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No description available.

Predictors of long-term academic outcomes among Naskapi adolescents from Kawawachikamach, a reserve in Northern Quebec, were examined. Adolescents from this community as from other First Nations communities are statistically at risk for high school drop out and lower levels of educational attainment. However, efforts by communities during the past two decades to narrow the gap in educational attainment between First Nations students and the general population has resulted in significant gains for students who live on reserves. / In a series of three initial visits that spanned a year, adolescents from grades 6 through 11 completed a battery of measures used to assess a broad range of components of social competence. Intelligence and school grades were used as markers of the academic success; social perspective coordination and attachment to father, mother, and peers as indices of social adaptation; and identity with Native culture as an index of cultural identity. The follow-up indicators of academic success were based on school records of graduation from high school and of admission and entrance into post-secondary institutions. As expected within the academic domain, both intelligence and school grades contributed to long-term academic achievement. Within the social domain, social perspective coordination skills and attachment to father, but not attachment to mother or peers, promoted academic achievement. Within the cultural domain, lower identification with Native status was associated with school achievement. These findings highlight the need to promote both social and academic competence in the quest to further improve rates of high school graduation and post-secondary enrolment. The link between attachment to father and academic success also suggests that educational interventions should be focused on the family as well as the child. With regard to educational planning, the government-mandated curriculum should be adapted so that the Naskapi and majority education can be integrated in complementary ways rather than being pitted against each other in a way that allows for success on only one. Although each First Nations community is unique with regard to history, culture, language, and educational values, the identification of multiple predictors of academic success among Naskapi adolescents is likely relevant to other communities.

During snowmelt net radiation above a snow surface was measured simultaneously at forty-four locations to permit comparison of measurements in a black spruce forest with those in the open. / Data, obtained during cloudy daylight and at night were used to produce meaningful surface radiation maps of the experimental site. For all periods of observation the range in values recorded between any two sensors was greatest between those positioned in the forest. Spatially, net radiation varied most within the forest. The location of high and low net radiation values recorded during the day are the reverse at night. The spruce canopy reduces net radiation at the snow surface on cloudy days by obstructing a portion of the incident diffuse sky radiation. Conversely, the canopy is shown to exert considerable effect as a source of longwave radiation. Surface net longwave radiation increases sharply with proximity to trees. The effect of local and snow surface topography is greatest on clear days when irradiance is highly directional. On clear nights the forest edge is distinguished by a steep gradient of net radiation. On cloudy nights the variability and range in surface net radiation are greatly reduced.

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No description available.

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The objective of this research is to explore the information content of repeat-pass cross-track Interferometric SAR (InSAR) with regard to snow, in particular Snow Water Equivalent (SWE) and snow depth. The study is an outgrowth of earlier snow cover modeling and radar interferometry experiments at Schefferville, Quebec, Canada and elsewhere which has shown that for reasons of loss of coherence repeat-pass InSAR is not useful for the purpose of snow cover mapping, even when used in differential InSAR mode. Repeat-pass cross-track InSAR would overcome this problem. As at radar wavelengths dry snow is transparent, the main reflection is at the snow/ground interface. The high refractive index of ice creates a phase delay which is linearly related to the water equivalent of the snow pack. When wet, the snow surface is the main reflector, and this enables measurement of snow depth. Algorithms are elaborated accordingly. Field experiments were conducted at two sites and employ two different types of digital elevation models (DEM) produced by means of cross track InSAR. One was from the Shuttle Radar Topography Mission digital elevation model (SRTM DEM), flown in February 2000. It was compared to the photogrammetrically produced Canadian Digital Elevation Model (CDEM) to examine snow-related effects at a site near Schefferville, where snow conditions are well known from half a century of snow and permafrost research. The second type of DEM was produced by means of airborne cross track InSAR (TOPSAR). Several missions were flown for this purpose in both summer and winter conditions during NASA's Cold Land Processes Experiment (CLPX) in Colorado, USA. Differences between these DEM's were compared to snow conditions that were well documented during the CLPX field campaigns. The results are not straightforward. As a result of automated correction routines employed in both SRTM and AIRSAR DEM extraction, the snow cover signal is contaminated. Fitting InSAR DEM's to known topography distorts the snow information, just as the snow cover distorts the topographic information. The analysis is therefore mostly qualitative, focusing on particular terrain situations. At Schefferville, where the SRTM was adjusted to known lake levels, the expected dry-snow signal is seen near such lakes. Mine pits and waste dumps not included in the CDEM are depicted and there is also a strong signal related to the spatial variations in SWE produced by wind redistribution of snow near lakes and on the alpine tundra. In Colorado, cross-sections across ploughed roads support the hypothesis that in dry snow the SWE is measurable by differential InSAR. They also support the hypothesis that snow depth may be measured when the snow cover is wet. Difference maps were also extracted for a 1 km2 Intensive Study Area (ISA) for which intensive ground truth was available. Initial comparison between estimated and observed snow properties yielded low correlations which improved after stratification of the data set.In conclusion, the study shows that snow-related signals are measurable. For operational applications satellite-borne cross-track InSAR would be necessary. The processing needs to be snow-specific with appropriate filtering routines to account for influences by terrain factors other than snow.