As part of a large international Arctic biodiversity expedition (Tundra Northwest '99), we examined the distribution of members of the arctic Daphnia pulex complex (Cladocera, Anomopoda) from 121 tundra ponds, spread across 16 sites spanning a large portion of arctic Canada (i.e. from 62 degrees 22' N to 79 degrees 01' N; 66 degrees 45' W to 139 degrees 37' W). Using allozyme electrophoresis an...

Recent Arctic sea ice changes have important societal and economic impacts and may lead to adverse effects on the Arctic ecosystem, weather, and climate. Understanding the predictability of Arctic sea ice melting is thus an important task. A vector autoregressive (VAR) model is evaluated for predicting the summertime (May–September) daily Arctic sea ice concentration on the intraseasonal time s...

BACKGROUND Quality of cardiac surgical care may vary between institutions. Mortality is low and large numbers are required to discriminate between hospitals. Measures other than mortality may provide better comparisons. OBJECTIVES To develop and assess the Acute Risk Change for Cardiothoracic Admissions to Intensive Care (ARCTIC) index, a new performance measure for cardiothoracic admissions ...

[1] Long-term observations at Arctic sites (Alert and Zeppelin) show large interannual variability (IAV) in atmospheric mercury (Hg), implying a strong sensitivity of Hg to environmental factors and potentially to climate change. We use the GEOS-Chem global biogeochemical Hg model to interpret these observations and identify the principal drivers of spring and summer IAV in the Arctic atmospher...

Inhibition of photosynthesis and epidermal damage resulting from ultraviolet irradiation were assessed for arctic and alpine plant species. These species were taken from a latitudinal gradient of the arctic-alpine life zone from the Andes to northern Alaska, which spans a steep change in solar UV-B irradiation (280 to 320 nm). Ecotypes and species from the Arctic, where solar UV-B flux is very ...

The Arctic is warming at an alarming rate, yet the processes that contribute to the enhanced warming are not well understood. Arctic aerosols have been targeted in studies for decades due to their consequential impacts on the energy budget, both directly and indirectly through their ability to modulate cloud microphysics. Even with the breadth of knowledge afforded from these previous studies, ...

-The flux of trace metals into the Arctic atmosphere between 0 and 3.5 km altitude for the period July 1979-June 1980 was determined using a chemical transport modeling approach used previously for sulfur. The total annual flux of antimony. arsenic. cadmium, lead, zinc and vanadium into the Arctic from Eurasia was 4.285.47. 2400, 1350 and 474 tonnes. respectively. This represents 3.4,6.0,4.2.3....

This study is presented within the context that climate warming and sea-ice decline has been occurring throughout much of the Arctic over the past several decades, and that terrestrial ecosystems at high latitudes are sensitive to the resultant alterations in surface temperatures. Results are from analyzing interannual satellite records of vegetation greenness across a bioclimate gradient of th...

The rapid Arctic summer sea ice reduction in the last decade has lead to debates in the maritime industries on the possibility of an increase in cargo transportation in the region. Average sailing times on the North Sea Route along the Siberian Coast have fallen from 20 days in the 1990s to 11 days in 2012– 2013, attributed to easing sea ice conditions along the Siberian coast. However, the eco...

[1] Model results and observations both indicate warming of the world ocean from 1955 to 2003. Forced by reanalysis data, the model also shows that the warming of the arctic ice–ocean system is faster than the global average since the 1960s; there is a small but widespread increase in heat content of the Arctic Ocean’s waters and a larger increase of latent heat embodied in the ocean’s decreasi...