Showing papers by "University of Lapland published in 2005"

Influence of large-scale atmospheric circulation on European sea level : results based on the wavelet transform method

Abstract: We examine relationships between the variability in the long-term time series of European sea level and the large-scale atmospheric circulation represented by the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices using the wavelet transform (WT). Results demonstrate that between 10% and 35% of the variance in winter mean sea level may be explained by the atmospheric circulation influence. However, the relationship between atmospheric circulation and sea level shows remarkable changes over time, especially between the earlier part of the twentieth century and the 1990s. Four dominant signals with periods 2.2, 3.5, 5.2 and 7.8 yr are detected and analysed by the WT using time series of sea level typically 150 yr long together with the NAO/AO indices. Cross-wavelet power and wavelet coherence confirm the linkages between the two parameters for selective time periods.

Two ice-core δ18O records from Svalbard illustrating climate and sea-ice variability over the last 400 years:

Abstract: Ice cores from the relatively low-lying ice caps in Svalbard have not been widely exploited in climatic studies owing to uncertainties about the effect of meltwater percolation. However, results from two new Svalbard ice cores, at Lomonosovfonna and Austfonna, have shown that with careful site selection, high-resolution sampling and multiple chemical analyses it is possible to recover ice cores from which part of the annual signals are preserved, despite the considerable meltwater percolation. The new Svalbard ice cores are positioned in different parts of Svalbard and cover the past 800 years. In this paper we focus on the last 400 years. The 6180 signals from the cores are qualitatively similar over most of the twentieth century, suggesting that they record the same atmospheric signal. Prior to AD 1920, the Austfonna ice core exhibits more negative 6180 values than Lomonosovfonna, although there are intermittent decadal-scale periods throughout the record with similar values. We suggest that the differences reflect the effect of the inversion layer during the winter. The pattern in the 6180 records is similar to the Longyearbyen airtemperature record, but on an annual level the correlation is low. The Austfonna record correlates well with the temperature record from the more distant and southwesterly located Jan Mayen. A comparison of the ice-core and sea-ice records from this period suggests that sea-ice extent and Austfonna 6180 are related over the past 400 years. This may reflect the position of the storm tracks and their direct influence on the relatively low-altitude Austfonna. Lomonosovfonna may be less sensitive to such changes and primarily record free atmospheric changes instead of variations in sea-ice extent, the latter is probably a result of its higher elevation.

The 800 year long ion record from the Lomonosovfonna (Svalbard) ice core

Abstract: We present a high-resolution record of water-soluble ion chemistry from a 121 m ice core spanning about 800 years. The core is well dated to 2/3 depth using cycle counting and reference horizons and a simple but close fitting model for the lower 1/3 of the core. This core suffers from modest seasonal melt, and so we present concentration data in decadal running means to minimize percolation effects. Sea-salt ions (Na+, Cl−, Mg2+, and K+) account for more than 70% of all ions. In general, sea-salt ion concentrations are rather variable and have no clear association with climatic variations. Sulfate, with 74% being from non-sea-salt sources, has higher concentrations than seen on Vestfonna ice cap but lower than in Ny-Alesund aerosols, suggesting central Spitsbergen receives more marine (westerly) air masses than Ny-Alesund but more sulfate enriched (easterly) air masses than Nordaustlandet. Clear anthropogenic impacts are found for sulfate, nitrate, and ammonium (and probably excess chloride) after the mid twentieth century, with sulfate showing a significant rise by the end of the nineteenth century. Sulfate and methanesulfonate concentrations correlate well during the twentieth century, and it is clear that most of the preindustrial sulfate is of biogenic origin. Terrestrial component (Ca2+) has the highest concentrations in the coldest part of the Little Ice Age, suggesting more windy conditions, transporting local terrestrial dust to the ice cap. All ion concentrations decrease at the end of the twentieth century, which reflects loss of ions by runoff, with non-sea-salt magnesium being particularly sensitive to melting.

Influence of freshwater inflow on the inorganic nutrient and dissolved organic matter within coastal sea ice and underlying waters in the Gulf of Finland (Baltic Sea)

Abstract: A study was conducted to measure the biogeochemical characteristics of freshwater plumes underlying Baltic Sea land-fast ice, and the overlying sea ice. A 40-km long transect was conducted in the northern Baltic Sea in March 2003, following a freshwater plume from its source into the fully mixed open-sea area. The spreading of river outflow below the ice resulted in a well-stratified low-salinity surface layer further out than normally occurs in the open-water period. The freshwaters were high in dissolved organic matter (DOC, DON and CDOM), and inorganic nutrients (ammonium, nitrate and silicate), although the levels of phosphate were low. In general these parameters changed concurrently with salinity in such a way that mixing was conservative. The characteristics of the ice varied from the freshwater source to the open water, with increasing salinity and brine volumes (porosity) occurring in the more open-sea stations. Coinciding with the changes in ice properties there was an increase in sea-ice algal growth in the more marine stations along the transect. Biological activity in the ice was largely confined to bottom ice assemblages. In contrast to the conditions in the underlying water, no relationship between salinity, inorganic nutrients and organic matter was observed in the ice. In particular ammonium, phosphate, DOC and DON were present in excess of those levels predicted from the dilution curves, indicating the presence of considerable DOM production by ice assemblages, inorganic nutrient uptake and remineralization within the ice.

