of the lake,CLM simulates the lake surface temperature and the temperature of different depths of the lake is better than that of the FLake.CLM simulates the net radiation and the cumulative net energy flux is also close to the observations.The reason why FLake is more deviated from the observed value than the CLM is related to the friction velocity used to calculate the latent heat and sensible heat.The observed friction velocity average is 0.22 m·s-1,and the friction velocity in the CLM is close to the observed value about 1.5 times of FLake,after replacing the friction velocity in the CLM into FLake,the simulation results were significantly improved.