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Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality.

Hou P, Wu S - Sci Rep (2016)

Bottom Line: We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions.Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events.We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

View Article: PubMed Central - PubMed

Affiliation: Atmospheric Sciences Program, Michigan Technological University, Houghton, MI, 49931, USA.

ABSTRACT
Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

No MeSH data available.


Related in: MedlinePlus

Changes in the frequency of extreme air pollution meteorological events in the past six decades (based on the NCEP reanalysis data): (a) heat waves (days/yr); (b) temperature inversions (hrs/yr); (c) atmospheric stagnation episodes (hrs/yr).Left: 1951–1980 average; right: percentage change (%) between 1951–1980 and 1981–2010. (Map is generated with coarse coastline built in MATLAB R2014b [URL: http://www.mathworks.com/products/matlab/]).
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f1: Changes in the frequency of extreme air pollution meteorological events in the past six decades (based on the NCEP reanalysis data): (a) heat waves (days/yr); (b) temperature inversions (hrs/yr); (c) atmospheric stagnation episodes (hrs/yr).Left: 1951–1980 average; right: percentage change (%) between 1951–1980 and 1981–2010. (Map is generated with coarse coastline built in MATLAB R2014b [URL: http://www.mathworks.com/products/matlab/]).

Mentions: We first examine the evolution of extreme air pollution meteorology in the past six decades. We follow the World Meteorological Organization method31 on the definition of heat waves with some modification - A heat wave is defined when the daily maximum temperature at a given location exceeds the “climatological” daily maximum temperature (averaged over the reference period of 1961–1990) by at least 5 K for more than two consecutive days. Fig. 1a shows the average annual occurrences of heat waves in the first 30-year (1951–1980) period as well as the percentage changes when compared with the more recent 30-year (1981–2010) period. Significant increases in heat waves in the more recent decades are observed over most continental regions, especially the high latitude regions. For most regions, the trends in the frequency of heat waves are similar to those identified in the literature31. It is noticeable that the frequency of heat waves have decreased over some areas in the United States in the past decades. The annual average frequency of heat waves for the global non-polar continental regions is found to increase by 25.8 ± 3.3% (Table 1). The largest increases (around 40%) are found during Northern Hemisphere spring (March-May) and summer (June-August) seasons.


Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality.

Hou P, Wu S - Sci Rep (2016)

Changes in the frequency of extreme air pollution meteorological events in the past six decades (based on the NCEP reanalysis data): (a) heat waves (days/yr); (b) temperature inversions (hrs/yr); (c) atmospheric stagnation episodes (hrs/yr).Left: 1951–1980 average; right: percentage change (%) between 1951–1980 and 1981–2010. (Map is generated with coarse coastline built in MATLAB R2014b [URL: http://www.mathworks.com/products/matlab/]).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4815017&req=5

f1: Changes in the frequency of extreme air pollution meteorological events in the past six decades (based on the NCEP reanalysis data): (a) heat waves (days/yr); (b) temperature inversions (hrs/yr); (c) atmospheric stagnation episodes (hrs/yr).Left: 1951–1980 average; right: percentage change (%) between 1951–1980 and 1981–2010. (Map is generated with coarse coastline built in MATLAB R2014b [URL: http://www.mathworks.com/products/matlab/]).
Mentions: We first examine the evolution of extreme air pollution meteorology in the past six decades. We follow the World Meteorological Organization method31 on the definition of heat waves with some modification - A heat wave is defined when the daily maximum temperature at a given location exceeds the “climatological” daily maximum temperature (averaged over the reference period of 1961–1990) by at least 5 K for more than two consecutive days. Fig. 1a shows the average annual occurrences of heat waves in the first 30-year (1951–1980) period as well as the percentage changes when compared with the more recent 30-year (1981–2010) period. Significant increases in heat waves in the more recent decades are observed over most continental regions, especially the high latitude regions. For most regions, the trends in the frequency of heat waves are similar to those identified in the literature31. It is noticeable that the frequency of heat waves have decreased over some areas in the United States in the past decades. The annual average frequency of heat waves for the global non-polar continental regions is found to increase by 25.8 ± 3.3% (Table 1). The largest increases (around 40%) are found during Northern Hemisphere spring (March-May) and summer (June-August) seasons.

Bottom Line: We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions.Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events.We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

View Article: PubMed Central - PubMed

Affiliation: Atmospheric Sciences Program, Michigan Technological University, Houghton, MI, 49931, USA.

ABSTRACT
Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

No MeSH data available.


Related in: MedlinePlus