Search

The influence of different climate variables on the first four years of otolith growth in Salangen Arctic charr, Salvelinus alpinus, was studied over the period 1939-2005. Salangen is a coastal, low altitude, subarctic lake system located in northern Norway. Climate data, including water temperature, air temperature, ice-cover and precipitation, were available for most of the 67 year period. Water temperatures in May and June had a significant effect on otolith growth during the second growth year, while no relationship between otolith growth and climate variables was found for the first, third and fourth years of otolith growth. Otolith increment size during the third and fourth growth year was autocorrelated with growth during the previous year. Spring snow fall and timing of ice break-up had an indirect effect on growth, as these variables were highly correlated with spring water temperatures. High variation in otolith growth within years and among individuals suggests that individual and age-specific variations in spatial habitat use may confound the direct effects of changing air temperatures and time of ice break-up. [ABSTRACT FROM AUTHOR]

The article explores the waveforms of seismic signals at the front of Kronebreen, Svalbard, Norway to determine the glacier-related seismic events and examine their relation to calving process. It employs a scheme which combines established seismic event detection utilizing a sensitive trigger algorithm. It reveals that the temporal distribution of glacier-related events demonstrates an increase in event rate during autumn, specifically for the category that is associated with iceberg calving.

The article presents a study aims at quantifying the impact of climate change on surface mass balance (SMB) of Svalbard, Norway and determining the proportion of projected changes in precipitation and SMB. A regional climate model investigation was forced with mean climatologies of sea surface temperature (SST) and sea ice concentration. The results indicate that an increase in precipitation due to sea ice decline may act to mass loss from Svalbard's glaciers due to future Arctic warming.

The vertical movement of the Earth's surface is the result of a number of internal processes in the solid Earth, tidal forces and mass redistribution in the atmosphere, oceans, terrestrial hydrosphere and cryosphere. Close to ice sheets and glaciers, the changes in the ice loads can induce large vertical motions at intraseasonal to secular timescales. The Global Positioning System (GPS) and Very Long Baseline Interferometry (VLBI) antennas in Ny-Ålesund, Svalbard that started observations in 1991 and 1995, respectively, observe vertical uplift rates on the order of mm yr−1, which are considerably larger than those predicted by postglacial rebound (PGR) models (order 2 mm yr−1). The observations also indicate increased uplift rates starting some time in 2000. A local GPS campaign network that has been reoccupied annually since 1998, reveals a tilting away from the neighbouring glaciers. The Svalbard glaciers have been undergoing melting and retreat during the last century, with increased melting since about 2000. We compared the observed vertical motion to the motion predicted by loading models using a detailed ice model with annual time resolution as forcing. The model predictions correlate well with the observations both with respect to the interannual variations and the spatial pattern of long-term trends. The regression coefficients for predicted and observed interannual variations in height is , whereas the regression coefficient for the predicted and observed spatial pattern turns out to be . Estimates of the predicted secular trend in height due to PGR and present-day melting are on the order of mm yr−1 and thus smaller than the observed secular trend in height. This discrepancy between predictions and observations is likely caused by the sum of errors in the secular rates determined from observations (due to technique-dependent large-scale offsets) and incomplete or erroneous models (unaccounted tectonic vertical motion, errors in the ice load history, scale errors in the viscoelastic PGR models and the elastic models for present-day melting). [ABSTRACT FROM AUTHOR]

A simple model using upper-air meteorological variables in the NCEP-NCAR Reanalysis database is used to model seasonal components of mass balance of three glaciers in Svalbard. The model was originally developed for glaciers in North America, and has been applied to glaciers in Norway, Sweden and Iceland. Over the period for which mass balance data are available for the three Svalbard glaciers, the model fit yields r 2 values ranging from 0.46 to 0.61 for winter balance Bw and from 0.56 to 0.59 for summer balance Bs. Sensitivity to +1°C warming was about −0.36 m yr−1 water equivalent (w.eq.), caused mainly by increased ablation and secondarily by shift of precipitation from snow to rain. Sensitivity to a 10% increase in precipitation was about +0.06 m yr−1 w.eq. The model, calibrated over the period of observations, was used to extend the mass balance series back to 1948. At annual resolution, observed mass balance of the three glaciers correlates poorly with both the North Atlantic Oscillation (NAO) and with glaciers in Norway. Over two multiyear periods, the strongly positive NAO period 1990–1996 and the period afterward, glaciers in both Svalbard and especially Norway showed a pronounced decline in Bw. However, Bs for Svalbard glaciers was not more strongly negative after 1996, in contrast to glaciers in Norway. [ABSTRACT FROM AUTHOR]

Global warming is inducing major environmental changes in the Arctic. These changes will differentially affect species owing to differences in climate sensitivity and behavioural plasticity. Arctic endemic marine mammals are expected to be impacted significantly by ongoing changes in their key habitats owing to their long life cycles and dependence on ice. Herein, unique biotelemetry datasets for ringed seals (RS; Pusa hispida) and white whales (WW; Delphinapterus leucas) from Svalbard, Norway, spanning two decades (1995-2016) are used to investigate how these species have responded to reduced sea-ice cover and increased Atlantic water influxes. Tidal glacier fronts were traditionally important foraging areas for both species. Following a period with dramatic environmental change, RS now spend significantly more time near tidal glaciers, where Arctic prey presumably still concentrate. Conversely, WW spend significantly less time near tidal glacier fronts and display spatial patterns that suggest that they are foraging on Atlantic fishes that are new to the region. Differences in levels of dietary specialization and overall behavioural plasticity are likely reasons for similar environmental pressures affecting these species differently. Climate change adjustments through behavioural plasticity will be vital for species survival in the Arctic, given the rapidity of change and limited dispersal options.

Across the Arctic, heavy rain-on-snow (ROS) is an "extreme" climatic event that is expected to become increasingly frequent with global warming. This has potentially large ecosystem implications through changes in snowpack properties and ground-icing, which can block the access to herbivores' winter food and thereby suppress their population growth rates. However, the supporting empirical evidence for this is still limited. We monitored late winter snowpack properties to examine the causes and consequences of ground-icing in a Svalbard reindeer (Rangifer tarandus platyrhynchus) metapopulation. In this high-arctic area, heavy ROS occurred annually, and ground-ice covered from 25% to 96% of low-altitude habitat in the sampling period (2000-2010). The extent of ground-icing increased with the annual number of days with heavy ROS (> or = 10 mm) and had a strong negative effect on reindeer population growth rates. Our results have important implications as a downscaled climate projection (2021-2050) suggests a substantial future increase in ROS and icing. The present study is the first to demonstrate empirically that warmer and wetter winter climate influences large herbivore population dynamics by generating ice-locked pastures. This may serve as an early warning of the importance of changes in winter climate and extreme weather events in arctic ecosystems.