Jørgen Saltbones

Modelling of long-range transport of sulphur over Europe: A two-year model run and some model experiments

Abstract The long-range transport of sulphur over Europe is quantified using a simple trajectory model with constant mixing height. Results from a model run covering a two-year period shows that average concentrations of sulphur dioxide and particulate sulphate are predicted reasonably well. The calculations confirm that, in most countries in Europe, the deposition of sulphur due to foreign sources represents an important contribution to the total deposition. Seasonal concentration variations are not well predicted with this simple model. The model experiments show that improvements are gained in this respect when a variable mixing height is introduced together with an increased transformation rate to sulphate in summer and a mechanism for exchange of air between the boundary layer and the free troposphere.

A Lagrangian Long Range Transport Model with Atmospheric Boundary Layer Chemistry

Abstract The present paper reports on the combination of a chemical model for the gas phase chemistry of the atmospheric boundary layer, with a Lagrangian model for the long-range transport of air pollutants. The resulting combined chemistry/transport model is applied in a case study where polluted air is transported toward Scandinavia. Calculations show good agreement with measured ozone concentrations, and strongly suggest that the measured ozone concentrations cannot be due to Scandinavian precursor emissions alone. In order to carry out the case study, the emissions of NOx and hydrocarbons were estimated for the different European countries. Such estimates will necessarily be uncertain. However, the degree of consistency obtained between calculations and measurements indicate that the estimated emissions by and large reflect reality. Various tests were carried out to investigate the sensitivity of the predicted ozone concentrations with respect to parameters such as advection wind, deposition velocity...

SEVERE NUCLEAR ACCIDENT PROGRAM (SNAP) A REAL TIME DISPERSION MODEL

The Chernobyl nuclear accident in April/May 1986 showed that Norway was not well prepared for this kind of emergency situation1. Scientists who had relevant information felt frustrated because there was no clear answer to the question: where and how their information should be delivered, assessed and synthesized1. In addition, there was no dispersion model implemented in an operational environment, ready to simulate and forecast atmospheric transport and deposition of the radioactive pollutants over Europe based on real-time meteorological data. This was also the situation in most countries in Europe2.

Real-time dispersion model calculations as part of NORMEM-WP19

Abstract The Chernobyl accident made it clear for all: Norway was badly prepared for an accident of this kind. Institutions and scientists who had relevant information, data and expertise on the subject, felt frustrated because there was no suited system where their contributions could be delivered, assessed and synthesized. An information crisis developed. Norway is better prepared to handle such a situation today. New tools are being developed. An improved administrative structure has been created which is more suitable for handling the flow of information and serves as a rational basis in the decision-making process. With the implementation of the Norwegian Application of MEMbrain, NORMEM, the situation is expected to improve significantly. The Norwegian Meteorological Institute (DNMI) has a central role to play and important contributions to give in this new administrative structure. In this paper we will describe DNMIs role in the decision-making process and show examples of use of the tools developed specially adopted to this role.

Analysis of Atmospheric Transport of Radioactive Debris Related to Nuclear Bomb Tests Performed at Novaya Zemlya

Tropospheric transport calculations of debris from nuclear bomb tests in the atmosphere at Novaya Zemlya in October 1958 and November 1962 have been performed and compared with daily measured radioactivity in air at Norwegian monitoring sites. Our analysis of potential vorticity (PV) anomaly strongly indicate that episodic intrusion of stratospheric air into the troposphere is the most probable transport mechanism for the peaks in radioactivity measured in Norway.

Long-Range Transport of Large Particles Released During a Nuclear Accident

In case of a nuclear accident such as an explosion or a fire in a nuclear power plant, a significant part of the refractory radionuclides is emitted to the atmosphere in the form of particulate matter. Existing dispersion models take only partly this fact into account, assuming that only small size (diameter of ∼1 μm) particles are subject to long-range transport in the air. Large particles (diameter 10 μm) are usually not included in most long-range transport models, assuming that they are deposited relatively close to the sources. A typical assumption in these models is the assignment of one dry deposition velocity to each radionuclide. This means that each radionuclide is transported and deposited as a separate small particle, whereas in reality several radionuclides are imbedded in particles and can be transported as large particles.

Services from the Norwegian Meteorological Institute Can Reduce the Effects of Disasters — Both Natural and Man-Made

Norway is a country which is strongly exposed to weather. Extreme weather events, often lead to loss of life and damage to property. Main economic activities in Norway such as fisheries and oil exploration are very sensitive to weather conditions. In the far north and in wintertime, conditions can be almost ‘hostile’ for many normal activities, such as communication (air, sea, rail and road). Furthermore, vital services such as the supply of electric energy to the Norwegian society can be interrupted due to extreme weather. Many of these activities, can only function well if good meteorological services are available and reliable.

Climatological Trajectory Analysis for Potential Accidents at the Kola Nuclear Power Plant

Norwegian Authorities have for a long time been concerned with different aspects of the safety at nuclear installations in former Soviet Union. As a result, Report to Norwe-gian Parliament, nu 34 for 1993 – 1994 was worked out: Nuclear Activity and Chemical Weapons in our near Northern Surroundings1. A plan for follow-up activities was worked out by the Ministry of Foreign Affairs2.