Insight from ozone and water vapour on transport in the tropical tropopause layer (TTL)
Insight from ozone and water vapour on transport in the tropical tropopause layer (TTL)
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DOI：
10.5194/acp-11-407-2011
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发表时间：
2010-10
影响因子：
6.3
通讯作者：
F. Ploeger;S. Fueglistaler;J. Grooß;G. Günther;P. Konopka;Y. Liu;R. Müller;F. Ravegnani;C. Schiller;A. Ulanovski;M. Riese
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作者：
F. Ploeger;S. Fueglistaler;J. Grooß;G. Günther;P. Konopka;Y. Liu;R. Müller;F. Ravegnani;C. Schiller;A. Ulanovski;M. Riese
抽象的。我们探讨了臭氧观测限制热带对流层顶层（TTL）的传输过程的潜力，并将其与可以从水蒸气中获得的见解进行对比。全球领域的卤素掩星实验（HALOE）和现场观测预测使用的反向轨迹的方法，捕捉平流，瞬时冷冻干燥和光解臭氧的生产。两种不同的运输表示（运动学和非绝热3个月的反向轨迹的基础上的ERA中期数据）被用来评估运输的差异的敏感性。结果表明，这两种示踪剂的平均廓线和季节性可以合理地重建。两种传输表示的水汽预测是相似的，但对臭氧的预测在运动学传输方面系统性较高。与全球HALOE观测相比，非绝热模式的预测低估了臭氧垂直梯度。在热带SCUT-O3运动的运动学预测与观测结果的比较表明，390 K以上的位温有很大的偏差。我们表明，臭氧的预测和垂直扩散的轨迹是高度相关的，使臭氧一个有趣的示踪剂方面的运输水蒸气是不敏感的。我们发现，分散和平均上升流对臭氧剖面有类似的影响，较慢的上升流和较大的分散都导致较高的臭氧浓度。基于平均传输特征的热带上升流分析和模型验证必须考虑到热带臭氧生产和平流层混合之间的这种模糊性。反过来，臭氧对TTL层和平流层下部的传输产生了限制，而这是水蒸气所不能提供的。
Abstract. We explore the potential of ozone observations to constrain transport processes in the tropical tropopause layer (TTL), and contrast it with insights that can be obtained from water vapour. Global fields from Halogen Occultation Experiment (HALOE) and in-situ observations are predicted using a backtrajectory approach that captures advection, instantaneous freeze-drying and photolytical ozone production. Two different representations of transport (kinematic and diabatic 3-month backtrajectories based on ERA-Interim data) are used to evaluate the sensitivity to differences in transport. Results show that mean profiles and seasonality of both tracers can be reasonably reconstructed. Water vapour predictions are similar for both transport representations, but predictions for ozone are systematically higher for kinematic transport. Compared to global HALOE observations, the diabatic model prediction underestimates the vertical ozone gradient. Comparison of the kinematic prediction with observations obtained during the tropical SCOUT-O3 campaign shows a large high bias above 390 K potential temperature. We show that ozone predictions and vertical dispersion of the trajectories are highly correlated, rendering ozone an interesting tracer for aspects of transport to which water vapour is not sensitive. We show that dispersion and mean upwelling have similar effects on ozone profiles, with slower upwelling and larger dispersion both leading to higher ozone concentrations. Analyses of tropical upwelling based on mean transport characteristics, and model validation have to take into account this ambiguity between tropical ozone production and in-mixing from the stratosphere. In turn, ozone provides constraints on transport in the TTL and lower stratosphere that cannot be obtained from water vapour.