Publications using GRIMM products

Environmental Dust Monitors

Author: N. Hiranuma, S. D. Brooks, J. Gramann, and B. W. Auvermann
Date of Publication: 2011
Hyperlink: Link
Product: 1108

Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the nominally upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 µm diameter. Raman microspectroscopy (RM) was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of fugitive dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 µm or less) were as high as 1200 µgm^-3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant percentage of the organic particles, up to 28 %, were composed of internally mixed with salts. Basic
characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences will lead to serious errors in estimates of aerosol effects on climate, visibility, and public health.

Date of Publication: 2011

During the 2010 eruption period of the Eyjafjallajökull the University of Applied Sciences of Duesseldorf and the University of Reykjavik performed several measurement flights with small aircraft in the volcanic plume. Whereas the University of Applied Sciences mapped the distal plume over Germany, the University of Iceland explored the airspace overwestern Iceland and near the Eyjafjallajökull, partly entering the volcanic plume boundary directly. The use of the small piston-motor driven research aircraft in the special situation of volcanic plumes has several advantages over jet engine driven research aircrafts: The piston-motor driven aircraft are robust enough to operate even at elevated ash concentration levels. The small aircrafts allow a low cruising speed during the measurements and have thus the advantage of delivering results with a high spatial resolution. The low possible aircraft cruising speed during the measurements simplifies the intake of even bigger ash particles into the measurement systems. Small aircraft allow a very cost effective operation. The aircraft were equipped with optical particle counters (OPCs) for on-line in-situ results. Moreover, the German aircraft was equipped with a DOAS system for SO2 and a
NDIR analyzer for CO2 measurements. The measurement flights revealed that the ash plume over Germany had a very inhomogeneous structure. Sub-plumes
and different vertical plume layers could be identified. Regional elevated SO2 concentrations could be detected. Peak ash particle concentrations of more than 330 µg/m3 could be found during the measurement flights over northern Germany, whereas the flights over Iceland showed low concentrations outside the plume, but values of about 2000 µg/m3 within the boundary of the plume.

Title: Feinstaubuntersuchung an einer emissionsgeminderten Straßen-Nassreinigungsmaschine
Author: C. Fischer, K, Weber, A. Vogel, G.van Haaren, T.Pohl, Eberhard Schmidt, Andreas Brandt
Date of Publication: 2011
Product: 107

Aufgrund der stark schwankenden Randbedingungen (z.B. meteorologischer Bedingungen) ist die Interpretation der Daten schwierig. Allerdings gibt es eher Hinweise für eine Erniedrigung im mittleren einstelligen mg/m³ Bereich der Immisionsbelastungen während der Nassreinigung in den Untersuchungsteitrum und Untersuchungsteilabschnitt von insgesamt drei Nassreinigungswochen. Ob diese repräsentativ auch für den Zeitraum eines Jahres ist, kann im Rahmen der Immisionsmessungen dieser Studie nicht abschliessend beurteiult werden.

Title: The Eyjafjallajökull eruption in April 2010
Author: H. Flentje, H. Claude, T. Elste, et al
Date of Publication: 2010

Volcanic emissions from the Eyjafjallaj¨okull volcano eruption on the Southern fringe of Iceland in April 2010 were detected at the Global Atmosphere Watch (GAW) station Zugspitze/Hohenpeissenberg (Germany) by means of in-situ measurements, ozone sondes and ceilometers. Information from the German Meteorological Service (DWD) ceilometer network (Flentje et al., 2010) aided identifying the air mass origin. We discuss ground level in-situ measurements of sulphur dioxide (SO2), sulphuric acid (H2SO4) and particulate matter as well as ozone sonde profiles and column measurements of SO2 by a Brewer spectrometer. At Hohenpeissenberg, a number of reactive gases, e.g. carbon monoxideand nitrogen oxides, and particle properties, e.g. size distribution and ionic composition, were additionally measured during this period. Our results describe the arrival of the volcanic plume at Zugspitze and Hohenpeissenberg during 16 and 17 April 2010 and its residence in the planetary boundary layer (PBL) for several days thereafter. The ash plume was first seen in the ceilometer backscatter profiles at Hohenpeissenberg in about 6–7 km altitude. After entrainment into the PBL at noon of 17 April, largely enhanced values of sulphur dioxide, sulphuric acid and super-micron-particle number concentration were recorded at Zugspitze/Hohenpeissenberg till 21 April.

