Impact of uncertainties in atmospheric mixing on simulated UTLS composition and related radiative effects
Impact of uncertainties in atmospheric mixing on simulated UTLS composition and related radiative effects
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DOI：
10.1029/2012jd017751
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发表时间：
2012-08
影响因子：
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通讯作者：
M. Riese;F. Ploeger;A. Rap;B. Vogel;P. Konopka;M. Dameris;P. Forster
中科院分区：
文献类型：
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作者：
M. Riese;F. Ploeger;A. Rap;B. Vogel;P. Konopka;M. Dameris;P. Forster
[1]上对流层/下平流层(UTLS)区域在气候系统中起着重要作用。该区域结构和化学成分的变化导致大气辐射作用力发生特别大的变化。因此，量化控制UTLS组成的过程(例如，平流层-对流层交换)是一项至关重要的任务。我们评估了大气混合强度的不确定性对全球温室气体(水蒸气、臭氧、甲烷和一氧化二氮)的UTLS分布以及相关的辐射效应的影响。这项研究是基于由ERA临时气象数据驱动的平流层化学拉格朗日模型(CLAMS)的多年模拟和最先进的辐射代码。混合是输送的不可逆部分，由大气流动的局部水平应变和垂直切变控制。我们发现，水汽和臭氧的模拟辐射效应对大气混合强度的不确定性特别敏感，这两种辐射效应的特征都是UTLS中的陡峭梯度。水汽和臭氧的全球平均辐射效应分别约为0.72和0.17 W/m2。对于臭氧，混合不确定性的影响最大的是热带外低平流层。
[1] The upper troposphere/lower stratosphere (UTLS) region plays an important role in the climate system. Changes in the structure and chemical composition of this region result in particularly large changes in radiative forcings of the atmosphere. Quantifying the processes that control UTLS composition (e.g., stratosphere-troposphere exchange) therefore represents a crucial task. We assess the influence of uncertainties in the atmospheric mixing strength on global UTLS distributions of greenhouse gases (water vapor, ozone, methane, and nitrous oxide) and associated radiative effects. The study is based on multiannual simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) driven by ERA-Interim meteorological data and on a state-of-the-art radiance code. Mixing, the irreversible part of transport, is controlled by the local horizontal strain and vertical shear of the atmospheric flow. We find that simulated radiative effects of water vapor and ozone, both characterized by steep gradients in the UTLS, are particularly sensitive to uncertainties of the atmospheric mixing strength. Globally averaged radiative effects are about 0.72 and 0.17 W/m2for water vapor and ozone, respectively. For ozone, the largest impact of mixing uncertainties is observed in the extra-tropical lower stratosphere.