|
|
|
| Registros recuperados: 50 | |
|
|
| Noone, K.J.; Johnson, D.W.; Taylor, J.P.; Ferek, R.J.; Garrett, T.; Hobbs, P.V.; Durkee, P.A.; Nielsen, K.; Öström, E.; O'Dowd, C.; Smith, M.H.; Russell, L.M.; Flagan, R.C.; Seinfeld, J.H.; De Bock, L.; Van Grieken, R.; Hudson, J.G.; Brooks, I.; Gasparovic, R.F.; Pockalny, R.A.. |
| A case study of the effects of ship emissions on the microphysical, radiative, and chemical properties of polluted marine boundary layer clouds is presented. Two ship tracks are discussed in detail. <i>In situ</i> measurements of cloud drop size distributions, liquid water content, and cloud radiative properties, as well as aerosol size distributions (outside-cloud, interstitial, and cloud droplet residual particles) and aerosol chemistry, are presented. These are related to remotely sensed measurements of cloud radiative properties. The authors examine the processes behind ship track formation in a polluted marine boundary layer as an example of the effects of anthropogenic particulate pollution on the albedo of marine stratiform clouds. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols; Air pollution; Albedo; Atmosphere; Atmosphere; Atmospheric boundary layer; Boundary layers; Cloud cover; Clouds; Man-induced effects; Marine environment; Marine pollution; Particulates; Remote sensing; Ships. |
| Ano: 2000 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8839 |
| |
|
|
| Struyf, H.; Van Grieken, R.. |
| An overview of the wet deposition of micropollutants (trace metals -Cd, Cr, Cu, Pb, Hg, Zn- and organic compounds -PAHs, PCBs, pesticides) to the North Sea and adjacent areas is presented. The results of (in)direct measurements of the wet flux are compared to modeling results. Attention is given to specific problems like revolatilization, sea-spray, contamination, gas-to-particle ratios in wet deposition of Hg and the organic substances. Also, the importance of wet deposition is weighted to that of dry deposition and non-atmospheric input routes to the North Sea. It is concluded that -especially for organic micropollutants- current knowledge is insufficient to yield an accurate and detailed image of the impact and importance of wet deposition to the North... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1993 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2785 |
| |
|
|
| Otten, P.; Injuk, J.; Rojas, C.; Van Grieken, R.. |
| The North Sea is being under loaded in many ways, both by organic and anorganic pollutants. Transport over rivers is the most evident way. Direct emission along the coastline and dumping of toxic materials by vessels are another two causes of pollution. Exploitation of oil and gas platforms also lead to operational emission of certain noxious substances. “Last but not least” a part of the pollutants also reach the North Sea through the atmosphere.This article specifically concerns the latter facet of North Sea Pollution. Both gaseous and particular material is being emitted in the atmosphere through incineration and other polluting processes. After physical dispersion and chemical transformation, these pollutants can end up in the sea through deposit... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2850 |
| |
|
|
| Injuk, J.; Van Grieken, R.. |
| A literature review of the atmospheric concentration rates and dry and wet deposition fluxes of particulate Cd, Cr, Cu, Pb and Zn to the North Sea and adjacent areas is given. The results of direct measurements of dry and wet deposition fluxes are compared to indirect estimates and to modelling values. This work points out the large uncertainties in results of different studies on atmospheric input of trace elements into the North Sea. The current knowledge about the dependence of the deposition velocity upon the particular size and about the processes controlling wet deposition fluxes, and the quality and completeness of the emission data are still adequate for describing the environmental cycle and impact of heavy metals in the North Sea. |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2981 |
| |
|
|
| Injuk, J.; Otten, Ph.; Laane, R.W.P.M.; Maenhaut, W.; Van Grieken, R.. |
| In an effort to assess the atmospheric input of heavy metals to the Southern Bight of the North Sea, aircraft-based aerosol samplings in the lower troposphere were performed between September 1988 and October 1989. Total atmospheric particulate and size-differentiated concentrations of Cd, Cu, Pb and Zn were determined as a function of altitude, wind direction, air-mass history and season. The obtained data are compared with results of ship-based measurements carried out previously and with literature values of Cu, Pb and Zn, for the marine troposphere of the southern North Sea. The results point out the high variability of the concentrations with the meteorological conditions, as well as with time and location. The experimentally found particle size... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2810 |
| |
|
|
| Stroobants, N.; Dehairs, F.A.; Goeyens, L.; Vanderheijden, N.; Van Grieken, R.. |
| The intensity of past biological activity can be correlated with the occurrence of suspended and sedimented barite (BaSO<sub>4</sub>). To date, there is a lack of information on the processes controlling the production of pelagic barite. During the EPOS-2 cruise (November-December 1988), situated in the Scotia Sea-Weddell Sea Confluence, suspended water samples were taken for analysis of total Ba by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and for scanning electron microscopy-electron microprobe (SEM-EMP).The vertical profiles of particulate barium generally show a Ba maximum between 200 and 500 m. SEM-EMP investigation on Scotia-Weddell Sea Confluence profiles provide a possible explanation for the origin of this... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2865 |
