The adjoint of CMAQ
The adjoint of CMAQ
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DOI：
10.1021/es070944p
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发表时间：
2007-11-15
影响因子：
11.4
通讯作者：
Li, Qinbin
中科院分区：
文献类型：
--
作者：
Hakami, Amir;Henze, Daven K.;Li, Qinbin
建立了国际通用的美国环保局社区多尺度空气质量（CMAQ）建模平台的伴随模型。CMAG的伴随版本（CMAQ-ADJ）为用户社区提供了前向（解耦直接法或DDM）和后向（伴随）灵敏度分析功能。目前的实施是气相工艺。对于除水平平流外的所有过程都实现了离散伴随，对于水平平流，由于平流方案中固有的不连续性，连续方法是优越的。化学的伴随函数是。通过将CMAG与动力学预处理器相连接构建，增加了化学解算剂选择的灵活性，并促进了新的化学机制的实现。伴随实现在逐个过程的基础上以及对整个模型进行评估。一般来说，伴随结果与蛮力和DDM敏感性具有较好的一致性，但对于非线性方案中的连续伴随实现，对于水平传输的一致性并不完美。使用伴随方法计算各种空气质量、公共卫生和环境指标对排放的敏感性。为了表明这些指标对区域气候研究的适用性，作为一个例子，计算了这些指标对当地温度的敏感性。
An adjoint model for the internationally used Community Multiscale Air Quality (CMAQ) modeling platform of the U.S. EPA is developed. The adjoint version for CMAG (CMAQ-ADJ) provides the user community with forward (decoupled direct method or DDM) and backward (adjoint) sensitivity analysis capabilities. Current implementation is for gasphase processes. Discrete adjoints are implemented for all processes with the exception of horizontal advection, for which, because of inherent discontinuities in the advection scheme, the continuous approach is superior. The adjoint of chemistry is. constructed by interfacing CMAG with the kinetic pre-processor, which provides for increased flexibility in the choice of chemical solver and facilitates the implementation of new chemical mechanisms. The adjoint implementation is evaluated both on a process-by-process basis and for the full model. In general, adjoint results show good agreement with brute-force and DDM sensitivities, As expected for a continuous adjoint implementation in a nonlinear scheme, the agreement is not perfect for horizontal transport. Sensitivities of various air quality, public health, and environmental metrics with respect to emissions are calculated using the adjoint method In order to show applicability to regional climate studies, as an example, the sensitivities of these metrics with respect to local temperatures are calculated.