The 2001 Phoenix Sunrise experiment: vertical mixing and chemistry during the morning transition in Phoenix
The 2001 Phoenix Sunrise experiment: vertical mixing and chemistry during the morning transition in Phoenix
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DOI：
10.1016/s1352-2310(03)00134-1
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发表时间：
2003-06
影响因子：
5
通讯作者：
J.C Doran;C.M Berkowitz;R.L Coulter;W.J Shaw;C.W Spicer
中科院分区：
文献类型：
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作者：
J.C Doran;C.M Berkowitz;R.L Coulter;W.J Shaw;C.W Spicer
2001年6月在菲尼克斯进行了一次实地试验，以考察在早晨从稳定大气条件向不稳定大气条件转变期间，垂直混合对边界层臭氧化学的作用。地面仪器、位于凤凰城市中心一栋39层建筑两层的仪器，以及一架仪表化的飞机，被用来表征大气最低650米处不断演变的化学物质。利用遥感和现场平台获得了清晨和日出后几个小时的风和温度的详细轮廓。本文着重分析了建筑物上测得的CO、O_3和NO/NO的垂直廓线及其与凤凰城早晨边界层演变的关系。发现这些剖面的一些特征与夜间将污染物捕获在稳定的表层并在第二天早上释放污染物的简单概念性图景一致。然而，在一些日子里，在清晨发现了明显的垂直混合的证据，远远早于日出后对流混合发展的预期时间。可能的原因包括平流、街道峡谷湍流和大范围辐合，但对于观测到的化学剖面的演变还没有找到令人满意的解释。
A field experiment was carried out in Phoenix during June 2001 to examine the role of vertical mixing on the O3chemistry of the boundary layer during the morning transition from stable to unstable atmospheric conditions. Surface instruments, instruments located on two floors of a 39 story building in downtown Phoenix, and an instrumented airplane were used to characterize the evolving chemistry in the lowest 650m of the atmosphere. Remote sensing and in situ platforms were used to obtain detailed profiles of winds and temperatures during the early morning hours and for several hours after sunrise. The analysis presented in this paper focuses on vertical profiles of CO, O3, and NO/NOymeasured on the building and their relationship to the morning boundary layer evolution over Phoenix. Some features of these profiles were found that are consistent with a simple conceptual picture of nighttime trapping of pollutants in a stable surface layer and a subsequent release the following morning. On some days, however, evidence of significant vertical mixing was found during the early morning hours well before the times expected for the development of convective mixing after sunrise. Possible causes include advection, street canyon turbulence, and large-scale convergence, but a satisfactory explanation for the observed evolution of the chemical profiles has not yet been found.