巴音布鲁克区域大气可降水量变化特征及其与降水的关系OA

Investigating the relationship between atmospheric precipitable water vapor(PWV)and precipitation is helpful not only for revealing regional cloud-precipitation physical characteristics and water cycle mechanisms,but also for providing key technical support for disaster prevention and mitigation,water resource utilization,and ecological protection.Based on hourly ground-based GPS atmospheric PWV data and precipitation data from Jan-uary 2021 to December 2025,and focusing on the climate-sensitive alpine region of Bayanbuluk as the study ar-ea,the temporal variation characteristics of PWV and its correlation mechanisms with precipitation were investi-gated.The results show that:(1)Both PWV and precipitation exhibit unimodal distributions at the monthly scale,with peak values occurring from June to August and troughs from December to February.At the daily scale,cumulative precipitation shows a notable increasing trend with PWV growth,indicating close synergistic variations between PWV and precipitation in the study area.(2)Before the occurrence of light rain events,the PWV peak usually appears 6 to 8 h earlier,while for moderate rain and heavy rain events,the lead time is rela-tively consistent,mainly 3 to 7 h before precipitation onset.This indicates that as the interval between the PWV peak and the start of precipitation becomes shorter,events with larger precipitation magnitudes are more likely to occur.(3)For events with rainfall intensities of R≤2.0 mm and 4.1 mm≤R≤6.0 mm at precipitation onset,the PWV peak mostly occurs 6 to 10 h before precipitation;for the 2.1 mm≤R≤4.0 mm range,it mostly occurs 5 to 7 h before;and for R≥6.1 mm,the PWV peak mostly occurs 3 to 6 h before.This indicates that as the interval be-tween the PWV peak and precipitation onset becomes shorter,the hourly precipitation at the initial moment tends to be larger.(4)When the duration of precipitation is less than 5 h,the precipitation conversion rate is generally high,exceeding 8.0%,while for durations of 5-14 h,the conversion rate is generally low,mostly less than 5.0%.In addition,the average precipitation conversion rate is highest for moderate rainfall events and R≥6.1 mm rain-fall intensity events in the afternoon,exceeding 11.3%and 40.0%,respectively.