Title: Aerosol mass and black carbon concentrations, a two year record at NCO-P (5079 m, Southern Himalayas)
Author: A. Marinoni, P. Cristofanelli, P. Laj, R Duchi, et al
Date of Publication: 2010
Hyperlink: Link
Product: 190

Aerosol mass and the absorbing fraction are important variables, needed to constrain the role of atmospheric particles in the Earth radiation budget, both directly and indirectly through CCN activation. In particular, their monitoring in remote areas and mountain sites is essential for determining source regions, elucidating the mechanisms of long range transport of anthropogenic pollutants, and validating regional and global models. Since March 2006, aerosol mass and black carbon concentration have been monitored at the Nepal Climate Observatory-Pyramid, a permanent high-altitude research station located in the Khumbu valley at 5079m a.s.l. below Mt. Everest. The first twoyear averages of PM1 and PM1−10 mass were 1.94 μgm^−3 and 1.88 μgm^−3, with standard deviations of 3.90 μgm^−3 and 4.45 μgm^−3, respectively, while the black carbon concentration average is 160.5 ngm^−3, with a standard deviationof 296.1 ngm−3. Both aerosol mass and black carbon show well defined annual cycles, with a maximum during the premonsoon season and a minimum during the monsoon. They also display a typical diurnal cycle during all the seasons, with the lowest particle concentration recorded during the night, and a considerable increase during the afternoon, revealing the major role played by thermal winds in influencing the behaviour of atmospheric compounds over the high Himalayas. The aerosol concentration is subject to high variability: in fact, as well as frequent “background conditions” (55% of the time) when BC concentrations are mainly below 100 ngm^−3, concentrations up to 5 μgm^−3 are reached during some episodes (a few days every year) in the premonsoon seasons. The variability of PM and BC is the result of both short-term changes due to thermal wind development in the valley, and long-range transport/synoptic circulation. At NCO-P, higher concentrations of PM1 and BC are mostly associated with regional circulation and westerly air masses from the Middle East, while the strongest contributions of mineral dust arrive from the Middle East and regional circulation, with a special contribution from North Africa and South-West Arabian Peninsula in post-monsoon and winter season.

Title: Atmospheric Brown Clouds in the Himalayas: first two years of continuous observations at the Nepal Climate Observatory-Pyramid (5079 m)
Author: P. Bonasoni, P. Laj, A. Marinoni, M. Sprenger, F. Angelini et al
Date of Publication: 2010
Product: 190

