| 摘要: |
| 本文利用观测资料对南充市雾的特征进行研究分析，结合实况和预报数据建立南充市辐射雾回归模型。通过国家级地面观测站逐日地面观测资料，采用14：00实测值法统计分析得出南充雾（水平能见度＜1000m）的时空分布特征：1980-2014年南充雾日总体呈波动下降趋势，雾日数最多月份集中在1月（全市平均15.9d）、12月（全市平均15.7d）；通过分析2012-2017年实况资料发现南充本地雾以辐射雾（85.7%）、平流雾（13%）两大类型为主，平流-辐射混合雾仅占1.3%，同时得出区分辐射雾和平流雾的天气概念模型及量化指标；辐射雾通常出现在晴空少云区，天气图上表现为：500hPa南充上游为西北气流或偏西气流、700hpa 南充以西风为主、850hPa通常为弱的暖性结构、925hPa以下层面为弱上升运动，以西南风为主； 平流雾易出现在500hpa南充上游西北方向甘肃一带以稳定西风带气流为主或有浅槽及南充本地多西南气流、700hpa、850hpa南充附近以偏南风为主。南充2015-2017年大雾个例对应的高空、地面填图资料和ECMWF0.125°×0.125°产品，通过相关性检验确定6个因子，建立南充本地24h辐射雾回归模型，其中700hpa相对湿度贡献率最高、1000hpa相对湿度贡献率次之，通过检验正确率73.8%。 |
| 关键词: 雾的特征分析 ;预报模型 ;预警技术 |
| DOI： |
| 投稿时间：2018-11-16修订日期：2019-03-25 |
| 基金项目:南充雾(霾)过程基本特征与预警技术集成和南充市重大气象灾害预警与评估协同创新团队 (2016002) 共同资助。 |
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| Analysis of Fog Characteristics and Early Warning Technology of Radiation Fog in Nanchong |
| LIUSHUHUI,李梦,liuyuanjiang |
| (NanChong Meteorologic Bureau;NanBu Meteorologic Bureau) |
| Abstract: |
| In this paper, the characteristics of fog in Nanchong were studied and analyzed by using the observed data, the radiation fog regression model of Nanchong city was established based on the real-time data and forecast data. Based on daily ground observation data of national ground observation stations, and used the 14:00 measured data, we obtained the spatial and temporal distribution characteristics of fog in Nanchong(horizontal visibility < 1000m) through statistical analysis: the general trend of fog in Nanchong has been a trend of fluctuating downward from 1980 to 2014, the months with the largest number of foggy days are January(15.9d), December(15.7d) ,respectively. Based on the observation data of upper air and ground from 2012 to 2017, it was found that the local fog in Nanchong was dominated by radiation fog (85.7%) and advection fog (13%), and advection and radiation mixed fog accounted for only 1.3%. we obtained the conceptual weather models and quantitative indexes for distinguishing between radiation fog and advection fog; Radiation fog tended to occur in areas with clear skies and few clouds, at 500hPa, the upstream region of Nanchong was the northwest airflow or the west-oriented airflow; at 700hpa, Nanchong was dominated by westerly winds; at 850hPa, it was usually a weak warm structure; at the level below 925hPa, it was a weak upward movement, dominated by southwest wind; Radiation fog tended to occur in areas: at 500hPa, in the upstream and northwest of Nanchong, Gansu area was dominated by the airflow of the stable westerly belt or had shallow trough, while in Nanchong, there were more local southwest airflow; at 700hpa and 850hpa, the area around Nanchong was dominated by southerly winds. According to the upper air and ground mapping data of the individual cases of fog in Nanchong from 2015 to 2017 and ECMWF0.125°x 0.125°forecast products, six factors were identified by correlation test, the linear equation of multiple regression method was established for the local 24h radiation fog model in Nanchong, the contribution rate of 700hpa relative humidity was the highest, followed by 1000hpa relative humidity, the accuracy rate of passing the test was 73.8%. |
| Key words: analysis of fog characteristics; forecasting model; early warning technology |