New tools for analyzing time series relationships and trends

Abstract: Geophysical studies are plagued by short and noisy time series. These time series are typically nonstationary contain various long-period quasi-periodic components, and have rather low signal-to-noise ratios and/or poor spatial sampling. Classic examples of these time series are tide gauge records, which are influenced by ocean and atmospheric circulation patterns, twentieth-century warming, and other long-term variability. Remarkable progress recently has been made in the statistical analysis of time series. Ghil et al. [2002] presented a general review of several advanced statistical methods with a solid theoretical foundation. This present article highlights several new approaches that are easy to use and that may be of general interest.

Separation of melting and environmental signals in an ice core with seasonal melt

Abstract: We examine the impact of melt water percolation on the soluble ion chemical record from the Lomonosovfonna ice core. Principle component analysis shows that melting produces only simple changes bet ...

The methanesulfonic acid (MSA) record in a Svalbard ice core

Abstract: Svalbard ice cores have not yet been fully exploited for studies of climate and environmental conditions. In one recently drilled ice core from Lomonosovfonna, we have studied the methanesulfonic acid (MSA) records in relation to temperature and sea ice. Under the present climatic conditions, MSA appears to be negatively correlated with the sea-ice conditions in the Barents Sea, and positively correlated with the instrumental temperature record from Svalbard. However, prior to about 1920 the MSA concentrations were about twice as high, despite the more extensive sea-ice coverage. After exploring different possibilities, we suggest that MSA concentrations were higher in the 19th century than in the 20th century due to increased primary production, in response to increased vertical stability of the sea surface layers, caused by increased meltwater production from the more extensive sea-ice cover. Thus, the MSA record from Lomonosovfonna probably both is a measure of the regional sea-ice variability on the multi-decadal scale and reflects locally favorable conditions for marine biogenic dimethyl sulfide (DMS) production on the sub-decadal scale.

Scales of horizontal patchiness in chlorophyll a, chemical and physical properties of landfast sea ice in the Gulf of Finland (Baltic Sea)

Abstract: Horizontal variation of first-year landfast sea ice properties was studied in the Gulf of Finland, the Baltic Sea. Several scales of variation were considered; a number of arrays with core spacings of 0.2, 2 and 20 m were sampled at different stages of the ice season for small-scale patchiness. Spacing between these arrays was from hundreds of meters to kilometers to study mesoscale variability, and once an onshore–offshore 40-km transect was sampled to study regional scale variability. Measured variables included salinity, stable oxygen isotopes (δ18O), chlorophyll a (chl-a), nutrients and dissolved organic carbon. On a large scale, a combination of variations in the under-ice water salinity (ice porosity), nutrient supply and the stage of ice development control the build-up of ice algal biomass. At scales of hundreds of meters to kilometers, there was significant variability in several parameters (salinity, chl-a, snow depth and ice thickness). Analyses of the data from the arrays did not show evidence of significant patchiness at scales <20 m for algal biomass. The results imply that the sampling effort in Baltic Sea ice studies should be concentrated on scales of hundreds of meters to kilometers. Using the variations observed in the study area, the estimate for depth-integrated algal biomass in landfast sea ice in the Gulf of Finland (March 2003) is 5.5±4.4 mg chl-a m−2.

The Icelandic Laki volcanic tephra layer in the Lomonosovfonna ice core, Svalbard

Abstract: The largest sulphuric acid event revealed in an ice core from the Lomonosovfonna ice cap, Svalbard, is associated with the densest concentration of microparticles in the ice core at 6699 m depth Electron microscope analysis of a volcanic ash particle shows it has the same chemical composition as reported for debris from the eruption of Iceland’s Laki fissure in 1783 and confirms the identification of the tephra Most of the particles in the deposit are not ash, but are common sand particles carried aloft during the eruption event and deposited relatively nearby and downwind of the long-lasting eruption The tephra layer was found 10 - 20 cm deeper than high sulphate concentrations, so it can be inferred that tephra arrived to Lomonosovfonna about 6 - 12 months earlier than gaseous sulphuric acid precipitation The sulphuric acid spike has a significant cooling impact recorded in the oxygen isotope profile from the core, which corresponds to a sudden drop in temperature of about 2 °C which took several years to recover to previous levels These data are the first particle analyses of Laki tephra from Svalbard and confirm the identification of the large acidic signal seen in other ice cores from the region They also confirm the very large impact that this Icelandic eruption, specifically the sulphuric acid rather than ash, had on regional temperatures