This paper provides a detailed description of the atmospheric conditions characterizing the high Himalayas, thanks to continuous observations begun in March 2006 at the Nepal Climate Observatory-Pyramid (NCO-P) located at 5079ma.s.l. on the southern foothills of Mt. Everest, in the framework of ABC-UNEP and SHARE-Ev-K2-CNR projects. The work presents a characterization of meteorological conditions and air-mass circulation at NCO-P during the first two years of activity. The mean values of atmospheric pressure, temperature and wind speed recorded at the site were: 551 hPa, −3.0 _C, 4.7ms^−1, respectively. The highest seasonal values of temperature (1.7 _C) and relative humidity (94%) were registered during the monsoon season, which was also characterized by thick clouds, present in about 80% of the afternoon hours, and by a frequency of cloud-free sky of less than 10%. The lowest temperature and relative humidity seasonal values were registered during winter, −6.3 _C and 22%, respectively, the season being characterised by mainly cloud-free sky conditions and rare thick clouds. The summer monsoon influenced rain precipitation (seasonal mean: 237 mm), while wind was dominated by flows from the bottom of the valley (S-SW) and upper mountain (N-NE). / The atmospheric composition at NCO-P has been studied thanks to measurements of black carbon (BC), aerosol scattering coefficient, PM1, coarse particles and ozone. The annual behaviour of the measured parameters shows the highest seasonal values during the premonsoon (BC: 316.9 ngm−3, PM1: 3.9 μgm^−3, scattering coefficient: 11.9Mm^−1, coarse particles: 0.37 cm^−3 and O3: 60.9 ppbv), while the lowest concentrations occurred during the monsoon (BC: 49.6 ngm−3, PM1: 0.6 μgm^−3, scattering coefficient: 2.2Mm ^−1, and O3: 38.9 ppbv) and, for coarse particles, during the post-monsoon (0.07 cm^−3). At NCO-P, the synoptic-scale circulation regimes present three principal contributions: Westerly, South-Westerly and Regional, as shown by the analysis of in-situ meteorological parameters and 5-day LAGRANTO back-trajectories. / The influence of the brown cloud (AOD>0.4) extending over Indo–Gangetic Plains up to the Himalayan foothills has been evaluated by analysing the in-situ concentrations of the ABC constituents. This analysis revealed that brown cloud hot spots mainly influence the South Himalayas during the pre-monsoon, in the presence of very high levels of atmospheric compounds (BC: 1974.1 ngm^−3, PM1: 23.5 μgm^−3, scattering coefficient: 57.7Mm^−1, coarse particles: 0.64 cm^−3, O3: 69.2 ppbv, respectively). During this season 20% of the days were characterised by a strong brown cloud influence during the afternoon, leading to a 5-fold increased in the BC and PM1 values, in comparison with seasonal means. Our investigations provide clear evidence that, especially during the pre-monsoon, the southern side of the high Himalayan valleys represent a “direct channel” able to transport brown cloud pollutants up to 5000ma.s.l., where the pristine atmospheric composition can be strongly influenced.

Title: Aerosol optical properties and radiative forcing in the high Himalaya based on
measurements at the Nepal Climate Observatory
Author: S. Marcq, P. Laj, J. C. Roger, P. Villani, K. Sellegri, P. Bonasoni et al
Date of Publication: 2010
Hyperlink: Link
Product: 190

Intense anthropogenic emissions over the Indian sub-continent lead to the formation of layers of particulate pollution that can be transported to the high altitude regions of the Himalaya-Hindu-Kush (HKH). Aerosol particles contain a substantial fraction of strongly 5 absorbing material, including black carbon (BC), organic compounds (OC), and dust all of which can contribute to atmospheric warming, in addition to greenhouse gases. Using a 3-year record of continuous measurements of aerosol optical properties, we present a time series of key climate relevant aerosol properties including the aerosol absorption ( ap) and scattering ( sp) coefficients as well as the single-scattering albedo 10 (w). Results of this investigation show substantial seasonal variability of these properties, with long range transport during the pre- and post-monsoon seasons and efficient precipitation scavenging of aerosol particles during the monsoon season. The monthly averaged scattering coefficients range from 0.1Mm^−1 (monsoon) to 20Mm^−1 while the average absorption coefficients range from 0.5Mm^−1 to 3.5Mm^−1. Both have their 15 maximum values during the pre-monsoon period (April) and reach a minimum during Monsoon (July–August). This leads to w values from 0.86 (pre-monsoon) to 0.79 (monsoon) seasons. Significant diurnal variability due to valley wind circulation is also reported. Using typical air mass trajectories encountered at the station, and aerosol optical depth (aod) measurements, we calculated the resulting direct local radiative 20 forcing due to aerosols. We found that the presence of absorbing particulate material can locally induce an additional top of the atmosphere (TOA) forcing of 10 to 20Wm^−2for the first atmospheric layer (500m above surface). The TOA positive forcing depends on the presence of snow at the surface, and takes place preferentially during episodes of regional pollution occurring on a very regular basis in the Himalayan valleys. Warming of the first atmospheric layer is paralleled by a substantial decrease of the amount of radiation reaching the surface. The surface forcing is estimated to range from −4 to −20Wm^−2 for small-scale regional pollution events and large-scale pollution events, respectively. The calculated surface forcing is also very dependent on surface albedo, with maximum values occurring over a snow-covered surface. Overall, this work presents the first estimates of aerosol direct radiative forcing over the high Himalaya based on in-situ aerosol measurements, and results suggest a TOA forcing significantly greater than the IPCC reported values for green house gases.

