1970—2021年粤北和珠三角地区地气温差对比分析

COMPARATIVE ANALYSIS OF GROUND-AIR TEMPERATURE DIFFERENCE BETWEEN NORTHERN GUANGDONG AND PEARL RIVER DELTA FROM 1970 TO 2021

关键词:  粤北  珠三角  地气温差  时空分布  变化趋势

Key words:  northern Guangdong  Pearl River Delta  ground-air temperature difference  spatio-temporal distribution  variation trend

摘要:

利用1970—2021年粤北和珠三角地区30个气象站的逐日地面温度和气温资料，分析了地气温差(地面温度-气温)空间分布、季节变化及气候变化背景下的年际变化趋势。(1) 近50年来粤北和珠三角年平均地气温差介于1.97~3.21 ℃之间，总体呈现北高南低的纬向型分布格局。(2) 夏季地气温差最大为3.25 ℃，冬季最小为1.71 ℃；其中冬季珠三角地气温差比粤北大，夏季则相反。(3) 珠三角的东莞在冬、夏两季均为下降趋势最明显的城市，降速为0.35 ℃/(10 a)和0.66 ℃/(10 a)；上升最明显位于珠三角的增城和粤北的仁化分别为0.30 ℃/(10 a)和0.32 ℃/(10 a)。(4) 近50年粤北和珠三角年平均地气温差呈不显著的下降趋势，降速为0.061 ℃/(10 a)；其中粤北呈上升趋势，升速为0.3 ℃/(10 a)；珠三角则呈下降趋势，降速为0.16 ℃/(10 a)；两者变化趋势呈南北反相分布态势。(5) 粤北地气温差月变化呈单峰型结构，珠三角则呈双峰型结构；两地地气温差最小值在汛期前的3月，粤北峰值在7月，珠三角峰值在7月和10月。此外，珠三角年平均气温及夏季地气温差均在1992年发生突变。粤北和珠三角地气温差在时空分布上存在不同程度的差异。

Abstract:

Using the daily ground temperature and air temperature data from 30 meteorological stations in northern Guangdong and the Pearl River Delta from 1970 to 2021, the present study analyzed the spatial distribution, seasonal changes, and interannual changes of ground-air temperature difference (surface temperature minus air temperature) under the background of climate change. The results show that: (1) The annual average ground-air temperature difference between northern Guangdong and the Pearl River Delta in the past 50 years is between 1.97 and 3.21?℃, showing a zonal distribution pattern with higher temperature in the north and lower temperature in the south. (2) The maximum ground-air temperature difference is 3.25?℃ in summer and the minimum is 1.71?℃ in winter. The temperature difference in the Pearl River Delta in winter is larger than that in northern Guangdong, while in summer it is the opposite. (3) Dongguan in the Pearl River Delta is the city with the most obvious downward trend in winter and summer, with decline rates of 0.35?℃/(10 a) and 0.66?℃/(10 a), respectively. By contrast, the most obvious increase is found in Zengcheng in the Pearl River Delta and Renhua in northern Guangdong, with increase rates of 0.30?℃/(10 a) and 0.32?℃/(10 a), respectively. (4) In the past 50 years, the annual average ground-air temperature difference between northern Guangdong and the Pearl River Delta has shown an insignificant downward trend, with a decrease rate of 0.061?℃/(10 a). An increasing trend is found in northern Guangdong with an increase rate of 0.3?℃/(10 a), whereas a downward trend is found in the Pearl River Delta with a decrease rate of 0.16 ℃/(10 a). (5) The monthly variation of the ground-air temperature difference in northern Guangdong has a single-peak structure, while that in the Pearl River Delta has a double-peak structure. The minimum ground-air temperature difference between the two places is in March, the peak in northern Guangdong is in July, and the peak in the Pearl River Delta is in July and October. Moreover, the annual average temperature and the ground-air temperature difference in summer in the Pearl River Delta both changed abruptly in 1992. There are differences in the spatio-temporal distribution of ground-air temperature difference between northern Guangdong and the Pearl River Delta.