Uwe Kaminski

The effect of mitigation measures on size distributed mass concentrations of atmospheric particles and black carbon concentrations during the Olympic Summer Games 2008 in Beijing

The period of the 2008 Olympic Summer Games in Beijing can be considered as a unique opportunity to study the influences of emission reduction measures on air quality improvement. Within this study atmospheric particles of different size classes (2.5 to 80 μm) were investigated before, during, and after the Olympic Games period in order to observe and assess the success of short-term measures to mitigate extreme urban aerosol pollution and also to investigate, which particle size classes were reduced most effectively. Furthermore, black carbon (BC) concentrations in fine particles (PM(2.5)) during the source control period were compared to those of the previous years in order to investigate the decrease of combustion-derived aerosols. It is shown that besides the implemented mitigation measures precipitation decisively contributed to a considerable decrease of particulate air pollution in Beijing compared to the respective concentrations during the time directly before and after the Olympic Games, and also compared to average August concentrations during the previous years and the following year 2009. Particles of the fine fraction of the coarse mode (2.5 to 5 μm), which have a residence time in the order of several days and which, therefore, are typically transported over long distances from outside of Beijing, were less efficiently reduced than coarser particles. This indicates that long-range transport of atmospheric particles is difficult to control and that presumably the established mitigation area was not large enough to also reduce the fine fraction of the coarse mode more efficiently. Furthermore, the study showed that coarse geogenic particles, which originated to a high percentage from construction sites and resuspension processes due to traffic seemed to be reduced most efficiently during the Olympic Games period.

Spatio-temporal variations of black carbon concentrations in the Megacity Beijing

The spatial and temporal distribution and the flux of black carbon (BC) concentration in Beijing were continuously investigated over a two-year period at five sites to highlight the relative influence of contributing sources. The results demonstrate firstly that there is significant spatio-temporal variability of BC in Beijing. Highest concentrations occurred during winter primarily due to stagnant meteorological conditions, and seasonal BC sources, such as coal combustion for heating purposes. Biomass burning was identified as a minor seasonal source during the summer months. BC also varied spatially with higher concentrations in the SE of Beijing and lower concentrations in the NW, due to the differing emission intensity of various local BC sources such as traffic and industry. Frequently, overnight BC concentrations were higher due to specific meteorological conditions, such as the lower urban mixing layer height and various anthropogenic activities, such as exclusive night-time heavy duty vehicle traffic in the inner-city.

Development of meteorological parameters and total ozone during the total solar eclipse of August 11, 1999

During the total eclipse of August 11, 1999 frequent showers occurred due to a unstable stratification of the air mass. At different observation sites, meteorological effects from the eclipse (99.4% coverage at Hohenpeissenberg) and from showers were superimposed making it partly difficult to unambiguously interpret the observations. The weather radar at Hohenpeissenberg observatory provided a general overview of the distribution of clouds and precipitation in this area (200 km diameter). From the Garching site in the zone of totality (100%) temperature and wind data taken on a 50 m mast were evaluated. By selecting periods with relatively low cloud cover it was possible to approximately follow the development of the vertical temperature and wind profiles during the eclipse. The minimum temperature at Hohenpeissenberg (about 450 m above the altitude of Garching) during the eclipse was comparable to that during the previous night, the corresponding value measured at Garching remained about 2 K above the minimum observed during clear sky conditions in the previous night. Showers before, during or after the eclipse may have induced vertical exchange of air parcels. Temperatures during a shower change towards the same direction at all altitudes, thus no inversion forms. Additionally, air parcels with relatively lower concentrations of trace constituents were transported down from aloft for time periods of 10-15 minutes. These mixing processes significantly determined the temporal variations of various trace substances measured during the eclipse. Total ozone measurements at Hohenpeissenberg were performed with both DOBSON and BREWER spectrophotometers and at another site within the zone of totality by using a portable Microtops II filter instrument. Different results were obtained for both sites. These differences can be to a large extend, but not exclusively, attributed to eclipse induced shifts (limb darkening and straylight effects in the atmosphere) in the wavelength pairs used to calculate total ozone. However, there also appeared to be real fluctuations in total ozone during the reemerging phase of the sun which may be related to eclipse induced gravity waves.

