摘要
利用1981—2013年湖南省9个地面气象站0—320 cm地面温度和气温的观测资料,采用统计方法分析了湖南省地温的变化特征,并与气温的变化特征进行了比较。结果表明:1981—2013年湖南省各层地温均呈东南高、西北低及东南高、西北和东北低两种典型分布。月地温变化在一定深度后与月气温变化由同步转为不同步,转折层为40 cm层;40 cm层以上的月地温最低值均出现在1月,月地温最高值均出现在7月,与月气温最低值和最高值出现的时间相同;40 cm层以下随着土壤深度增加,月地温最低值和最高值出现时间后推,320 cm月地温最低值出现在4月,320 cm月地温最高值出现在10月。浅层地温与气温的相关系数为0.97以上,自40 cm层地温开始,随着土壤深度增加地温与气温的相关系数减小。冬季浅层地温的年际变化最大,春季次之;冬季和春季深层地温的年际变化明显大于夏季和秋季;春季和夏季地温随土壤深度增加逐渐降低,秋季和冬季地温随土壤深度增加逐渐升高,导致冬季深层地温明显高于气温,夏季深层地温明显低于气温。1981—2013年湖南省各层年平均地温均呈极显著上升的趋势,除0 cm地温外,各层地温升温速率均低于气温;四季各层地温与气温的升温趋势一致,其中春季升温速率最大,秋季次之,冬季升温不明显。各层年平均地温在1993—1995年出现了增温的突变现象,冬季地温突变时间最早,春季和秋季次之,夏季地温突变时间较晚;各层年平均地温均存在2—3 a、3—4 a和6—9 a的周期变化。
Based on air temperature and ground temperature measured at 0-320 cm soil depths of nine meteorologi- cal observation stations in Hu＇ nan province from 1981 to 2013, the comparison of variation characteristics of ground temperature and air temperature was made using the relevant statistical methods. The results show that ground temperature of each depth exists two typical spatial structures, i. e. high in the southeast versus low in the northwest and high in the southeast versus low in the northeast and northwest. Under a certain depth, variation of monthly ground temperature is not synchronized with air temperature, and the transition, layer is at 40 cm depth. The minimum monthly ground temperature for the layers between the surface and 40 cm depth occurs in January, and the maximum monthly ground temperature occurs in July, which are in accordance with the occurrence times of the minimum and maximum monthly air temperature. Along with increasing of soil depth （below 40 cm depth）, the occurrence times of the minimum and maximum monthly ground temperature delay. The minimum ground temperature of 320 cm occurs in April, and the maximum occurs in October. The correlation coefficients of shallow ground temperature and air temperature are more than 0. 97, which reduce along with the increasing of soil depth below 40 cm layer. Inter-annual variation of shallow ground temperature is large in winter, followed in spring. Inter-annual variation of deep ground temperature in winter and spring are obviously larger than that in summer and autumn. With increasing of soil depth, the ground temperature is gradually decreasing in spring and summer and increasing in autumn and winter. As a result, the deep ground temperature is significantly higher than air temperature in winter ,and lower than air temperature in summer. The annual average ground temperature of dif- ferent layers shows an increasing trend significantly. The increasing rates of ground temperature of different layers are slower than air temperature except for 0 cm ground temperature. The warming trends of ground temperature at different layers are consistent with air temperature in all seasons ,and temperature increasing rate is the most rapid in spring, followed in autumn, not obvious in winter. Annual average ground temperature at different layers presen- ted increasing abrupt during 1993-1995. Abrupt in winter are the earliest, followed in spring and autumn,late in summer. Quasi-oscillations of 2-3 years ,3-4 years and 6-9 years are found for annual average ground temperature of different layers.
出处
《气象与环境学报》
2016年第6期122-129,共8页
Journal of Meteorology and Environment
基金
中国气象局气候变化专项(ccsf 201525)
公益性(气象)行业专项(GYHY201506017)共同资助
关键词
地温
转折层
相关分析
周期
Ground temperature
Transition layer
Correlation analiysis
Period
