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.

Anthropogenic forcing dominates sea level rise since 1850

Abstract: The rate of sea level rise and its causes are topics of active debate. Here we use a delayed response statistical model to attribute the past 1000 years of sea level variability to various natural (volcanic and solar radiative) and anthropogenic (greenhouse gases and aerosols) forcings. We show that until 1800 the main drivers of sea level change are volcanic and solar radiative forcings. For the past 200 years sea level rise is mostly associated with anthropogenic factors. Only 4 +/- 1.5 cm (25% of total sea level rise) during the 20th century is attributed to natural forcings, the remaining 14 +/- 1.5 cm are due to a rapid increase in CO2 and other greenhouse gases. Citation: Jevrejeva, S., A. Grinsted, and J. C. Moore (2009), Anthropogenic forcing dominates sea level rise since 1850, Geophys. Res. Lett., 36, L20706, doi: 10.1029/2009GL040216.

What are the impacts of reindeer/caribou (Rangifer tarandus L.) on arctic and alpine vegetation?: A systematic review

Abstract: Background: Reindeer and caribou (both belonging to the species Rangifer tarandus L.) are among the most important large herbivores in Eurasia’s and North America’s arctic, alpine and boreal zones. In Sweden, the impact of reindeer grazing on arctic and alpine vegetation has recently been re-evaluated. In the 1990s, records of grazing-related vegetation degradation helped to form a widespread perception that some mountain areas were overgrazed. However, later analyses have shown no evidence of large-scale overutilisation of reindeer ranges in the Swedish mountains. The present-day consensus is that overgrazing has been temporary and local, and that it rarely has caused permanent damage, but it is imperative to examine the scientific support for these views. Moreover, the Swedish Parliament has adopted an environmental quality objective according to which it is essential to preserve ‘a mountain landscape characterised by grazing’. No details have been given on how this goal is to be interpreted, which is another reason why the significance of reindeer grazing for arctic/alpine vegetation needs to be assessed. This protocol presents the methodology that will be used in a systematic review of the impact of reindeer herbivory in arctic and alpine ecosystems. The focus will be on Fennoscandia, but data from other parts of the range of R. tarandus will be used when deemed appropriate. Methods: The review will be based on primary field studies that compare vegetation subject to different degrees of reindeer/caribou herbivory (including grazing and browsing as well as trampling). Such comparisons can be either temporal, spatial or both. The review will cover impacts of herbivory in arctic, subarctic, alpine and subalpine areas (including the forest-tundra ecotone) across the range of R. tarandus, but not in boreal forests. Relevant aspects of vegetation include cover (abundance), biomass, diversity (e.g. species richness), structure, composition (including functional groups) and productivity.

Detection of snow surface thawing and refreezing in the Eurasian Arctic with QuikSCAT: implications for reindeer herding.

Abstract: Snow conditions play an important role for reindeer herding. In particular, the formation of ice crusts after rain-on-snow (ROS) events or general surface thawing with subsequent refreezing impedes foraging. Such events can be monitored using satellite data. A monitoring scheme has been developed for observation at the circumpolar scale based on data from the active microwave sensor SeaWinds on QuikSCAT (Ku-band), which is sensitive to changes on the snow surface. Ground observations on Yamal Peninsula were used for algorithm development. Snow refreezing patterns are presented for northern Eurasia above 60° N from autumn 2001 to spring 2008. Western Siberia is more affected than Central and Eastern Siberia in accordance with climate data, and most events occur in November and April. Ice layers in late winter have an especially negative effect on reindeer as they are already weakened. Yamal Peninsula is located within a transition zone between high and low frequency of events. Refreezing was observed more ...

Effect of periodic melting on geochemical and isotopic signals in an ice core from Lomonosovfonna, Svalbard

Abstract: [1] We examine the quality of atmospherically deposited ion and isotope signals in an ice core taken from a periodically melting ice field, Lomonosovfonna in central Spitsbergen, Svalbard. The aim is to determine the degree to which the signals are altered by periodic melting of the ice. We use three diagnostics: (1) the relation between peak values in the ice chemical and isotopic record and ice facies type, (2) the number of apparent annual cycles in these records compared with independently determined number of years represented in the ice core, and (3) a statistical comparison of the isotopic record in the ice core and the isotope records from coastal stations from the same region. We find that during warm summers, as much as 50% of the annual accumulation may melt and percolate into the firn; in a median year this decreases to similar to25%. As a consequence of percolation, the most mobile acids show up to 50% higher concentrations in bubble-poor ice facies compared with facies that are less affected by melt. Most of the other chemical species are less affected than the strong acids, and the stable water isotopes show little evidence of mobility. Annual or biannual cycles are detected in most parameters, and the water isotope record has a comparable statistical distribution to isotopic records from coastal stations. We conclude that ice cores from sites like Lomonosovfonna contain a useful environmental record, despite melt events and percolation and that most parameters preserve an annual, or in the worst cases, a biannual atmospheric signal.