Convective Redistribution of Ozone and Oxides of Nitrogen in the Troposphere over Europe in Summer and Fall     

Øystein Hov  Frode Flatøy 《Journal of Atmospheric Chemistry》1997,28(1-3):319-337

The fluxes of ozone and NO_x out of the atmospheric boundary layer (ABL) over Europe are calculated in a mesoscale chemical transport model (MCT) and compared with the net chemical production or destruction of ozone and the emissions of precursors within the ABL for two 10 days' periods which had quite different synoptic situations and levels of photochemical activity (1–10 July 1991 (JUL91) and 26 October–4 November 1994 (ON94)). Over the European continent, about 8% of the NO_x emissions were brought from the ABL to the free troposphere as NO_x, while about 15% of the NO_x emissions were brought to the free troposphere as NO_y–NO_x, i.e. as PAN or HNO₃. The convection dominates over the synoptic scale vertical advection as a transport mechanism both for NO_x and NO_y out of the boundary layer in the summertime high pressure situation (JUL91), while in the fall situation (ON94) the convective part was calculated to be the smallest. NO_x was almost completely transformed to NO_y–NO_x or removed within the ABL. Also for NO_y the major part of the atmospheric cycle is confined to the ABL both for JUL91 and ON94. The vertical transport time out of the ABL is of the order of 100h both for the total model domain and over the European continent. The net convective exchange of ozone from the ABL is not a dominant process for the amount of ozone in the ABL averaged over 10 days and the whole domain, but convection reduces the maximum ozone concentration in episodes significantly. The ozone producing efficiency of NO_x is calculated to increase with height to typically 15–20 in the upper half of the troposphere from around 5 in the ABL, but in the middle free troposphere the concentration of NO_x is often too low to cause net chemical formation of ozone there.  相似文献   

Groundwater study of a volcanic area near Bandung,Java, Indonesia     

Bogdan Pulawski  Hans Øbro 《Journal of Hydrology》1976,28(1):53-72

A hydrogeological investigation of the Bandung area, Java, Indonesia, is described. The investigation was carried out as part of a feasibility study directed towards improvement and development of the city's water supply.The area is situated in a tropic mountainous region, dominated by pyroclastic volcanic deposits and with abundant rainfall. The main activities of the investigation were compilation and evaluation of existing climatological and hydrogeological data, testing of four existing wells, a geo-electrical survey, drilling and testing of a new test well, study of water quality by analysis of samples from both springs and wells, and measurements of spring yields.The results of the investigation indicated presence of large groundwater resources within a distance of 15–20 km from the city. The feasibility study recommended that Bandung's water supply be based on these groundwater resources and this recommendation is being implemented.During the investigation some results concerning rainfall, infiltration, aquifers, geoelectrical surveying, and groundwater quality were obtained, which may be of general interest for hydrologists and geologists working in tropical volcanic and mountainous regions. These results are summarized in the conclusion of this paper.  相似文献   

The chemistry of the Lillebukt carbonatite,Stjernøy,Norway     

T. Strand 《Lithos》1980,13(2):223

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Model analysis of the measured concentration of organic gases in the Norwegian Arctic     

Ivar S. A. Isaksen  Øystein Hov  Stuart A. Penkett  Arne Semb 《Journal of Atmospheric Chemistry》1985,3(1):3-27

A 2-D meridional model for the chemistry and transport in the troposphere is used to study the seasonal variation of the concentration of organic gases like C₂H₂, C₂H₆, C₃H₈, C₆H₆, C₇H₈. CHCl₃ and C₂Cl₄ at high latitudes. The anthropogenic sources for these species were estimated, and the temporal and latitudinal distribution of OH and O₃ was calculated using a complex photochemical reaction system. There is fair agreement between the calculated annual variation and the measured concentrations for C₂H₂, C₂H₆, C₃H₈, C₇H₈ and C₂Cl₄ at Spitsbergen during July 1982 and March/April 1983, with a distinct late winter maximum and summer minimum. For CHCl₃, the direct anthropogenic source is minor compared to indirect anthropogenic or natural sources. For benzene, emission in car exhaust is important, but other anthropogenic sources are required for the calculations to agree with the measurements. Measured C₂H₄ and C₃H₆ concentrations are much higher than the calculated ones based on anthropogenic emissions, and show opposite seasonal trends. This indicates biogenic sources for these compounds.A buildup of PAN (300 pptv) is calculated at high latitudes during winter. This makes it the dominant source for NO_x as the temperature increases in the spring. NO_x is found to be a limiting factor for O₃ production at high latitudes during spring.  相似文献   

