华东地区热量资源的气候变化特征

Characteristics of Climate Change for Heat Resources in East China

为了弄清全球气候变暖对华东地区热量资源的影响,本文应用M-K检验、EOF展开等数理统计方法,分析了华东地区1961年～2005年热量的时间变化和空间分布特征。结果表明:①华东地区年平均气温为16.2℃,有明显升高趋势,平均每10年增加0.21℃,冬季的增温最为明显;M-K检验显示年平均气温在1993年出现了突变;②稳定通过0℃、10℃积温有明显增加的趋势,积温的突变点分别发生在1996年和1999年;③稳定通过0℃积温EOF展开前3个特征向量的累计方差为84.1%,其中第一特征向量表明了华东地区为整体积温增加的一致性,第二特征向量表现为南北相反的分布特征,第3特征向量表现为东西相反的分布特征,稳定通过10℃积温EOF展开前3个特征向量的累计方差为74.2%,前三个特征向量的分布特征与稳定通过0℃积温的分布特征类似;④华东地区无霜冻期平均为239.2d,呈明显增长趋势,无霜冻期在1996年出现了突变,年代际变化显示,无霜冻期的增幅随年代有增大的变化趋势。

According to daily temperature data of 86 observational stations in East China （EC） between 1961 and 2005 provided by data department of Chinese Meteorological Information Center, we took the long-term changes of temperature, accumulated temperature and frost-free season duration into account before studying the characteristics of temporal and spatial distribution of heat resources in EC during that period, in order to,investigate influences of climate warming on heat resources over EC. Statistical methods, including M-K test, power spectrum and EOF analysis, were employed. It turned out that in EC region, annual average temperature and accumulated temperature had gradually overrun 0℃ and 10℃ respectively, while frost-free season period also exhibited an increasing trend. The annual average temperature, with 1971-2000 climate average of 16.2℃, increased 0.21℃ per decade for the period of 1961-2005, during which, the climate in winter showed the most significant warming trend. In addition, M-K test on the above three physical variables, which are closely related to heat resources, revealed that the annual average temperature and accumulated temperature, which stably overrun 0℃ and 10℃, changed abruptly in 1993, 1996 and 1999. EOF-analysis of accumulated temperature, which steadily overran 0℃, showed that the foremost 3 eigenvectors could be used to denote spatial features of accumulated temperature, because their accumulated differenciation could reach as high as 84.1%. To specify, the first, second and third eigenvector respectively reflected consistent regional increase, north-south counter-phase trends and east-west counter-phase trends. For the spatial change of heat resources represented by accumulated temperature that gradually overran 10℃, the foremost 3 eigenvectors by EOF analysis also had comparatively large accumulated differentiation（74.2%）, and the spatial distributions were similar with those of accumulated temperature that gradually overran 0℃. Considering frost-free season, from 1971 to 2000, climate average of frost-free season duration in EC was 239.2dy. The interannual changes of frost-free season duration in EC exhibited distinct increasing trends during 1961-2005. M-K test indicated that abrupt change of frost-free season duration in EC with statistical significance occurred in 1996. Likewise, increasing trend per decade existed in frost-free season duration in EC. Furthermore, amplitude of frost-free season duration change per decade in EC also showed an expanding trend for the period of 1961-2005. All the above results about climate change of heat resources in EC reflected by temperature, accumulated temperature and frost-free season duration would provide favorable scientific foundations for adjusting agricultural cultivation system and constitution of strategies on climate warming in EC.