Quansheng Ge, Fang Wang(通讯),Juerg Luterbacher. Improved estimation of average warming trend of China from 1951-2010 based on satellite observed land-use data, Climatic Change, 2013, doi: 10.1007/s10584-013-0867-4 (IF=3.634)
Improved estimation of average warming trend of China from 1951–2010 based on satellite observed land-use data
Abstract
This paper provides new evidence of regional warming trends from local Chinese observations covering the period 1951–2010. We used satellite-derived land data and weighted urban and rural temperature records (a weighted method) and estimate the regional warming trend, which involves natural climate change and human impact. The annual warming rate over the whole of China is 0.21±0.02 °C/decade. The seasonal warming is 0.30±0.05 °C/decade (Winter), 0.24 °C±0.03 °C/decade (Spring); 0.16±0.02 °C/decade (Summer) and 0.21±0.03 °C/decade (Autumn). The mean warming trend is lower than previous estimates (e.g. NMIC, CRU-China) using un-weighted methods (arithmetic average of all records). The warming difference between the weighted and un-weighted accounts for 27 % (12 %) of the NMIC (CRU-China) un-weighted estimate on the total warming. This indicates that previous estimations overestimated a regional warming trend. The differences can be partly attributed to the weighting of the urban effect which is taken into consideration in this study, resulting in a much slower temperature increase. Spatially, the northern part of China shows a larger difference than the south especially for winter and spring. We argue that it is of importance to take into consideration the influence of urban land-use change to improve the physical understanding of surface warming in China over past decades.
在估计大尺度的区域气温变化趋势时,一般根据气象观测站的点记录建立格网数据,然后估计大尺度的区域平均气温趋势。这些气象站有些位于城市,有些位于农村。然而,如果所有站点被直接平均的话(包含城市站和农村站),则区域平均变暖趋势常常被夸大了。例如,一个格点内有5个站点(2个为城市站,3个为农村站),如果我们采用算术平均法计算格点平均温度,则2个城市站就代表了格点40%的区域。然而,由于城市范围往往只占地表的很小一部分(根据卫星观测数据),则上述方法就夸大了城市站气温的影响,同时也就夸大了全国平均变暖趋势。因此本研究根据卫星观测的土地数据和均一化的气温数据,考虑全国城市用地的面积比例,采用加权平均法重新估计了中国1951-2010年的气候变暖趋势。新估计的中国气候变暖趋势低于以往估计值。新估计的变暖趋势既包含气温的自然变化也包含人类活动影响(温室效应和热岛效应),未剔除任何因素的影响,它代表真实的气温变化。
论文链接:http://link.springer.com/article/10.1007/s10584-013-0867-4