Modelling of the long-range transport of peroxyacetylnitrate to Scandinavia     

Øystein Hov 《Journal of Atmospheric Chemistry》1984,1(2):187-202

Model calculations and field measurements have shown that when air masses accumulate emissions of hydrocarbons and nitrogen oxides from sources in continental Europe and then move towards Scandinavia without any synoptic scale break-up of the atmospheric boundary layer (e.g. frontal passages), elevated PAN concentrations in southern Norway or Sweden in the range 1–5 ppb may be caused by long-range transport. The model calculations showed that over sea, the persistence of PAN was comparable to that of ozone in an ageing air mass when the temperatures were fairly low (5–10°C). At higher temperatures the thermal decomposition of PAN made the compound less persistent than ozone. Over land, the situation may be different since the ground removal is typically three times more efficient for ozone than for PAN.According to the model, the concentration of PAN did not change very much when an ageing air mass was exposed to moderate emissions of hydrocarbons, nitrogen oxides, or both. The concentration of PAN decreased less than the concentration of ozone when an ageing air mass was exposed to high emissions of nitrogen oxides.  相似文献   

Survival of crucian carp,Carassius carassius,exposed to a high low-molecular weight inorganic aluminium challenge     

Antonio B. S. Poléo  Sigurd A. Øxnevad  Kjartan Østbye  Ronny A. Andersen  Deborah H. Oughton  Leif A. Vøllestad 《Aquatic Sciences - Research Across Boundaries》1995,57(4):350-359

Crucian carp were exposed to three combinations of pH and inorganic aluminium concentrations for 25 days. Mortality, plasma chloride and haematocrit, and gill aluminium content were investigated. No mortality was observed in any of the three exposures. Crucian carp survived acidic Al-rich water (pH 5.17) with a high concentration of low-molecular weight inorganic Al species (242 µgl^–1) for 25 days. These fish had lowered plasma chloride levels and high amounts of aluminium on their gills compared to fish exposed to acidic Al-poor water (pH 5.16 and 12 µgl^–1 Al_i) and control water (pH 6.29 and 4 µgl^–1 Al_i). Haematocrit was the same in all three exposures. Because aluminium was not acutely toxic to the anoxia tolerant crucian carp, the present results give support to the hypothesis that Al polymerization with subsequent hypoxia is of high importance for the mechanism of acute Al toxicity to fish.  相似文献   

Reply to the comment on “The biosphere: A homogenizer of Pb-isotope signals” by Gaël Le Roux,Jeroen Sonke,Christophe Cloquet,Dominique Aubert,and François de Vleeschouwer     

Clemens Reimann  Belinda Flem  Arnold Arnoldussen  Peter Englmaier  Tor Erik Finne  Friedrich Koller  Øystein Nordgulen 《Applied Geochemistry》2008

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Co-evolutionary dynamics and institutions: Innovation in a guild community in Norway     

Øystein Stavø Høvig 《Norsk geografisk tidsskrift. Norwegian journal of geography》2016,70(3):152-161

ABSTRACT

The video game industry is often portrayed as a ‘footloose industry’ in which electronic goods can be produced and distributed from any location without positive or negative effects from factors such as resources or proximity to market. Hence, a conventional assumption is that the role of place is greatly diminished in the case of such industries. The author tests this assumption by analysing firms’ practice in a game developer community in Bergen, Norway, and the spatiality of linkages between the community and the environment. He proposes an alternative analytical framework for understanding practice in the industry, one that recognizes that a firm's practice is either embedded within or related to networks and institutional structures. The question of how contextual conditions, embeddedness and networks are treated in the literature on innovation is discussed, and the concept of community as an analytical concept is introduced and applied. After showing how practice in the case community has evolved within the cultural, social and territorial context, the author concludes that a portrayal of the game industry as a ‘footloose industry’ disembedded from its surroundings should be avoided, and instead the dynamic relationship between actors, context and practice should be heeded.  相似文献   

Prediction of Brittle Failure for TBM Tunnels in Anisotropic Rock: A Case Study from Northern Norway     

Øyvind Dammyr 《Rock Mechanics and Rock Engineering》2016,49(6):2131-2153

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The 1st International Workshop on Waves,Storm Surges and Coastal Hazards incorporating the 15th International Workshop on Wave Hindcasting and Forecasting     

Swail  Val  Alves  Jose-Henrique  Breivik  Øyvind  Brown  Jennifer  Greenslade  Diana 《Ocean Dynamics》2019,69(4):513-517

Following the 1st International Workshop on Waves, Storm Surges and Coastal Hazards, which incorporated the 15th session of the long-standing the International Workshop on Wave Hindcasting and Forecasting, in September 2017 in Liverpool, United Kingdom, a topical collection has appeared in recent issues of Ocean Dynamics. Here, we give a brief overview of the 15 papers published in this topical collection as well as an overview of the widening scope of the conference in recent years. The continuing trend towards closer integration between the wave and ocean modeling communities is reflected in this workshop, culminating in the renaming of the workshop, while maintaining the connection with the three-decade long history of the wave workshop. This is also seen in this topical collection, with several papers exploring wave-generated storm surge, wave-tide contributions to coastal flooding, forcing a global ocean model with fluxes from a wave model and interaction between surface waves and sea ice.

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