石岛地区1991~2020年气候特征分析

Analysis of Climatic Characteristics of Shidao Area from 1991 to 2020

摘要: 为明确石岛地区近30年来的气候特征及变化规律，基于石岛气象台1991~2020年地面气象观测站资料，采用气候倾向率方法对石岛地区各气象要素的变化特征进行了分析，结果表明：(1) 石岛地区多年平均气温为12.4℃，具有由冷变暖的特点，平均气温气候倾向率以0.18℃∙(10a)⁻¹上升，增温幅度从大到小依次为：年平均日最高气温 > 年平均气温 > 年平均日最低气温。春季、夏季气温为变暖趋势，冬季气温为变冷趋势。对石岛地区增温贡献最大的是夏季；(2) 30年降水量平均值为740.9 mm，降水量以21.11 mm∙(10a)⁻¹的速率增加；降水日数呈下降趋势，以11天∙(10a)⁻¹的速率减少。出现最多的降雨量级为小雨，其次为中雨、大雨。春、夏季降水量呈增加趋势，秋、冬季呈降低趋势。(3) 石岛日最大风速平均值在5.4~8.1 m∙s⁻¹，30年平均值为7.0 m∙s⁻¹，每10年下降0.39 m∙s⁻¹；春季平均风速最大，冬季次之；一年中4月份平均风速最大；北风、西北风、西南风风力较大，最大风向为北风，风速最小的是东风；出现频率最多的风为SSW，出现频率最小的是东风；年均大风日数19 d，每10年下降5.4 d；大风集中发生在春季、冬季；偏北大风占总大风次数的77%。(4) 石岛地区年日照时数的多年平均值为2434.8 h，呈显著的下降趋势，趋势率达18.0 h/10年；年平均日照百分率在47.6%~65.8%，多年平均日照百分率55.7%；5月日照时数最多，7月最少。

Abstract: To clarify the climate characteristics and change patterns of Shidao area over the past 30 years, based on the ground meteorological observation data of Shidao Meteorological Station from 1991 to 2020, the climate tendency rate method was adopted to analyze the variation characteristics of various meteorological elements in Shidao area. The results show that: (1) The multi-year average temperature of Shidao area is 12.4˚C, showing a warming trend. The climate tendency rate of average temperature is 0.18˚C∙(10a)⁻¹, with the warming amplitude from large to small being: annual average daily maximum temperature > annual average temperature > annual average daily minimum temperature. The temperature in spring and summer shows a warming trend, while that in winter shows a cooling trend. The contribution to warming in Shidao area is the greatest in summer. (2) The average annual precipitation over 30 years is 740.9 mm, with an increasing rate of 21.11 mm∙(10a)⁻¹. The number of precipitation days shows a decreasing trend, with a rate of 11 days∙(10a)⁻¹. The most frequent precipitation intensity is light rain, followed by moderate rain and heavy rain. The precipitation in spring and summer shows an increasing trend, while that in autumn and winter shows a decreasing trend. (3) The average daily maximum wind speed in Shidao area is between 5.4 and 8.1 m∙s⁻¹, with a 30-year average of 7.0 m∙s⁻¹, decreasing by 0.39 m∙s⁻¹ every 10 years. The average wind speed is the highest in spring and the second highest in winter. The average wind speed is the highest in April throughout the year. The wind force is relatively strong in the north, northwest and southwest directions, with the maximum wind direction being north and the minimum wind speed being east. The most frequent wind direction is SSW and the least frequent is east. The average number of strong wind days per year is 19, decreasing by 5.4 days every 10 years. Strong winds mainly occur in spring and winter. Northerly strong winds account for 77% of the total strong wind days. (4) The multi-year average annual sunshine duration in Shidao area is 2434.8 hours, showing a significant downward trend, with a tendency rate of 18.0 hours/10 years. The annual average sunshine percentage is between 47.6% and 65.8%, with a multi-year average of 55.7%. The duration of sunshine is the longest in May and the shortest in July.