Climatic Characteristics And Forecast Of Heavy Fog In Jinnan Region

With the rapid development of national economy, heavy fog has brought moreaffect to traffic and people's daily life, especially with the construction of expresswayhas increasingly enhanced, the rate of accidents caused by heavy fog has alsoincreased. The accidents caused by fog result in lots of injuries and deaths, but alsolead to large economic loss. So it has received more attention from communicationdepartments and other units.Using the history data of heavy fog in Jinnan region, the forming mechanismand the climatic features and the regional characteristics of heavy fog are analyzed.The results show that the surface layer humidity, a lower temperature, the breeze andthe low altitude inversion layer are the necessary conditions of forming fog. Thedistribution of fog in Jinnan region presents the characteristics of having more fog inthe basin area and few in the mountainous area. The heavy fog can form in eachmonth of a year. Fog mainly appears in the autumn and the winter, spring andsummer foggy day less, The occurring frequency of heavy fog during November isthe most, and that during May is the least. Studied the change of heavy fog ofannual and interannual in Jinnan region, the results show that it has the increasetendency and the obvious long-term trend, and has the oscillation period of 6.7a and4a. It has the obvious increasing trend during 1960s～1980s, and slightly decreasingduring 1990s. The formation and dissipation and continue time of fog are studied.The frequency of forming fog mainly concentrates from 5 to 8 BST, 6～7 o'clock isthe highest fog production time; The fog dissipated time mainly concentrates from7to 13 BST, the highest dissipated time is during 8～10 o'clock. The fog continue timeis long during December and January, and short during August. The circulation of Jinnan fog are summarized, the straight westerly wind or theweak southwest air current and high pressure (non-high pressure center) in surfacein Hetao area are the main circulation which the Jinnan heavy fog produced; Byusing the method of index disappear and traditional forecast method, the objectiveforecasting method of Jinnan heavy fog is studied. The fitting test has been better,and the forecast method can be operated in the actual weather forecast.The system of monitor early warning and forecast has been established, mainlyusing the modernized meteorology equipment (satellite cloud chart, weather radar,meteorological ground and high observation station, environment meteorologyinspection siation) and MICAPS2.0 establish the Jinnan fog early warning andforecast model.