A novel approach to forecast urban surface-level ozone considering heterogeneous locations and limited information

Surface ozone (O3) is considered an hazard to human health, affecting vegetation crops and ecosystems. Accurate time and location O3 forecasting can help to protect citizens to unhealthy exposures when high levels are expected. Usually, forecasting models use numerous O3 precursors as predictors, limiting the reproducibility of these models to the availability of such information from data providers. This study introduces a 24 h-ahead hourly O3 concentrations forecasting methodology based on bagging and ensemble learning, using just two predictors with lagged O3 concentrations. This methodology was applied on ten-year time series (2006–2015) from three major urban areas of Andalusia (Spain). Its forecasting performance was contrasted with an algorithm especially designed to forecast time series exhibiting temporal patterns. The proposed methodology outperforms the contrast algorithm and yields comparable results to others existing in literature. Its use is encouraged due to its forecasting performance and wide applicability, but also as benchmark methodology

Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interactions : (RECONCILE) ; activities and results

The international research project RECONCILE has addressed central questions regarding polar ozone depletion, with the objective to quantify some of the most relevant yet still uncertain physical and chemical processes and thereby improve prognostic modelling capabilities to realistically predict the response of the ozone layer to climate change. This overview paper outlines the scope and the general approach of RECONCILE, and it provides a summary of observations and modelling in 2010 and 2011 that have generated an in many respects unprecedented dataset to study processes in the Arctic winter stratosphere. Principally, it summarises important outcomes of RECONCILE including (i) better constraints and enhanced consistency on the set of parameters governing catalytic ozone destruction cycles, (ii) a better understanding of the role of cold binary aerosols in heterogeneous chlorine activation, (iii) an improved scheme of polar stratospheric cloud (PSC) processes that includes heterogeneous nucleation of nitric acid trihydrate (NAT) and ice on non-volatile background aerosol leading to better model parameterisations with respect to denitrification, and (iv) long transient simulations with a chemistry-climate model (CCM) updated based on the results of RECONCILE that better reproduce past ozone trends in Antarctica and are deemed to produce more reliable predictions of future ozone trends. The process studies and the global simulations conducted in RECONCILE show that in the Arctic, ozone depletion uncertainties in the chemical and microphysical processes are now clearly smaller than the sensitivity to dynamic variability

Proceedings of Abstracts 12th International Conference on Air Quality Science and Application

© 2020 The Author(s). This an open access work distributed under the terms of the Creative Commons Attribution Licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Final Published versio

Proceedings of Abstracts 10th International Conference on Air Quality Science and Application

This 10th International Conference in Air Quality - Science and Application is being held in the elegant and vibrant city of Milan, Italy. Our local hosts are ARIANET and ARPA Lombardia both of whom play a leading role in assessing and managing air pollution in the area. The meeting builds upon the series that began at the University of Hertfordshire, UK in July 1996. Subsequent meetings have been held at the Technical University of Madrid, Spain (1999), Loutraki, Greece (2001), Charles University, Prague, Czech Republic (2003), Valencia, Spain (2005), Cyprus (2007), Istanbul, Turkey (2009) Athens, Greece (2012) and Garmisch-Partenkirchen, Germany (2014). Over the last two decades controls to limit air pollution have increased but the problem of poor air quality persists in all cities of the world. Consequently, the issue of the quality of air that we breathe remains at the forefront of societal concerns and continues to demand the attention of scientists and policy makers to reduce health impacts and to achieve sustainable development. Although urbanisation is growing in terms of population, transport, energy consumption and utilities, science has shown that impact from air pollution in cities is not restricted to local scales but depends on contributions from regional and global scales including interactions with climate change. Despite improvements in technology, users still demand robust management and assessment tools to formulate effective control policies and strategies for reducing the health impact of air pollution. The topics of papers presented at the conference reflect the diversity of scales, processes and interactions affecting air pollution and its impact on health and the environment. As usual, the conference is stimulating cross-fertilisation of ideas and cooperation between the different air pollution science and user communities. In particular, there is greater involvement of city, regional and global air pollution, climate change, users and health communities at the meeting. This international conference brings together scientists, users and policy makers from across the globe to discuss the latest scientific advances in our understanding of air pollution and its impacts on our health and environment. In addition to the scientific advances, the conference will also seek to highlight applications and developments in management strategies and assessment tools for policy and decision makers. This volume presents a collection of abstracts of papers presented at the Conference. The main themes covered in the Conference include: Air quality and impact on regional to global scales Development/application/evaluation of air quality and related models Environmental and health impact resulting from air pollution Measurement of air pollutants and process studies Source apportionment and emission models/inventories Urban meteorology Special session: Air quality impacts of the increasing use of biomass fuels Special session: Air quality management for policy support and decisions Special session: Air pollution meteorology from local to global scales Special session: Climate change and human health Special Session: Modelling and measuring non-exhaust emissions from traffic Special session: Transport related air pollution - PM and its impact on cities and across EuropeFinal Published versio

Ozone in the atmospheric boundary layer: Transport mechanisms and predictive indicators at 36�N

