Comment on “The added value to global model projections of climate change by dynamical downscaling: A case study over the continental U.S. using the GISS‐ModelE2 and WRF models” by Racherla et al.
Comment on “The added value to global model projections of climate change by dynamical downscaling: A case study over the continental U.S. using the GISS‐ModelE2 and WRF models” by Racherla et al.
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DOI：
10.1002/2013jd019945
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发表时间：
2014-04
期刊：
影响因子：
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通讯作者：
R. Laprise
中科院分区：
文献类型：
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作者：
R. Laprise
Racherla等人[2012年，以下简称RSF 12]分析了1968-1978年和1995-2005年两个十年，将全球和区域气候模式模拟的时间片与观测分析进行比较，特别是验证模式捕捉美国11个地区20年来季节平均地表气温和降水变化的能力。模拟来自戈达德空间研究所（GISS）-ModelE 2耦合大气-海洋全球气候模式（AOGCM），在2° × 2.5°网格上集成，并将人为和自然强迫与气相、硫酸盐、黑碳、硝酸盐和二次有机气溶胶化学的详细表示结合起来。动态降尺度是用天气研究和预报大气区域气候模式的一个版本实现的，该模式在北美区域内集成在一个45公里的网格上，在东西和南北方向分别有216乘126个单元。WRF是由大气场和海表面温度（SST）和海冰浓度（SIC）从GISSModelE 2模拟驱动的。WRF模型不包括人为气溶胶强迫，也不包括土地利用变化。RSF 12发现，在再现过去37年来观测到的温度和降水趋势方面，他们的单一AOGCM模拟技术非常有限，而且使用更高分辨率的RCM进行动态降尺度的改进非常小。
Racherla et al. [2012, hereinafter RSF12] analyzed two decades, 1968–1978 and 1995–2005, comparing time slices of global and regional climate models simulations with analyses of observations and in particular verifying the skill of models at capturing the changes in seasonal mean surface air temperature and precipitation between the two decades over 11 regions of the U.S. The global simulation is from the Goddard Institute for Space Studies (GISS)-ModelE2 coupled atmosphere-ocean global climate model (AOGCM), integrated on a 2° by 2.5° grid and incorporating anthropogenic and natural forcings with a detailed representation of gas phase, sulfate, black carbon, nitrate, and secondary organic aerosol chemistry. Dynamical downscaling was achieved with a version of the Weather Research and Forecasting (WRF) atmospheric regional climate model (RCM), integrated over a North American domain on a 45 km mesh with 216 by 126 cells in the west-east and south-north directions, respectively. WRF was driven by atmospheric fields and sea surface temperature (SST) and sea ice concentrations (SIC) from the GISSModelE2 simulation. The WRF model did not include anthropogenic aerosol forcings nor land use changes. RSF12 found very modest skill at reproducing the observed trend of temperature and precipitation over the past 37 years for their single AOGCM simulation, and very little improvement if any from dynamical downscaling with the higher-resolution RCM.