An intercomparison of regional climate model data for hydrological impact studies in Denmark
An intercomparison of regional climate model data for hydrological impact studies in Denmark
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DOI：
10.1016/j.jhydrol.2009.11.014
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发表时间：
2010-01
影响因子：
6.4
通讯作者：
L. V. Roosmalen;J. Christensen;M. Butts;K. Jensen;J. Refsgaard
中科院分区：
文献类型：
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作者：
L. V. Roosmalen;J. Christensen;M. Butts;K. Jensen;J. Refsgaard
近年来，利用高分辨率区域气候模式（RCM）来研究气候变化的水文影响，由于当地气候的代表性得到了改善。然而，应用程序并不简单，因为大多数rcm都受到相当大的系统错误的影响。在本研究中，利用RCM HIRHAM4预估的气候变化数据生成了2071-2100年期间丹麦降水、温度和参考蒸散的气候情景时间序列，用于水文影响评估。将当前时期（1961-1990年）的RCM输出与观测数据集进行比较，并对未捕获降水和湿润损失进行校正，以量化系统模式误差。采用增量变化法来处理这些偏差。出现了一个问题，即气候变化信号的可变性有多大，因为它们受到强迫GCM、排放情景和RCM选择的影响。在这里，我们重点讨论了RCM的选择和提高水平分辨率的效果。HIRHAM4输出与7个类似rcm的比较表明，对于降水，HIRHAM4模式与集合中的任何rcm一样具有代表性。对于温度，分辨率为50km的HIRHAM4模拟的温度高于其他模式，而分辨率为12km的HIRHAM4在其他模式的范围内。本研究强调了与在水文研究中使用RCM数据有关的一些不确定性，这有助于气候变化的水文影响范围，主要源于模拟降水量。
The use of high-resolution regional climate models (RCM) to examine the hydrological impacts of climate change has grown significantly in recent years due to the improved representation of the local climate. However, the application is not straightforward because most RCMs are subject to considerable systematic errors. In this study, projected climate change data from the RCM HIRHAM4 are used to generate climate scenario time series of precipitation, temperature, and reference evapotranspiration for the period 2071–2100 for hydrological impact assessments in Denmark. RCM output for the present-day period (1961–1990) are compared to an observational data set, with precipitation corrected for undercatch and wetting losses, to quantify systematic model errors. A delta change method is applied to cope with these biases. A question arises as to how variable the climate change signals are, as they are influenced by the forcing GCM, the emissions scenario, and the choice of RCM. Here, we focus on the choice of RCM and the effect of increasing horizontal resolution. A comparison of HIRHAM4 output to seven similar RCMs showed that for precipitation the HIRHAM4 model is as representative as any of the RCMs in the ensemble. For temperature HIRHAM4 at 50km resolution simulates higher temperatures than the other RCMs, while HIRHAM4 at 12km resolution is within the range of the other models. This study highlights some of the uncertainties related to the use of RCM data in hydrological studies, which contribute to a range in hydrological effects of climate change, mainly originating from simulated precipitation amounts.