Sökresultat

The Swedish regional climate modelling programme, SWECLIM, started in 1997 with the main goal being to produce regional climate change scenarios over the Nordic area on a time scale of 50 to 100 yr. An additional goal is to produce water resources scenarios with a focus on hydropower production, dam safety, water supply and environmental aspects of water resources. The scenarios are produced by a

Two 2 x 10-year climate change experiments made with the Rossby Centre regional Atmospheric climate model (RCA) are reported. These two experiments are driven by boundary data from two global climate change simulations, one made with HadCM2 and the other with ECHAM4/OPYC3, in which the global mean warning is virtually the same, 2.6°C. The changes in mean temperature and precipitation show similari

This work presents a regional climate model, the Rossby Centre regional Atmospheric model (RCA1), recently developed from the High Resolution Limited Area Model (HIRLAM). The changes in the HIRLAM parametrizations, necessary for climate-length integrations, are described. A regional Baltic Sea ocean model and a modeling system for the Nordic inland lake systems have been coupled with RCA1. The cou

The chemically induced ozone loss inside the Arctic vortex during the winter 1994/95 has been quantified by coordinated launches of over 1000 ozonesondes from 35 stations within the Match 94/95 campaign. Trajectory calculations, which allow diabatic heating or cooling, were used to trigger the balloon launches so that the ozone concentrations in a large number of air parcels are each measured twic

Microbial contamination in coastal environments and groundwater is explored within this thesis, focusing onfecal contamination from anthropogenic sources and microbial community dynamics. The spread andpersistence of microbial contaminants in complex aquatic environments with multiple intermittent and pointsources of contamination, was studied in order to lay a groundwork for developing more robus

The paper presents a new global modeling tool, Stratospheric Chemical Transport Model 2. It has been developed for effective three-dimensional multiyear stratospheric chemistry studies, featuring an extensive chemistry scheme, heterogeneous processing on sulfate aerosols, and some polar stratospheric cloud processes. The transport algorithm maintains sub-grid-scale distributions and connects verti

The total ozone reduction in the Arctic during the winters of 1993/94 acid 1994/95 has been evaluated using the ground-based total ozone measurements of five SAOZ spectrometers distributed in the Arctic and from number density profiles of a balloon-borne version of the instrument. The ozone change resulting from transport has been removed using a 3D Chemistry Transport Model (CTM) run without chem

Assessments of the possible future climate change, driven by anthropogenic emissions of greenhouse gases, are made with global climate models. These describe the large-scale features rather than regional details of climate, such as variations due to mountains, lakes, and inland oceans. Regional climate modelling improves the details in climate projections. Examples for the Nordic region illustrate

Polar stratospheric clouds (PSC) were observed with the multi-wavelength lidar of the MOANA project (Modelling and Observations of Aerosols in the Northern Atmosphere) during SESAME (Second European Stratospheric Arctic and Mid-latitude Experiment). The physical state, liquid or solid, of the cloud particles can be inferred from the lidar data. Using isentropic back-trajectories to obtain the ther

A Lagrangian approach has been used to assess the degree of chemically induced ozone loss in the Arctic lower stratosphere in winter 1991/1992. Trajectory calculations are used to identify air parcels probed by two ozonesondes at different points along the trajectories. A statistical analysis of the measured differences in ozone mixing ratio and the time the air parcel spent in sunlight between th

This explorative thesis observes how European integration was framed in Lithuanian mass media in the years leading to the accession to the European Union, using it as a case study in the Central Eastern European region entering the EU in 2004. It is situated in the context of the emergence of the concept of European identity in the 1970s expressing the need for European Union countries to develop

Aim: To evaluate (1) whether three migratory nightjar species (Family Caprimulgidae) adhere to Bergmann's rule, (2) whether environmental factors on the breeding or wintering grounds determine body size, and (3) which mechanistic hypotheses best explain Bergmannian patterns in body size. Location: North and South America; Europe and Africa. Taxon: Eastern whip-poor-will (Antrostomus vociferus), Co

In this study we address the question of temporal ozone trends on isentropic surfaces within the Arctic polar vortex during EASOE. We have combined ozone sonde data from twelve campaign stations distributed throughout the European sector of the Arctic. The development of ozone at the 425, 475, 550 and 700K levels is presented, using analysed fields of isentropic potential vorticity and isentropic

The thermal performance curve (TPC) of an organism captures how population growth depends on temperature. When populations experience increased temperatures, such as during global climate change, one prediction is that their TPC can evolve to accommodate the new environmental temperature. Although studies on TPC evolution have mostly focused on modifications in population growth rates, TPC evoluti

Within the field of cell biology, an essential tool is to deliver molecules to cells to manipulate cell behaviour and function. This enables the study of, for example, how a specific change in a cellular process contributes to a disease state. However, cells have barriers, such as the cell membrane, that need to be overcome for the molecules to have an effect. Current transfection methods, such asWithin the field of cell biology, an essential tool is to deliver molecules to cells to manipulate cell behaviour and function. This enables the study of, for example, how a specific change in a cellular process contributes to a disease state. However, cells have barriers, such as the cell membrane, that need to be overcome for the molecules to have an effect. Current transfection methods, such as

A Finnish national climate research programme, SILMU, has funded three projects in the field of ozone and UV radiation research during 1990-1995. The results of these projects are summarised here. The study of temperature sounding records made in Finland 1958-94 has revealed a warming trend in the lower and middle troposphere (up to 0.3 K/decade) and a cooling of similar order of magnitude in the

Measurements of tropospheric ozone at three sites at the Arctic Circle in the Finnish Lapland are presented. The variability of ground-level ozone over the diurnal and seasonal cycles in 1992-93 is discussed for the sites of Oulanka and Pallas. The variability with height and over the annual cycle in 1989-94 is discussed for the Sodankyla aerological Observatory, which has the longest record on th

Birds periodically replace their flight feathers through moulting, a process needed to restore aerodynamic function that temporarily reduces the wing surface and flight performance. To mitigate these effects, birds adjust their wings, the angle of attack, and undergo mass loss to compensate for altered aerodynamics.Studying the aerodynamic impact of moult gaps in live birds is challenging, so we u

Balloon borne frost-point hygrometers and backscatter sondes were launched at Sodankylä, Finland in January and February of 1996. These instruments measure water vapor and the backscatter ratio of light due to polar stratospheric clouds in the Arctic stratospheric vortex. Here we report the results of a hygrometer sonde and a backscatter sonde launched within 3.5 hours of each other on January 22/

It is well established that extensive depletion of ozone, initiated by heterogenous reactions on polar stratospheric clouds (PSCs) can occur in both the Arctic and Antarctic lower stratosphere. Moreover, it has been shown that ozone loss rates in the Arctic region in recent years reached values comparable to those over the Antarctic. But until now the accumulated ozone losses over the Arctic have