Spatial Representativeness of Climatic Data from Baffin Island, N.W.T., with Implications for Muskoxen and Caribou Distribution

Climatic records from often widely scattered arctic stations are commonly used to draw conclusions about such matters as wildlife habitat and distribution, yet little is known about the validity of extrapolating from such limited data. Statistical tests of meteorological network representativeness can be applied where station numbers and record length permit. Such an analysis was carried out on 29 years of temperature and precipitation data from five stations in central Baffin Island and Foxe Basin. It was found that seasonal temperatures and degree-days correlate highly across the region, indicating that interpolation and extrapolation can be carried out with confidence. Such was not the case for rainfall, snowfall, and depth of snow cover, all of which showed large extrapolation errors over modest (mesoscale) distances. This is attributed to the intrinsic variability of precipitation in the region and, in the case of snowfall and snowdepth, the inadequacy of the measurement method. The result have been applied in an evaluation of suggestions concerning climatic constraints on the distribution and numbers of muskoxen and caribou, with the conclusion that the data do not support a causal relationship based on climate.Key words: climate, spatial representativeness, Baffin Island, muskoxen, caribouMots clés: climat, représentativité spatiale, terre de Baffin, boeuf musqué, caribo

Recent Year-to-year Variations in Seasonal Temperatures and Sea Ice Conditions in the Eastern Canadian Arctic

Mean summer and winter temperatures for the 1957-1978 period have been analyzed for four eastern Arctic stations. Standard deviations on the order of 3° C in winter and 10° C in summer indicate the magnitude of the interannual variations, and these departures are found to be synchronous over the region. Several indices of sea ice severity also show significant year-to-year variations, but these are not spatially coherent. Relationships between climatic parameters and sea ice are examined in order to explain these differences

Aspects of Thule Culture Adaptations in Southern Baffin Island

An archaeological sequence of Neo-Eskimo occupations, based upon excavations of eight Thule winter houses near Lake Harbour, Baffin Island, is outlined, beginning around A.D. 1100 and extending into the present century. Relationships between past climatic events, local environmental characteristics, and the organization of Neo-Eskimo subsistence-settlement systems are traced throughout this period of time, based on analysis of artifactual, faunal, and midden deposit data. A rescheduling of procurement systems, coupled with a shift in the emphasis of fall/winter settlement options, is seen in response to climatic/ecological changes, commencing after A.D. 1250, which affected the accessibility of bowhead whales, ringed seal, and caribou. It is suggested that flexibility in the organization of domestic units and demographic arrangements was an important cultural mechanism permitting Thule and recent Inuit populations to respond effectively to changes in their biophysical environments

University of Colorado: 1972 Field Season on East Baffin Island

SEA ICE. Studies of surface energy budgets on the fast ice at Broughton Island 67°35' N, 63°50' W) were undertaken from late May to August 1972. The program included micrometeorological measurements on the fast ice and ice thickness surveys. Climatological observations including radiation studies begun in June 1971 by The Institute of Arctic and Alpine Research at a site in Broughton village were continued. The summer of 1972 was one of unusually severe ice conditions for this section of Davis Strait, and the results of our winter 1971-72 and summer 1972 fieldwork are being examined together with synoptic data in an attempt to understand this situation. Meteorological satellite data are being analyzed to obtain regional extrapolations of synoptic surface energy budgets. BOAS GLACIER. The Boas Glacier was visited in early June, at which time snow pits and probing were used to estimate the winter balance. The mean snow depth based on 190 probes was 0.948 m with a standard error of ±0.06 m. Average snow density was 0.326 g/cm³ giving a specific winter balance of 0.31 m H2O. The glacier could not be visited in August due to extremely bad ice conditions, but on the basis of the weather in previous years we predict that the net specific balance will be positive and greater than 0.3 m H2O. The strain diamond was remeasured and analysis indicates that the principal strain axis is directed down-glacier and shows a compressive strain of 10**-6 yr (based on 2 years of measurements). Using the Boas Glacier mass balance data, a discriminant equation has been developed based on September to May accumulation at Broughton Island, and accumulated summer degree days (June, July, August). Investigations of other mass balance data suggest that the Broughton Island data constitute a sensitive predictor of mass balances as far north as Devon Island. This finding ... indicates a broad similarity of climatic events throughout major sections of the Arctic. QUATERNARY GEOLOGY. Investigations on Neoglacial, Wisconsin and pre-Wisconsin local ice advances were carried out in the area between Cape Dyer and Padloping Island. Echo soundings indicated the presence of glacio-marine deltas at depths of 30 m below sea level. Dr. G. Boulton, University of East Anglia, Norwich, visited the area and collected a peat monolith in front of the Maktak Glacier, and Dr. M. Church, University of British Columbia, carried out investigations on the Maktak sandur

Climatology of the Forest-Tundra Ecotone at a Maritime Subarctic-Alpine Site, Mealy Mountains, Labrador

