基于溃变理论的沙尘大风天气预测研究

依据溃变理论和溃变V-3θ结构图的信息数字化,预测天气的转折性变化取得了应用的有效性突破。文中针对沙尘大风天气的预测分析,利用单站探空资料的特性层资料,通过V-3θ图直观反映大气层结的滚流方向、稳定度和水汽含量等信息,以此判断大风、沙尘天气的转折性变化。结果表明,沙尘大风发生前,V-3θ图中位温(θ)、露点温度的假相当位温(θsed)曲线非常靠近,θ曲线左倾明显,整层大气存在顺滚流,且对流层上层存在"超低温"现象;当θsed曲线数值增大,明显靠右,则表明沙尘大风天气将结束。溃变图方法显示了简捷、直观和应用有效的特征。

Study of Dust Windy Weather Forecasting Based on“Blown-up”Theory

Based on ＂blown-up＂theory and the digitalized V-3θ diagrams,the prediction for turning change of weather makes effective breakthrough. To predict and analyze dust wind,the characteristic layer data from sounding,and the tumble-flow direction,layer stability,moisture amount and other information reflected from V-3θ diagrams are used to judge the turning change of weather.The results show that dust wind will emerge when potential temperature θ curve is near θsedcurve very closely,θ curve left-leans obviously,＂clockwise＂tumble flow arises in troposphere and super-cool temperature appears at the upper troposphere. When θsed values increase and θsedcurve right-leans obviously,the dust wind will terminate. It implies that the ＂blown-up＂diagram method presents features of succinctness,direct-viewing and effective application.