Detectability of the trend in precipitation characteristics over China from 1961 to 2017. (13th September 2020)

• Record Type: Journal Article
• Authors: Li, Wei; Chen, Yang
• Is Part Of: International journal of climatology. Volume 41(2021)Supplement 1
• Page Start: E1980
• Page End: E1991
• Publication Date: 2020-09-13
• Subjects: Precipitation in Monsoon Region -- Time of Emergence -- Trend Detection; Climatology -- Periodicals; Climat -- Périodiques; Climatologie -- Périodiques; 551.605
• DOI: 10.1002/joc.6826
• Languages: English
• ISSNs: 0899-8418

Abstract

Abstract: The detection and attribution of precipitation changes are fundamental for adaptation and mitigation planning. Based on high‐quality observations, we determined the detectability of the trends of multiple precipitation characteristics across China using a field significance test. Furthermore, the timing at which spatially aggregated changes become significant and do not reflect random internal variability was also estimated. The results show that the significant increases in the annual total precipitation (PRCPTOT) and simple precipitation intensity (SDII) and significant decreases in the wet days (WD) are detectable from 1961 to 2017. Namely, the percentage of stations showing significant trends exceeds that expected by chance. The time of the trend emergence from the mimicked range of internal variability is around 2000 for SDII and WD, while the PRCPTOT trend can only be significantly detected for recent years. The analysis on precipitation of various intensity levels unearths that the significant increases in the amount and frequency of extreme heavy precipitation emerged around 2014, while a significant decreasing trend in light precipitation might be detected as early as 2000. Global warming is expected to affect the detection of precipitation trends because the timing at which global warming signal in trend of precipitation emerges is consistent with the time at which the trends become significant. In general, significant changes in the PRCPTOT, SDII and WD occur more frequently in winter than in summer. Key findings: An overall increasing trend signal in annual total precipitation (PRCPTOT) and simple precipitation intensity (SDII) and a decreasing trend signal in wet days (WD) have been already detectable during 1961 to 2017. The trend signal for WD and SDII is detected earlier than that for PRCPTOT. For the four precipitation categories based on percentiles, a significant increasing trend in extreme heavy precipitation was detected recently (close to the year 2014). The detectability of the significant decreasing trend in the light precipitation is the most robust and the overall trend become significant close to the year 2000. The anthropogenic warming may play a dominant role in the detectability of significant trend in precipitation characteristics, because the time at which global warming signal in trend of precipitation characteristics emerges is almost the same as the time at which the trend became significant. Abstract : Blue (red) squares denote the percentage of stations showing a significant increasing (decreasing) trend in light precipitation (LP), moderate precipitation (MP), heavy precipitation (HP) and extreme heavy precipitation (EHP), in term of magnitude, frequency and intensity during 1961 to 2017. Grey bars denote the 95% probability in the distribution constructed with 1, 000 bootstrap samples.