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Diurnal variations of particle number concentrations - influencing factors and possible implications for climate and epidemiological studies
0
Pergamon
J. AemsolSci. Vol. 29, Suppl. 1. pp. S213-S214. 1998 1998 Published by Elsevier Science Ltd. All rights reserved Printed in Great Britain 0021-850298 $19.00 + 0.00
DIURNAL VARIATIONS OF PARTICLE NUMBER CONCENTRATIONS - INFLUENCING FACTORS AND POSSIBLE IMPLICATIONS FOR CLIMATE AND EPIDEMIOLOGICAL STUDIES T.A.J. KUHLBUSCH,
A.C. JOHN, H. FISSAN, K.-G. SCHMIDT H.-U. PFEFFER I, D. GLADTKE 1:
Process and Aerosol Measurement Technology, 47057 Duisburg, ‘Chemical
Engineering,
t Landesumweltamt
University Germany
University
of Duisburg,
of Duisburg,
Nordrhein-Westfalen,
+, F. SCHMIDT
Bismarckstr.
+,
8 1,
Germany
Essen, Germany
KEYWOFCDS PM,, aerosol characterisation, measurements
sources, environmental
influences,
size distribution,
field
A field campaign to determine influencing factors on particle size distribution and chemical composition was conducted at a rural site approximately 30 km north-west of an industrialised area (R&r-area). Quasi on-line instruments used during this campaign were an aerodynamic particle sizer (APS, number size distribution and concentrations), two TEOM’s (mass concentrations), and an aethalometer (black carbon concentrations). The number size concentration data obtained from the APS were grouped into three size classes corresponding to sources and environmental processes: < 1 pm in diameter (PM l), l-2.5 pm in diameter (PM l-2.5), and 2.510 pm in diameter (PM 2.5-10). Four discontinuous aerosol high and low volume sampler were also used for the determination of particle mass concentrations (< 10 pm in diameter, PM 10; and < 2.5 pm in diameter, PM 2.5) and the corresponding chemical composition.
Fig. 1: Average
diurnal variation
of particle number
S213
concentration
(PM 1) and black carbon
S214
Abstracts
of the 5th International
Aerosol Conference
1998
Analyses of the diurnal variations determined with the on-line instruments showed clear diurnal variations with nearly stable black carbon, mass and number concentrations during the night (Fig. 1). Concentrations started to increase in the early morning hours and show different patterns during the day. Fig. 1 shows, as an example, the correlation of the diurnal black carbon concentrations with that of number concentrations for particles < 1 urn. Clearly, both peaks (8 and 10 AM) in number concentrations in the early morning hours can now be attributed to the main source of black carbon. the combustion of fossil fuel.
Fig. 2: Average diurnal variation of coarse mode particle number concentrations (2.510 in diameter, expressed in % of total PM 10 number concentrations) and windspeed.
urn
Figure 2 shows the average diurnal variations of the particle size fraction PM 2.5-10 and windspeed. The correlation between the two diurnal variations indicates the influence of windspeed on the aerosol number size distribution. PM 1 number concentrations increase by a factor of 1.5 during the day compared to the night. Black carbon concentrations show their maximum in the morning (Fig. 1). The comparison of PM 1 number and black carbon concentrations indicates significant changes in chemical composition during the day. Figure 2 gives an example of the influence of meteorological parameters on number size distributions. The findings, increased number concentrations, and changing number size distribution and chemical composition during the day, are important for epidemiological and climate studies. Most human outdoor activities and the influencing time of aerosols in the radiation budget are during the day. The diurnal variations of the number concentrations for PM 1, 2.5, and 10 will be analysed in this presentation. Therefore, ancillary data such as SO,-, NO-, NO,-concentrations, meteorological information and chemical composition data will be used to identify the influencing factors and sources. It is concluded that diurnal variations should be included in epidemiological and climate studies beside longer term changes and daily averages in aerosol concentrations.
