伊春近30a大雾天气的统计分析

Statistical Analysis of the Heavy Fog Weather of Yichun in Recent 30 Years

统计分析伊春1979～2008年大雾天气的日变化、月际变化、年际变化规律,伊春大雾多出现在夜间,日出后消散,持续时间以3～6 h为多。大雾主要集中在夏季,其次为春秋两季,而冬季大雾出现很少。20世纪90年代大雾日数最多,2000年以来大雾日数又缓慢减少,但没有明显的周期性。当相对湿度为75%～80%、气温为15～20℃、风速为静风或0～0.5 m/s、气压为980.0～985.0hPa时,出现大雾频率最高。

This article statistically analyses the change rule of Yichun＇s heavy fog weather diurnal variation, month border change, year border change during1979-2008. The heavy fog in Yichun appears at night, dissipates after the sunrise, generally lasts for 3-6 hours. The heavy fog mainly concentrates in the summer, next for spring and autumn, but rarely appears in the winter The great ibggy day was to be highest in 1990s, entered 2000 year great foggy day slowly reduced, but it did not have the obvious periodicity. The frequency of bad fog is the highest,when the relative humidity is 75%-80%, temperatures for 15-20 ℃, the wind speed for the still or 0-0.5 m.s^-1, the barometric pressure is 980.0-985.0 hPao