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| 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 |
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| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262330.pdf |
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| Otten, P.; Injuk, J.; Van Grieken, R.. |
| Air sampling on a series of 10 cruises, spanning the whole area of the North Sea, yielded detailed spatial distributions of atmospheric concentrations of Al, Si, S, Cl, P, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb determined by EDXRF. A strong influence of the air mass history on the heavy metal concentrations was demonstrated for the whole sampling period of 5 years. Factor analysis performed on all samples collected with a stack filter unit resulted in the identification of three factors for the coarse particle fraction (sulphate particles with trace metals, sea salt particles and soil dust or metallurgic particles containing Fe) and four factors for the fine particle fraction (sea salt, sulphate with Pb and Zn), trace metal particles with Cu, Ni, Zn... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1994 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3896 |
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| Otten, P.; Bruynseels, F.; Van Grieken, R.. |
| Ammonia is important in the atmosphere because it neutralizes acidic species. The relative importance of different inorganic ammonium compounds (chloride, nitrate and sulfate) in marine air chemistry was studied by single-particle characterization with the laser microprobe mass analyser. Standard aerosols were generated as a reference for compound identification, based on the fingerprint spectra obtained, and calculation of the relative sensitivity achieved for different ions in a marine aerosol matrix. The relative sensitivity for ammonium was low. Aerosol samples were collected in the Southern Bight of the North Sea under different meteorological conditions and examined for their ammonium compounds. Samples collected during an inversion period with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Absorption spectroscopy; Aerosols; Ammonium compounds. |
| Ano: 1987 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3256 |
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| 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 |
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| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2850 |
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| Otten, P.. |
| In this work, attention was focused on the lower troposphere above the North Sea. It is well known that the marine atmosphere acts as a source, a sink and a reaction reservoir for various chemical constituents. In the past 15 years it has become clear that the atmosphere above the North Sea can be an important source of pollutants for the sea. In chapter 1, the sampling of marine aerosols with a cascade impactor was studied with regard to the possible interaction between particles collected on an impaction surface and reactive gaseous atmospheric components that are drawn through the impactor . NaCI particles, generated by pneumatic nebulisation of a NaCI solution, were collected on an impaction plate of a cascade impactor . After passing through the... |
| Tipo: Info:eu-repo/semantics/doctoralThesis |
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| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/226615.pdf |
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| Otten, P.; Injuk, J.; Van Grieken, R.. |
| Vertical profiles of SO<sub>2</sub> and O<sub>3</sub> concentrations were measured continuously within the lower atmosphere during 18 flights over the Southern Bight of the North Sea. The average SO<sub>2</sub> concentration below the temperature inversion layer ranged from 1.9 to 19.5 ppb. The highest levels were observed when the air masses came from the southeast-east and under variable wind sector conditions: 15.2 and 12.0 ppb, respectively. The highest SO<sub>2</sub> concentrations were found at altitudes between 100 and 200 m. The overall average O<sub>3</sub> concentration was 46 ppb, with values of 30-40 ppb at sea level to 60-70 ppb at altitudes above 100 m. Low O<sub>3</sub>... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1994 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2648 |
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