Research on Surface Map Analysis

该项目的目标是改进地面天气图分析，从而改进短期天气预报。业务气象界目前的做法依赖于挪威气旋模式。然而，这些分析中的许多分界线锋面并不像模型所要求的那样与显著的水平温度对比有关。在目前的分析中确定的许多锋面似乎是根据气旋风向变化确定的。这种特征最好用斜压槽来表示，其相关的云和降水不同于与实际锋面相关的云和降水。这项研究将基于对从现有档案中挑选的真实锋面事件的研究。在这些过程中锋面的形成、演变和消散的天气情况将被记录下来。将进行前沿成因计算。这些结果将会相互比较，并与在一系列地图上观测到的温度梯度的变化作比较。PI也将开始对亚利桑那州图森市风向的显著和一致的日变化进行初步调查-夜间为东南风，白天为西北风。据观察，这种变化与陆风和海风一样一致。这种流动结构似乎是由于城市西北部的小山脉和东南部干燥的隆起高原之间的不同水平表面特征造成的。对造成这种流动结构的物理过程进行了研究。这项研究的成功完成可能对业务预报人员以及将其纳入气象课程和教科书具有潜在价值。

The goal of this project is to improve surface weather map analysis and, thus, short-term weather forecasting. Present practice by the operational meteorological community relies on the Norwegian Cyclone Model. Many of these analyses, however, demark fronts not associated with significant horizontal temperature contrast as required by the model. Many fronts identified in current analyses appear to be determined on the basis of a cyclonic wind shift. Such features are better denoted as baroclinic troughs with the associated clouds and precipitation that differ from those associated with actual fronts.The research will be based on study of episodes of real fronts selected from an existing archive. The synoptic circumstances for the formation, evolution and dissipation of fronts in these episodes will be documented. Frontogenetical calculations will be made. The results will be compared with each other and with the observed change in the temperature gradient on a series of maps for each episode.The PI also will begin a preliminary investigation into a pronounced and consistent diurnal change of wind direction at Tucson, Arizona - southeasterly at night and northwesterly during the daytime. This variation has been observed to be as consistent as land and sea breezes. This flow structure appears to be due to the differential horizontal surface characteristics between a small mountain range to the northwest of the city and a dry elevated plateau to the southeast. The physical processes responsible for this flow structure will be investigated. Successful completion of this research can potentially be of value to operational forecasters as well as finding its way into meteorological courses and text books.