大气化学传输模型

我们大气化学研究主要运用GEOS-Chem全球化学传输模型，以及关注在东亚地区的嵌套网格模型－该嵌套网格模型由哈佛大学中国项目的前学生研究员王聿绚教授（现任职于清华大学和休斯顿大学）和项目主席Michael B. McElroy教授共同研发。

经地面、飞机和卫星观测验证，嵌套网格模型较之以往可以以更精细准确的分辨率模拟中国地区大气传输的机理。它能够准确模拟关注区域外污染物传输和季节性气象条件变化的影响－譬如冬季冷锋来袭和夏季季风时区域空气质量的特征。

运用这一模型及其他分析手段，我们的研究团队已经研究了多种空气污染物的传播和化学反应，以及污染物浓度控制策略的有效性。应用GEOS-Chem的反演工具也可以根据地面、飞机和卫星观测反算和优化污染物浓度和排放清单——为氮氧化物、二氧化碳、一氧化碳及其他污染物和温室气体的自下而上排放清单提供独立检验。

哈佛大学中国项目的大气研究工作致力于就中国大气环境物理和化学两方面，从城市尺度到全球尺度，建立可通过观测验证的基础性研究框架。除了这里介绍的以模型为基础的研究方法以外，其他研究方法还包括实地观测(点击这里查看详情)以及自下而上的排放研究(点击这里查看详情)。同时，大气研究也是哈佛大学中国项目跨学科研究架构中极为核心的组成部分——目前主要应用于国家温室气体和污染防治政策的评估(点击这里查看详情)。

显示更多

声明：此处援引的部分论文出自美国国家科学基金会(NSF)ATM-1019134号或ATM-0635548号基金赞助项目(被引用论文中已注明)。这些论文中表达的任何观点、结论或建议均为作者本人观点，不代表美国国家科学基金会(NSF)的立场。

相关文献

Yu Zhao, Yutong Wang, Yiming Liu, Yueqi Jiang, Bo Zheng, Jia Xing, Yang Liu, Shuai Wang, and Chris Nielsen. 2023. “Sustained emission reductions have restrained the ozone pollution over China.” Nature Geoscience. Publisher's Version Abstract

Near-surface ozone pollution, associated with complex responses to changing precursor emissions and meteorological conditions, has become one of the biggest challenges in China’s air quality management. Here, we present the spatiotemporal evolution of ozone concentrations from 2010 to 2021 using measurements of the national air quality monitoring network. We evaluate the effectiveness of the national air pollution control programme, including Phase 1 (2013–2017) and Phase 2 (2018–2021), in reducing the ozone level over China, using an optimized machine learning approach, high-resolution emission estimates and an improved air quality model. We find that while emission changes in Phase 1 increased the ozone level over the five highly developed regions, further reductions of nitrogen oxide emissions in Phase 2 have generally constrained the ozone pollution. The changing effect of emission controls on ozone pollution is due to the shift in the prevailing regime for ozone formation and the weakened effects of aerosol declines, as emission reductions continue. We further find that current emission controls have been more effective in rural locales in four of the five regions, and more effective in summer than winter. Therefore, further control of ozone pollution should consider these regional and seasonal variations to identify the most important precursors for the pollution.

Xi Yang, Chris P. Nielsen, Shaojie Song, and Michael B. McElroy. 2022. “Breaking the “hard-to-abate” bottleneck in China’s path to carbon neutrality with clean hydrogen.” Nature Energy. Publisher's Version Abstract

Countries such as China are facing a bottleneck in their paths to carbon neutrality: abating emissions in heavy industries and heavy-duty transport. There are few in-depth studies of the prospective role for clean hydrogen in these ‘hard-to-abate’ (HTA) sectors. Here we carry out an integrated dynamic least-cost modelling analysis. Results show that, first, clean hydrogen can be both a major energy carrier and feedstock that can significantly reduce carbon emissions of heavy industry. It can also fuel up to 50% of China’s heavy-duty truck and bus fleets by 2060 and significant shares of shipping. Second, a realistic clean hydrogen scenario that reaches 65.7 Mt of production in 2060 could avoid US$1.72 trillion of new investment compared with a no-hydrogen scenario. This study provides evidence of the value of clean hydrogen in HTA sectors for China and countries facing similar challenges in reducing emissions to achieve net-zero goals.

Peter Sherman, Haiyang Lin, and Michael B. McElroy. 2022. “Projected global demand for air conditioning associated with extreme heat and implications for electricity grids in poorer countries.” Energy and Buildings. Publisher's Version Abstract

Human-induced climate change will increase surface temperatures globally over the next several decades. Climate models project that global mean surface temperature could increase by over 2˚C by 2050 relative to the preindustrial period, with even greater changes at the regional level. These temperature changes have clear and pertinent implications for extremes, and consequentially, heat-induced health issues for people living in particularly hot climates. Here, we study future projections in the demand for AC globally in the 2050s associated with extreme heat events. To do this, we employ an ensemble of CMIP6 models under high and low emissions scenarios. We find that the increasing frequency of extreme temperatures will cause a significant portion of the global population to be exposed to conditions that require cooling. This issue will be especially pervasive in poor countries such as India and Indonesia, which at present lack the AC units required to handle rapidly growing populations and increased frequencies of extreme temperatures. The electricity needed for cooling in these countries could reach as high as 75% of the current total annual electricity demand, which could place serious strain on the electricity grid infrastructure during peak cooling hours. We conclude that demand for cooling in the future will pose a significant challenge for poorer countries whose people will require AC units to handle extreme temperatures. In some countries, the grid infrastructure is insufficient at present to meet projected AC demands, and this need must be considered in future power systems planning.

更多文献

大气化学传输模型

显示更多

相关文献

styles

dc804a161f42566200e415af6eb01e9b

4eda2b572805bc18fa86a52a87e25bd6