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Precipitation deficits increase high diurnal temperature range extremes.

He B, Huang L, Wang Q - Sci Rep (2015)

Bottom Line: However, it is unclear whether and how increases in maximum temperatures will impact diurnal temperature range (DTR) extremes.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.Knowledge from this study has important implications for interpreting climate anomalies.

View Article: PubMed Central - PubMed

Affiliation: 1] College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China [2] Joint Center for Global Change Studies, Beijing 100875, China.

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.

No MeSH data available.


Related in: MedlinePlus

Trends tests.Linear trends in %HDD for different seasons from 1971–2013. The %HDD was calculated from 215 values (5 × 43yr) based on 5-consecutive-day moving windows centered on each calendar day and 90th percentile thresholds from 1971–2013. The linear trend in %HDD was examined with linear regressions. Slopes were considered significant for p < 0.05. Red dots indicate negative trends, and blue dots indicate positive trends. The map was generated with MeteoInfo 1.1.3 (http://www.meteothinker.com/).
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f1: Trends tests.Linear trends in %HDD for different seasons from 1971–2013. The %HDD was calculated from 215 values (5 × 43yr) based on 5-consecutive-day moving windows centered on each calendar day and 90th percentile thresholds from 1971–2013. The linear trend in %HDD was examined with linear regressions. Slopes were considered significant for p < 0.05. Red dots indicate negative trends, and blue dots indicate positive trends. The map was generated with MeteoInfo 1.1.3 (http://www.meteothinker.com/).

Mentions: Figure 1 shows the linear trends in %HDD for each station from 1971–2013. Previous studies have agreed that the DTR has continuously decreased throughout China1617, especially in winter; however, variations in seasonal high extreme DTR events are very complex, and both positive and negative trends exist. An obvious north–south division in the distribution of the %HDD trends was identified in the spring, with significant positive trends mainly observed in South China and significant negative trends mainly observed in North China. From spring to winter, the number of stations with significant positive trends gradually decreased, but the number of stations with significant negative trends increased and seemed to gradually expand from the northern to the eastern and southern parts of China. These results indicate that a continued decrease in DTR does not correspond to a similar decrease in DTR extreme events. Considering its potential impacts on public health, the change in the variability in DTR extreme events should be taken seriously. The linear trends in the DTR extremes indicated by the MHDD had a similar spatial distribution (Fig. S1).


Precipitation deficits increase high diurnal temperature range extremes.

He B, Huang L, Wang Q - Sci Rep (2015)

Trends tests.Linear trends in %HDD for different seasons from 1971–2013. The %HDD was calculated from 215 values (5 × 43yr) based on 5-consecutive-day moving windows centered on each calendar day and 90th percentile thresholds from 1971–2013. The linear trend in %HDD was examined with linear regressions. Slopes were considered significant for p < 0.05. Red dots indicate negative trends, and blue dots indicate positive trends. The map was generated with MeteoInfo 1.1.3 (http://www.meteothinker.com/).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495382&req=5

f1: Trends tests.Linear trends in %HDD for different seasons from 1971–2013. The %HDD was calculated from 215 values (5 × 43yr) based on 5-consecutive-day moving windows centered on each calendar day and 90th percentile thresholds from 1971–2013. The linear trend in %HDD was examined with linear regressions. Slopes were considered significant for p < 0.05. Red dots indicate negative trends, and blue dots indicate positive trends. The map was generated with MeteoInfo 1.1.3 (http://www.meteothinker.com/).
Mentions: Figure 1 shows the linear trends in %HDD for each station from 1971–2013. Previous studies have agreed that the DTR has continuously decreased throughout China1617, especially in winter; however, variations in seasonal high extreme DTR events are very complex, and both positive and negative trends exist. An obvious north–south division in the distribution of the %HDD trends was identified in the spring, with significant positive trends mainly observed in South China and significant negative trends mainly observed in North China. From spring to winter, the number of stations with significant positive trends gradually decreased, but the number of stations with significant negative trends increased and seemed to gradually expand from the northern to the eastern and southern parts of China. These results indicate that a continued decrease in DTR does not correspond to a similar decrease in DTR extreme events. Considering its potential impacts on public health, the change in the variability in DTR extreme events should be taken seriously. The linear trends in the DTR extremes indicated by the MHDD had a similar spatial distribution (Fig. S1).

Bottom Line: However, it is unclear whether and how increases in maximum temperatures will impact diurnal temperature range (DTR) extremes.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.Knowledge from this study has important implications for interpreting climate anomalies.

View Article: PubMed Central - PubMed

Affiliation: 1] College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China [2] Joint Center for Global Change Studies, Beijing 100875, China.

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.

No MeSH data available.


Related in: MedlinePlus