μ‐Scale Variations Of Elemental Composition In Individual Atmospheric Particles By Means Of Synchrotron Radiation Based μ‐XRF Analysis

Atmospheric pollution poses a huge challenge especially for densely populated urban areas. Although a tremendous knowledge already exists on atmospheric particulate pollution, only very limited knowledge is available on mineral and chemical composition of single atmospheric particles because most studies on air pollution focus on total mass concentrations or bulk elemental analysis. However, it is of particular importance to investigate the properties of single particles since according to their individually composition they differ in their specific impact on climate change, negative environment and health effects, as well as accelerating the weathering of stone buildings in urban areas. Particles with sulfate and nitrate coatings together with sufficient moisture increase metal solubility and possibly catalyze further surface reactions on stone facades of buildings. From the viewpoint of health effects of aerosols it is important to consider agglomerations processes of fine anthropogenic and highly toxic...

Increasing submicron particle mass concentration at Hamburg. I: Observations

Abstract In the Federal Republic of Germany the emissions of particulate matter have been reduced from 6.5 million tons (1954) to less than 1 million tons at present. In spite of retrograde emissions an increase of the aerosol mass concentration of about 4–7% per year has been observed at the Meteorological Observatory, Hamburg since the beginning of the record in 1975. In order to eliminate variations arising from meteorological fluctuations (respectively: wind direction, origin of air mass, wind velocity and scavenging due to precipitation), appropriate homogenization methods have been applied to the data, which make the trend more obvious. Two other records, both the number concentration of particles > 0.15 μm and the water soluble aerosol fraction, exhibit a similar trend, excluding the possibility that it was caused by instrumental drift. The trend is confined to submicron particles as confirmed by size segregated determination of the water soluble aerosol fraction.

Are there changes in Germany regarding the start of the pollen season, the season length and the pollen concentration of the most important allergenic pollens?

For the regions Northwest, Northeast and Southern Germany we examined the main allergic pollen (Hazel, Alder, Birch, grasses and Mugwort) for trends on the basis of the pollen counts of the Pollen Information Service (PID) reference-stations. From these stations information about changes on the start of the pollen season, the season length and the total amount as well as the peak-concentration of pollen during the last years (1988–2009 for Northwest and Southern Germany and 1994–2009 for Northeast Germany) are examined. Possible trends are analysed by means of the Mann-Kendall test for their signif cance. The results demonstrate that the changes, regarding the start of the pollen season and the total pollen amount, are strongest in Southern and Northeast Germany. Data show for all regions that tree pollen becomes the signif cant allergen.

Increasing submicron particle mass concentration at Hamburg—II. Source discussion

Abstract Increasing mass of TSP has been established at Hamburg since 1975, the beginning of observations. A trajectory analysis shows that air masses that have passed industrialized areas exhibit the most pronounced trend, but also that air masses coming over the North Sea show increasing TSP. Contemporary measurements of Aitken nuclei and optically active particles ( r > 0.15 μm) show that gas-toparticle conversion is one important process being responsible for the observed trend and that particle production obviously occurs at situations with high radiation or high temperatures. Also however, increasing production (e.g. traffic or due to low efficiency of emission reducing filter devices in the submicron particle range) may contribute to some degree to the rising TSP mass. A plausibility consideration confirms that in spite of a reduction of the total dust emissions an increase of TSP may be observed at a sufficiently large source distance if the emission reduction is mainly confined to the coarse particles.

