Biogeophysical impacts of forestation in Europe: first results from the LUCAS (Land Use and Climate Across Scales) regional climate model intercomparison
Biogeophysical impacts of forestation in Europe: first results from the LUCAS (Land Use and Climate Across Scales) regional climate model intercomparison
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DOI：
10.5194/esd-11-183-2020
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发表时间：
2020-02-20
影响因子：
7.3
通讯作者：
Wulfmeyer, Volker
中科院分区：
文献类型：
--
作者：
Davin, Edouard L.;Rechid, Diana;Wulfmeyer, Volker
土地利用和气候跨尺度旗舰试点研究(Lucas FPS)是一项协调一致的社区努力，旨在改善区域气候模型(RCM)中土地利用变化(LUC)的整合，并量化LUC对欧洲当地和区域气候的生物地球物理影响。在LUCAS的第一阶段，9个RCM被用来探索欧洲重新造林/植树造林的生物地球物理影响：比较了分别代表无森林和森林最多的欧洲的两个理想化实验，以量化区域气候对森林的敏感性的时空变化。我们在模拟的对森林的反应中发现了一些稳健的特征。特别是，所有模型都表明地面反照率全年都在下降，这在高纬度地区的冬季和春季最为明显。这导致了冬季变暖的影响，根据型号的不同，斯堪的纳维亚半岛上的平均值从+0.2到+1K不等。然而，也有一些截然不同的回应。例如，关于夏季气温变化的迹象没有达成一致意见，一些区域气候监测机构预测，由于森林砍伐(大多数地区远低于-2K)、普遍变暖(大多数地区约为+2K或更高)或混合反应，将出现大范围降温。模型间的扩散很大程度上归因于陆地过程的表现。特别是，显热和潜热分配的差异被认为是夏季不确定性的一个关键来源。大气过程，如云层反馈引起的入射辐射的变化，在大多数季节也会影响模拟的响应。总而言之，与基于单一模型的结果相比，我们在这里使用的多模型方法有可能向参与土地利用规划的利益相关者提供更有力和可靠的信息。然而，考虑到已确定的相互矛盾的反应，我们的结果也表明，仍有一些根本性的不确定性需要解决，以更好地预测LUC可能对区域气候造成的有意或无意的后果。
The Land Use and Climate Across Scales Flagship Pilot Study (LUCAS FPS) is a coordinated community effort to improve the integration of land use change (LUC) in regional climate models (RCMs) and to quantify the biogeophysical effects of LUC on local to regional climate in Europe. In the first phase of LUCAS, nine RCMs are used to explore the biogeophysical impacts of re-/afforestation over Europe: two idealized experiments representing respectively a non-forested and a maximally forested Europe are compared in order to quantify spatial and temporal variations in the regional climate sensitivity to forestation. We find some robust features in the simulated response to forestation. In particular, all models indicate a year-round decrease in surface albedo, which is most pronounced in winter and spring at high latitudes. This results in a winter warming effect, with values ranging from + 0.2 to +1 K on average over Scandinavia depending on models. However, there are also a number of strongly diverging responses. For instance, there is no agreement on the sign of temperature changes in summer with some RCMs predicting a widespread cooling from forestation (well below -2 K in most regions), a widespread warming (around +2 K or above in most regions) or a mixed response. A large part of the inter-model spread is attributed to the representation of land processes. In particular, differences in the partitioning of sensible and latent heat are identified as a key source of uncertainty in summer. Atmospheric processes, such as changes in incoming radiation due to cloud cover feedbacks, also influence the simulated response in most seasons. In conclusion, the multi-model approach we use here has the potential to deliver more robust and reliable information to stakeholders involved in land use planning, as compared to results based on single models. However, given the contradictory responses identified, our results also show that there are still fundamental uncertainties that need to be tackled to better anticipate the possible intended or unintended consequences of LUC on regional climates.