Variability, Trend, and Extremes of the South American Vegetation‐Climate System: Results From a Coupled Regional Model
Variability, Trend, and Extremes of the South American Vegetation‐Climate System: Results From a Coupled Regional Model
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DOI：
10.1029/2021jd035691
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
A. Erfanian;Yelin Jiang;Lori Fomenko;R. Fu;A. Seth;Guiling Wang
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文献类型：
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作者：
A. Erfanian;Yelin Jiang;Lori Fomenko;R. Fu;A. Seth;Guiling Wang
南美洲，特别是亚马逊地区，被认为是生物圈-大气相互作用的热点地区，对区域气候建模提出了独特的挑战。在这里，我们评估了一个区域模型在模拟南美洲气候-植被系统方面的性能，并使用该模型来研究大规模变暖在最近观察到的水文气候和植被趋势中的潜在作用。与基于观测数据的植被处方相比，在区域气候模式中加入植被预测能力，使模式能够模拟植被对气候的响应，同时保持模式在再现区域气候的平均值、变率和极端值方面的性能。耦合植被气候模型捕捉最近的趋势，水文气候和植被生产力和空间对比，包括一个趋势，在亚马逊和Nordeste地区的温暖，干燥，生产力较低的条件下，和一个趋势，凉爽，湿润，更富有成效的条件下，在拉普拉塔地区。由区域气候的去趋势边界强迫驱动的敏感性实验的结果表明，亚马逊和Nordeste地区的大部分趋势可以归因于大规模变暖的影响，但年代际变率的贡献也发挥了作用，特别是在最近十年。然而，在拉普拉塔地区的趋势不能通过边界强迫趋势的消除而减弱，这表明大尺度环流模式变化的作用。最近植被生产力的趋势可能是亚马逊和周边地区未来变化的早期表现。
South America, especially the Amazon region, is considered a hotspot of biosphere–atmosphere interactions and presents a unique challenge for regional climate modeling. Here, we evaluate the performance of a regional model in simulating the climate–vegetation system in South America and use the model to investigate the potential role of large‐scale warming in the recently observed trend of hydroclimate and vegetation. Compared with prescribing vegetation based on observational data, adding the predictive vegetation capacity to the regional climate model enabled the model to simulate the vegetation response to climate while sustaining the model performance in reproducing the mean, variability and extremes of the regional climate. The coupled vegetation–climate model captures the recent trends in hydroclimate and vegetation productivity and their spatial contrasts, including a trend toward warmer, drier, and less productive conditions in the Amazon and Nordeste regions and a trend toward cooler, wetter, and more productive condition in the La Plata region. Results from sensitivity experiment driven by detrended boundary forcing for the regional climate suggest that much of the trends in the Amazon and Nordeste regions can be attributed to the effects of large‐scale warming, but contribution from decadal variability also plays a role especially for the most recent decade. However, the trend in the La Plata region cannot be attenuated by the removal of the boundary forcing trend, indicating the role of large‐scale circulation pattern changes. The recent trends in vegetation productivity may be early manifestation of future changes in the Amazon and surrounding regions.