Acknowledgements This work has received financial support by the Ministerium Landwirtschaft des Landes Nordrhein-Westfalen.
ftir Umwelt,
Raumordnung
und
Pergamon
J. AemsolSci. Vol. 29, Suppl. 1. pp. S213-S214. 1998 1998 Published by Elsevier Science Ltd. All rights reserved Printed in Great Britain 0021-850298 $19.00 + 0.00
DIURNAL VARIATIONS OF PARTICLE NUMBER CONCENTRATIONS - INFLUENCING FACTORS AND POSSIBLE IMPLICATIONS FOR CLIMATE AND EPIDEMIOLOGICAL STUDIES T.A.J. KUHLBUSCH,
A.C. JOHN, H. FISSAN, K.-G. SCHMIDT H.-U. PFEFFER I, D. GLADTKE 1:
Process and Aerosol Measurement Technology, 47057 Duisburg, ‘Chemical
Engineering,
t Landesumweltamt
University Germany
University
of Duisburg,
of Duisburg,
Nordrhein-Westfalen,
+, F. SCHMIDT
Bismarckstr.
+,
8 1,
Germany
Essen, Germany
KEYWOFCDS PM,, aerosol characterisation, measurements
sources, environmental
influences,
size distribution,
field
A field campaign to determine influencing factors on particle size distribution and chemical composition was conducted at a rural site approximately 30 km north-west of an industrialised area (R&r-area). Quasi on-line instruments used during this campaign were an aerodynamic particle sizer (APS, number size distribution and concentrations), two TEOM’s (mass concentrations), and an aethalometer (black carbon concentrations). The number size concentration data obtained from the APS were grouped into three size classes corresponding to sources and environmental processes: < 1 pm in diameter (PM l), l-2.5 pm in diameter (PM l-2.5), and 2.510 pm in diameter (PM 2.5-10). Four discontinuous aerosol high and low volume sampler were also used for the determination of particle mass concentrations (< 10 pm in diameter, PM 10; and < 2.5 pm in diameter, PM 2.5) and the corresponding chemical composition.
Fig. 1: Average
diurnal variation
of particle number
S213
concentration
(PM 1) and black carbon
S214
Abstracts
of the 5th International
Aerosol Conference
1998
Analyses of the diurnal variations determined with the on-line instruments showed clear diurnal variations with nearly stable black carbon, mass and number concentrations during the night (Fig. 1). Concentrations started to increase in the early morning hours and show different patterns during the day. Fig. 1 shows, as an example, the correlation of the diurnal black carbon concentrations with that of number concentrations for particles < 1 urn. Clearly, both peaks (8 and 10 AM) in number concentrations in the early morning hours can now be attributed to the main source of black carbon. the combustion of fossil fuel.
Fig. 2: Average diurnal variation of coarse mode particle number concentrations (2.510 in diameter, expressed in % of total PM 10 number concentrations) and windspeed.
urn
Figure 2 shows the average diurnal variations of the particle size fraction PM 2.5-10 and windspeed. The correlation between the two diurnal variations indicates the influence of windspeed on the aerosol number size distribution. PM 1 number concentrations increase by a factor of 1.5 during the day compared to the night. Black carbon concentrations show their maximum in the morning (Fig. 1). The comparison of PM 1 number and black carbon concentrations indicates significant changes in chemical composition during the day. Figure 2 gives an example of the influence of meteorological parameters on number size distributions. The findings, increased number concentrations, and changing number size distribution and chemical composition during the day, are important for epidemiological and climate studies. Most human outdoor activities and the influencing time of aerosols in the radiation budget are during the day. The diurnal variations of the number concentrations for PM 1, 2.5, and 10 will be analysed in this presentation. Therefore, ancillary data such as SO,-, NO-, NO,-concentrations, meteorological information and chemical composition data will be used to identify the influencing factors and sources. It is concluded that diurnal variations should be included in epidemiological and climate studies beside longer term changes and daily averages in aerosol concentrations.
Acknowledgements This work has received financial support by the Ministerium Landwirtschaft des Landes Nordrhein-Westfalen.
ftir Umwelt,
Raumordnung
und