Holocene Development and Permafrost History of the Usinsk Mire, Northeast European Russia

Abstract: This study discusses Holocene vegetation succession, permafrost dynamics and peat accumulation in the Usinsk mire, located in the Pechora lowlands of Northeast European Russia. At present, the area is situated in the extreme northern taiga subzone near the southern limit of permafrost. Reconstructions are based on plant macrofossil analysis, physico-chemical analysis and AMS (accelerator mass spectrometry) radiocarbon dating of two peat profiles investigated in detail. Additional information is available from seven other sites. Organic accumulation started at ca. 11 350 BP (14C yrs). Terrestrialization of ponds was the most common pathway for mire initiation. During a large part of their history, the sites have been Cyperaceae-dominated fens. A change into Sphagnum-dominated ecosystems is recorded at 3700-3000 BP. Permafrost became established around 2300 BP, although first signs of embryonic palsa formation can be tentatively traced back to about 2900 BP. Palsas and peat plateaus have experienced several periods of freezing and entire or partial thawing. The extant permafrost stages are young. The long-term carbon accumulation rate in the investigated sites is 19 g/m2/yr. The average rate of carbon accumulation in the dynamic permafrost stage is 23 g/m2/yr.

Agreement between Children's and Mothers' Perceptions of Maternal Acceptance and Rejection: A Comparative Study in Finland and Pakistan

Abstract: The primary purpose of this study was to explore the relative level of agreement or disagreement between mothers' reports versus children's reports of maternal acceptance-rejection in Finland and Pakistan. Of special interest was the question whether the level of agreement varied significantly in loving families (as defined by children) versus less than loving families (as defined by children). Data were collected from 144 mother/child dyads. The Child version of the Parental Acceptance-Rejection Questionnaire for Mothers (Child PARQ: Mother) and the Parent version of the Parental Acceptance-Rejection Questionnaire for Mothers (Parent PARQ: Mother) were used for these assessments. Results showed that, overall, children in both nations experienced considerable maternal acceptance, and that, overall, there appeared to be a significant level of agreement between mothers' reports and children's reports in both nations; however, the level of agreement was much higher in loving families than in less than loving families.

Simulations as Mental Tools for Network-Based Group Learning

Abstract: The article presents pedagogical and technological applications developed and studied as part of the research project ‘Web-supported Mental Tools in Technology Education’ at the University of Lapland. The applications allow simulation tools, modern network-based solutions that support learning, and other mental tools, as well as traditional and modern digital learning materials, to be smoothly integrated into normal teaching-studying-learning activity. For example, efforts have been made make use of edutainment as part of the nature of tools and materials and game-like interactivity to enhance the learning process. The broader framework for the model of learning activity that is being developed and studied in the project centers on the question how and through which learning activity (learning process) study and learning in the field of electric technology and electronics (technical work and technology education) can be organized to take into account the challenges posed by the post-industrial information society.

Environmental Protection in the Arctic and Antarctic: Can the Polar Regimes Learn from Each Other?

Abstract: There has been increasing dissatisfaction with the way Arctic-wide cooperation under the Arctic Council operates. Scholars and nongovernmental organizations (NGOs) have taken up the idea of finding a new direction for the work of the Council by drawing on the experience of the other pole, the Antarctic, and its well-established structures of governance. At first sight, this may seem like a misdirected idea, given that the two poles show more differences than similarities: the Arctic consists of ocean surrounded by continents, whereas the Antarctic is a continent surrounded by ocean; the Antarctic has no permanent human habitation, while the Arctic is inhabited by indigenous peoples and other local communities. Yet, the two polar areas also resemble each other in many respects. Both have extreme climatic conditions, receiving less radiation from the sun than other parts of the globe, and the ecosystems have had to adapt to very cold and dark environments with short and light-filled growing seasons. In such conditions, the ecosystems are simple, containing only a few key species, and are thus more vulnerable to human-induced pollution than those of more temperate areas. The purpose of this article is to examine the differences and similarities between the polar governance systems, especially from the perspective of environmental protection, and analyze whether the two regimes can benefit from each other. Of particular interest here is whether the Arctic Council could benefit from the better-developed regime of the Antarctic Treaty System (ATS). Considerations of space require that the discussion proceed on a relatively general level and focus on the basic elements of the two regimes and the differences between them.

