1 JUNE 2013 | SETH WESTRA, LISA V. ALEXANDER, FRANCIS W. ZWIER
This study investigates trends in annual maximum daily precipitation data from 8326 high-quality land-based stations with over 30 years of records from 1900 to 2009. Two statistical methods were used: the Mann–Kendall test for monotonic trends and a nonstationary generalized extreme value analysis to assess the relationship between precipitation extremes and global near-surface temperature. Results show statistically significant increasing trends in precipitation at the global scale, with two-thirds of stations showing increases. The median intensity of extreme precipitation changes in proportion to global mean temperature at a rate of 5.9–7.7% K⁻¹, consistent across different record lengths and time periods. There is a distinct meridional variation, with the greatest sensitivity in the tropics and higher latitudes, and minima around 13°S and 11°N. The equator has the greatest uncertainty due to limited long records. The study also finds a significant positive association between annual maximum precipitation and global near-surface temperature, with a global median sensitivity of 7.7% K⁻¹. The results are consistent across different data periods and are not strongly biased by uneven global coverage. The study highlights the importance of improving data collection in the tropics to better understand future changes in precipitation. The findings suggest that extreme precipitation is increasing in line with warming, but other factors like atmospheric circulation may also play a role. The results apply to daily time scale precipitation extremes and may not be directly applicable to shorter durations.This study investigates trends in annual maximum daily precipitation data from 8326 high-quality land-based stations with over 30 years of records from 1900 to 2009. Two statistical methods were used: the Mann–Kendall test for monotonic trends and a nonstationary generalized extreme value analysis to assess the relationship between precipitation extremes and global near-surface temperature. Results show statistically significant increasing trends in precipitation at the global scale, with two-thirds of stations showing increases. The median intensity of extreme precipitation changes in proportion to global mean temperature at a rate of 5.9–7.7% K⁻¹, consistent across different record lengths and time periods. There is a distinct meridional variation, with the greatest sensitivity in the tropics and higher latitudes, and minima around 13°S and 11°N. The equator has the greatest uncertainty due to limited long records. The study also finds a significant positive association between annual maximum precipitation and global near-surface temperature, with a global median sensitivity of 7.7% K⁻¹. The results are consistent across different data periods and are not strongly biased by uneven global coverage. The study highlights the importance of improving data collection in the tropics to better understand future changes in precipitation. The findings suggest that extreme precipitation is increasing in line with warming, but other factors like atmospheric circulation may also play a role. The results apply to daily time scale precipitation extremes and may not be directly applicable to shorter durations.