Changing temperature trends at subtropical mountains in southeastern China

Abstract

In the context of global warming, mountain warming has significantly elevation-dependent. Currently, most studies focusing on high-altitude mountainous areas lack examples of middle and low-altitude mountainous areas. Southeastern China's Fujian Province has the Wuyi Mountains in the northwest and coastal plains in the southeast, making it an ideal place to study temperature warming change with elevation. Therefore, based on 64 meteorological stations' daily observation data in Fujian Province from 1961 to 2018, the Mann-Kendall nonparametric test method was used to analyze the spatial-temporal patterns of temperatures and their elevation-dependent warming characteristics. The results show that (1) Fujian Province has experienced significant warming from 1961 to 2018, where the mean temperature is 0.20°C/decade, the maximum temperature is 0.17°C/decade, and the minimum temperature is 0.26°C/decade. The mean, maximum, and minimum temperatures abruptly changed around 1997, 2000, and 1998, respectively. (2) In 1961-1990, more than 63% of stations experienced a decline in annual mean temperature, mainly because the maximum temperature decreased during this period, whereas for 1971-2000, 1981-2010, and 1991-2018, the maximum, minimum and mean temperatures have been increasing. (3) In Fujian Province, there are significant spatial differences in temperature variations, with the maximum warming trend of mean temperature occurring in the southeast coastal plains, the maximum warming trend of maximum temperature occurring in the northwestern mountainous region, and the minimum temperature is warming faster in the southeast coast and northwestern mountains than in the central region. (4) In the study area, no elevation-dependent warming of mean, maximum, and minimum temperatures was observed, indicating that middle and low-altitude mountainous regions of the subtropics do not experience elevation-dependent warming of temperatures.