Evaluation of CORDEX regional climate models in simulating temperature and precipitation over the Tibetan Plateau
Evaluation of CORDEX regional climate models in simulating temperature and precipitation over the Tibetan Plateau
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DOI：
10.1080/16742834.2018.1451725
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发表时间：
2018-04
影响因子：
2.3
通讯作者：
Donglin Guo;Jianqi Sun;Entao Yu
中科院分区：
文献类型：
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作者：
Donglin Guo;Jianqi Sun;Entao Yu
摘要 由于区域气候模型（RCM）高分辨率的优势，通常被认为是研究青藏高原气候的一种有前途的方法。虽然以前的研究主要集中在单个 RCM 模拟上，但在这里，使用站和网格观测来模拟青藏高原表面气温和降水变化，对协调区域气候降尺度实验中的多个 RCM 进行了评估。结果表明：(1) 所有 RCM 始终显示相似的空间模式，但与台站观测相比，温度（降水）气候学存在平均冷（湿）偏差。 RCM 无法重现观测到的温度和降水趋势的空间模式，并且平均而言产生比观测结果更大的温度趋势和更小的降水趋势。相对于单个模型，多模型集合总体上在模拟温度和降水方面产生了更好的趋势。同时，RegCM4 呈现了五种 RCM 中最合理的模拟趋势。 (2)不同RCM的模拟定量结果存在较大差异，表明青藏高原气候模拟存在较大的模型依赖性。这意味着，当使用单独的 RCM 来估计青藏高原气候变化的幅度时，可能需要谨慎。 (3) 多模式集合预测，在RCP4.5和RCP8.5情景下，2016-35年气温（降水）较1986-2005年分别上升1.38±0.09℃（0.8%±4.0%）和1.77±0.28℃（7.3%±2.5%）。这项研究的结果加深了我们对RCM在多RCM视角下青藏高原气候变化研究中的适用性的理解。
Abstract Using a regional climate model (RCM) is generally regarded as a promising approach in researching the climate of the Tibetan Plateau, due to the advantages provided by the high resolutions of these models. Whilst previous studies have focused mostly on individual RCM simulations, here, multiple RCMs from the Coordinated Regional Climate Downscaling Experiment are evaluated in simulating surface air temperature and precipitation changes over the Tibetan Plateau using station and gridded observations. The results show the following: (1) All RCMs consistently show similar spatial patterns, but a mean cold (wet) bias in the temperature (precipitation) climatology compared to station observations. The RCMs fail to reproduce the observed spatial patterns of temperature and precipitation trends, and on average produce greater trends in temperature and smaller trends in precipitation than observed results. The multi-model ensemble overall produces superior trends in both simulated temperature and precipitation relative to individual models. Meanwhile, RegCM4 presents the most reasonable simulated trends among the five RCMs. (2) Considerable dissimilarities are shown in the simulated quantitative results from the different RCMs, which indicates a large model dependency in the simulation of climate over the Tibetan Plateau. This implies that caution may be needed when an individual RCM is used to estimate the amplitude of climate change over the Tibetan Plateau. (3) The temperature (precipitation) in 2016–35, relative to 1986–2005, is projected by the multi-model ensemble to increase by 1.38 ± 0.09 °C (0.8% ± 4.0%) and 1.77 ± 0.28 °C (7.3% ± 2.5%) under the RCP4.5 and RCP8.5 scenario, respectively. The results of this study advance our understanding of the applicability of RCMs in studies of climate change over the Tibetan Plateau from a multiple-RCM perspective.