中国人为热变化及其对地表能量平衡的影响

Spatio-temporal changes ofanthropogenic heat release and its impact on land surface energy balanceover China

利用人口统计、分布数据及能源消费统计资料,对中国1980～2015年人为热通量(Q_a)的时空变化进行了研究,并将其与地表净太阳辐射(R_n)进行了对比分析,以探讨人为热对不同尺度地表能量平衡的影响.结果表明,在研究时段内,全国平均Q_a呈显著升高趋势(0.11W/m^2/10a,P<0.001),从1980年的0.07W/m^2上升到2015年的0.45W/m^2,已经约相当于全球工业革命以来CO_2排放引起辐射强迫(1.68W/m^2)的27%;其中Q_a高值区(≥1.00W/m^2)已由1990年的点状分布变为2015年的面状分布,占到全国面积的10%;全国平均R_n的趋势率(0.18W/m^2/10a)略大于Q_a,但未通过显著性检验(P=0.381).对于参与计算的31个省会城市,2015年市区Q_a平均值在1～32W/m^2之间,平均达17W/m^2,相当于R_n平均值(147W/m^2)的12%;在栅格尺度上(0.5min×0.5min),除拉萨外,其余城市的Q_a像元最大值均超过了120W/m^2,已经导致局地的热平衡发生了本质变化.研究认为,人为热释放因素不但需要在城市气候模拟研究中给予更多考虑,而且在全球和区域气候模拟与评价中以及制定气候变化应对策略时也有必要给予充分考虑,以促进全面认识并减缓气温升高.

The spatio-temporal changes of anthropogenic heat flux (Q a ) in 1980~2015 over China were investigated based on the statistical and gridded population data and the statistics of energy consumption. The surface net solar radiation (R n ) was used to describe the impact of Q a on land surface energy balance. The results showed that the national average Q a increased from 0.07W/m^2 in 1980 to 0.45W/m^2 in 2015, with an increasing trend of 0.11W/m^2 /10a(P<0.001). The national average Q a in 2015 accounted for 27% of the global radiative forcing resulting from anthropogenic CO 2 emissions since the beginning of the industrial revolution. The sites with aQ a more than 1.00W/m^2 extended from spotted distribution to continuous areasfrom1990 to 2015, and its area accountedfor 10% of China's total area in 2015. Moreover, the changeof R n was slightlyfaster than that of Q a , but not significantly (P=0.381). The mean Q a in urban areas of the 31provincial capital cities ranged from 1 to 32W/m^2 and the mean intensity was up to17W/m 2 in 2015. The ratio of mean Q a to mean R n (149W/m^2 ) of the 31capital cities on average was approximately12%. Except for Lhasa, the maximum pixel (0.5min×0.5min) value of Q a exceeded120W/m^2 ineach city that implying the local energy balancehas already been changed substantially. We strongly suggested that anthropogenic heat release should be considered in the study of urban climate simulation, regional climate simulation and assessment, and making coping strategy about climate change for better strategy to slow down the warming trend.