Reversed asymmetric warming of sub-diurnal temperature over land during recent decades

Abstract

In the latter half of the twentieth century, a significant climate phenomenon “diurnal asymmetric warming” emerged, wherein global land surface temperatures increased more rapidly during the night than during the day. However, recent episodes of global brightening and regional droughts and heatwaves have brought notable alterations to this asymmetric warming trend. Here, we re-evaluate sub-diurnal temperature patterns, revealing a substantial increase in the warming rates of daily maximum temperatures (Tmax), while daily minimum temperatures have remained relatively stable. This shift has resulted in a reversal of the diurnal warming trend, expanding the diurnal temperature range over recent decades. The intensified Tmax warming is attributed to a widespread reduction in cloud cover, which has led to increased solar irradiance at the surface. Our findings underscore the urgent need for enhanced scrutiny of recent temperature trends and their implications for the wider earth system.

Interannual Variations in Terrestrial Net Ecosystem Productivity and Climate Attribution in the Southern Hilly Region of China

“…Due to the large coverage and diverse vegetation types in the study area, as well as significant variations in NPP for different vegetation types under different climatic and seasonal conditions, future research should focus on further subdividing vegetation types and exploring the changing trends of vegetation NPP in different seasons and over longer time scales in the SHRC. Additionally, in analyzing the relationship between NPP and climatic factors, here we only considered multiple temperature factors and precipitation and did not incorporate other factors such as the regional atmospheric circulation, solar radiation, evapotranspiration, atmospheric water vapor or cloud cover into the impact of climate change on vegetation NPP [ 25 , 27 , 50 ]. These omissions may introduce some uncertainty into the results.…”

“…Additionally, in analyzing the relationship between NPP and climatic factors, here we only considered multiple temperature factors and precipitation and did not incorporate other factors such as the regional atmospheric circulation, solar radiation, evapotranspiration, atmospheric water vapor or cloud cover into the impact of climate change on vegetation NPP [25,27,50]. These omissions may introduce some uncertainty into the results.…”

“…For instance, an increase in total cloud cover tends to reduce the amplitude of daytime warming while enhancing the rate of nighttime warming [ 22 ], because the reduction in shortwave solar radiation reaching the Earth’s surface during the day is offset by an increase in the downward longwave radiation received by the surface at night [ 22 ]. The asymmetry in the rates of daytime and nighttime warming has also gained attention due to its impact on vegetation activity [ 25 ]. Research findings based on satellite observations and field experiments indicate differences in the response of vegetation dynamics and NPP to daytime and nighttime warming [ 25 , 26 , 27 , 28 ].…”

“…The asymmetry in the rates of daytime and nighttime warming has also gained attention due to its impact on vegetation activity [ 25 ]. Research findings based on satellite observations and field experiments indicate differences in the response of vegetation dynamics and NPP to daytime and nighttime warming [ 25 , 26 , 27 , 28 ]. For example, Peng et al [ 26 ] found that in the majority of humid and cold ecosystems in northern regions, daytime warming typically exhibited a positive impact on the increase in vegetation greenness, whereas nighttime warming was usually negatively correlated with vegetation greenness.…”

Tropical nights in the Mediterranean: A spatiotemporal analysis of trends from 1950 to 2022

“…For instance, Cook and Vizy (2015) found that from 1979 to 2012, the Sahara Desert warmed 2-4 times more than all It can be thought that "diurnal asymmetric warming" also plays an important role in the change in the number of tropical nights in the Mediterranean Basin. Indeed, the land surface air temperature observations showed that evidently nights have been warming much faster than days, and daily minimum temperatures have increased about 40% faster than daily maximum temperatures due to changes in the cloud cover, solar radiation, aerosols, precipitation, planetary boundary layer depth, land use change and deforestation in the latter half of the twentieth century (Davy et al, 2017;Doan et al, 2022;Zhong et al, 2023;Zhou, 2021). The asymmetry is most substantial at the surface, gradually decreases with height, and disappears above approximately 1 km from the ground.…”