Evening Transition Observations in Phoenix, Arizona
Evening Transition Observations in Phoenix, Arizona
复制标题
亚利桑那州凤凰城的夜间过渡观测
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
E. Pardyjak
中科院分区：
文献类型：
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作者：
A. Brazel;H. Fernando;J. Hunt;N. Selover;B. Hedquist;E. Pardyjak
过去的研究表明，复杂地形下的傍晚转捩通常有几个主要特征，如（a）日落后持续3-5小时的弱上坡流（如果山谷的侧壁阻止科里奥利诱导的风转向），因此意味着延迟转变;（B）地面以上几十米范围内的非定常局部停滞和垂直混合;及（c）在傍晚时分，特别是在较高海拔（较陡）的斜坡上，滞流锋转变为下坡/下坡重力流，并以“斜坡风”的形式抵达毗邻的低海拔缓坡。这种过渡过程通常发生在亚利桑那州凤凰城等地区，该地区在一个方向（西部和南部）有广阔的平原，并在其他方向（主要是北部和东部）与地形突变相邻。对几个自动气象站和雷达风廓线仪的风记录进行了分析，以确定选定的特征风速。
Abstract Past research has suggested that the evening transition in complex topography typically has several main features, such as (a) continued weak upslope flows persisting 3–5 h after sunset (if the sidewalls of the valley prevent Coriolis-induced turning of winds), thus signifying delayed transition; (b) unsteady local stagnation and vertical mixing within tens of meters above the surface; and (c) transition of stagnation fronts to downslope/downvalley gravity currents during the evening hours, especially at higher-elevation (steeper) slopes, and their arrival at adjoining low-elevation gentle slopes as “slope breezes.” This transition process typically occurs in locales such as Phoenix, Arizona, which has expansive exposure to plains in one direction (to the west and south) and is adjacent to abrupt change in the terrain in other directions (primarily to the north and east). An analysis of wind records from several automated weather stations and a radar wind profiler for selected characteristic peri...