Using a coupled lake model with WRF for dynamical downscaling
Using a coupled lake model with WRF for dynamical downscaling
复制标题
DOI：
10.1002/2014jd021785
复制
发表时间：
2014-06
期刊：
影响因子：
--
通讯作者：
Megan S. Mallard;C. Nolte;O. Bullock;T. Spero;J. Gula
中科院分区：
文献类型：
--
作者：
Megan S. Mallard;C. Nolte;O. Bullock;T. Spero;J. Gula
天气研究和预报（WRF）模型被用来缩小粗糙的再分析（国家环境预测中心-能源部大气模型相互比较项目再分析，以下简称R2）作为全球气候模型（GCM）的代理，以检查使用不同的方法来设置湖的温度和冰预测的2米的温度和降水在五大湖地区的后果。一个控制模拟进行湖泊表面温度和冰覆盖率内插从GCM代理。由于R2代表五个五大湖，只有三个网格点，冰的形成是不好的代表，与大，深湖冻结突然。不真实的温度梯度出现在粗尺度场附近没有内陆水点的区域，而更细网格上的湖泊温度是使用GCM代理的海洋点设置的。使用WRF与淡水湖（FLake）模型相结合，减少了湖泊温度的误差，并显着改善了冰层覆盖的时间和范围。总的来说，与控制模拟相比，WRF‐FLake提高了2 m温度的准确性，其中湖泊变量是从R2插值的。然而，FLake模拟湖泊温度的误差减小加剧了月降水量相对于对照运行的现有湿偏差，因为对照运行中从R2插值的错误的冷湖温度往往会抑制过度活跃的降水。
The Weather Research and Forecasting (WRF) model is used to downscale a coarse reanalysis (National Centers for Environmental Prediction–Department of Energy Atmospheric Model Intercomparison Project reanalysis, hereafter R2) as a proxy for a global climate model (GCM) to examine the consequences of using different methods for setting lake temperatures and ice on predicted 2 m temperature and precipitation in the Great Lakes region. A control simulation is performed where lake surface temperatures and ice coverage are interpolated from the GCM proxy. Because the R2 represents the five Great Lakes with only three grid points, ice formation is poorly represented, with large, deep lakes freezing abruptly. Unrealistic temperature gradients appear in areas where the coarse‐scale fields have no inland water points nearby and lake temperatures on the finer grid are set using oceanic points from the GCM proxy. Using WRF coupled with the Freshwater Lake (FLake) model reduces errors in lake temperatures and significantly improves the timing and extent of ice coverage. Overall, WRF‐FLake increases the accuracy of 2 m temperature compared to the control simulation where lake variables are interpolated from R2. However, the decreased error in FLake‐simulated lake temperatures exacerbates an existing wet bias in monthly precipitation relative to the control run because the erroneously cool lake temperatures interpolated from R2 in the control run tend to suppress overactive precipitation.