四川西南地区热量资源分析

利用四川西南地区1960至2007年7个气象观测站点的逐日气温资料,分析了该地区日平均气温稳定通过0、5、10℃的初日、终日、持续日数、积温的年际变化、空间变化特征。结果发现,四川西南地区≥0℃、≥5℃、≥10℃的积温变化均呈增加趋势;在这48年里,1998～2007年是热量和持续日数增加幅度最大的时期,其中四川西南的东、西部地区≥0℃、≥5℃、≥10℃的平均年积温增加幅度最显著,中部的西昌平原地区次之,盐源地区增加最少;≥5℃的初日提前、终日推迟、持续日数增加最显著;在空间上,东、西部地区≥5℃、≥10℃的持续日数增加最显著。

Variations of the thermal growing season during the period 1961–2015 in northern China

Researching into changes in thermal growing season has been one of the most important scientific issues in studies of the impact of global climate change on terrestrial ecosystems. However, few studies investigated the differences under various definitions of thermal growing season and compared the trends of thermal growing season in different parts of China. Based on the daily mean air temperatures collected from 877 meteorological stations over northern China from 1961 to 2015, we investigated the variations of the thermal growing season parameters including the onset, ending and duration of the growing season using the methods of differential analysis, trend analysis, comparative analysis, and Kriging interpolation technique. Results indicate that the differences of the maximum values of those indices for the thermal growing season were significant, while they were insignificant for the mean values. For indices with the same length of the spells exceeding 5°C, frost criterion had a significant effect on the differences of the maximum values. The differences of the mean values between frost and non-frost indices were also slight, even smaller than those from the different lengths of the spells. Temporally, the starting date of the thermal growing season advanced by 10.0–11.0 days, while the ending dates delayed by 5.0–6.0 days during the period 1961–2015. Consequently, the duration of the thermal growing season was prolonged 15.0–16.0 days. Spatially, the advanced onset of the thermal growing season occurred in the southwestern, eastern, and northeastern parts of northern China, whereas the delayed ending of the thermal growing season appeared in the western part, and the length of the thermal growing season was prolonged significantly in the vast majority of northern China. The trend values of the thermal growing season were affected by altitude. The magnitude of the earlier onset of the thermal growing season decreased, and that of the later ending increased rapidly as the altitude increased, causing the magnitude of the prolonged growing season increased correspondingly. Comparing the applicability of selected indices and considering the impacts of frost on the definitions are important and necessary for determining the timing and length of the thermal growing season in northern China.

黑龙江流域中俄跨境地区0.25°×0.25°有效积温数据集(2002–2020)

作者以黑龙江流域中俄跨境地区为研究区,以0、5、10和15℃为基础温度,基于大气再分析数据产品ECMWF Re-Analysis 5中的逐小时2 m气温数据,通过时空筛选与尺度转换、有效温度始末日期甄别,以及区间数据批量统计等步骤,得到黑龙江流域中俄跨境地区0.25°×0.25°有效积温数据集(2002–2020)。将本数据产品(有效积温)与基于气象实测数据及其关联产品的有效积温进行相关性分析表明,本产品与两者均呈正相关关系,并且年际间波动情况基本一致。本数据集内容包括:(1)研究区边界数据;(2)研究区2002–2020逐年0.25°×0.25°有效温度(≥0、≥5、≥10和≥15℃)始末时间数据;(3)研究区2002–2020逐年0.25°×0.25°有效积温(≥0、≥5、≥10和≥15℃)数据;(4)有效积温的验证数据。数据集存储为.shp、.tif和.xlsx格式,由305个文件组成,数据量为19.9 MB(压缩为1个文件,1.69 MB)。