A comparative study on the varying exposure to atmospheric fine and coarse particles under urban and rural conditions

This paper is based on the results of three air quality studies conducted in Buenos Aires in Berlin, and in German spas between 2003 and 2007. A high comparability of results was ensured by using the same sampling techniques and analytical methods. Total particle sampling was achieved by active sampling of fine (PM2.5) and passive sampling of coarse particles ≥2.5 µm and giant particles ≥10 µm. The highly absorbing, black, predominantly carbonaceous particles (BC) of fine particle samples were determined by measuring the total light attenuation of filter samples and interpreting the extinction value as black carbon. The difference between the gravimetric total mass concentration of the PM2.5 samples and the BC is defined as the transparent, mostly mineral fine fraction. In coarse/giant particle samples the mean gray value was determined by means of automated light microscopy with subsequent single-particle analysis. “Opaque” particles were separated from the “transparent” particle fraction by applying a grey value threshold level. Microscopic measurement of individual particles was employed to establish the size distribution of the coarse and giant fraction. Due to different health effects, the separate detection of these components is suggested. Decline functions of particles are given, possibly providing useful information for a more detailed specification of the local particle distribution, and for a better estimate of the individual exposure. Atmospheric dispersal of particles was found effected mainly by source characteristics. An increased, spatially largely constant level of fine transparent particles in Berlin indicates a particle plume originating from photochemical processes. Buenos Aires, in contrast, is characterized by a lower background level of fine transparent particles but is considerably affected by fine black particles from diesel emissions and by a higher resuspension of coarse/giant transparent, mainly soil particles. Implications: Mini-volume and passive sampling combined proved to be suitable for measuring total particles by collecting fine, coarse, and giant particles. This approach allows the acquisition of highly space-resolved data on a weekly basis. A method was employed to calculate a size-fractionated particle concentration from passive samples. The results from three air quality studies using this method demonstrate that the black/opaque and transparent particles distinguished differ considerably in spatial distribution, not only due to varying atmospheric residence. Estimates of the exposure of humans, therefore, have to consider the different effects of rural and urban conditions, and differences between regional climates.

Aktuelle Aerosoltrends an der GAW Globalstation Hohenpeißenberg und ihre Relevanz für Luftreinhaltung und Klima

