The POLARCAT Model Intercomparison Project (POLMIP): overview and evaluation with observations
The POLARCAT Model Intercomparison Project (POLMIP): overview and evaluation with observations
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DOI：
10.5194/acp-15-6721-2015
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发表时间：
2015-01-01
影响因子：
6.3
通讯作者：
Helmig, D.
中科院分区：
文献类型：
--
作者：
Emmons, L. K.;Arnold, S. R.;Helmig, D.
在国际极地年（2008年）期间对北极大气成分进行的大量观测启发了一项模型相互比较活动。九个全球和两个区域化学迁移模型参加了这一相互比较，并使用一个共同的排放清单对2008年进行了模拟，以评估模型化学和迁移方案的差异。本文总结了这些模型，并比较了它们对臭氧及其前体物的模拟，并提出了使用各种表面，气球，飞机和卫星观测的模拟评估。每种类型的测量在空间或时间覆盖范围或组成方面都有一些局限性，但它们共同有助于量化北极和周边地区模型的局限性。尽管使用相同的排放量，但模型之间存在很大差异。云场和光解率的模型之间的差异很大，表明在模拟的化学物种的差异的一个来源。模型之间以及模型和观测之间的最大差异在于NOy分配（PAN与HNO3）和含氧挥发性有机化合物（VOC），如乙醛和丙酮。比较地面站点测量的乙烷和丙烷表明，这些物种的排放量被大大低估。来自OMI（臭氧监测仪器）的NO2卫星观测已被用于评估源区域的模型，表明东亚的人为排放被低估，但火灾排放通常被高估。在加拿大野火的排放因子进行评估，使用的相关性的挥发性有机化合物CO在模型输出中的增强因子来自飞机观测，甲醇和乙醛，但低估了乙醇，丙烷和丙酮的合理协议，而高估乙烷的排放因子。
A model intercomparison activity was inspired by the large suite of observations of atmospheric composition made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models participated in this intercomparison and performed simulations for 2008 using a common emissions inventory to assess the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Each type of measurement has some limitations in spatial or temporal coverage or in composition, but together they assist in quantifying the limitations of the models in the Arctic and surrounding regions. Despite using the same emissions, large differences are seen among the models. The cloud fields and photolysis rates are shown to vary greatly among the models, indicating one source of the differences in the simulated chemical species. The largest differences among models, and between models and observations, are in NOy partitioning (PAN vs. HNO3) and in oxygenated volatile organic compounds (VOCs) such as acetaldehyde and acetone. Comparisons to surface site measurements of ethane and propane indicate that the emissions of these species are significantly underestimated. Satellite observations of NO2 from the OMI (Ozone Monitoring Instrument) have been used to evaluate the models over source regions, indicating anthropogenic emissions are underestimated in East Asia, but fire emissions are generally overestimated. The emission factors for wildfires in Canada are evaluated using the correlations of VOCs to CO in the model output in comparison to enhancement factors derived from aircraft observations, showing reasonable agreement for methanol and acetaldehyde but underestimate ethanol, propane and acetone, while overestimating ethane emission factors.