Title: Chemical composition of PM10 and PM1 at the high-altitude Himalayan station Nepal
Climate Observatory-Pyramid (NCO-P) (5079ma.s.l.)
Author: S. Decesari, M. C. Facchini, C. Carbone, L. Giulianelli /et al
Date of Publication: 2010
Hyperlink: External Link
Product: 190

We report chemical composition data for PM10 and PM1 from the Nepal Climate Observatory-Pyramid (NCO-P), the world’s highest aerosol observatory, located at 5079m a.s.l. at the foothills of Mt. Everest. Despite its high altitude, the average PM10 mass apportioned by the chemical analyses is of the order of 6 μgm−3 (i.e., 10 μg/scm), with almost a half of this mass accounted for by organic matter, elemental carbon (EC) and inorganic ions, the rest being mineral dust. Organic matter, in particular, accounted for by 2.0 μgm^−3 (i.e., 3.6 μg/scm) on a yearly basis, and it is by far the major PM10 component beside mineral oxides. Non-negligible concentrations of EC were also observed (0.36 μg/scm), confirming that light-absorbing aerosol produced from combustion sources can be efficiently transported up the altitudes of Himalayan glaciers. The concentrations of carbonaceous and ionic aerosols follow a common time trend with a maximum in the premonsoon season, a minimum during the monsoon and a slow recovery during the postmonsoon and dry seasons, which is the same phenomenology observed for other Nepalese Himalayan sites in previous studies. Such seasonal cycle can be explained by the seasonal variations of dry and moist convection and of wet scavenging processes characterizing the climate of north Indian subcontinent. We document the effect of orographic transport of carbonaceous and sulphate particles upslope the Himalayas, showing that the valley breeze circulation, which is almost permanently active during the out-of-monsoon season, greatly impacts the chemical composition of PM10 and PM1 in the high Himalayas and provides an efficient mechanism for bringing anthropogenic aerosols into the Asian upper troposphere (>5000m a.s.l.). The concentrations of mineral dust are impacted to a smaller extent by valley breezes and follow a unique seasonal cycle which suggest multiple source areas in central and south-west Asia. Our findings, based on two years of observations of the aerosol chemical composition, provide clear evidence that the southern side of the high Himalayas is impacted by transport of anthropogenic aerosols which constitute the Asian brown cloud.

Title: Airborne Measurements of the Eyjafjallajökull volcanic ash plume over North-Western
Germany with a light aircraft and an optical particle counter
Author: K. Weber, A. Vogel, C. Fischer, G. van Haren, T. Pohl
Date of Publication: 2010
Hyperlink: External Link
Product: EDM107

During the eruption phase of the Icelandic volcano Eyjafjallajökull in April/May 2010 the University of Applied Sciences Duesseldorf has performed 14 measurement flights over north-western Germany in the time period of 23 April 2010 to 21 May 2010. Additionally 4 flights have been performed for visual observations, referencing and transfer. The measurement flights have been performed in situations, where the ash plume was present over north-western Germany as well as in situations, when there was no ash plume predicted. For the measurements a light aircraft (Flight Design CTSW Shortwing) was used, which was equipped with an optical particle counter (Grimm 1.107). Additionally the aircraft was equipped for one flight with an UV-DOAS system and a CO2-measurement system. The optical particle counter allowed in-situ measurements of the particle distribution between 250 nm and 32 μm and of PM10, PM2.5 and PM1. The ash plume appeared during the measurements as inhomogeneous in structure. Layers or multilayers of one hundred meters to a few hundred meters vertical depth of ash plume could be identified. Sub-plumes with a horizontal extension of several kilometres to several tenths of kilometres could be found. The layers of the ash plume could be found in altitudes between 2500m and 4500m. The measured concentrations have been compared with the concentration and extension of the ash plume predicted by the Volcanic Ash Advisory Centre (VAAC)

