Variations in tropospheric ozone related to transport at
Variations in tropospheric ozone related to transport at
复制标题
对流层臭氧的变化与运输有关
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
S. Oltmans
中科院分区：
文献类型：
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作者：
J. Harris;S. Oltmans
利用聚类分析总结了美属萨摩亚10年来的等熵轨迹，以描述其流动模式。然后将这些轨迹与地面臭氧数据配对，以确定地面臭氧对运输的依赖性。影响地面臭氧的两种主要输送方式是信风输送和中纬度输送，信风输送的轨迹显示气流将臭氧从热带海洋边界层的东部带到中纬度，中纬度输送的轨迹显示在南部中纬度较高的海拔地区有强烈的西风气流，然后以反气旋曲率下降。这两种传输机制产生的臭氧来源明显不同，具有不同的混合比。运输类型的季节性变化的频率被证明是部分负责萨摩亚表面臭氧的季节性周期和变化的变异。平均而言，45%的冬季臭氧变化可以解释运输类型的差异。然而，在1991年，这种强烈的关系并不存在，这可能是因为皮纳图博火山喷发产生的气溶胶阻挡了紫外线。1992年冬季臭氧柱总量的减少可能是导致该季节的地面臭氧水平最低的原因。
Ten years of isentropic trajectories were summarized using cluster analysis to describe flow patterns for American Samoa. The trajectories were then paired with surface ozone data to determine the dependence of surface ozone on transport. The two main transport regimes affecting surface ozone are trade wind transport, where trajectories show flow bringing ozone from the east in the tropical marine boundary layer, and midlatitude transport, where trajectories show strong westerly flow at higher elevations of southern midlatitudes, followed by descent with anticyclonic curvature. These two transport regimes yield ozone from distinctly different origins, having different mixing ratios. The seasonally changing frequency of transport type is shown to be partly responsible for the seasonal cycle and changes in variability of Samoa surface ozone. On average, 45% of winter ozone variation can be explained by differences in transport type. This strong relationship was absent, however, during 1991, probably because of UV blocking by aerosols from the eruption of Mount Pinatubo. Reduced total column ozone during winter 1992 may have contributed to this season having the lowest surface ozone levels of the study period.