钱忠华,周前进,刘莉,封国林. 2020. 中国东部雨季降水事件的静默时间特征及存在动力学机制初探[J]. 气象学报, (0):-, doi:10.11676/qxxb2020.068
中国东部雨季降水事件的静默时间特征及存在动力学机制初探
Preliminary research on the characteristics of quiet time and the dynamic mechanism of precipitation events in the rainy season in eastern China
投稿时间:2019-09-02  修订日期:2020-06-01
DOI:10.11676/qxxb2020.068
中文关键词:  静默时间,时空演化,幂律分布,自组织临界
英文关键词:quiet  time, spatiotemporal  evolution, power  law distribution, self-organized  critical
基金项目:国家自然科学基金,国家重点研发计划
作者单位E-mail
钱忠华 扬州大学 qianzh@yzu.edu.cn 
周前进 扬州大学 17712586795@163.com 
刘莉 南京信息工程大学 liyoyuliu@163.com 
封国林 国家气候中心中国气象局气候研究开放实验室 fenggl@cma.gov.cn 
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中文摘要:
      基于1960-2017年4-9月的中国日降水数据,利用百分位阈值法确定不同强度的降水事件,定义相邻同强度降水事件之间的时间间隔为“静默时间”以描述同阈值降水事件再次发生的历时长短。计算“平均静默时间”以表征不同强度降水事件的群发性特征,即某一时间段内,平均静默时间越小(大),同类型降水事件再次发生的历时越短(长),其群发性程度越强(弱)。分析不同强度降水事件的平均静默时间在中国东部地区的空间分布和时间演变特征,并探究其可能遵循的非线性动力学特征。结果表明: 1960-2017期间,一般强度降水事件在长江中游地区较其余地区群发性强,而东北南部地区则较弱; 极端降水事件在中国东部北方地区群发性较强,而在南方地区则偏弱。就气候态演化过程而言,一般强度降水事件的群发性在长江以南地区有所增强,在东北南部地区表现则呈减弱趋势。极端降水事件的群发性特征在中国东部北方地区不断减弱,但在南方地区持续增强。此外,降水以及垂直速度和相对湿度的静默时间概率密度分布的均具有幂律性和无标度性特征,说明我们可通过具有相似无标度性特征的沙堆模型(自组织临界模型)的理论标度函数来描述降水事件。因此,我们可以将极端降水事件的发生视为自组织临界系统的由量变向质变转换的崩塌行为,进而有助于从时间序列分析的角度对东亚降水事件形成的非线性动力学机制给出新的解释。
英文摘要:
      Based on the daily precipitation data from April to September of 1960-2017.The intensities of precipitation is determined by the percentile threshold method and the time interval between adjacent same-intensity precipitation events is defined as “quiet time” to describe the duration of the recurrence of the same intensity precipitation. Then using the "average quiet time" to characterize the characteristics of different intensity precipitation events’ massive feature. Specifically, in a certain period, the intervals are shorter (long) for the recurrence of the same type of precipitation event while the stronger (weak) the degree of clustering of precipitation events become, if the average quiet time is smaller (larger). Next, the spatial and temporal evolution characteristics of the average quiet time of different intensity precipitation events in eastern China are given. Deeply analysis will also focus on the nonlinear dynamic characteristics of the precipitation. The final results show that the massive feature of general intensity precipitation event was stronger in the middle regions of the Yangtze River than in other areas while the southeastern part was weaker; The massive feature of extreme precipitation events was stronger in the northern part of China but the opposite in the south from 1960 to 2017. As far as the climatic state evolution process is concerned, the massive feature of the general intensity precipitation group has a certain enhancement in the south of the Yangtze River, and the weakening trend in the southeastern part of the eastern part of China; The cluster characteristics of the extreme precipitation events are weakening in the northeastern part of China but the opposite in the south. In addition, it further reveals that the probability distribution of the quiet time of different threshold precipitation vents and the time interval of the sand collapse (self-organized critical classical model) are in good agreement with the power law distribution and the scale-free feature, the same feature are also found in the distribution of the quiet time of the vertical velocity and relative humidity which have a direct impact on the formation of precipitation. Finally, we find that a theoretical scale function can be used to describe the precipitation events who have a self-organized critical characteristic and the extreme precipitation events can be treated as the collapse behavior that from the quantitative change to the qualitative change of the self-organized critical systems. Finally, a new interpretation of the nonlinear dynamic mechanism of precipitation events in East Asia can be given through the perspective of time series analysis.
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