|
|
|
|
|
| Hoornaert, S.; Treiger, B.; Van Grieken, R.; Laane, R.W.P.M.. |
| A literature review is given of atmospheric trace metal concentrations in aerosols above the North Sea and the English Channel over the period 1971-1994. Literature data have been gathered and intercompared to look for possible trends in the reported concentrations. Six trace metals are considered: Cd, Cu, Pb, Zn, Ni, and Cr. A distinction is made between measurements in different regions of the North Sea, and between coastal and marine areas. The majority of the data deals with the Southern Bight, providing the most reliable trends. Strong decreasing trends are observed for the Pb and Zn concentrations above the North Sea during the years 1971-1994. For Cd, Cu, Ni, and Cr, much less data are available in the literature. Despite this, also for Cd and Cu a... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8158 |
| |
|
|
| Bot, P.V.M.; Van Raaphorst, W.; Batten, S.; Laane, R.W.P.M.; Philippart, K.; Radach, G.; Frohse, A.; Schultz, H.; Van den Eynde, D.; Colijn, F.. |
| Seasonal cycles of salinity, nutrients, chlorophyll and zooplankton at 8 locations on the West-European shelf were analysed with respect to their timing and magnitude in the period 1980-1984. A late spring bloom with low chlorophyll values (2-4 mg.m-³) is observed in the Irish Sea, off the Scottish east coast and the Channel entrance. An early spring bloom and relatively high chlorophyll values (7-12 mg.m-³) are found in the southern Bight and the Skagerrak, whereas a late spring bloom with high chlorophyll concentrations (24 mg.m-³) is found along the Dutch and Belgian coast. In contrast to the other regions, the peak of the phytoplankton cycle in the German Bight (Helgoland) occurs in the summer period instead of the spring period. The peak in the yearly... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1996 |
URL: http://www.vliz.be/imisdocs/publications/256556.pdf |
| |
|
|
| 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 |
| |
|
|
| Rojas, C.M.; Injuk, J.; Van Grieken, R.; Laane, R.W.P.M.. |
| During the period from September 1988 to October 1989, 23 sampling flights were carried out over the Southern Bight of the North Sea. In the campaign, both bulk and size-segregated airborne particulate matter samples were collected. Dry deposition velocities for Cd, Cu, Pb and Zn have been estimated using a modified version of the two-layer of Slinn and Slinn and the particle size distribution obtained from size-fractionated samples. Results pointed out that the main difference between our results and those reported in the literature lies in the aerosol size distribution. Dry deposition rates calculated using these deposition velocities as a function of wind sector showed that continental air masses, particularly those associated with the wind sector west... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1993 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2745 |
| |
|
|
| Berlamont, J.; Radach, G.; Becker, G.; Colijn, F.; Gekeler, J.; Laane, R.W.P.M.; Monbaliu, J.; Prandle, D.; Sündermann, J.; Van Raaphorst, W.; Yu, C.S.. |
| NOWESP has compiled a vast quantity of existing data from the North-West European Shelf. Such a focused task is without precedence. It is now highly recommended that one, or a few national and international data centres or agencies should be chosen and properly supported by the EU, where all available observational data, including the NOWESP data, are collected, stored, regularly updated by the providers of the data, and made available to the researchers. International agreement must be reached on the quality control procedures and quality standards for data to be stored in these data bases. Proper arrangements should be made to preserve the economic value of the data for their "owners" without compromising use of the data by researchers or duplicating... |
| Tipo: Info:eu-repo/semantics/article |
|
| Ano: 1996 |
URL: http://www.vliz.be/imisdocs/publications/276638.pdf |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
|
