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.

Upper Limit for Sea Level Projections by 2100

Abstract: We construct the probability density function of global sea level at 2100, estimating that sea level rises larger than 180 cm are less than 5% probable. An upper limit for global sea level rise of 190 cm is assembled by summing the highest estimates of individual sea level rise components simulated by process based models with the RCP8.5 scenario. The agreement between the methods may suggest more confidence than is warranted since large uncertainties remain due to the lack of scenario-dependent projections from ice sheet dynamical models, particularly for mass loss from marine-based fast flowing outlet glaciers in Antarctica. This leads to an intrinsically hard to quantify fat tail in the probability distribution for global mean sea level rise. Thus our low probability upper limit of sea level projections cannot be considered definitive. Nevertheless, our upper limit of 180 cm for sea level rise by 2100 is based on both expert opinion and process studies and hence indicates that other lines of evidence are needed to justify a larger sea level rise this century.

Dynamic response of Antarctic ice shelves to bedrock uncertainty

Abstract: Accurate and extensive bedrock geometry data is essential in ice sheet modelling. The shape of the bedrock on fine scales can influence ice sheet evolution, for example through the formation of pinning points that alter grounding line dynamics. Here we test the sensitivity of the BISICLES adaptive mesh ice sheet model to small-amplitude height fluctuations on different spatial scales in the bedrock topography provided by Bedmap2 in the catchments of Pine Island Glacier, the Amery Ice shelf and a region of East Antarctica including the Aurora Basin, Law Dome and Totten Glacier. We generate an ensemble of bedrock topographies by adding random noise to the Bedmap2 data with amplitude determined by the accompanying estimates of bedrock uncertainty. We find that the small-amplitude fluctuations result in only minor changes in the way these glaciers evolve. However, lower-frequency noise, with a broad spatial scale (over tens of kilometres) is more important than higher-frequency noise even when the features have the same height amplitudes and the total noise power is maintained. This is cause for optimism regarding credible sea level rise estimates with presently achievable density of thickness measurements. Pine Island Glacier and the region around Totten Glacier and Law Dome undergo substantial retreat and appear to be more sensitive to errors in bed topography than the Amery Ice shelf region which remains stable under the present-day observational data uncertainty.

Sulfate source inventories from a Svalbard ice core record spanning the Industrial Revolution

Abstract: [1] The 800-year sulfate record from Lomonosovfonna was analyzed by a novel multiple linear regression algorithm that attempts to explain sulfate variability in terms of other chemical species measured in the core and sulfur emission inventories. We use three statistical approaches to determine sulfate sources. We examine trends using singular spectrum analysis with confidence intervals, finding clear evidence that anthropogenic sources are important but not dominant; we use cross-wavelet coherence to examine significant multidecadal covariance in terrestrial sulfate; but our main tool is multiple regression analysis of the sulfate dependency on other ions and anthropogenic emission inventories. Models are fitted in a moving time window of typically 50 years length, explaining 80% of the sulfate variance. A suite of model predictors are examined, and the variation in relative magnitudes of the model coefficients along the core can be used to infer variations in the strength of various sulfate sources. We observe large changes in sulfate sources at the end of the Little Ice Age associated with changes in Barents Sea marine productivity, changes in North Atlantic sulfate input and a long-lasting period of disturbance caused by the large Laki volcanic eruption. Modeling sulfur emission inventories shows that western Europe contributes about 15% of the sulfate budget, with essentially no input from other regions, in contrast with predictions from global circulation models incorporating sulfur chemistry. Multidecadal cycles are mainly confined to the Little Ice Age and most likely associated with increased storminess and enhanced deposition of both marine aerosol and biogenic sulfate from the Atlantic Ocean. The model residuals do not show a normal distribution but display very large spikes. Unexpectedly, those significant at the 99% level can be closely matched to major volcanic eruptions using independent dating methods. The 20th century sulfate in the core is inventoried as sea salt (15%), terrestrial (10%), volcanic (5–10%), western European anthropogenic (10–25%), Barents Sea biogenic (20–40%), and Atlantic biogenic (10–15%).

When do grazers accelerate or decelerate soil carbon and nitrogen cycling in tundra? A test of theory on grazing effects in fertile and infertile habitats

Abstract: It is generally predicted that grazers enhance soil microbial activity and nutrient availability and promote soil bacteria in fertile ecosystems, but retard microbial activity and nutrient availability and promote soil fungi in infertile ecosystems. We tested these predictions in tundra by comparing grazing effects between fertile and infertile habitats and with/without nutrient manipulation by fertilization. Grazing decreased soil N content in fertile and in fertilized plots in infertile habitats while increased it in infertile tundra habitats, which directly opposed our prediction. We conclude that this unpredicted outcome probably resulted from nutrient transport between habitats. Also contrasting with our hypothesis, grazing increased fungal rather than bacterial abundance in fertilized plots at both habitats. In support with predictions, grazing increased microbial activity for soil C decomposition in fertile but decreased it in infertile habitats. The effect of grazing on soil C decomposition followed same patterns as grazer-induced changes in the activity of β-glucosidase, which is an extracellular enzyme synthesized by soil microorganisms for degrading soil cellulose. We suggest that the theoretical framework on grazer–soil interactions should incorporate microbial potential for extracellular enzyme production (‘microscale’ grazer effects) and nutrient translocation by grazers among habitats (‘macroscale’ grazer effects) as important mechanisms by which grazers influence soil processes and nutrient availability for plants at contrasting levels of habitat fertility.

Squeezy bracelet: designing a wearable communication device for tactile interaction

Abstract: While smartphones are increasing in size and complex features, new form factors for simple communication devices are emerging In this paper, we present the design process for a wrist worn communication device, which enables the user to send text messages over a paired mobile phone The process includes concept design, user evaluation, design iteration, prototype implementation, and evaluation of alternative interaction techniques Our particular focus is towards the use of naturally tactile interfaces in a wearable wristband form factor We present how users perceive deformable communication device concepts and two alternative squeeze based interaction techniques