Changes in the diurnal temperature range over East Asia from 1901 to 2018 and its relationship with precipitation

Xiubao Sun,Chunzai Wang,Guoyu Ren

doi:10.1007/s10584-021-03120-1

Abstract

Since the 1950s, the East Asian diurnal temperature range (DTR), defined as the difference between the daily maximum (Tmax) and minimum temperatures (Tmin), has gradually decreased. Precipitation changes have often been cited as a primary cause of the change. However, the East Asian DTR change before 1950 and its relationship with precipitation remain unclear. Here, we used a newly developed China Meteorological Administration-Land Surface Air Temperature dataset v1.1 to examine the climatological patterns and long-term trends of the DTR in East Asia from 1901 to 2018 and its relationship with precipitation. The mean annual DTR averaged over East Asia for 1951–2018 was approximately 10.0 °C. East Asian DTR changes during 1901–2018 show two distinct characteristics. First, the DTR decreased significantly by approximately 0.60 °C during 1901–2018, and the decrease rate in the second half of the twentieth century (by ~0.53 °C) was significantly larger than that over the rest of the Northern Hemisphere and the global land due to rapid urbanization over East Asia. Second, before the 1950s, the DTR in East Asia showed a significant non-linear increase especially in middle latitude areas, mainly due to the warming rate of Tmax is higher than that of Tmin. Additionally, we found that the spatial pattern of long-term DTR change shows a significant negative correlation with mean precipitation patterns except in arid and semi-arid areas during 1901–2018. The decreasing trend of DTR gradually became smaller from arid regions to humid regions during 1901–2018, mainly because the difference between Tmax and Tmin warming rate gradually became smaller.

Highlights

Maximum (Tmax) and minimum (Tmin) surface air temperatures have shown significant asymmetric warming since the 1950s over most land areas, with more significant increases in nighttime Tmin than in daytime the daily maximum (Tmax), resulting in decreases in the diurnal temperature range (DTR; DTR = Tmax–Tmin) worldwide (e.g., Karl et al 1991; Easterling et al 1997; Vose et al 2005; Alexander et al 2006; Alexander al. 2013; Thorne et al 2016; Sun et al 2019)
Decreases in the DTR driven by cloud cover, precipitation, and the related soil moisture after 1950 all resulted from their asymmetrical impacts on the surface solar radiation and evaporative cooling that directly affect daytime Tmax (Dai et al 1997, 1999; Zhou et al 2009)
The negative correlation between the DTR and precipitation results mainly from precipitation’s association with cloudiness and soil moisture (Dai et al 1997; Zhou et al 2009). This significant negative correlation between precipitation and the DTR was found to be especially apparent in the warm season (Zhou et al 2009), as dry conditions are more associated with solar radiation and less associated with evaporative cooling (Trenberth and Shea 2005)

Summary

Introduction

Decreases in the DTR driven by cloud cover, precipitation, and the related soil moisture after 1950 all resulted from their asymmetrical impacts on the surface solar radiation and evaporative cooling that directly affect daytime Tmax (Dai et al 1997, 1999; Zhou et al 2009). The negative correlation between the DTR and precipitation results mainly from precipitation’s association with cloudiness and soil moisture (Dai et al 1997; Zhou et al 2009) This significant negative correlation between precipitation and the DTR was found to be especially apparent in the warm season (Zhou et al 2009), as dry conditions are more associated with solar radiation and less associated with evaporative cooling (Trenberth and Shea 2005). Greenhouse gases, aerosols, land-use changes (e.g., urbanization), and other climate factors can indirectly cause DTR changes by affecting clouds and solar radiation (Gallo et al 1996; Braganza et al 2004; Wang et al 2012)

Methods

Results

Discussion

Conclusion