中国区域土壤温度的时空变化特征

Temporal and Spatial Distribution Characteristics of Soil Temperature over China

摘要: 本文利用全球陆面数据同化系统(GLDAS)CLM陆面模式的土壤温度月资料，对1982~2019年中国区域土壤温度时空变化特征进行研究。采用线性回归、Morlet小波分析以及MK趋势检验方法，分析中国区域两个深度土壤层(0~10 cm、10~50 cm)的年、四季土壤温度的空间变化特征，月、年际、年代际变化趋势和周期变化特征。结果表明：1) 中国区域两个深度层土壤温度时空变化特征基本一致；2) 年、四季土壤温度空间分布均为中国东南部大于西北部，青藏高原西北侧土壤温度变化趋势会随着季节发生明显变化；3) 土壤温度月变化呈现“倒U型”，春夏季大于秋冬季。年际变化中土壤温度最高值出现在1998年，最低值出现在2003年。年代际变化最高值出现在20世纪90年代，最小值出现在21世纪初；4) 年、四季土壤温度均存在两类尺度的周期变化，其中春、夏季时间尺度周期相似，秋、冬季时间尺度周期相似；5) 20世纪末，年、春季、夏季、秋季土壤温度有增暖的突变现象。21世纪初，冬季有降温的突变现象。

Abstract: In this paper, we use the monthly soil temperature data of the Global Land Data Assimilation System (GLDAS) CLM land surface model to study the spatial and temporal changes of soil temperature in China from 1982 to 2019. Linear regression, Morlet wavelet analysis and MK trend test were used to analyze the spatial variation characteristics of annual and seasonal soil temperature, monthly, interannual and interdecadal trends and periodic variation characteristics of soil temperature in two deep soil layers (0~10 cm, 10~50 cm) in China in year. The results show that: 1) The spatial and temporal changes of soil temperature in two depth layers in China are basically the same. 2) The spatial distribution of annual and seasonal soil temperature in southeastern China is greater than that in northwestern China. The change trend of soil temperature on the northwestern side of the Tibetan Plateau will change significantly with the seasonal changes. 3) Monthly changes in soil temperature show an “inverted U shape”, which is greater in spring and summer than in autumn and winter. The maximum value of soil temperature in the inter-annual variability occurred in 1998, while the lowest value occurred in 2003. The maximum value of the inter-decadal change occurred in the 1990s, while the minimum value appeared in the early 21st century. 4) There are two types of periodic changes in the annual soil temperature and the soil temperature in the four seasons. The spring and summer time scale cycles are similar, and the autumn and winter scale cycles are similar. 5) At the end of the 20th century, there was a sudden change in soil temperature in years, spring, summer and autumn. At the beginning of the 21st century, there was a sudden change in temperature in winter.