Detection and attribution of anthropogenic forcing to diurnal temperature range changes from 1950 to 1999: comparing multi-model simulations with observations

Abstract

Observations show that the surface diurnal temperature range (DTR) has decreased since 1950s over most global land areas due to a smaller warming in maximum temperatures (T max ) than in minimum temperatures (T min ). This paper analyzes the trends and variability in T max , T min , and DTR over land in observations and 48 simulations from 12 global coupled atmosphere-ocean general circulation models for the later half of the 20th century. It uses the modeled changes in surface downward solar and longwave radiation to interpret the modeled temperature changes. When anthropogenic and natural forcings are included, the models generally reproduce observed major features of the warming of T max and T min and the reduction of DTR. As expected the greenhouse gases enhanced surface downward longwave radiation (DLW) explains most of the warming of T max and T min while decreased surface downward shortwave radiation (DSW) due to increasing aerosols and water vapor contributes most to the decreases in DTR in the models. When only natural forcings are used, none of the observed trends are simulated. The simulated DTR decreases are much smaller than the observed (mainly due to the small simulated T min trend) but still outside the range of natural internal variability estimated from the models. The much larger observed decrease in DTR suggests the possibility of additional regional effects of anthropogenic forcing that the models can not realistically simulate, likely connected to changes in cloud cover, precipitation, and soil moisture. The small magnitude of the simulated DTR trends may be attributed to the lack of an increasing trend in cloud cover and deficiencies in charactering aerosols and important surface and boundary-layer processes in the models.

Variability and trend of diurnal temperature range in China and their relationship to total cloud cover and sunshine duration

“…Furthermore, the DTR reduction in spring (drier season) and in north China (drier regions) was generally larger than that in summer and in south China. This feature is in agreement with the results of Zhou et al (2010) who pointed out that the magnitude of the decreasing DTR trend decreased with increasing precipitation amount and cloud cover. Although DTR and TCC showed a decreasing trend during 1954-2009, it was still shown that short-term DTR variability co-varied inversely with that of TCC.…”

“…Data analysis showed that the long-term DTR trend exhibited a significant correlation with precipitation amount. Stronger DTR decreasing trends were observed over drier regions (Zhou et al, 2010). Up to 80 % of the DTR variance was explained by the cloud and precipitation records (Dai et al, 1999).…”

North American Climate in CMIP5 Experiments. Part II: Evaluation of Historical Simulations of Intraseasonal to Decadal Variability

“…The model skill in simulating DTR trends does not appear to have improved from CMIP3 (Zhou et al 2010) and earlier model comparisons (e.g., Braganza et al 2004); however, the role of anthropogenic forcings appears to be essential in producing a decline in DTR (Zhou et al 2010), even if it is underestimated.…”

The relationship between anthropogenic dust and population over global semi-arid regions

“…The released GHGs and heat have induced a strong influence on temperature spatial distribution in recent years (Li and Zhao, 2012), especially in developing countries, where the economic policy relies on extensive growth, which favours results, despite lower resource efficiency and energy waste. Jiang and Hardee (2011) noted that main factors influencing anthropogenic effects on aerosol emission are economic growth, technological change, and population growth, which cannot be easily simulated using numerical models (Zhou et al, 2010). Recently, better understanding about the effects of human activities on dryland expansion in various scenarios has been achieved (Huang et al, 2016b).…”