基于多源观测揭示极端气候事件对青藏高原高寒草甸碳循环的影响

随着全球变暖极端气候事件发生的频率和强度都在显著增加。气候变化如何影响陆地生态系统碳循环一直是全球变化研究的主要内容之一。以往的研究主要集中在温度升高对陆地生态系统碳循环的影响，很少关注极端气候事件，近年来随着极端气候事件的频发，研究者开始注重其对碳循环的影响。因此本研究以高寒草甸为研究对象，利用野外观测、碳循环模型和数据同化等方法，从不同的时间和空间尺度认识极端气候事件的变化规律，及其对高寒草甸碳循环变量的影响。探讨青藏高原高寒草甸碳循环极端事件的主要原因，极端事件对碳循环的干扰是否存在显著的变化特征；在极端气候事件发生的时段，常规碳循环模型的模拟精度如何；在融合地表观测后模型是否能够准确模拟极端气候条件下高寒草甸碳循环等问题。进而深入认识全球变化背景下高寒草甸碳循环过程。为这一区域应对全球变化提供参考意见。

With the global warming, the frequency and intensity of extreme climate events (ECE) is obviously increasing. How the changing climate affects the terrestrial ecosystem carbon cycle is one of most important research subjects in climate change. Most of the conducted researches focused on how increased temperature changes the terrestrial ecosystem carbon cycle, only very few research was about ECE. In recent years, with the increasing of frequency and intensity of ECE, the impact of ECE on carbon cycle has aroused more attention. Therefore, in this study, we intend to study the impact of ECE on carbon cycle of alpine meadow in Tibetan Plateau by integrating multi-source observations including in-situ observations and satellite remote sensing observations with light use efficiency model and process based carbon cycle model. We will analyze the changing characteristic of ECE in Tibetan Plateau at various time and spatial scale. We will examine what are the main forces that cause carbon fluxes abnormal change; whether there is a significant change characteristic of ECE disturbed carbon fluxes; how the carbon cycle model perform during ECE happening; in what extent the model-data fusion will improve the carbon cycle simulation accuracy during ECE happening. Finally, greatly improving the understanding of how ECE affect the carbon cycle in Tibetan Plateau, and providing constructive suggestions to cope with climate change in this region.