土地覆盖变化对于模拟未来气候的重要性
Johannes J Feddema1, Keith W Oleson, Gordon B Bonan
1Department of Geography, University of Kansas, Lawrence, KS 66045, USA. feddema@ku.edu
概括
到2100年,土地覆盖的变化将显著改变区域气候,影响温度和大气循环. A2情景显示的影响比B1更为明显,农业扩张导致不同地区的变暖和变冷.
科学领域:
- 气候科学 气候科学
- 环境科学 环境科学
- 地球系统科学 地球系统科学
背景情况:
- 政府间气候变化专门委员会关于排放场景的特别报告 (SRES) 提供过渡性气候模拟 (A2和B1).
- 以前的气候建模往往只关注大气强迫,可能低估了土地覆盖面变化的影响.
研究的目的:
- 调查将土地覆盖变化纳入SRES气候模拟中的影响.
- 为了比较A2和B1情景的区域气候结果,当包括土地覆盖变化时.
主要方法:
- 利用基于SRES A2和B1场景的过渡性气候模拟.
- 将土地覆盖变化的影响纳入现有气候模型.
- 分析了模拟与没有土地覆盖变化的模拟之间的区域气候差异.
主要成果:
- 到2100年,土地覆盖的变化将显著改变区域气候,而不是仅仅是大气强迫.
- 在A2情景中,农业扩张导致亚马逊大气上层和海洋的大幅变暖和降温.
- 中度农业扩张导致冷却和降低每日温度范围,A2的影响更为显著,通常与B1相反.
结论:
- 土地覆盖的变化是区域气候的关键驱动因素,需要将它们纳入未来的气候预测.
- A2排放场景,加上土地覆盖面的变化,比B1场景更为激烈的区域气候变化.
- 对大气循环的影响,如哈德利和季风系统,影响了热带以外的气候变化.
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