自1960年以来,北方生态系统加强了二氧化碳的季节性交换
H D Graven1, R F Keeling, S C Piper
1Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA. hgraven@ucsd.edu
概括
大气中的二氧化碳 (CO2) 季节性变化在北半球显示显著增加,特别是在北极地区. 这表明北方森林发生了重大生态变化,影响了全球碳循环.
科学领域:
- * 地球与环境科学
- * 大气化学
- * 生态学 * 生态学
背景情况:
- *北半球大气中二氧化碳 (CO2) 的季节性变化自20世纪50年代以来得到了放大.
- *有限的观测数据阻碍了对长期变化及其驱动因素的全面理解.
- *以前的研究表明,二氧化碳的季节性增加,但区域模式和数量仍不清楚.
研究的目的:
- *评估大气二氧化碳的长期变化,北太平洋和北冰洋的季节性变化.
- * 调查驱动观察到的二氧化碳模式的潜在机制.
- * 将最近的飞机观测与1958年至1961年的历史数据进行比较.
主要方法:
- * 分析最近基于飞机的大气二氧化碳观测结果.
- *与1958年至1961年的历史CO2数据进行比较.
- * 检查CO2季节幅度在3-6公里的高度,跨越不同度带 (10°-45°北和45°-90°北).
主要成果:
- *在45°-90°N的3-6公里高度观察到大气二氧化碳季节幅度增加了50%.
- * 发现10°-45°N的季节性CO2振幅增加不到25%.
- * 北部外热带陆地生态系统,特别是北极森林,季节性二氧化碳交换量增加了30-60%.
结论:
- *观察到的二氧化碳增加表明北方森林发生了重大生态变化.
- *这些发现表明全球碳循环发生了实质性的转变,超过了当前的陆地生态系统模型模拟.
- *增强的二氧化碳季节性表明,陆地生态系统与大气之间的相互作用更为动态.
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