天津地区雾霾低能见度短临预报预警方法研究  

Research on method of short-impending prediction and early warning for foghaze in Tianjin

作　　者：王雪娇 杨旭 孙玫玲 蔡子颖 郭玲 张希帆 WANG Xuejiao;YANG Xu;SUN Meiling;CAI Ziying;GUO Ling;ZHANG Xifan(Tianjin Key Laboratory for Oceanic Meteorology,Tianjin 300074;Tianjin Meteorological Service Center,Tianjin 300074;Tianjin Environmental Meteorological Center,Tianjin 300074)

机构地区：[1]天津市海洋气象重点实验室,天津300074 [2]天津市气象服务中心,天津300074 [3]天津市环境气象中心,天津300074

出　　处：《环境科学学报》2023年第4期93-101,共9页Acta Scientiae Circumstantiae

基　　金：天津市科技计划项目(No.18ZXAQSF00130);天津市气象局科研项目(No.202229ybxm13);天津市海洋气象重点实验室开放基金项目(No.2022TKLOM06)。

摘　　要：雾霾低能见度天气对海事交通有显著的影响,当能见度低于3 km时天津港航道采取单向通航管理,能见度低于1 km时封航管理,基于港口海事交通气象服务需求,以天津港为例,采用多种方法开展基于观测的雾霾低能见度0~12 h短临预报预警技术研究.通过分钟级能见度观测的跃迁信号分析、基于观测的未来1 h能见度递推和能见度数值模式三维变分同化3种方法,分别实现60 min内、1~2 h、12 h多时间尺度无缝隙的能见度短临预报预警.结果表明:(1)浓雾天气来临前,大概率会出现“象鼻形”先期振荡,称为象鼻效应.当夜间能见度低于或者接近1 km时,超过200 m能见度异常升高定义为跃迁信号(未有明显天气系统变化,且出现在日出前),通过港口分钟级的能见度观测,能够提前30~60 min清晰捕捉低于200 m的浓雾天气,跃迁信号可作为未来低能见度短临预报预警的指示.(2)以能见度和相对湿度观测为基础,结合数值模式预测影响能见度变化趋势的PM_(2.5)质量浓度和相对湿度的未来1~2 h变量,根据消光经验公式构建基于观测的短临递推能见度预报方法.实测数据表明,提前1 h能见度预报值与观测值相关系数为0.95,平均相对误差为14.7%.(3)基于三维变分同化模块将观测的能见度和PM_(2.5)质量浓度融入模式初始场,使得模式污染初始场快速逼近观测场,以提升1~12 h能见度预报能力.实测数据表明,1 h能见度预报值与观测值之间的相关系数为0.94,平均相对误差为22.5%;12 h内能见度预报值与观测值之间的相关系数为0.86,平均相对误差为33.3%.Fog-haze weather has a significant impact on maritime traffic.When visibility is less than 3 km,Tianjin Port channel adopts one-way navigation management.And when visibility is less than 1 km,Tianjin Port channel adopts closure management.Based on the demand for maritime traffic meteorological services and taking Tianjin Port as an example,this paper studied the technique of short-impending prediction and early warning for fog-haze of 0~12 h based on observance by various methods.Using three methods that transition signal analysis of minute-level visibility observation,visibility recursion of 1 h based on observation and 3-DVAR assimilation of visibility numerical model,we achieved short-impending prediction and early warning with multiple and seamless timescale of 60 minutes,1~2 hours and 12 hours,respectively.①The results showed that there was a high probability of"elephant-nose"early oscillation before the fog happened,known as the elephant-nose effect.When the visibility at night was lower than 1km,the abnormal increase of visibility over 200 m was defined as the transition signal(there was no significant weather system change and it occurred before sunrise).By the visibility observation on the order of minutes in port,the fog-haze weather of less than 200 m could be clearly captured 30~60 minutes early,and the transition signal could be used as the indicator for the short-impending prediction and early warning of low visibility.②Based on the observation of visibility and relative humidity,the 1~2 h variables of PM_(2.5)concentration and relative humidity that affected the change trend of visibility were predicted with the numerical model.Then according to the extinction empirical formula,we constructed the visibility prediction method of short-impending recursion based on observation.The results indicated that the correlation coefficient between the visibility of forecast and observation was 0.95,and the average relative error was 14.7%.③According to the 3-DVAR assimilation of visibility numerical mode

关 键 词：天津港 象鼻效应 短临递推 三维变分同化 数值预报 

分 类 号：X513[环境科学与工程—环境工程]