| |
|
| |
|
|
| Van Malderen, H.; Rojas, C.; Van Grieken, R.. |
| In order to investigate the importance of giant airborne particles, air sampling was carried out using an aircraft which flew at different altitudes over the Southern Bight of the North Sea. A set of 25 samples was collected with a steel rod on top of the airplane. Some 12,500 individual particles were analyzed using electron probe X-ray microanalysis. Principal factor analysis allowed identification of four sources of giant aerosol particles: aluminosilicates, combustion processes, industrial processes, and marine sources. Hierarchical and nonhierarchical cluster analysis enabled us to classify the analyzed particles. A clear distinction was found between flights for which the associated air masses were marine or continental. The experimentally found size... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2887 |
| |
|
|
| Xhoffer, C.; Wouters, G.; Van Grieken, R.. |
| Five pairs of North Sea bulk waters and their corresponding surface microlayer samples were investigated for their particulate matter content and chemically analyzed and characterized by electron probe X-ray microanalysis and laser microprobe mass analysis. Multivariate techniques as hierarchical and nonhierarchical clustering in association with principal component analysis was performed on a data set containing more than 3,000 individual particles. This classification procedure yielded eight different particle types. Differences in particle type abundances for the microlayer and bulk water were observed. They were apportioned to their most probable sources. The results were compared with atmospheric and riverine particle data. The domination of the major... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2909 |
| |
|
|
| Bruynseels, F.; Storms, H.; Van Grieken, R.; Van der Auwera, L.. |
| On aerosol and rain water samples, collected in the Southern Bight of the North Sea, single particle analyses were performed using both laser microprobe mass analysis and electron-probe X-ray microanalysis in combination with an automated image analysis system.In the aerosols collected from an air mass that had traveled from the Atlantic Ocean along the coast of North France, pure seasalt constituted the most abundant particle type, while aluminosilicates (mostly spherical fly-ash particles) amounted to about 20% and mixed seasalt/aluminosilicates, carbonaceous particles, CaSO<sub>4</sub> and spherical iron oxides contributed each 5-10%. In air masses that had a longer residence time over the continent, spherical iron oxides, carbonaceous... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols; Rain. |
| Ano: 1988 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3125 |
| |
|
|
| Maenhaut, W.; Raemdonck, H.; Selen, A.; Van Grieken, R.; Winchester, J.W.. |
| By using a polyester sailboat as sampling platform, a series of duplicate aerosol samples was collected by cascade impactors on a trip from Panama to Tahiti in 1979. Elemental analysis mainly by particle-produced X-ray emission (PIXE) indicated, in the samples collected between Panama and the Galapagos Islands, the presence of a substantial crustal component (0.4 µg/m³), fine Cu (0.4 ng/m³ and Zn (0.6 ng/m³), and excess fine S and K (100 and 2.4 ng/m³, respectively in addition to the major sea salt elements. The crustal component and fine Cu and Zn are suggested to result from natural continental sources (i.e., eolian dust transport from the American continents and perhaps geothermal emissions). Samples collected west of the Galapagos Islands in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols IS; Equatorial Pacific. |
| Ano: 1983 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3398 |
| |
|
|
| Xhoffer, C.; Bernard, P.; Van Grieken, R.; Van der Auwera, L.. |
| More than 25,000 individual aerosol particles in 51 particulate matter samples, all taken from a research vessel over the North Sea and the English Channel, in a time range of 4 years, were analyzed by automated electron probe X-ray microanalysis (EPXMA). Multivariate methods were used to reduce the total data set. Single-particle analysis combined with hierarchical cluster analysis yields nine major particle types. The North Sea aerosol is predominantly composed of sea salt, sulfur-rich particles, silicates and calcium sulfate particles. Their abundance is dependent on meteorological conditions and sample location. Differences between all samples were studied on the basis of the abundance variations by using principal component analysis. Three factors... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1991 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2915 |
| |
|
|
| Rojas, C.M.; Van Grieken, R.; Laane, R.W.P.M.. |
| Dry deposition velocities have been calculated using three different approaches. Turbulent wind profile theory has been used to predict the drag coefficient, wind speed and friction velocity at 10m height when the wind speed is measured at a higher altitude. The resulting parameters were introduced in a two-layer deposition model. The second approach was the well-known model of Slinn and Slinn (1980, Atmospheric Environment 14, 1013-1016), whereas the third corresponded to the model published by Williams (1982, Atmospheric Environment 16, 1933-1938). Results point to clear differences. However, in a field experiment carried out at the Southern Bight of the North Sea, all three approaches show relatively comparable results. The role played by the size... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1993 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2748 |
