Sensible and latent heat fluxes in a subarctic valley in northern Quebec, Canada
Abstract
The southern limit of the Arctic is delimited by the forest-tundra ecotone: the transition zone between the boreal forest and the arctic tundra. As global warming progresses, this region will very likely experience profound changes, most notably an increasing shrubification and eventually the disappearance of the tundra in favor of the boreal forest. This change provokes subsequent modifications such as new radiative properties of the surface in summer and winter and altered evapotranspiration and sublimation rates.
In the need of spatially distributed in-situ measurements to better understand the current state of the surface energy budget (SEB) all over the Arctic and to evaluate the performance of current surface models, the objective of this research is to measure all components of the SEB throughout the year in an entirely unexplored region regarding turbulent flux measurements, namely the northeastern region of Canada. More precisely a n extensively equipped site near the village of Umiujaq (56°32'N 76°33'W) on the eastern shore of Hudson Bay in northern Quebec was chosen for this campaign. There, t urbulent fluxes are recorded continuously since 2017 while basic meteorological data is available since 2012. Results indicate significantly lower latent heat fluxes in summer compared to other sites in western Canada and Alaska, which is preliminarily attributed to distinct soil properties that limit water storage. In winter, while precipitation is more abundant, measurements indicate that sublimation only plays a negligible role for water loss and during very cold times in mid-winter even deposition occurs over longer periods.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B23G2494N
- Keywords:
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- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES;
- 0718 Tundra;
- CRYOSPHERE;
- 0764 Energy balance;
- CRYOSPHERE;
- 9315 Arctic region;
- GEOGRAPHIC LOCATION