全球近40年地表温度时空变化分析

SPATIO-TEMPORAL VARIATION OF GLOBAL LAND SURFACE TEMPERATURE IN RECENT 40 YEARS

关键词:  ERA5  地表温度  全球  时空变化

Key words:  ERA5  land surface temperature  global  spatiotemporal variation

摘要:

目的 地表温度是研究全球气候变化的关键参数之一，气候同化数据集具有大尺度、连续、时空代表性强的优点，非常适合用来探究全球地表温度的长期变化规律。方法 文章基于1981—2020年ERA5地表温度逐月数据，利用MATLAB编程以及GIS空间分析功能，研究了全球地表温度在年际和季节尺度上的时空变化规律。结果 （1）近40年的全球平均地表温度接近14.92℃，最冷和最暖地表温度分别出现在1985年和2020年。（2）全球地表温度分布具有较强的空间差异，呈现出大致与纬度平行，从赤道到向两极递减的分布格局，且北半球地表温度稍高于南半球的特点。（3）从时间变化趋势来看，全球绝大部分区域地表温度呈现0.02℃/年的增长速率，其中北半球增长速率高于南半球，欧洲、亚洲和北美洲增长速率高于其他大洲。（4）从区域尺度上来看，全球变暖并不是绝对的，比如北美洲中部、南美洲北部、大西洋北部、印度半岛、太平洋中部和东北部、澳大利亚西部地区以及南极洲大部分地区和沿海呈现降温趋势。结论 全球绝大部分地区近40年地表温度呈现出缓慢的增长趋势，且增长速率北半球大于南半球。

Abstract:

Land surface temperature (LST) is one of the key parameters in the study of global climate change. Climate assimilation datasets have the advantages of large scale, continuous and strong spatio-temporal representation, which are very suitable for exploring the long-term variation of global LST. Based on the monthly ERA5 LST data from 1981 to 2020, this paper used MATLAB programming and GIS spatial analysis function to study the temporal and spatial variation of global LST at the inter-annual and seasonal scales. The results were showed as follows. The global average surface temperature in the past 40 years was close to 14.92℃, and the coldest and warmest surface temperature occurred in 1985 and 2020, respectively. The global surface temperature distribution had a strong spatial difference, showing a distribution pattern from the equator to the poles, which was roughly parallel to the latitude, and the surface temperature in the northern hemisphere was slightly higher than that in the southern hemisphere. From the perspective of time variation trend, the LST in most regions of the world showed an increase rate of 0.02℃/a, and the growth rate in the Northern hemisphere was higher than that in the Southern hemisphere, and the growth rate in Europe, Asia and North America was higher than that in other continents. On a regional scale, however, global warming was not absolute, with cooling trends in central North America, northern South America, the northern Atlantic, the Indian Peninsula, the central and northeastern Pacific, western Australia, and much of and along the coast of Antarctica. In summary, LST in most parts of the world shows a slow growth trend in recent 40 years, and the growth rate is greater in the Northern hemisphere than in the southern hemisphere.