Spatiotemporal high resolution reconstruction of climatic variation over the eastern Tibetan Plateau during the last 2000 years

青藏高原东部近2000年气候变化时空高分辨率重建

• 批准号: 29447019
• 负责人: Professor Dr. Achim Bräuning
• 金额: --
• 依托单位: Institut für Geographie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/29447019?language=en
• 关键词: Spatiotemporal; resolution; reconstruction; climatic; variation

We intend to apply a multiproxy analysis approach to newly collected tree-ring material from a study area in north-eastern Tibet: beside ring width, maximum latewood density, wood anatomy and the content of stable 13C and 18O isotopes in the wood shall be measured. These parameters are sensitive to different seasonal climate elements and enable a comprehensive reconstruction of past climate variability. Due to the scarcity of climatic data from the investigation area, a regional climate modelling approach will be implemented. This will provide spatially high resolution monthly estimated topoclimatic variables (radiation, temperature, evapotranspiration, precipitation) for the calibration of climate-tree growth transfer functions. The modelling work will consist of the design and integrated implementation of GCM (statistical) downscaling and terrain parameterization methods to bridge the spatial scale gap between the coarse GCM resolution and the required high-resolution estimates of climate variables relevant for dendroclimatological analyses. By reconstructing air pressure fields and resulting circulation patterns we want to disentangle the dynamic behaviour of the South Asian and the East Asian Summer Monsoons during important past climate episodes. This helps to verify the predictive power of regional climate models to gain better forecast skills for future regional development of monsoon intensity.

我们打算对西藏东北部研究区新采集的树木年轮材料采用多代理分析方法：除了年轮宽度外，还应测量最大晚材密度、木材解剖结构以及木材中稳定的 13C 和 18O 同位素含量。这些参数对不同的季节性气候要素敏感，能够全面重建过去的气候变化。由于调查区域气候数据稀缺，将采用区域气候模拟方法。这将为气候树木生长传递函数的校准提供空间高分辨率的每月估计地形气候变量（辐射、温度、蒸散量、降水）。建模工作将包括 GCM（统计）降尺度和地形参数化方法的设计和综合实施，以弥合粗 GCM 分辨率与树木气候分析相关气候变量所需高分辨率估计之间的空间尺度差距。通过重建气压场和由此产生的环流模式，我们希望理清南亚和东亚夏季风在过去重要气候事件期间的动态行为。这有助于验证区域气候模型的预测能力，从而为未来区域季风强度的发展获得更好的预测技能。