白天和夜间变暖对北半球植被的不对称影响
Shushi Peng1, Shilong Piao, Philippe Ciais
1Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
Nature
|September 6, 2013
概括
全球陆地在夜间的变暖速度比白天快. 这种不对称的变暖会对植被生长和碳捕获产生不同的影响,这是气候模型中经常被忽视的因素.
科学领域:
- 环境科学环境科学
- 气候科学是气候科学.
- 生态生态学 生态生态学
背景情况:
- 在过去的五十年中,全球陆地表面温度在夜间比白天更快地变暖.
- 这种不对称的变暖影响了植物的碳同化 (光合作用) 和呼吸,这是由于温度敏感度的差异 (Tmax与Tmin).
- 目前的气候变暖研究往往忽视了不对称的日间变暖对陆地生态系统和二氧化碳 (CO2) 流量的影响.
研究的目的:
- 研究北半球不对称日间变暖与植被绿化 (NDVI) 之间的关系.
- 分析每日最高温度 (Tmax) 和每日最低温度 (Tmin) 对植被生长和陆地二氧化碳交换的影响.
- 评估这些发现对全球碳循环模型的影响.
主要方法:
- 在北半球上对来自卫星的NDVI和每日Tmax/Tmin之间的跨年共变的分析.
- 统计分析消除Tmax和Tmin之间的相关性,以确定与NDVI的部分相关性.
- 从全球大气逆转模型中检查陆地净二氧化碳交换地图.
- 来自阿拉斯加巴罗角的长期大气二氧化碳度数据的分析.
主要成果:
- 在潮湿/凉爽的北极地区,Tmax和NDVI之间的部分相关性是正的,但在干燥温带地区是负的.
- 在北极地区,Tmin与NDVI之间的部分相关性是负的,而在干燥温带地区则是复杂的.
- 不对称的变暖对植被生长和二氧化碳封存产生了不同的影响,Tmax异常增加了北极的二氧化碳幅度,Tmin异常减少了它.
结论:
- 不对称的日间变暖显著影响北半球植被对温度上升的反应.
- 在全球碳循环模型中,Tmax和Tmin对植被生长和碳捕获的差异影响至关重要,目前代表性不足.
- 纳入不对称的变暖效应对于准确预测未来的陆地生态系统功能和碳预算至关重要.
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