The GRIMM model 107 monitor is designed to measure particle size distribution and particulate mass based on a light scattering measurement of individual particles in the sampled air. The design and operation of the instrument are described. Protocols used to convert the measured size number distribution to a mass concentration consistent with U.S. Environmental Protection Agency protocols for measuring particulate matter (PM) less than 10 m (PM10) and less than 2.5 m (PM2.5) in aerodynamic diameter are described. The performance of the resulting continuous monitor has been evaluated by comparing GRIMM monitor PM2.5 measurements with results obtained by the Rupprecht and Patashnick Co. (R&P) filter dynamic measurement system (FDMS). Data were obtained during month-long studies in Rubidoux, CA, in July 2003 and in Fresno, CA, in December 2003. The results indicate that the GRIMM monitor does respond to total PM2.5 mass, including the semi-volatile components, giving results comparable to the FDMS. The data also indicate that the monitor can be used to estimate water content of the fine particles. However, if the inlet to the monitor is heated, then the instrument measures only the nonvolatile material, more comparable to results obtained with a conventional heated filter tapered element oscillating microbalance (TEOM) monitor. A recent modification of the model 180, with a Nafion dryer at the inlet, measures total PM2.5 including the nonvolatile and semi-volatile components, but excluding fine particulate water. Model 180 was in agreement with FDMS data obtained in Lindon, UT, during January through February 2007.

Title: Coupling of urban street canyon and backyard particle concentrations
Author: Weber, Stephan; Weber, Konradin
Date of Publication: 2008
Hyperlink: External Link
Product: 1107

Differences in particle mass and number concentrations between a busy urban street canyon (north-south orientation, about 50,000 vehicles 24 h-1) and an adjacent backyard were measured with optical particle counters. The influence of meteorological quantities, especially turbulent flow within the urban canopy layer, was also studied. Particle mass concentrations PM10 and PM1 were consistently larger within the street canyon due to enhanced emission and resuspension. For the study period this resulted in higher concentrations in the canyon of on average 30 % (PM10) and 22 % (PM1). Although elevated transport of submicrometer particles was related to easterly wind directions, the largest relative concentration differences between both sites were associated to cross-canyon flow from westerly wind directions. This is due to the canyon vortex being able to direct polluted air masses to the measurement site during flow being directed perpendicular to the canyon axis. For less polluted air within the backyard the backyard vortex is of minor influence. We found different influence of thermal and mechanical turbulence on the temporal evolution of concentration differences at both sites. Thermal turbulence was positively correlated with particle concentrations, while the latter was characterised by negative correlation coefficients.

Title: Flow characteristics and particle mass and number concentration variability within a busy urban street canyon
Author: Stephan Weber, Wilhelm Kuttler, Konradin Weber
Date of Publication: 2006
Product: 1107

Mean and turbulent flow characteristics together with particle concentrations were measured in a busy urban street canyon in Essen, Germany, at five (flow characteristics) and three heights (particles) above ground, respectively. Particle mass and number concentrations were sampled in the size range 0.3<Dp<10 μm. The flow characteristics within the canyon were significantly influenced by canyon geometry and were shown to have significant impact on particle concentrations. During flow being directed perpendicular to the canyon a vortex circulation leads to a doubling of ambient particles when the measurement site is situated upwind to ambient flow. The vertical profiles of fine particles have maximum vertical differences of 12% between measurement levels. In the upper part of the canyon, concentrations decrease due to enhanced turbulence and mixing. Significant differences in the dynamics of particle number concentration for different size ranges are analysed. While submicron particles are inversely related to turbulence parameters, i.e. lower concentrations during enhanced turbulence, coarser particles (1<Dp<10 μm) are positively correlated to mixing within the canyon.

