海南岛霾高发月异常年的海气特征

Ocean-Atmosphere Characteristics of Haze Peak Months Anomalous Years in Hainan Island

利用海南岛18个国家地面气象站1981—2014年的气象观测资料和再分析资料,分析了海南岛霾的时空分布特征和霾高发月异常年的大气环流和海洋表面温度特征,为霾的月气候预测提供依据.结果表明:海南岛霾日多发生于当年10月至翌年2月,当年12月最多.各地霾高发月的霾日数以北部内陆和中部山区较多,东南部沿海地区几乎没有霾出现.霾高发月异常年的海气特征具有一定的相似性.大部分月份(10月除外)霾偏多(少)年一般呈现出类似拉尼娜(厄尔尼诺)状态年的海温分布型,使850 hPa风场上海南岛受到异常的偏北(南)气流控制,有利于(不利于)我国大陆地区污染物向海南岛的输送,并使降水减少(增多)削弱(增强)其对污染物的清除作用;霾偏多年500 hPa位势高度场上海南岛为正距平,不利于污染物的垂直扩散,有利于霾日数偏多.但不同月份的霾偏多、偏少年这些异常特征的配置有所不同.

In the report,the meteorological observation data of 18 national meteorological stations in Hainan Island and reanalysis data during 1981 to 2014 were used to analyze the spatial and temporal distribution characteristics and the characteristics of atmospheric circulation and sea surface temperature of anomalous years in haze peak months,and provide the basis for the monthly climate prediction of haze.The results indicated that Haze days occurred mostly from October to February,with the most in December;There were more haze days of haze peak months in the northern inland and central mountainous areas,however,there were almost no haze days in southeast coast.The ocean-atmosphere characteristics of anomalous years in each haze peak month have certain similarity.Generally,the distribution of La Ni?a(El Ni?o)state years are presented in most months(except October)of more(less)haze years,Hainan island is controlled by abnormal northerly(southerly)air flow at 850 hPa wind field,which is favorable(unfavorable)for the transport of pollutants from Chinese mainland to Hainan Island,and reduce(increase)the precipitation to weaken(enhance)the purging of pollutants;Hainan Island is positive anomaly in potential height field at 500 hPa,which is not conducive to the vertical diffusion of pollutants,and it resulted in more haze days.However,the configuration of these abnormal characteristics was different in different months.