Tropical troposphere to stratosphere transport of carbon monoxide and long-lived trace species in the Chemical Lagrangian Model of the Stratosphere (CLaMS)
Tropical troposphere to stratosphere transport of carbon monoxide and long-lived trace species in the Chemical Lagrangian Model of the Stratosphere (CLaMS)
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DOI：
10.5194/gmd-7-2895-2014
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发表时间：
2014-12
影响因子：
5.1
通讯作者：
R. Pommrich;R. Müller;J. Grooß;P. Konopka;F. Ploeger;B. Vogel;Mengchu Tao;C. Hoppe;G. Günther-G.
中科院分区：
文献类型：
--
作者：
R. Pommrich;R. Müller;J. Grooß;P. Konopka;F. Ploeger;B. Vogel;Mengchu Tao;C. Hoppe;G. Günther-G.
抽象。热带地区进入平流层的源自对流层的微量气体混合比的变化，对于评估热带地区对流层到平流层的输送通量以及这些输送通量对热带平流层下部组成的影响都是有意义的。热带平流层下部一氧化碳（CO）和长寿命示踪剂的异常模式可以得出有关热带上升流速率和变化的结论。在这里，我们提出了一个简化的化学方案的平流层的化学拉格朗日模型（CLaMS）的模拟，在相对较低的数值成本，CO，臭氧和长寿命的微量物质（CH 4，N2 O，CCl 3F（CFC-11），CCl 2F 2（CFC-12），和CO2）在热带平流层下部。对于长寿命的痕量物质，在地面上的边界条件规定的基础上，在最低的模式水平的地面测量。对流层低层（约4 km以下）CO边界条件是由MOPITT观测资料推导出来的。由于缺乏一个具体的表示在对流层中的混合和对流隆起在这个模式版本中，增强CO值，特别是那些由对流流出被低估。然而，在热带对流层顶层和热带平流层下部，模拟的CO与现场测量结果有较好的一致性（TROCCINOX活动除外，模拟中的CO偏低a10-15 ppbv）。此外，模型的结果（因此也是ERA-Interim风，在模型中的传输的基础上）是足够的质量来描述大规模的异常模式的CO在平流层下部。特别是，纬向平均热带CO异常模式（所谓的“磁带记录器”模式）模拟的CLaMS模型版本与观测结果吻合良好，虽然模拟显示出太快的上升流相比，作为结果的ERA-Interim再分析数据集的高估垂直速度的观测。此外，模拟的热带N_2O距平场与观测结果吻合较好。在模拟中，异常模式的CH 4和CFC-11被发现是非常相似的N2 O;所有长寿命的示踪剂，正异常模拟，因为增强的热带上升流在东风切变阶段的准两年振荡。
Abstract. Variations in the mixing ratio of trace gases of tropospheric origin entering the stratosphere in the tropics are of interest for assessing both troposphere to stratosphere transport fluxes in the tropics and the impact of these transport fluxes on the composition of the tropical lower stratosphere. Anomaly patterns of carbon monoxide (CO) and long-lived tracers in the lower tropical stratosphere allow conclusions about the rate and the variability of tropical upwelling to be drawn. Here, we present a simplified chemistry scheme for the Chemical Lagrangian Model of the Stratosphere (CLaMS) for the simulation, at comparatively low numerical cost, of CO, ozone, and long-lived trace substances (CH4, N2O, CCl3F (CFC-11), CCl2F2 (CFC-12), and CO2) in the lower tropical stratosphere. For the long-lived trace substances, the boundary conditions at the surface are prescribed based on ground-based measurements in the lowest model level. The boundary condition for CO in the lower troposphere (below about 4 km) is deduced from MOPITT measurements. Due to the lack of a specific representation of mixing and convective uplift in the troposphere in this model version, enhanced CO values, in particular those resulting from convective outflow are underestimated. However, in the tropical tropopause layer and the lower tropical stratosphere, there is relatively good agreement of simulated CO with in situ measurements (with the exception of the TROCCINOX campaign, where CO in the simulation is biased low a10–15 ppbv). Further, the model results (and therefore also the ERA-Interim winds, on which the transport in the model is based) are of sufficient quality to describe large scale anomaly patterns of CO in the lower stratosphere. In particular, the zonally averaged tropical CO anomaly patterns (the so called "tape recorder" patterns) simulated by this model version of CLaMS are in good agreement with observations, although the simulations show a too rapid upwelling compared to observations as a consequence of the overestimated vertical velocities in the ERA-Interim reanalysis data set. Moreover, the simulated tropical anomaly patterns of N2O are in good agreement with observations. In the simulations, anomaly patterns of CH4 and CFC-11 were found to be very similar to those of N2O; for all long-lived tracers, positive anomalies are simulated because of the enhanced tropical upwelling in the easterly shear phase of the quasi-biennial oscillation.