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Toward relaxed eddy accumulation measurements of sediment‐water exchange in aquatic ecosystems
Author(s) -
Lemaire Bruno J.,
Noss Christian,
Lorke Andreas
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl074625
Subject(s) - eddy covariance , environmental science , biogeochemical cycle , aquatic ecosystem , covariance , sediment , atmospheric sciences , hydrology (agriculture) , soil science , ecosystem , geology , oceanography , ecology , geomorphology , environmental chemistry , chemistry , statistics , mathematics , geotechnical engineering , biology
Solute transport across the sediment‐water interface has major implications for water quality and biogeochemical cycling in aquatic ecosystems. Existing measurement techniques, however, are not capable of resolving sediment‐water fluxes of most constituents under in situ flow conditions. We investigated whether relaxed eddy accumulation (REA), a micrometeorological technique with conditional sampling of turbulent updrafts and downdrafts, can be adapted to the aquatic environment. We simulated REA fluxes by reanalyzing eddy covariance measurements from a riverine lake. We found that the empirical coefficient that relates mass fluxes to the concentration difference between both REA samples is invariant with scalar and flow and responds as predicted by a joint Gaussian distribution of linearly correlated variables. Simulated REA fluxes differed on average by around 30% from eddy covariance fluxes (mean absolute error). Assessment of the lower quantification limit suggests that REA can potentially be applied for measuring benthic fluxes of a new range of constituents that cannot be assessed by standard eddy covariance methods.