School of GeoSciences, The University of Edinburgh, High School Yards, Infirmary St, Edinburgh, EH1 1LZ, United Kingdom.
School of GeoSciences, The University of Edinburgh, High School Yards, Infirmary St, Edinburgh, EH1 1LZ, United Kingdom.
Sci Total Environ. 2019 Mar 1;654:378-392. doi: 10.1016/j.scitotenv.2018.11.098. Epub 2018 Nov 10.
Malawi is highlighted as one of the most vulnerable countries in the world to the effects of climate change. The large uncertainty around future climate change in the region remains a barrier to adaptation planning. Despite this high potential vulnerability, relatively little research has gone into determining how well available models represent this country's climate. This work therefore evaluates the ability of existing General Circulation Models (GCMs) and Regional Climate Models (RCMs) to hindcast climatic variables in Malawi at a resolution appropriate for climate change impact assessment and adaptation planning. We focus on monthly precipitation rate, and mean, maximum and minimum surface air temperature. This assessment compares available observed datasets against the outputs of six ERA-interim driven RCMs and 21 GCM-driven RCMs from the Coordinated Regional Climate Downscaling Experiment (CORDEX) initiative, and the 11 GCMs which form their boundary conditions. It was found that the performance of the RCMs is highly influenced by their boundary conditions. None of the individual or ensemble RCMs or GCMs assessed in this paper correlate well with the observed datasets for any of the assessed climatic variables. While, they do simulate the trending change in temperature variables well, the simulated outputs for precipitation are highly divergent. Based on these findings we suggest that either the ensemble RCMs or ensemble GCMs would be suitable for understanding projected temperature trends, with the RCMs providing better spatial resolution. However, none of the assessed models provide certainty over future precipitation trends in Malawi. As such we suggest that impact assessments and adaptation plans in Malawi will need to be designed and tested against a range of future precipitation scenarios. To improve modelling for Malawi it is recommended that regional climate models be improved for higher spatial resolution and inclusion of the impacts from large water bodies, including Lake Malawi.
马拉维是世界上受气候变化影响最脆弱的国家之一。该地区对未来气候变化的巨大不确定性仍然是适应规划的一个障碍。尽管存在这种高潜在脆弱性，但相对较少的研究致力于确定现有模型在多大程度上代表了该国的气候。因此，这项工作评估了现有通用环流模型（GCM）和区域气候模型（RCM）在适合气候变化影响评估和适应规划的分辨率下，对马拉维气候变量进行后报的能力。我们专注于月降水率以及平均、最高和最低地面空气温度。这项评估将可用观测数据集与六个由 ERA-interim 驱动的 RCM 和协调区域气候降尺度实验（CORDEX）倡议中的 21 个 GCM 驱动的 RCM 的输出以及形成其边界条件的 11 个 GCM 进行了比较。结果发现，RCM 的性能受到其边界条件的高度影响。在本文评估的任何评估气候变量中，没有一个单独的或集合的 RCM 或 GCM 与观测数据集很好地相关。虽然它们很好地模拟了温度变量的趋势变化，但降水的模拟输出却存在很大差异。基于这些发现，我们建议集合 RCM 或集合 GCM 都适合了解预测的温度趋势，而 RCM 提供更好的空间分辨率。然而，在马拉维，没有任何评估的模型可以确定未来降水趋势。因此，我们建议，马拉维的影响评估和适应计划需要针对一系列未来降水情景进行设计和测试。为了改进对马拉维的建模，建议提高区域气候模型的空间分辨率，并纳入包括马拉维湖在内的大型水体的影响。