Nuances of Human-Centredness in Information Systems Development

Abstract: Numerous methods, methodologies, approaches, techniques and tools have been developed over the years to ensure successful accomplishment of information system development (ISD) projects in terms of user satisfaction. However, different methodologies and approaches perceive the user differently; sometimes the user is seen as an anonymous 'object' that is going to use the system, or as an evaluator confirming the correctness of the design, or even as a critical contributor along the way to user-friendly information system. Each of these approaches has their own benefits from the ISD point of view but they lack a holistic view of the user. In this paper, we will review the trajectories of ISD approaches and elucidate the nuances of human-centredness in ISD. We aim at offering a holistic picture that illustrates an overview of different understandings of the user in ISD, so that, first, the systems designers' awareness about the user in general is increased, and second, future research directions are portrayed to the researchers.

Rates and Processes of Natural Regeneration in Disturbed Habitats

Abstract: Surface disturbance from recreational hiking and camping has been reported from a number of ecosystems in various parts of the world, and is also common in the Nordic mountain birch ecosystem. This will be of increasing importance in the future as the use of these birch forests and adjacent alpinearctic areas for tourism purposes has grown dramatically in recent decades (Back et al. 1989; Ilyina and Mieczkowski 1992; Sippola et al. 1995; Gnieser 2000; Godde et al. 2000; Prokosch 2001; Monz 2002; Chaps. 15 and 24). Recovery after surface disturbances in high altitude and latitude mountain birch systems is normally slow due to the generally low temperatures, short growing seasons, and the often nutrient-poor soil (see below). In dense mountain birch forests also low light intensity may reduce the recovery rate. Very few controlled field experiments have been carried out on the ecological effect of surface disturbance within the northern mountain birch forest itself. However, it may be postulated that the effects will be of the same order as in similar vegetation types above and north of the present tree line. The Nordic mountain birch forest is also expected to expand in response to climate change to higher elevation and further north, as stressed in several chapters in this volume (see, e.g., Chaps. 1 and 21). This means that the plant field and bottom layers of today’s low alpine-arctic ecosystems in the future may be within the subalpine–subarctic mountain birch forests in Fennoscandia. Ecological impacts of surface disturbance, natural or man-made, are many and include, among others, reductions in the diversity and abundance of plant species (Liddle 1997), growth forms (Bayfield et al. 1981; Forbes 1992b) and soil fauna (Bayfield 1979a; Kevan et al. 1995), changes in vegetation cover, structure and productivity (Cole and Bayfield 1993; Forbes et al. 2001), floristic convergence among sites and colonization by non-native species (Schreiner 1982; Gorchakovskii 1985; Gorchakovskii and Korobeinikova

Recreation at Tree Line and Interactions with Other Land-Use Activities

Abstract: Contents:Case Study AreasMonitoring Studies on the Impact of Recreation on the Environment in LaplandInteraction of Recreation with Other Land-use ActivitiesRecreation vs Nature ConservationRecreation vs ForestryRecreation vs Traditional LivelihoodsRecreation vs RecreationSustainable Tourism

The effect of customer satisfaction with leisure services on behavioral intentions: a study of visitors to SantaPark in Lapland.

Abstract: This study investigates the effect of customer satisfaction with leisure services on tourists' positive word-of-mouth and revisit intentions. The study is carried out within the context of visitors to the SantaPark in Rovaniemi, Finland. In this study, customer satisfaction is measured via a multi-attribute approach. Study results and their implications are discussed.

Impact of Investors' Trading Activity to Post-earnings Announcement Drift

Abstract: This study focuses on post-earnings-announcement drift in an emerging market and whether it is associated with the trading activity of non-institutional trading around interim earnings announcements. We separate the stock trading activity of Finnish households into five trading classes. Data is all trades executed on the Helsinki Stock Exchange during 1996-2000. Results show that when earnings news contains only moderate price effects no clear evidence is found to show that trading by any of the specified non-institutional trading activity classes is particularly associated with price changes. However, excess buying of passive and intermediate individual investors after extremely negative earnings news seems to intensify the negative post-earnings returns. Also for extremely positive earnings news trading by individuals seems to be related to the post-earnings returns. In that sense post-earnings returns are related with the trading of non-institutional activity classes. However, the net trading of non-institutional investors with different trading activities on the announcement day does not affect the correlation between earnings surprises and subsequent returns. This suggests that the net trading of non-institutional investors' trading activity on the announcement event does not predict subsequent returns. Thus this result is consistent with that of Hirshleifer, Myers, Myers and Teoh (2003).