BAERLIN2014 – the influence of land surface types on and the horizontal heterogeneity of air pollutant levels in Berlin
Urban air quality and human health are among the key aspects of future urban planning. In order to address pollutants such as ozone and particulate matter, efforts need to be made to quantify and reduce their concentrations. One important aspect in understanding urban air quality is the influence...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2016-06-01
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Series: | Atmospheric Chemistry and Physics |
Online Access: | https://www.atmos-chem-phys.net/16/7785/2016/acp-16-7785-2016.pdf |
Summary: | Urban air quality and human health are among the key aspects of future urban
planning. In order to address pollutants such as ozone and particulate
matter, efforts need to be made to quantify and reduce their concentrations.
One important aspect in understanding urban air quality is the influence of
urban vegetation which may act as both emitter and sink for trace gases and
aerosol particles. In this context, the "Berlin Air quality and Ecosystem
Research: Local and long-range Impact of anthropogenic and Natural
hydrocarbons 2014" (BAERLIN2014) campaign was conducted between 2 June and
29 August in the metropolitan area of Berlin and Brandenburg, Germany. The predominant goals of the campaign
were (1) the characterization of urban gaseous and particulate pollution and
its attribution to anthropogenic and natural sources in the region of
interest, especially considering the connection between biogenic volatile
organic compounds and particulates and ozone; (2) the quantification of the
impact of urban vegetation on organic trace gas levels and the presence of
oxidants such as ozone; and (3) to explain the local heterogeneity of
pollutants by defining the distribution of sources and sinks relevant for the
interpretation of model simulations. In order to do so, the campaign included
stationary measurements at urban background station and mobile observations
carried out from bicycle, van and airborne platforms. This paper provides an
overview of the mobile measurements (Mobile BAERLIN2014) and general
conclusions drawn from the analysis. Bicycle measurements showed micro-scale
variations of temperature and particulate matter, displaying a substantial
reduction of mean temperatures and particulate levels in the proximity of
vegetated areas compared to typical urban residential area (background)
measurements. Van measurements extended the area covered by bicycle
observations and included continuous measurements of O<sub>3</sub>, NO<sub><i>x</i></sub>, CO,
CO<sub>2</sub> and point-wise measurement of volatile organic compounds (VOCs) at
representative sites for traffic- and vegetation-affected sites. The
quantification displayed notable horizontal heterogeneity of the short-lived
gases and particle number concentrations. For example, baseline
concentrations of the traffic-related chemical species CO and NO varied on
average by up to ±22.2 and ±63.5 %, respectively, on the scale of
100 m around any measurement location. Airborne observations revealed the
dominant source of elevated urban particulate number and mass concentrations
being local, i.e., not being caused by long-range transport. Surface-based
observations related these two parameters predominantly to traffic sources.
Vegetated areas lowered the pollutant concentrations substantially with ozone
being reduced most by coniferous forests, which is most likely caused by
their reactive biogenic VOC emissions. With respect to the overall potential
to reduce air pollutant levels, forests were found to result in the largest
decrease, followed by parks and facilities for sports and leisure. Surface
temperature was generally 0.6–2.1 °C lower in vegetated regions,
which in turn will have an impact on tropospheric chemical processes. Based
on our findings, effective future mitigation activities to provide a more
sustainable and healthier urban environment should focus predominantly on
reducing fossil-fuel emissions from traffic as well as on increasing
vegetated areas. |
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ISSN: | 1680-7316 1680-7324 |