{"title":"最新观测数据为加拿大每小时以下至每小时极端降雨量的增加提供了更有力的证据","authors":"Alex J. Cannon, Dae-Il Jeong, Ka-Hing Yau","doi":"10.1175/jcli-d-23-0501.1","DOIUrl":null,"url":null,"abstract":"Abstract Global warming is expected to lead to increases in atmospheric moisture and intensify sub-hourly to hourly rainfall extremes. However, signal-to-noise ratios are low, especially at the local scale, making detection of changes in the observational record difficult. For Canada, previous studies based on short data records from 1965-2005 did not show conclusive evidence of increases in short-duration extreme rainfall. This study updates single-site and regional trend analyses of 5 minute to 24 hour annual maximum rainfall in Canada using data from 1950-2021. Estimates of temporal trends are extended to also consider the association between rainfall intensity and dew point temperature, a measure of moisture availability. With longer records, evidence for increases in extreme rainfall at individual sites is stronger. Field significant increasing trends are found for the majority of durations, whereas before results were mixed and typically not statistically significant. Intensification is even more pronounced in single-site scaling of rainfall intensity with summer mean dew point temperature. Field significant positive scaling rates are detected for all durations. When data are pooled in space – irrespective of choice of regionalization – the results are even more clear. Notably, the strongest and most spatially homogeneous intensification of short-duration extreme rainfall is detected in sub-hourly to 2 hour durations. When data are pooled across Canadian climate regions, field significant positive scaling is found in 72.7% to 81.8% of regions for 5 minute to 2 hour durations, with median scaling rates ranging from 5.3 to 9.4% °C−1. For durations ≥ 6 hours, this falls to 27.3% to 53% of regions, with scaling rates less than 4% °C−1.","PeriodicalId":15472,"journal":{"name":"Journal of Climate","volume":"10 1","pages":""},"PeriodicalIF":4.8000,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Updated Observations Provide Stronger Evidence for Increases in Sub-hourly to Hourly Extreme Rainfall in Canada\",\"authors\":\"Alex J. Cannon, Dae-Il Jeong, Ka-Hing Yau\",\"doi\":\"10.1175/jcli-d-23-0501.1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract Global warming is expected to lead to increases in atmospheric moisture and intensify sub-hourly to hourly rainfall extremes. However, signal-to-noise ratios are low, especially at the local scale, making detection of changes in the observational record difficult. For Canada, previous studies based on short data records from 1965-2005 did not show conclusive evidence of increases in short-duration extreme rainfall. This study updates single-site and regional trend analyses of 5 minute to 24 hour annual maximum rainfall in Canada using data from 1950-2021. Estimates of temporal trends are extended to also consider the association between rainfall intensity and dew point temperature, a measure of moisture availability. With longer records, evidence for increases in extreme rainfall at individual sites is stronger. Field significant increasing trends are found for the majority of durations, whereas before results were mixed and typically not statistically significant. Intensification is even more pronounced in single-site scaling of rainfall intensity with summer mean dew point temperature. Field significant positive scaling rates are detected for all durations. When data are pooled in space – irrespective of choice of regionalization – the results are even more clear. Notably, the strongest and most spatially homogeneous intensification of short-duration extreme rainfall is detected in sub-hourly to 2 hour durations. When data are pooled across Canadian climate regions, field significant positive scaling is found in 72.7% to 81.8% of regions for 5 minute to 2 hour durations, with median scaling rates ranging from 5.3 to 9.4% °C−1. For durations ≥ 6 hours, this falls to 27.3% to 53% of regions, with scaling rates less than 4% °C−1.\",\"PeriodicalId\":15472,\"journal\":{\"name\":\"Journal of Climate\",\"volume\":\"10 1\",\"pages\":\"\"},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-03-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Climate\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1175/jcli-d-23-0501.1\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Climate","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1175/jcli-d-23-0501.1","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
Updated Observations Provide Stronger Evidence for Increases in Sub-hourly to Hourly Extreme Rainfall in Canada
Abstract Global warming is expected to lead to increases in atmospheric moisture and intensify sub-hourly to hourly rainfall extremes. However, signal-to-noise ratios are low, especially at the local scale, making detection of changes in the observational record difficult. For Canada, previous studies based on short data records from 1965-2005 did not show conclusive evidence of increases in short-duration extreme rainfall. This study updates single-site and regional trend analyses of 5 minute to 24 hour annual maximum rainfall in Canada using data from 1950-2021. Estimates of temporal trends are extended to also consider the association between rainfall intensity and dew point temperature, a measure of moisture availability. With longer records, evidence for increases in extreme rainfall at individual sites is stronger. Field significant increasing trends are found for the majority of durations, whereas before results were mixed and typically not statistically significant. Intensification is even more pronounced in single-site scaling of rainfall intensity with summer mean dew point temperature. Field significant positive scaling rates are detected for all durations. When data are pooled in space – irrespective of choice of regionalization – the results are even more clear. Notably, the strongest and most spatially homogeneous intensification of short-duration extreme rainfall is detected in sub-hourly to 2 hour durations. When data are pooled across Canadian climate regions, field significant positive scaling is found in 72.7% to 81.8% of regions for 5 minute to 2 hour durations, with median scaling rates ranging from 5.3 to 9.4% °C−1. For durations ≥ 6 hours, this falls to 27.3% to 53% of regions, with scaling rates less than 4% °C−1.
期刊介绍:
The Journal of Climate (JCLI) (ISSN: 0894-8755; eISSN: 1520-0442) publishes research that advances basic understanding of the dynamics and physics of the climate system on large spatial scales, including variability of the atmosphere, oceans, land surface, and cryosphere; past, present, and projected future changes in the climate system; and climate simulation and prediction.