University of Lapland

About: University of Lapland is a education organization based out in Rovaniemi, Finland. It is known for research contribution in the topics: Arctic & Context (language use). The organization has 665 authors who have published 1870 publications receiving 39129 citations. The organization is also known as: University of Rovaniemi & Lapin yliopisto.

Singular spectrum analysis of Baltic Sea ice conditions and large-scale atmospheric patterns since 1708

Abstract: We examine the relationship between ice conditions in the Baltic Sea and the large-scale atmospheric circulation patterns that create them. Singular Spectrum Analysis (SSA) is used to extract long-term trends and quasi-regular oscillations from time series of winter air temperature, date of ice break-up, maximum annual ice extent in the Baltic Sea (BMI) since 1708 and seasonal North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices. The AO exhibits power at periods of 2.3 and 13.9 years as well as at 7.8 years, and in general the NAO can be viewed as a subset of the AO as regards the Baltic region. Time series of ice break-up date also reflects variations in winter AO power in the 13.9-year power band, but not in the NAO 7.8-year band. The BMI seems to act as a non-linear filter on the fairly weak climate oscillations, increasing the signal-to-noise ratio of the oscillations significantly.

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.

Food availability at birth limited reproductive success in historical humans.

Abstract: Environmental conditions in early life can profoundly affect individual development and have consequences for reproductive success. Limited food availability may be one of the reasons for this, but direct evidence linking variation in early-life nutrition to reproductive performance in adulthood in natural populations is sparse. We combined historical agricultural data with detailed demographic church records to investigate the effect of food availability around the time of birth on the reproductive success of 927 men and women born in 18th-century Finland. Our study population exhibits natural mortality and fertility rates typical of many preindustrial societies, and individuals experienced differing access to resources due to social stratification. We found that among both men and women born into landless families (i.e., with low access to resources), marital prospects, probability of reproduction, and offspring viability were all positively related to local crop yield during the birth year. Such effects were generally absent among those born into landowning families. Among landless individuals born when yields of the two main crops, rye and barley, were both below median, only 50% of adult males and 55% of adult females gained any reproductive success in their lifetime, whereas 97% and 95% of those born when both yields were above the median did so. Our results suggest that maternal investment in offspring in prenatal or early postnatal life may have profound implications for the evolutionary fitness of human offspring, particularly among those for which resources are more limiting. Our study adds support to the idea that early nutrition can limit reproductive success in natural animal populations, and provides the most direct evidence to date that this process applies to humans.

Diagnostic and prognostic simulations with a full Stokes model accounting for superimposed ice of Midtre Lovénbreen, Svalbard

Abstract: . We present steady state (diagnostic) and transient (prognostic) simulations of Midtre Lovenbreen, Svalbard performed with the thermo-mechanically coupled full-Stokes code Elmer. This glacier has an extensive data set of geophysical measurements available spanning several decades, that allow for constraints on model descriptions. Consistent with this data set, we included a simple model accounting for the formation of superimposed ice. Diagnostic results indicated that a dynamic adaptation of the free surface is necessary, to prevent non-physically high velocities in a region of under determined bedrock depths. Observations from ground penetrating radar of the basal thermal state agree very well with model predictions, while the dip angles of isochrones in radar data also match reasonably well with modelled isochrones, despite the numerical deficiencies of estimating ages with a steady state model. Prognostic runs for 53 years, using a constant accumulation/ablation pattern starting from the steady state solution obtained from the configuration of the 1977 DEM show that: 1 the unrealistic velocities in the under determined parts of the DEM quickly damp out; 2 the free surface evolution matches well measured elevation changes; 3 the retreat of the glacier under this scenario continues with the glacier tongue in a projection to 2030 being situated ≈500 m behind the position in 1977.

Let's talk about "us": a reflexive account of a cross-cultural research collaboration

Abstract: In this article, we reflect on our experiences of collaborative working in a cross-cultural research team. We reflexively interrogate the construction of the univocal “we” that is expressed in our dissemination of the research findings. We show how cross-cultural collaborative research brings into sharp relief underlying complex culturally and theoretically determined patterns of thinking within the research team that may otherwise remain unquestioned. We conclude by considering the power dynamics within collaborative research, arguing for greater critical reflection by research members at all stages of the research engagement.