1961~2018年中国生长季变化

Changes in the Growing Season Across China during 1961–2018

在全球变暖背景下,中国区域生长季发生了改变,但以往研究时段偏短、数据分辨率低且空间覆盖相对有限。本文利用0.25°×0.25°高水平分辨率日平均气温资料CN05.1,研究了1961~2018年中国生长季开始日、结束日和长度的气候态特征、变化趋势及其与季节平均温度的关系。结果表明,1961~2018年中国平均生长季开始日和结束日分别为3月31日和10月29日,长度为212 d。空间上,开始日由东南向西北逐渐推迟,结束日呈反向变化,长度由东南向西北缩短。整体而言,1961~2018年中国平均生长季开始日提前、结束日推迟、长度延长,其速率分别为-1.3 d(10 a)^(-1)、0.9 d(10 a)^(-1)、2.2 d(10 a)^(-1),其中开始日提前对长度延长的影响更大。此外,中国平均生长季开始日提前和长度增加主要源于春季升温,而结束日推迟则与秋季变暖有关。

As global warming intensifies,the growing season changes correspondingly across China.Earlier,pertinent studies of the growing season have only covered short-term periods,used low-resolution horizontal data,and focused on limited regions.Based on these premises,the authors investigated the climatological trends of the start of the growing season(GSS),end of the growing season(GSE),and growing season length(GSL)across China during 1961-2018.The authors used daily mean temperature data from a high-resolution horizontal gridded dataset CN05.1(0.25°×0.25°).The relationship between the changes in the growing season and seasonal average temperature was also analyzed.The results indicated that the national average GSS and GSE were 31 March and 29 October,respectively,and GSL was 212 d across China during 1961-2018.Spatially,annual average GSS was delayed from southeast to northwest,whereas,GSE showed the opposite trend;GSL decreased from southeast to northwest.In generally,the trends in the national average growing season displayed an early start[-1.3 d(10 a)^(-1)],a late end[0.9 d(10 a)^(-1)],and a long length[2.2 d(10 a)^(-1)]across China from 1961 to 2018.Finally,both the advance of the national average GSS and extension of the GSL were mainly related to increased spring temperatures,whereas,the delay in the GSE originated from increased autumn temperatures.