Precipitation deficits increase high diurnal temperature range extremes

Abstract

The relationship between precipitation deficits and extreme hot temperatures has been documented in observation and modeling studies. However, it is unclear whether and how increases in maximum temperatures will impact diurnal temperature range (DTR) extremes. Here, we used observational data sets from meteorological stations in China to examine the trends in high DTR extremes from 1971 to 2013, represented by the percentage of high DTR days (%HDD) and maximum high DTR duration (MHDD), as well as their relationships with precipitation deficits over the past four decades in China. We identified both positive and negative trends in the %HDD and MHDD in China during each season, implying an inhomogeneous behavior of DTR and DTR extremes. Furthermore, we observed a significant negative relationship between precipitation deficits and the %HDD and MHDD during each season, and the relationship was strongest in the summer. The statistical analysis of this coupled behavior indicated that precipitation deficits were related to an increase in high DTR extremes, with a 22% average higher probability of the occurrence of DTR extremes after dry conditions than wet conditions in the summer. Knowledge from this study has important implications for interpreting climate anomalies.

Quantifying the shifts and intensification in the annual cycles of diurnal temperature extremes for human comfort and crop production

“…As a preliminary investigation, the spatio-temporal long-term average ALC of T max and T min obtained using EEMD shown in figure 1(a), reveals a bimodal pattern of T max , with the peak of T max appearing approximately one month earlier than that of T min . The lag between the peaks of T max and T min is chiefly attributed to the monsoon, western disturbances (extratropical storm originating in the Mediterranean region that brings sudden winter rain to the northwestern parts of the Indian subcontinent), and expected higher night-time temperatures during monsoon/rainy days (Dai et al 1999, Rai et al 2012, He et al 2015, Vinnarasi et al 2017. The spatial variation of this peak value for T max and T min are shown in figures 1(b) and (c) respectively and the corresponding months of occurrences are shown in figures 1(d) and (e).…”

Impacts of Initial Soil Moisture and Vegetation on the Diurnal Temperature Range in Arid and Semiarid Regions in China

“…Increased soil exposure to solar irradiance (decreased Fg) can increase the amount of incoming radiation which is transformed into thermal energy stored in the soil during the daytime and released at night to enhance the nighttime air temperature (D'Odorico et al, ; D'Odorico et al, ; He et al, , ; B. He et al, ). While the forest land cover appears to have opposite effects to this research, D'Odorico et al () showed that in the cases of arctic and alpine tree lines and the transition between mangrove forests and salt marshes in coastal ecosystems, the warming effect at night is due to the ability of the canopy to reduce nocturnal radiative cooling.…”

“…Shrub encroachment has a similar mechanism as our research due to the transition from grassland to shrubland reduces the vegetation cover, which is similar to the decrease in Fg in this research. Increased soil exposure to solar irradiance (decreased Fg) can increase the amount of incoming radiation which is transformed into thermal energy stored in the soil during the daytime and released at night to enhance the nighttime air temperature D'Odorico et al, 2013;He et al, 2010He et al, , 2011B. He et al, 2015).…”

“…Improvement in the ability to predict DTR anomalies is critical for public management (B. He et al, ). The daily minimum temperature (Tmin) has continued to increase about twice as fast as the maximum temperature (Tmax) over global land since the 1950s, resulting in an increasing global mean temperature and a broad reduction in the DTR (especially in the Northern Hemisphere) (Braganza et al, ; Dai et al, , ; Easterling et al, ; Folland et al, ; Karl et al, ; Zhou et al, ).…”

Implication of cell-in-cell structures in the transmission of HIV to epithelial cells

“…This novel mechanism was termed in-cell infection [2]. Given the formation of similar heterotypic cell-in-cell structures between other EC-lymphocyte pairs, such as epithelial tumor cells and T lymphocytes [3], we wonder whether in-cell infection also plays a role in mediating transmission of other viruses.…”