2023年夏季山东降水异常特征及成因分析

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中图分类号：P461.2 文献标志码：A 文章编号：2096-3599（2025）04-0097-08

DOI：10.19513/j.cnki.hyqxxb.20240725001

Analysis on characteristics and causes of summer precipitation anomalies in Shandong in 2023

AbstractIn 2O23， the average summer precipitation in Shandong was 414.4 mm， 1.0% less than that in normal years. The precipitation processs were less，and the precipitation was mainly caused by Typhoon Doksuri.If the typhoon precipitation was removed，the summer precipitation in Shandong would be 15.9% less than that in normal years.Based on the daily precipitation observation data of 122 national meteorological stations in Shandong from 1961 to 2023 and ERA5 monthly reanalysis data，this study analyzes the characteristics of summer precipitation in Shandong in 2O23 and explores the circulation patterns during the early-onset El Nino years.The results are as folows.In summer，the western section of the western Pacific subtropical high lies southward and the conditions for transfer of water vapor are poor，accompanied with positive geopotential height anomalies over Lake Baikal and weaker cold air affecting Shandong，which directly cause the less summer precipitation.The year 2O23 featured an earlyonsetEl Nino event.During such early-onset El Nino years，anomalously cold sea surface temperatures in the western Pacific trigger anomalous Walker circulation，consequently inducing a weakened and southward-displaced Hadley cell，while concurrently intensifying the Ferrel cell. Consequently，the western Pacific subtropical high shifts southward，and with subsiding airflow prevailing particularly over Shandong and insufficient moisture transport，the summer precipitation is suppressed.

Keywordssummer precipitation anomaly；western Pacific subtropical high；early-onset El Nino

0 引言

为暖温带季风气候区，受特殊地理位置影响，其属于南北气候的中间过渡带，气候的影响因素复杂，区域气候差异大，是短期气候预测的难点地域之一。（剩余8978字）