An essential component of a three-dimensional air quality model is its gas-phase mechanism. We present an overview of the necessary atmospheric chemistry and a discussion of the types of mechanisms with some specific examples such as the Master Chemical Mechanism, the Carbon Bond, SAPRC and the Regional Atmospheric Chemistry Mechanism (RACM). The first versions of the Carbon Bond and SAPRC mechanisms were developed through a hierarchy of chemical species approach that relied heavily on chemical environmental chamber data. Now a new approach has been proposed where the first step is to develop a highly detailed explicit mechanism such as the Master Chemical Mechanism and the second step is to test the detailed explicit mechanism against laboratory and field data. Finally, the detailed mechanism is condensed for use in a three-dimensional air quality model. Here it is argued that the development of highly detailed explicit mechanisms is very valuable for research, but we suggest that combining the hierarchy of chemical species and the detailed explicit mechanism approaches would be better than either alone.Implication: Many gas-phase mechanisms are available for urban, regional and global air quality modeling. A "hierarchy of chemical species approach," relying heavily on smog-chamber data was used for the development of the early series of mechanisms. Now the development of large, explicit master mechanisms that may be condensed is a significant, trend. However, a continuing problem with air quality mechanism development is due to the high complexity of atmospheric chemistry and the current availability of laboratory measurements. This problem requires a balance between completeness and speculation so that models maintain their utility for policymakers.

中文翻译：

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欧拉空气质量模型气相化学机理的发展前景。

三维空气质量模型的重要组成部分是其气相机制。我们提供了必要的大气化学概述，并讨论了机理类型，并列举了一些具体示例，例如主化学机理，碳键，SAPRC和区域大气化学机理（RACM）。碳键和SAPRC机制的第一个版本是通过化学物种方法的层次结构开发的，该方法严重依赖于化学环境室的数据。现在已经提出了一种新方法，第一步是开发高度详细的显式机制，例如主化学机制，第二步是针对实验室和现场数据测试详细的显式机制。最后，浓缩了详细的机制，以用于三维空气质量模型。本文认为开发高度详细的显式机理对于研究非常有价值，但我们建议将化学物种的层次结构与详细的显式机理方法相结合将比单独使用更好。用于城市，区域和全球空气质量建模。严重依赖烟雾室数据的“化学物种层次结构方法”被用于早期机制的开发。现在，大型，显式主机制的发展可能是一个重要的趋势。然而，空气质量机制开发的一个持续问题是由于大气化学的高度复杂性和实验室测量的当前可用性。这个问题要求在完整性和推测性之间取得平衡，以便模型能够维持其对决策者的效用。