Scope and Method of Study: The objectives of this study were the estimation of the background ozone concentration specific to the study location, correlation between the background concentration and ground-level ozone, evaluation of the relationship between meteorological parameters and ozone (measured as the background concentration and at ground level), and identification of transport pathways for the component of local ozone concentrations not explained by local photochemistry. Ozone was measured in 1-hour averages at an elevation of 210 meters above ground level, with a companion set of control data measured in 1-hour averages at ground level. Data collection occurred in Tulsa, Oklahoma, a mid-sized city located at a latitude of 36ºN, over the period beginning on 01 June 2005 and ending on 30 November 2005. Additionally, meteorological data were collected at the 210-meter ozone installation and were retrieved from National Oceanic and Atmospheric Administration sites that measure and record ground-level conditions, upper-air soundings, and vertical wind profiles. Solar radiation data was retrieved from the Oklahoma Mesonet.Findings and Conclusions: Local meteorological conditions were found to be more important to local photochemical generation of ozone than to the behavior of the 210-meter concentration, representative of background ozone in the troposphere. Specifically, a negative correlation with an R2 of 0.5286 was achieved between ground-level ozone and relative humidity, while a positive correlation with an R2 of 0.4897 was achieved between ground-level ozone and dry-bulb temperature. All ground-level ozone concentrations ≥ 0.08 ppm occurred at dry-bulb temperatures ≥ 27ºC and relative humidity ≤ 50%. Solar radiation was of marked importance to ground-level concentrations as well, as R2 equaled 0.6065. Wind speed had a lower correlation with ground-level ozone (R2 = 0.1121), but all occurrences of ground-level ozone ≥ 0.08 ppm during the study were accompanied by ground-level wind speeds < 5 m·s^-1. When compared with 210-meter ozone, local meteorological conditions showed poor or no correlation. Instead, the 210-meter concentration was found to be correlated with geopotential heights at 300 hPa, representative of the height of the polar jet stream. This correlation improved as heights in close proximity to the mean position of the polar jet were considered, with a maximum R2 of 0.38 when 210-meter ozone was compared with 300 hPa geopotential heights at 46ºN. Furthermore, the best correlation was achieved with an 18-hour lag between 210-meter ozone and 300 hPa geopotential heights, accounting for the vertically-tilted structure of atmospheric waves. From the correlation between 210-meter ozone and 300 hPa geopotential heights, it can be concluded that atmospheric disturbances, both as Rossby and baroclinic waves, strongly influence the tropospheric background ozone concentration, as high concentrations were favored during large-scale anti-cyclonic subsidence, while low concentrations were favored during large-scale cyclonic lift. These processes ultimately affected ground-level ozone, as a strong correlation was shown with 210-meter ozone (R2 = 0.8781) during the afternoon hours. Horizontal ozone transport was shown to be appreciable at a distance of 80 km, but based on dispersion modeling, transport at a horizontal distance of 400 km did not appear to contribute significantly to ground-level concentrations

Advanced Air Quality Management with Machine Learning

Air pollution has been a significant health risk factor at a regional and global scale. Although the present method can provide assessment indices like exposure risks or air pollutant concentrations for air quality management, the modeling estimations still remain non-negligible bias which could deviate from reality and limit the effectiveness of emission control strategies to reduce air pollution and derive health benefits. The current development in air quality management is still impeded by two major obstacles: (1) biased air quality concentrations from air quality models and (2) inaccurate exposure risk estimations Inspired by more available and overwhelming data, machine learning techniques provide promising opportunities to solve the above-mentioned obstacles and bridge the gap between model results and reality. This dissertation illustrates three machine learning applications to strengthen air quality management: (1) identifying heterogeneous exposure risk to air pollutants among diverse urbanization levels, (2) correcting modeled air pollutant concentrations and quantifying the bias of sources from model inputs, and (3) examine nonlinear air pollutant responses to local emissions. This dissertation uses Taiwan as a case study, due to its well-established hospital data, emission inventory, and air quality monitoring network. In conclusion, although ML models have become common in atmospheric and environmental health science in recent years, the modeling processes and output interpretation should rely on interdisciplinary professions and judgment. Except for meeting the basic modeling performance, future ML applications in atmospheric and environmental health science should provide interpretability and explainability in terms of human-environment interactions and interpretable physical/chemical mechanisms. Such applications are expected to feedback to traditional methods and deepen our understanding of environmental science

Atmospheric Composition Observations

The composition of the atmosphere is a critical factor in understanding the nature and magnitude of processes associated with the planet’s energy balance, clouds and precipitation, biogeochemical cycling of nutrients, and public health and welfare. A detailed understanding of trace gases, aerosol particles, and hydrometeors is challenging due to the combination of their physicochemical complexity, variable lifetimes, and spatial inhomogeneity. Recent advances in instrumentation have resulted in improved measurements and an increased understanding of atmospheric composition. Laboratory and field in-situ measurement studies have benefited from such improvements, including improved spatial and temporal resolution, the ability to sample in challenging conditions (e.g., on airborne platforms, in clouds, at widely ranging pressure and temperature conditions), and the ability to measure a wider range of chemical species, and, in the case of aerosol particles, to detect smaller sizes. Remote sensing capabilities have increased in recent years, thus offering new views of atmospheric composition across broad spatiotemporal ranges. Manuscripts related to all aspects of atmospheric observations are included in this Special Issue, including advances in observational techniques and scientific insights into atmospheric composition

Air Quality Monitoring, Assessment and Management

Human beings need to breathe oxygen diluted in certain quantity of inert gas for living. In the atmosphere, there is a gas mixture of, mainly, oxygen and nitrogen, in appropriate proportions. However, the air also contains other gases, vapours and aerosols that humans incorporate when breathing and whose composition and concentration vary spatially. Some of these are physiologically inert. Air pollution has become a problem of major concern in the last few decades as it has caused negative effects on human health, nature and properties. This book presents the results of research studies carried out by international researchers in seventeen chapters which can be grouped into two main sections: a) air quality monitoring and b) air quality assessment and management, and serves as a source of material for all those involved in the field, whether as a student, scientific researcher, industrialist, consultant, or government agency with responsibility in this area