ZusammenfassungZiel der ArbeitZiel der Untersuchung war es, aktuelle Aerosoltrends darzustellen, die an der GAW Globalstation gemessen werden und ihre Relevanz für die gegenwärtige Feinstaubdiskussion und mögliche Einflüsse auf das Klima zu untersuchen.Ergebnisse und Diskussion1) Das umfangreiche GAW Mess-programm am Hohenpeißenberg umfasst zahlreiche Parameter zur Charakterisierung der physikalischen, optischen und chemischen Eigenschaften des atmosphärischen Aerosols. Die Zeitreihe der Anzahl von ultrafeinen Partikeln mit Durchmessern von etwa 0.004 bis 3 μm zeigt seit 1995 an der GAW Globalstation einen Anstieg von etwa 50%. 2) Die Einführung von Dieselruß-Partikelfiltern würde die Staubmasse nur geringfügig senken, da Ruß-Partikeln aus Dieselfahrzeugen nur etwa 8–10% zur Staubmasse beitragen, aber etwa 90% zur Partikelanzahl. 3) Die Single Scattering Albedo (SSA), die eine Aussage darüber macht, ob das vorhandene Aerosolgemisch eine Abkühlung (negativer Strahlungsantrieb) oder eine Erwärmung (positiver Strahlungsantrieb) bewirkt, hat sich von 1999 bis 2005 am Hohenpeißenberg von 0.85 auf 0.91 verändert, d.h. dass sich das regionale Aerosol in der Summe mehr aus streuenden als absorbierenden Partikeln zusammensetzt.Schlussfolgerungen und AusblickAus aktuellen Aerosoltrends an der GAW Globalstation Hohenpeißenberg konnte ihre Relevanz für die Luftreinhaltung und mögliche Klimaeinflüsse untersucht werden. Im Zusammenhang mit der Feinstaubdiskussion ist die Staubmasse nicht der geeignete Parameter, um den Einfluss von Dieselfahrzeugen am Feinstaub zu untersuchen. Die Messung der Partikelanzahl spiegelt den Einfluss von Dieselfahrzeugen wesentlich besser wider und zeigt auch einen zu erwartenden positiven Trend auf Grund der starken Zunahme des Anteils von Diesel-Pkws an der gesamten Fahrzeugflotte. Aerosolpartikeln streuen und absorbieren die solare Strahlung und beeinflussen damit das Klima. Die Hohenpeißenberger Werte der Single Scattering Albedo zeigen, dass in den Anfangsjahren das Aerosol den beobachteten Temperaturanstieg nicht gedämpft, sondern eher verstärkt hat. Ob die Ergebnisse auch für die großräumige Situation repräsentativ sind, kann nur ein Vergleich der Daten eines globalen Messnetzes wie GAW zeigen.AbstractAim and ScopeThis study was aimed at representing current aerosol trends measured at the GAW global station and their relevance for the present fine dust discussion and a possible impact on climate.Results and Discussion1) The intensive GAW measuring program at Hohenpeissenberg covers numerous parameters for the characterization of the physical, optical and chemical characteristics of the atmospheric aerosol. The time series of the number concentration of ultra fine particles with diameters of about 0.004 to 3 μm shows an increase of about 50% since 1995. 2) The introduction of soot particle filters would lower the dust mass only slightly since soot particles from diesel cars only about 8–10% contribute to the dust mass, but about 90% to the number concentration of particles. 3) The single scattering albedo (SSA) is a key parameter determining whether the existing aerosol mixture causes a cooling (negative radiative forcing) or a warming (positive radiative forcing) in the atmosphere. At Hohenpeißenberg the SSA changed from 0.85 to 0.91 in the time period 1999 to 2005, i.e. the regional aerosol as a whole is dominated by scattering rather than absorbing particles.Conclusion and PerspectiveFrom current aerosol trends at the GAW global station Hohenpeißenberg it was possible to analyze their relevance for air pollution control and possible influences on climate. Dust mass is not a suitable parameter for accessing the contribution of diesel engined vehicles. Measuring the number concentration of particles much more reflects the influence of diesel engined vehicles and also shows, as expected, an upward trend due to a strong increase of the fraction of diesel vehicles in comparison to the total number of cars. Aerosol particles scatter and absorb solar radiation and thus cause a cooling or warming in the atmosphere. Calculated values of the single scattering albedo at Hohenpeissenberg show, that in the initial years the aerosol did not diminish the temperature rise, but rather caused it to increase. Only a data comparison from a global network like GAW can demonstrate, if the results are even representative for the large scale situation.

The PM2.5 Fine Particle Background Network of the German Meteorological Service-First Results

Since 2009, the measurement of the background concentration of the fine particle fraction has been a part of the climate-monitoring program of the German Meteorological Service (DWD). These particles are of high health relevance as a critical air pollutant affecting processes like the scattering and absorption of solar radiation and influencing cloud formation and visibility. At 12 weather stations, the coarse (2.5 to 10 lm) and the fine particle fractions (PM2.5) are measured by means of passive and active samplers. First results are presented for the mass concentrations of coarse and fine particles as well as for the black carbon (BC) content and the concentration of certain inorganic ions of fine particles. There is not only a seasonal correlation between the fraction of fine and coarse particles, but also a correlation with the location (urban background or rural background).With the help of light microscopy, coarse particles can be differentiated for a geogenic (predominantly wind blown mineral and sea salt particles of natural origin and road abrasion) and for an anthropogenic opaque component (combustion residues, e.g. fly ash and non-exhaust vehicle emissions, e.g. abrasion particles of brakes and tires). Measuring the fine fraction and the coarse fraction separately instead of PM10 allows for a better source allocation and thus is a more appropriate method for the improvement of the air quality in, e. g. low emission zones.