Description and evaluation of aerosol in UKESM1 and HadGEM3-GC3.1 CMIP6 historical simulations
Description and evaluation of aerosol in UKESM1 and HadGEM3-GC3.1 CMIP6 historical simulations
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DOI：
10.5194/gmd-2019-357
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发表时间：
2020-03
影响因子：
5.1
通讯作者：
J. Mulcahy;Colin E. Johnson;Colin G. Jones;A. Povey;C. Scott;A. Sellar;S. Turnock;M. Woodhouse;N. Abraham;M. Andrews;N. Bellouin;J. Browse;K. Carslaw;M. Dalvi;G. Folberth;M. Glover;D. Grosvenor;C. Hardacre;R. Hill;B. Johnson;Andy Jones;Z. Kipling;G. Mann;J. Mollard;F. O’Connor;J. Palmiéri;C. Reddington;S. Rumbold;M. Richardson;N. Schutgens;P. Stier;M. Stringer;Yongming Tang;J. Walton;S. Woodward;A. Yool
中科院分区：
文献类型：
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作者：
J. Mulcahy;Colin E. Johnson;Colin G. Jones;A. Povey;C. Scott;A. Sellar;S. Turnock;M. Woodhouse;N. Abraham;M. Andrews;N. Bellouin;J. Browse;K. Carslaw;M. Dalvi;G. Folberth;M. Glover;D. Grosvenor;C. Hardacre;R. Hill;B. Johnson;Andy Jones;Z. Kipling;G. Mann;J. Mollard;F. O’Connor;J. Palmiéri;C. Reddington;S. Rumbold;M. Richardson;N. Schutgens;P. Stier;M. Stringer;Yongming Tang;J. Walton;S. Woodward;A. Yool
抽象的。我们的文件和评估气溶胶方案中实施的物理和地球系统模型，全球耦合3.1配置的哈德利中心全球环境模型第3版（HadGEM 3-GC3.1）和英国地球系统模型（UKESM 1），这是有助于第六耦合模型相互比较项目（CMIP 6）。气溶胶的模拟在当今时期的历史合奏这些模式进行评估对一系列的观测。记录了气溶胶微物理方案的更新以及物理系统配置和地球系统配置之间气溶胶表示的差异。UKESM 1中包含的额外地球系统相互作用导致天然气溶胶源（如二甲基硫醚、矿物粉尘和有机气溶胶）排放的差异，以及模型中这些物种的后续演变。UKESM 1还包括一个与气溶胶方案完全耦合的平流层-对流层化学方案，而GC 3.1采用了由相关氧化剂的规定月度气候驱动的简化气溶胶化学机制。总体而言，模拟的物种气溶胶质量浓度比较合理，以及与观测。这两个模型都捕捉到了欧洲和美国东部硫酸盐气溶胶浓度的负趋势，尽管模型往往低估了这两个地区的硫酸盐浓度。生物挥发性有机化合物在UKESM 1的相互作用的排放导致了美国的有机气溶胶协议的改善。模拟粉尘负荷是相似的，尽管在粉尘排放量的2倍的差异，在两个模型。气溶胶光学厚度偏低的尘埃源和外流的地区，但在其他地区的一些卫星和地面检索气溶胶光学厚度相比，表现良好。模拟的气溶胶数浓度一般在观测值的2倍之内，两种模式都倾向于高估偏远海洋区域的数浓度，除了高纬度地区，而低估了北方大陆。最后，一个新的初级海洋有机气溶胶源是在UKESM 1首次实施。这种新的气溶胶源的影响进行了评估。在原始的南大洋，它被发现，以改善有机气溶胶质量和云滴数浓度的季节性循环相对于GC 3.1，虽然低估云滴数浓度仍然存在。本文提供了一个有用的表征气溶胶气候学在这两个模式，并将促进在众多的气溶胶气候相互作用的研究，将进行CMIP 6及以后的一部分的理解。
Abstract. We document and evaluate the aerosol schemes as implemented in the physical and Earth system models, the Global Coupled 3.1 configuration of the Hadley Centre Global Environment Model version 3 (HadGEM3-GC3.1) and the United Kingdom Earth System Model (UKESM1), which are contributing to the sixth Coupled Model Intercomparison Project (CMIP6). The simulation of aerosols in the present-day period of the historical ensemble of these models is evaluated against a range of observations. Updates to the aerosol microphysics scheme are documented as well as differences in the aerosol representation between the physical and Earth system configurations. The additional Earth system interactions included in UKESM1 lead to differences in the emissions of natural aerosol sources such as dimethyl sulfide, mineral dust and organic aerosol and subsequent evolution of these species in the model. UKESM1 also includes a stratospheric–tropospheric chemistry scheme which is fully coupled to the aerosol scheme, while GC3.1 employs a simplified aerosol chemistry mechanism driven by prescribed monthly climatologies of the relevant oxidants. Overall, the simulated speciated aerosol mass concentrations compare reasonably well with observations. Both models capture the negative trend in sulfate aerosol concentrations over Europe and the eastern United States of America (US) although the models tend to underestimate sulfate concentrations in both regions. Interactive emissions of biogenic volatile organic compounds in UKESM1 lead to an improved agreement of organic aerosol over the US. Simulated dust burdens are similar in both models despite a 2-fold difference in dust emissions. Aerosol optical depth is biased low in dust source and outflow regions but performs well in other regions compared to a number of satellite and ground-based retrievals of aerosol optical depth. Simulated aerosol number concentrations are generally within a factor of 2 of the observations, with both models tending to overestimate number concentrations over remote ocean regions, apart from at high latitudes, and underestimate over Northern Hemisphere continents. Finally, a new primary marine organic aerosol source is implemented in UKESM1 for the first time. The impact of this new aerosol source is evaluated. Over the pristine Southern Ocean, it is found to improve the seasonal cycle of organic aerosol mass and cloud droplet number concentrations relative to GC3.1 although underestimations in cloud droplet number concentrations remain. This paper provides a useful characterisation of the aerosol climatology in both models and will facilitate understanding in the numerous aerosol–climate interaction studies that will be conducted as part of CMIP6 and beyond.