Title: Höhentauglichkeitstest Partikelmessgeräte
Author: Robert Hagler
Date of Publication: 2004
Product: EDM107

Die Geräte messen Partikel (Anzahl/Volumen)- bzw. Massenkonzentrationen (Masse/Volumen) in verschiedenen Fraktionen auf optischer Basis durch Streulicht. / Die Umrechnung der im Sampleintervall/Messintervall gezählten Teilchen in Teilchen- bzw. Massen- Konzentrationen erfolgt in Abhängigkeit des Messintervalls unter Annahme eines konstanten Durchflusses. Letzteres wird mittels einer geräteinternen Durchflussregelung realisiert wobei der Istwert über eine Differenzdruckmessung an einer Blende erfasst wird. Die Genauigkeit der Durchflussregelung hängt in erster Linie von Temperatur und Dichte der
angesaugten Luft ab und reicht unter „normalen“ Bedingungen (Urbaner Bereich, Europa) aus./Werden die Geräte in großer Höhe betrieben, so entstehen (ohne zusätzliche Maßnahmen wie später beschrieben) Messfehler.

Title: Environmental Science and Pollution Research
Author: Md Firoz Khan, Mohd Talib Latif, Norhaniza Amil, Liew Juneng, Noorlin Mohamad, Mohd Shahrul Mohd Nadzir & Hossain Mohammed Syedul Hoque
Date of Publication: 1 Mai. 2015
Hyperlink: Khan et al PNC_2015 [3.285 KB]
Product: EDM 365 SVC

Principal component analysis (PCA) and correlation have been used to study the variability of particle mass and particle number concentrations (PNC) in a tropical semiurban
environment. PNC and mass concentration (diameter in the range of 0.25–>32.0 μm) have been measured from 1 February to 26 February 2013 using an in situ Grimm aerosol
sampler. We found that the 24-h average total suspended particulates (TSP), particulate matter ≤10 μm (PM10), particulate matter ≤2.5 μm (PM2.5) and particulate matter ≤1 μm (PM1)
were 14.37±4.43, 14.11±4.39, 12.53±4.13 and 10.53± 3.98 μg m−3, respectively. PNC in the accumulation mode (<500 nm) was the most abundant (at about 99 %). Five principal
components (PCs) resulted from the PCA analysis where PC1 (43.8%variance) predominates with PNC in the fine andsub-microme tre range. PC2, PC3, PC4 and PC5 explain 16.5,
12.4, 6.0 and 5.6 % of the variance to address the coarse, coarser, accumulation and giant fraction of PNC, respectively. Our particle distribution results show good agreement with the
moderate resolution imaging spectroradiometer (MODIS) distribution.
Hyperlink:Link [659 KB]

We evaluated the effect of ionization in reducing particulate and gaseous emissions in broiler houses and its effect on particle size distribution. Furthermore, we evaluated the performance of the tested ionization system and its influence on bird performance. The experiment was done during two consecutive rearing cycles in a pilot‐scale broiler house with four identical rooms. We measured concentrations of PM10 and PM2.5, airborne micro‐organisms, ammonia, and odor of the incoming and outgoing air. Emissions were calculated by multiplying measured concentration difference of each pollutant by measured ventilation exchange rates. Performance of the system was evaluated through quantifying ion concentration, ozone production, and ultrafine particle concentration. Moreover, we recorded bird weight gain, consumption variables, mortality, exterior quality, and foot pad lesions. Overall measured mass emissions reductions were 36% for PM10 and 10% for PM2.5. Total mass was reduced less for PM2.5 because reduction efficiency decreased to the end of the growing period (P < 0.10). This coincided with increased particulate concentrations, increased ventilation exchange rates, and dust accumulation on surfaces. Higher reduction efficiencies were observed in relation to increased particle size. Ionization did not have a significant effect on micro‐organism, ammonia, or odor emissions or on bird performance. Ionization proved to be a practical and effective technique for particulate reduction, with minimal maintenance required for use in broiler houses. It is recommended to evaluate the use of ionization in commercial broiler houses to validate these results.
Hyperlink:Link [8.590 KB]