Observed and SST-forced multidecadal variability in global land surface air temperature
Observed and SST-forced multidecadal variability in global land surface air temperature
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DOI：
10.1007/s00382-014-2121-9
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发表时间：
2014
期刊：
影响因子：
4.6
通讯作者：
L. Gao;Z. Yan;X. Quan
中科院分区：
文献类型：
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作者：
L. Gao;Z. Yan;X. Quan
基于观测分析了全球陆地表面气温（SAT）的多年变率（MDV）特征。利用观测到的 SST 强制进行的大气环流模型模拟，评估了海面温度 (SST) 变化在陆地 SAT 中生成 MDV 中的作用。陆地卫星MDV表现出区域差异，1902-2004年研究期间振幅大于0.3°C的区域主要集中在北美、东亚、欧亚大陆北部、北非和格陵兰岛。 MDV对大多数地区上世纪长期气温变化的影响超过30%，尤其是上述地区的部分地区超过50%。海温强制模拟再现了陆地 SAT 中纬向平均 MDV 的观测特征，但幅度较弱，特别是在北部高纬度地区。陆地卫星上的MDV有两种类型，一种是60年时间尺度，主要出现在北部中高纬度地区，另一种是20-30年时间尺度，主要出现在低纬度地区。在大多数地区，海温强制 MDV 占观测到的 MDV 幅度的 40% 以上。除欧亚大陆中部、南美洲和西澳大利亚的一些零星分布区域外，海温驱动的数十年变化与观测结果完全同步。大西洋数十年涛动和太平洋年代际涛动信号在观测到的和海温强制陆地 SAT 的 MDV 中占主导地位，表明这些海洋涛动在全球陆地 SAT 中产生 MDV 中发挥着重要作用。
The characteristics of multidecadal variability (MDV) in global land surface air temperature (SAT) are analyzed based on observations. The role of sea surface temperature (SST) variations in generating MDV in land SAT is assessed using atmospheric general circulation model simulations forced by observed SST. MDV in land SAT exhibits regional differences, with amplitude larger than 0.3 °C mainly over North America, East Asia, Northern Eurasia, Northern Africa and Greenland for the study period of 1902–2004. MDV can account for more than 30 % of long-term temperature variation during the last century in most regions, especially more than 50 % in parts of the above-mentioned regions. The SST-forced simulations reproduce the observed feature of zonal mean MDV in land SAT, though with weaker amplitude especially at the northern high-latitudes. Two types of MDV in land SAT, one of 60-year-timescale, mainly observed in the northern mid-high-latitude lands, and another of 20–30-year-timescale, mainly observed in the low-latitude lands, are also well reproduced. The SST-forced MDV accounts for more than 40 % amplitude of observed MDV in most regions. Except for some sporadically distributed regions in central Eurasia, South America and Western Australia, the SST-forced multidecadal variations are well in-phase with observations. The Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation signals are found dominant in MDV of both the observed and SST-forced land SAT, suggesting important roles of these oceanic oscillations in generating MDV in global land SAT.