| 摘要: |
| 【目的】为了分析江西主汛期（４—７月）降水日变化特征。【方法】利用 ２００１—２０２０年江西省 ８７个国家气象观测站和 ２０１１—２０２０年江西省 ７３６个区域气象监测站逐小时降水数据，采用气候统计方法进行分析研究。【结果】（１）江西省主汛期降水量、降水频次的日变化总体为双峰结构特征，降水量的主峰值出现在 １８时前后，降水频次的主峰值在 ２０时前后。（２）降水日变化有明显的区域差异，赣北沿江地区和赣北其他地区的降水量、降水强度主峰值多出现在清晨到上午，赣中和赣南的降水量、降水频次、降水强度主峰值多出现在午后到傍晚。（３）不同持续时间降水事件，降水日变化也不同，并且不同区域不同月份降水日变化还有差异，≥６ｈ持续性降水事件的降水量峰值易出现在清晨到上午，这一特征在 ６月更为显著；而 ＜６ｈ降水事件的降水量峰值则易出现在午后到傍晚，这一特征在 ７月份最为明显。（４）一般性降水（＜２０ｍｍ·ｈ－１）、短时强降水（≥２０ｍｍ·ｈ－１）和 ５ａ一遇的小时极端降水，有双峰特征，一般性降水量主峰出现在 １６时前后，而短时强降水和 ５ａ一遇的小时极端降水主峰在 １８时前后。（５）纬度接近的河谷、平原测站降水日变化存在差异，鄱阳湖平原的观测站降水量日内大部分时段较信江、昌江河谷偏少；海拔高度不同的观测站降水日变化存在差异，赣南山区海拔偏高的观测站降水量较海拔偏低的观测站在白天各时段都要大，差异最大时段出现在 １６—１８时。【结论】通过以上分析结果，进一步提高了对江西主汛期复杂降水过程的认识，为数值模式降水产品的订正和应用提供了科学依据。 |
| 关键词: 降水日变化，降水量，降水频次，区域差异 |
| DOI： |
| 投稿时间：2023-10-17修订日期：2024-05-07 |
| 基金项目:江西省气象局2021年面上项目《2018年到2020年江西区域梅雨锋强降水过程的数值预报检验评估》 |
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| Diurnal Variation Characteristics of Precipitation in Jiangxi Province During the Main Rainy Season from 2001 to 2020 |
| hongjun,Chen Haoming,Wu Wenxin,Xiang Zhengxin,Lai Shiqi |
| (Shangrao Meteorological Bureau;state Key laboratory of Severe Weather, Chinese Academy of Meteorological Sciences) |
| Abstract: |
| This article uses hourly precipitation data from 87 national basic meteorological stations in Jiangxi Province from 2001 to 2020 and 736 regional meteorological monitoring stations in Jiangxi Province from 2010 to 2020, and uses climate statistical methods to analyze the daily variation characteristics of precipitation during the main flood season (April July) in Jiangxi. The results indicate that: 1) The overall daily variation of precipitation and precipitation frequency during the main flood season in Jiangxi Province is characterized by a bimodal structure, with the main peak of precipitation occurring around 18:00 and the main peak of precipitation frequency around 20:00. 2) The diurnal variation of precipitation has regional differences. The main peak time of precipitation and intensity in the northern Jiangxi region along the Yangtze River and other northern Jiangxi regions mostly occurs from morning to morning, while the precipitation, frequency, and intensity in central and southern Jiangxi mostly occur from afternoon to evening. 3) There are also monthly differences in the daily variation of precipitation, and it is related to the duration of precipitation events. The peak precipitation of ≥ 6h continuous precipitation events is prone to occur from morning to morning, which is more prominent in June, while the peak precipitation of ≤ 4h precipitation events is prone to occur from afternoon to evening, which is most obvious in July. 4) General precipitation (<20mm . h-1), short-term strong precipitation (≥ 20mm . h-1), and hourly extreme precipitation with a 5-year return period have a bimodal feature. The main peak of general precipitation is at 16:00, while short-term strong precipitation and hourly extreme precipitation with a 5-year return period are at 18:00. 5) There are differences in daily precipitation changes between river valleys and plain stations with similar latitudes. The precipitation at the selected stations in the Poyang Lake Plain is mostly lower during the day than in the Xinjiang and Changjiang river valleys; There are also differences in the daily variation of precipitation at different altitudes of stations. The precipitation at stations with higher altitudes in the mountainous areas of Gannan is greater than that at stations with lower altitudes at all times of the day, with the maximum difference occurring from 17:00 to 18:00 |
| Key words: Daily variation of precipitation， precipitation，Precipitation frequency，Regional differences |
