Continental-scale convection-permitting modeling of the current and future climate of North America
Continental-scale convection-permitting modeling of the current and future climate of North America
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DOI：
10.1007/s00382-016-3327-9
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发表时间：
2017-07-01
期刊：
影响因子：
4.6
通讯作者：
Yates, David
中科院分区：
文献类型：
--
作者：
Liu, Changhai;Ikeda, Kyoko;Yates, David
地形降水量和积雪为美国西部提供了重要的水资源，而对流降水占美国东部年度降水的很大一部分，因此，水管理者对在气候变化下的命运非常感兴趣。但是，以前对美国水周期变化的研究是通过相对粗糙的气候模型进行的，导致对关键物理过程的潜在虚假陈述。本文介绍了高分辨率的气候变化模拟引起的，该模拟允许对流并通过天气研究和预测（WRF）模型在北美大部分地区的4公里网格间距上解决中尺度的地形。进行了两个13年的模拟，包括回顾性仿真（2000年10月至2013年10月至9月），具有ERA-Interim的初始和边界条件以及未来的气候灵敏度模拟，并通过添加CMIP5 Ensemble-Ensemble-进行了修改的重新分析衍生的初始和边界条件。平均高端排放场景气候变化。回顾性模拟是通过针对Snowpack遥测（Snotel）和网格观测数据集的合奏来评估的。它显示了总体表现良好的表现，可以捕获年度/季节/季节性降水和表面温度气候，除了美国中部夏季干燥和温暖的偏见外，WRF季节性降水与山区范围相比的Snotel观察一致。 ，对模型对西方季节性降雪和积雪的估计提供了信心。在大多数连续美国（CONUS），以温暖和炎热的边界条件强迫的未来气候模拟增强了年度和冬季春季 - 季节性降水（CONUS），但抑制了美国中部的夏季降水量，WRF下降的气候变化提供了一个。高分辨率数据集（即高分辨率圆锥形缩减，HRCONUS），用于研究区域的一种可能情况气候变化和影响。
Orographic precipitation and snowpack provide a vital water resource for the western U.S., while convective precipitation accounts for a significant part of annual precipitation in the eastern U.S. As a result, water managers are keenly interested in their fate under climate change. However, previous studies of water cycle changes in the U.S. have been conducted with climate models of relatively coarse resolution, leading to potential misrepresentation of key physical processes. This paper presents results from a high-resolution climate change simulation that permits convection and resolves mesoscale orography at 4-km grid spacing over much of North America using the Weather Research and Forecasting (WRF) model. Two 13-year simulations were performed, consisting of a retrospective simulation (October 2000-September 2013) with initial and boundary conditions from ERA-interim and a future climate sensitivity simulation with modified reanalysis-derived initial and boundary conditions through adding the CMIP5 ensemble-mean high-end emission scenario climate change. The retrospective simulation is evaluated by validating against Snowpack Telemetry (SNOTEL) and an ensemble of gridded observational datasets. It shows overall good performance capturing the annual/seasonal/sub-seasonal precipitation and surface temperature climatology except for a summer dry and warm bias in the central U.S. In particular, the WRF seasonal precipitation agrees with SNOTEL observations within a few percent over the mountain ranges, providing confidence in the model's estimation of western U.S. seasonal snowfall and snowpack. The future climate simulation forced with warmer and moister perturbed boundary conditions enhances annual and winter-spring-fall seasonal precipitation over most of the contiguous United States (CONUS), but suppresses summertime precipitation in the central U.S. The WRF-downscaled climate change simulations provide a high-resolution dataset (i.e., High-Resolution CONUS downscaling, HRCONUS) to the community for studying one possible scenario of regional climate changes and impacts.