From 10 Hz to 30 Minutes: Standardized Procedures for (Post)-Processing Eddy Covariance Measurements of the Taiga Plains Flux Tower Meso-Network in Northwestern Canada
Karoline Wischnewski, Université de Montréal, Département de géographie, Montréal, QC, Canada, Manuel Helbig, Dalhousie University, Physics and Atmospheric Science, Halifax, NS, Canada, Natascha Kljun, Swansea University, Geography, Swansea, United Kingdom, Laura Chasmer, Wilfrid Laurier University, Waterloo, ON, Canada, Philip Marsh, Wilfrid Laurier University, Geography, Waterloo, ON, Canada, William L Quinton, Wilfrid Laurier University, Cold Regions Research Centre, Waterloo, ON, Canada and Oliver Sonnentag, University of Montreal, Geography, Montreal, QC, Canada
Contact First Author: Karoline Wischnewski; Karoline.Wischnewski@gmail.com
English Abstract:
Warming air temperatures and widespread degradation of permafrost in the Taiga Plains in northwestern Canada potentially alters biosphere-atmosphere interactions by modifying the net exchanges of greenhouse gases and energy. To enhance our understanding of the underlying biophysical and biogeochemical ecosystem processes, we are establishing a meso-network of four micrometeorological towers along a 1000-km permafrost gradient ranging from the sporadic/discontinuous permafrost zone experiencing continental climate to the continuous permafrost zone with a coastal climate. Identical low power-low maintenance micrometeorological instrumentation and standardized procedures for processing high-frequency measurements and for post-processing half-hour flux data are crucial to ensure consistency and inter-site comparability.
The open-path flux tower at the southern margin of permafrost is located in a highly heterogeneous boreal forest-peatland landscape. Detailed footprint analyses are conducted combining a 2D-footprint model (Kljun et al. 2002), landcover classification maps, and canopy structure information derived from high-resolution LiDAR data. In addition, to better interpret the mixed signal obtained form the heterogeneous landscape, a nearby shorter nested tower collects flux data from a homogeneous footprint within the heterogeneous footprint of the taller tower. With this contribution, we outline the development of standardized (post-) processing procedures for eddy covariance measurements across the evolving flux tower meso-network, highlighting the importance to incorporate site-specific conditions characteristic to different permafrost regimes (e.g., landscape heterogeneity).
