Tropospheric chemical ozone tendencies in CO‐CH4‐NOy‐H2O system: Their sensitivity to variations in environmental parameters and their application to a global chemistry transport model study
Tropospheric chemical ozone tendencies in CO‐CH4‐NOy‐H2O system: Their sensitivity to variations in environmental parameters and their application to a global chemistry transport model study
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CO-CH4-NOy-H2O系统中的对流层化学臭氧趋势：它们对环境参数变化的敏感性及其在全球化学传输模型研究中的应用
DOI：
10.1029/97jd01805
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发表时间：
1997
影响因子：
--
通讯作者：
H. Levy
中科院分区：
文献类型：
--
作者：
A. Klonecki;H. Levy
本文用CO-CH_4-NCyH_2 O化学盒模式计算了对流层中不同参数NOx值下的臭氧日平均净光化学变化率（以下称为化学臭氧趋势）。臭氧浓度、温度、湿度、CO浓度、地表温度。为了了解化学臭氧趋势对输入参数的依赖性，进行了详细的敏感性研究。随后，臭氧的趋势与高度，纬度和季节的预期变化进行了分析。这种趋势的幅度随高度迅速减小，主要是由于绝对湿度和温度较低。在对流层上部（190毫巴），最大趋势低于2 ppb（体积/天）。较低的温度和比湿度导致NOx值的偏移。在该点上，臭氧的产生平衡了臭氧的破坏（平衡点）和较低的NOx值;这两个参数在很大程度上也是造成高纬度和冬季趋势幅度较低的原因。在对流层上部，我们发现，净趋势至少是敏感的H2O浓度的变化，氮氧化物。这表明，飞机造成的直接氮氧化物污染与气候变化对H2O的间接改变之间可能存在协同作用。在第二部分的文件中，箱模式计算率被用作臭氧的化学趋势项进行模拟与三维全球化学输送模式（GCTM）。箱模型是用来计算的趋势作为一个功能的NOx和臭氧在所有对流层水平的GCTM，在九个纬度和四个季节使用纬向和月度平均数据：水蒸气和温度的观测和模型CO。这些表格连同NOx字段中获得的早期GCTM模拟中使用的GCTM模拟的O3，如果非甲烷碳氢化合物水平低。在模拟过程中保存的全球月平均化学臭氧趋势场，并分析了目前和工业化前的条件。化学趋势场与NOx场具有很强的相关性。与对流层中、低层相比，在对流层中，海洋上空的偏远地区的趋势是负的，在对流层上层，NOx的体积一般大于万亿分之五十，平衡点较低，趋势一般较小，但为正。GCTM对工业化前臭氧的模拟表明，在对流层上层，当今的臭氧趋势大于模拟的工业化前趋势。在边界层和对流层中部，目前的趋势是更大的人为NOx附近。在不受这些来源影响的区域，由于臭氧水平较高，对臭氧污染的影响较小（通常更为负面）。
A photochemical box model with CO-CH4-NCyH2O chemistry is used to calculate the diurnally averaged net photochemical rate of change of ozone (hereinafter called the chemical ozone tendency) in the troposphere for different values of parameters: NOx. and ozone concentration, temperature, humidity, CO concentration, and surface albedo. To understand the dependency of the chemical ozone tendency on the input parameters, a detailed sensitivity study is performed. Subsequently, the expected variations of the ozone tendencies with altitude, latitude, and season are analyzed. The magnitude of the tendency decreases rapidly with height mostly as a result of lower absolute humidity and temperature. In the upper troposphere (at 190 mbar) the maximum tendencies are below 2 parts per billion by volume/day. Lower temperature and specific humidity cause a shift of the value of NOx. at which the ozone production balances the destruction of ozone (balance point) to lower NOx values; these two parameters are also, to a large extent, responsible for lower magnitudes of the tendency at higher latitudes and in winter. In the upper troposphere we find that the net tendency is at least as sensitive to variations in H2O concentration as to NOx. This suggests a possible synergism between direct NOx pollution by aircraft and the indirect modification of H2O by climate change. In the second part of the paper the box model calculated rates are used as ozone's chemical tendency terms during a simulation conducted with the three-dimensional global chemistry transport model (GCTM). The box model is used to calculate the tendencies as a function of NOx and ozone at all tropospheric levels of the GCTM, at nine latitudes and for four seasons using zonally and monthly averaged data: water vapor and temperature from observations and model CO. These tables together with the NOx fields obtained in an earlier GCTM simulation are used in the GCTM simulation of O3 if nonmethane hydrocarbon levels are low. The global monthly averaged chemical ozone tendency fields saved during the simulation are presented and analyzed for the present-day and preindustrial conditions. The chemical tendency fields show a strong correlation with the NOx fields. In contrast with the lower and middle troposphere where the tendencies are negative in remote regions over the oceans, in the upper troposphere, where NOx is generally greater than 50 parts per trillion by volume and the balance point is low, the tendencies are generally small but positive. The GCTM simulations of the preindustrial ozone show that in the upper troposphere the present-day ozone tendencies are greater than the simulated preindustrial tendencies. In the boundary layer and in the midtroposphere the present-day tendencies are greater near anthropogenic NOx. sources and smaller (generally more negative), due to higher ozone levels, in regions not affected by these sources.