Historical Land-Cover Change Impacts on Climate: Comparative Assessment of LUCID and CMIP5 Multimodel Experiments
Historical Land-Cover Change Impacts on Climate: Comparative Assessment of LUCID and CMIP5 Multimodel Experiments
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DOI：
10.1175/jcli-d-16-0213.1
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发表时间：
2017-02-01
影响因子：
4.9
通讯作者：
Davin, Edouard L.
中科院分区：
文献类型：
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作者：
Lejeune, Quentin;Seneviratne, Sonia I.;Davin, Edouard L.
在工业化时期，许多地区经历了森林覆盖面积的减少和农业面积的扩大，特别是北美、欧亚大陆北部和南亚。本文通过比较土地利用与气候、强效影响识别（LUCID）和CMIP5模式相互比较项目的结果，探讨了这些地区土地覆盖变化（LCC）如何局部影响反照率和蒸散发等陆地表面生物物理特性，以及这种变化如何影响季节平均温度及其日循环。LCC的影响是从气候模拟中提取出来的，包括所有的历史强迫，使用的方法在大多数情况下可以很好地捕捉到从单一强迫实验中诊断出来的影响的标志和季节周期。模式对比表明，LUCID模式和CMIP5模式在中纬度地区反照率导致冬季平均气温降低的观点一致。相比之下，关于潜热通量的响应，以及随后的夏季平均温度的响应则不太一致，此时蒸发冷却起着更重要的作用。总的来说，与LUCID研究的结果相比，大多数模式在这个季节表现出LCC的局部变暖效应。一个引人注目的结果是，所分析的模型中没有一个能很好地再现当今对森林砍伐影响的观测所确定的日循环变化。但总体而言，CMIP5模式较LUCID模式更好地模拟了观测到的夏季白天增温效应，以及冬季夜间降温效应。
During the industrial period, many regions experienced a reduction in forest cover and an expansion of agricultural areas, in particular North America, northern Eurasia, and South Asia. Here, results from the Land-Use and Climate, Identification of Robust Impacts (LUCID) and CMIP5 model intercomparison projects are compared in order to investigate how land-cover changes (LCC) in these regions have locally impacted the biophysical land surface properties, like albedo and evapotranspiration, and how this has affected seasonal mean temperature as well as its diurnal cycle. The impact of LCC is extracted from climate simulations, including all historical forcings, using a method that is shown to capture well the sign and the seasonal cycle of the impacts diagnosed from single-forcing experiments in most cases.The model comparison reveals that both the LUCID and CMIP5 models agree on the albedo-induced reduction of mean winter temperatures over midlatitudes. In contrast, there is less agreement concerning the response of the latent heat flux and, subsequently, mean temperature during summer, when evaporative cooling plays a more important role. Overall, a majority of models exhibit a local warming effect of LCC during this season, contrasting with results from the LUCID studies. A striking result is that none of the analyzed models reproduce well the changes in the diurnal cycle identified in present-day observations of the effect of deforestation. However, overall the CMIP5 models better simulate the observed summer daytime warming effect compared to the LUCID models, as well as the winter nighttime cooling effect.