Global Two-Dimensional Chemistry Model and Simulation of Atmospheric Chemical Composition

A global two-dimensional zonally averaged chemistry model is developed to study the chemi-cal composition of atmosphere. The region of the model is from 90°S to 90°N and from the ground to the altitude of 20 km with a resolution of 5° x 1 km. The wind field is residual circulation calcu-lated from diabatic rate. 34 species and 104 chemical and photochemical reactions are considered in the model. The sources of CH4, CO and NOx, which are divided into seasonal sources and non-seasonal sources, are parameterized as a function of latitude and time. The chemical composi-tion of atmosphere was simulated with emission level of CH4, CO and NOx in 1990. The results are compared with observations and other model results, showing that the model is successful to simu-late the atmospheric chemical composition and distribution of CH4. Key words Global two-dimensional chemistry model - Atmospheric composition - Emission This work was supported by the State Key Program for basic research “ Climate Dynamics and Cli-mate Prediction Theory” (Pandeng-yu-21).The authors would like to express their thanks to the National Oceanic and Atmospheric Administration (NOAA), Climate Monitoring and Diagnostics Laboratory (CMDL), Carbon Cycle Group for providing the observational data of CO and CH4.

Long-term variations of major atmospheric compositions observed at the background stations in three key areas of China

Atmospheric compositions and acid rain are closely related to atmospheric environment,weather,and climate change.In this study,the concentration levels and long-term trends of CO_(2),CH_(4),O_(3),PM_(2.5),PM_(10),and acid rain were presented at the Mt.Waliguan global baseline station in Qinghai,Shangdianzi and Lin'an regional background stations in the North China Plain(NCP)and the Yangtze River Delta region(YRD)of China based on the data observed until 2018.Significant increasing trends of CO_(2) were found at all of these stations.At Mt.Waliguan,the concentration levels and growth rate were consistent with the average values in the Northern Hemisphere(NH)and those observed at the Mauna Loa station in Hawaii.The CH_(4) also showed a upward tendency similar to that observed in NH.Compared with the observations at Mt.Waliguan global baseline station,the CO_(2) and CH_(4) mole fractions were higher at Shangdianzi and Lin'an regional background stations,indicating the important contributions of anthropogenic activities to the regional background level of CO_(2) and CH_(4).The annual averaged surface ozone showed increasing trends at Mt.Waliguan and Shangdianzi stations,whereas no clear trend was found at Lin'an station.Similar variations in the patterns of aerosol concentrations at Shangdianzi and Lin'an were found according to the PM_(2.5) or PM_(10) observations.Overall,the aerosol concentrations at both stations shown declining trends since the observations.However,two periods of high particle concentrations occurred in 2006-2007 and 2013-2014.The annual mean aerosol concentrations have continuously decreased after 2013-2014,indicating the effectiveness of pollution control in the NCP and YRD,especially since the implementation of the‘Action Plan for Prevention and Control of Air Pollution’in September 2013.Comparative analysis of aerosol with acid rain showed that the period with high concentrations of aerosols in the early years was consistent with that of severe acid rain pollution,suggesting that both aerosol pollution and severe acid rain are closely related to coal combustion emissions in China.As a result of the control of coal combustion emissions for acid and SO_(2),NO_(x) emissions have contributed more substantially to aerosols due to the rapid growth of vehicle ownership.A comparison of the trends of aerosols with the maximum daily 8-h average of surface ozone(MDA8)at Shangdianzi and Lin'an stations revealed the complicated relationship between aerosol reduction and ozone production,i.e.,together with the continuous improvement of particulate pollution in the NCP and YRD,the MDA8 at both stations showed a decreasing trend at first but subsequently increased after 2014 with aerosols remaining reduced.Such different variation patterns of the MDA8 with PM_(2.5)(or PM_(10))indicated the high challenge of synergic control of aerosol and ozone pollution in China.

A demonstration project of Global Alliance against Chronic Respiratory Diseases:Prediction of interactions between air pollution and allergen exposure—the Mobile Airways Sentinel NetworK-Impact of air POLLution on Asthma and Rhinitis approach

This review analyzes the state and recent progress in the field of information support for pollen allergy sufferers.For decades,information available for the patients and allergologists consisted of pollen counts,which are vital but insufficient.New technology paves the way to substantial increase in amount and diversity of the data.This paper reviews old and newly suggested methods to predict pollen and air pollutant concentrations in the air and proposes an allergy risk concept,which combines the pollen and pollution information and transforms it into a qualitative risk index.This new index is available in an app(Mobile Airways Sentinel NetworK-air)that was developed in the frame of the European Union grant Impact of Air POLLution on sleep,Asthma and Rhinitis(a project of European Institute of Innovation and Technology-Health).On-going transformation of the pollen allergy information support is based on new technological solutions for pollen and air quality monitoring and predictions.The new information-technology and artificial-intelligence-based solutions help to convert this information into easy-to-use services for both medical practitioners and allergy sufferers.