Exploring atmospheric stagnation during a severe particulate matter air pollution episode over complex terrain in Santiago, Chile

Autor: Marko Kvakić, Zvjezdana Bencetić Klaić, Richard Toro A, Manuel A. Leiva G, Darko Koracin, Raúl G.E. Morales S
Přispěvatelé: Universidad de Chile, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), University of Zagreb, Division of Atmospheric Sciences, Desert Research Institute, University of Split
Rok vydání: 2019
Předmět:
stagnation event
010504 meteorology & atmospheric sciences
Threshold limit value
[SDV]Life Sciences [q-bio]
Health
Toxicology and Mutagenesis
Air pollution event
Particulate matter
Weather research forecast
Cross-sections
Thermal inversions
Stagnation event
Air pollution
Wind
010501 environmental sciences
Toxicology
Atmospheric sciences
medicine.disease_cause
01 natural sciences
Air pollution episode
Air Pollution
medicine
thermal inversions
Chile
cross-sections
Weather
Air quality index
0105 earth and related environmental sciences
particulate matter
Pollutant
Air Pollutants
Humidity
General Medicine
Particulates
Pollution
weather research forecast
air pollution event
13. Climate action
Weather Research and Forecasting Model
[SDE]Environmental Sciences
Environmental science
Environmental Monitoring
Zdroj: Environmental Pollution
Environmental Pollution, Elsevier, 2019, 244, pp.705-714. ⟨10.1016/j.envpol.2018.10.067⟩
ISSN: 0269-7491
1873-6424
DOI: 10.1016/j.envpol.2018.10.067
Popis: International audience; A severe air quality degradation event occurred in the Santiago Metropolitan Area (SMA), Chile, in June 2014. Meteorological and air quality measurements from 11 stations in the area as well as numerical simulations using the Weather and Research Forecasting (WRF) model were used to explain the main reasons for the occurrence of elevated particulate matter (PM) concentrations. The conditions were characterized with formation of a coastal low in central Chile between the southeastern anticyclone and a high-pressure system over Argentina. At a local scale, these conditions generated a depression at the base of the inversion layer, an increase in the vertical thermal stability, lower humidity and low-wind conditions, which were conducive to a decrease in pollutant dispersion and insufficient ventilation of the polluted air. Measurements and simulations using the WRF model revealed a vertical structure of the boundary layer during these stagnant conditions and provided a basis for a trajectory analysis. The back-trajectory calculation showed that the transport of air parcels was contained in the valley during the highest concentrations. The analysis also enabled the definition of the threshold values of a simple indicator of air pollution (ventilation coefficient, VC), which confirmed the evolution of the episode and divided the observed daily concentrations into two groups, with one including values above the limits prescribed by the national air quality standards (NAQS) and the other including values below these limits. For the SMA, the daily PM concentrations above the NASQ limits were associated with an overall mean threshold value of VC below 500 m2 s−1 (for PM2.5) and 300 m2 s−1 (for PM10). To apply the VC analysis to other pollutants and different geographic locations, different threshold values should be evaluated.
Databáze: OpenAIRE
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