Climatological investigations were conducted from 2001 to 2009 in the central Mealy Mountains, Labrador (53.6˚ N), as part of interdisciplinary research on tree line ecology and climate change. The aim was to describe local climatic and edaphic variables along an altitudinal gradient from the closed forest edge to the alpine tundra and to relate recent changes in regional climate to potential changes in the forest tundra ecotone. Results show relatively warm, moist summers and cool winters, with abundant precipitation and moderate to gale-force winds. At ca. 600 m a.s.l., the tree line was characterized by 694 ± 85 growing degree-days and a mean July air temperature of 12.9 ± 0.8˚C. Growing season soil temperatures of ca. 8˚C were similar across the forest-tundra ecotone, but their seasonal regimes differed among subzones. Soil nutrient fluxes showed some variation but no consistent pattern that would suggest nutrients as a limiting factor. Snow depth in the forest-tundra subzone was more variable than in the forest, indicating that microtopography is an important factor for tree survival there in winter. Comparisons of the field data with long-term regional climatic and hydrographic records show that conditions have become warmer and drier in the most recent decade compared with the previous half-century or more. Concurrent vegetation studies indicate that changes expected with a warming climate are already occurring.De 2001 à 2009, des études climatologiques ont été effectuées dans les monts centraux Mealy, au Labrador (53,6˚ N) dans le cadre d’une recherche interdisciplinaire sur l’écologie de la limite forestière et le changement climatique. Ces études avaient pour but de décrire les variables climatiques et édaphiques locales le long d’une pente altitudinale allant de la lisière de la forêt dense jusqu’à la toundra alpine. Elles avaient également pour but de faire le lien entre les récents changements enregistrés dans le climat régional et les changements susceptibles de se produire dans l’écotone de la toundra forestière. Les résultats montrent des étés humides et relativement chauds ainsi que des hivers frais, avec des précipitations abondantes et des vents allant de modérés à coups de vent. À environ 600 m ASL, la limite forestière était caractérisée par 694 ± 85 degrés-jours de croissance et une température de l’air moyenne de 12,9 ± 0,8 ˚C en juillet. En saison de croissance, les températures du sol d’environ 8 ˚C étaient semblables à la grandeur de l’écotone de la forêt-toundra, bien que les régimes saisonniers différaient d’une sous-zone à l’autre. Les flux de nutriments du sol affichaient une certaine variation, mais il n’existait aucun modèle uniforme laissant entrevoir que les nutriments pouvaient être un facteur limitant. L’épaisseur de la neige dans la sous-zone forêt-toundra variait plus que dans la forêt, ce qui indique que la microtopographie est un facteur important pour la survie des arbres dans cet endroit-là l’hiver. La comparaison des données obtenues sur le terrain aux données climatiques et hydrographiques régionales à long terme laisse entrevoir que les conditions se sont réchauffées et asséchées au cours de la toute dernière décennie comparativement au demi-siècle précédent ou plus. Les études concurrentes sur la végétation indiquent que les changements qui étaient escomptés de même que le réchauffement du climat se manifestent déjà

Preservation of glaciochemical time-series in snow and ice from the Penny Ice Cap, Baffin Island

A detailed investigation of major ion concentrations of snow and ice in the summit region of Penny Ice Cap (PIC) was performed to determine the effects of summer melt on the glaciochemical time-series. While ion migration due to meltwater percolation makes it difficult to confidently count annual layers in the glaciochemical profiles, time-series of these parameters do show good structure and a strong one year spectral component, suggesting that annual to biannual signals are preserved in PIC glaciochemical records

Disappearance and Appearance of an Indigestible Marker in Feces from Growing Pigs as Affected by Previous- and Current-Diet Composition

Background: Indigestible markers are commonly utilized in digestion studies, but the complete disappearance or maximum appearance of a marker in feces can be affected by diet composition, feed intake, or an animal’s BW. The objectives of this study were to determine the impact of previous (Phase 1, P1) and current- (Phase 2, P2) diet composition on marker disappearance (Cr) and appearance (Ti) in pigs fed 3 diets differing in NDF content. Results: When pigs were maintained on the 25.1, 72.5, and 125.0 g/kg NDF diets, it took 5.1, 4.1, and 2.5 d, respectively, for Cr levels to decrease below the limit of quantitation; or 4.6, 3.7, or 2.8 d, respectively, for Ti to be maximized. These effects were not, however, independent of the previous diet as indicated by the interaction between P1 and P2 diets on fecal marker concentrations (P \u3c 0.01). When dietary NDF increased from P1 to P2, it took less time for fecal Cr to decrease or fecal Ti to be maximized (an average of 2.5 d), than if NDF decreased from P1 to P2 where it took longer for fecal Cr to decrease or fecal Ti to be maximized (an average of 3.4 d). Conclusions: Because of the wide range in excretion times reported in the literature and improved laboratory methods for elemental detection, the data suggests that caution must be taken in considering dietary fiber concentrations of the past and currently fed diets so that no previous dietary marker addition remains in the digestive tract or feces such that a small amount of maker is present to confound subsequent experimental results, and that marker concentration have stabilized when these samples are collected

Lanthanides: Applications in Cancer Diagnosis and Therapy

Lanthanide complexes are of increasing importance in cancer diagnosis and therapy, owing to the versatile chemical and magnetic properties of the lanthanide-ion 4f electronic configuration. Following the first implementation of gadolinium(III)-based contrast agents in magnetic resonance imaging in the 1980s, lanthanide-based small molecules and nanomaterials have been investigated as cytotoxic agents and inhibitors, in photodynamic therapy, radiation therapy, drug/gene delivery, biosensing, and bioimaging. As the potential utility of lanthanides in these areas continues to increase, this timely review of current applications will be useful to medicinal chemists and other investigators interested in the latest developments and trends in this emerging field

Beyond Survey Self-Reports: Using Physiology to Tap Political Orientations

Some aspects of our attitudes are composed of things outside of our consciousness. However, traditional survey research does not use measurements that are able to tap into these aspects of public opinion. We describe, recommend, and demonstrate a procedure by which non-self-reported responses can be measured in order to test whether these responses have independent effects on individuals’ preferences. We use one of the better-known physiological measures—electrodermal activity or skin conductance—and illustrate its potential by reporting our own study of attitudes toward President Barack Obama. We find that both self-reported emotional responses and physiological responses to Obama’s image independently correlate with variation in the intensity of attitudes regarding his job approval and his central policy proposal: health-care reform