| |
|
|
| Ganor, E.; Levin, Z.; Van Grieken, R.. |
| Aerosol particles were collected aboard a ship in Haifa and Tel Aviv, Israel, during the summer time. The aerosol particles (6170) were analyzed as individual particles and classified according to their chemical composition, size, number concentration per cubic centimeter and morphology. Most of the aerosol particles could be classified into four groups. The first contains gypsum from the sea and from industrial sources brought in by land breezes. A second group is characterized by continental aluminosilicate and quartz. A third group consists of sea salt mixed with sulphate particles. The fourth group is characterized by an abundance of sulphate particles, some of which are ammonium sulphate brought by the land breezes. The particles were identified as... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=304 |
| |
|
|
| Eltayeb, M.A.H.; Van Grieken, R.. |
| Coprecipitation of trace elements on aluminium hydroxide was combined with energy-dispersive x-ray fluorescence for the analysis of environmental water. The parameters for the preconcentration method were studied. The optimum procedure involves addition of 1 mg of the carrier, at pH 7.3, to a 200-ml water sample. The pH was adjusted by addition of ammonia solution. Quantitative recoveries were obtained for Ti(IV), Cr(III_, As(V), Pb(II) and Th(IV). The precision was 4–6% and the detection limits were in the range 0.2–0.8 µg l-1. |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8455 |
| |
|
|
| Injuk, J.; Van Grieken, R.; De Leeuw, G.. |
| The atmospheric input of up to 16 trace and other elements into the North Sea is further assessed from aerosol concentrations measured at a coastal station in Belgium, on ships during two cruises, and on a platform, in the years 1992-1994. The Slinn and Slinn model is used to calculate the dry deposition from the measured aerosol concentrations. The total (dry and wet) deposition into the North Sea environment is estimated to be (in tonnes per year): 560 for V, 1300 for Cr, 650 for Ni, 690 for Cu, 3500 for Zn and 1970 for Pb. The 'giant' particles dominate the fluxes. The atmospheric contribution to the total input into the North Sea, including riverine inputs and direct discharges, are estimated to be 28% for Cu, 29% for Zn and 57% for Pb. The inputs... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols Experimental data Fallout Heavy metals Measurement Modelling ANE; North Sea. |
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=309 |
| |
|
|
| Ro, C.-U.; Osán, J.; Van Grieken, R.. |
| The determination of low-Z elements such as carbon, nitrogen, and oxygen in atmospheric aerosol particles is of interest in studying environmental pollution. Conventional electron probe microanalysis technique has a limitation for the determination of the low-Z elements, mainly because the Be window in an energy-dispersive X-ray (EDX) detector hinders the detection of characteristic X-rays from light elements. The feasibility of low-Z element determination in individual particles using a windowless EDX detector is investigated. To develop a method capable of identifying chemical species of individual particles, both the matrix and the geometric effects of particles have to be evaluated. X-rays of low-Z elements generated by an electron beam are so soft... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=4028 |
| |
|
|
| Kolaitis, L.N.; Bruynseels, F.; Van Grieken, R.; Andreae, M.O.. |
| In open ocean waters the predominant volatile sulfur compound is dimethyl sulfide (DMS), representing almost 90% of the marine sulfur emissions. Methanesulfonic acid (MSA), one of the oxidation products of DMS, is consequently an important constituent of marine aerosols. Laser microprobe mass analysis (LAMMA) has been used for single-particle analysis of particles collected in the marine boundary layer. MSA, like the non-sea-salt sulfate, is mainly associated with the smallest aerosol particles, whose LAMMA spectra match the reference fingerprint spectra of MSA salts, sodium methanesulfonate and ammonium methanesulfonate. The presence of nitrate and heavy metal ions in the LAMMA spectra can reveal, to a certain extent, the degree of air pollution at the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols; Air pollution; Boundary layers; Heavy metals; Marine environment; Nitrates; Particle size; Sulphates. |
| Ano: 1989 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3177 |
| |
|
| |
|
|
| Rojas, C.; Otten, P.; Van Grieken, R.; Laane, R.W.P.M.. |
| A mathematical approach based on the Monin-Obukhov similarity theory is used to predict the wind speed, friction velocity and drag coefficient, which are then introduced in the well-known deposition model of Slinn and Slinn (1980), to calculate the dry deposition of heavy metals into the North Sea. This model is perfectly suitable for aircraft sampling considering the fact that usually due to safety reasons, flights at the reference height used in deposition models (10m), are not possible. To check this approach, deposition velocities were calculated based on the airborne concentrations of Cu, Cd, Zn and Pb obtained by sampling with the aid of an aircraft over the Dutch continental shelf of the North Sea. Results are in agreement with those found in the... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262330.pdf |
| |
| Registros recuperados: 50 | |
|
|
|
