Challenges of predicting gas transfer velocity from wind measurements over global lakes. Klaus, M. & Vachon, D. Aquatic Sciences, 82(3):53, May, 2020.
Challenges of predicting gas transfer velocity from wind measurements over global lakes [link]Paper  doi  abstract   bibtex   1 download  
Estimating air–water gas transfer velocities (k) is integral to understand biogeochemical and ecological processes in aquatic systems. In lakes, k is commonly predicted using wind-based empirical models, however, their predictive performance under conditions that differ from their original calibration remains largely unassessed. Here, we collected 2222 published k estimates derived from various methods in 46 globally distributed lakes to (1) evaluate the predictions of a selection of six available wind-speed based k models for lakes and (2) explore and develop new empirical models to predict k over global lakes. We found that selected k models generally performed poorly in predicting k in lakes. Model predictions were more accurate than simply assuming a mean k in only 2–39% of all lakes, however, we could not identify with confidence the specific conditions in which some models outperformed others. We developed new wind-based models in which additional variables describing the spatial coverage of k estimates and the lake size and shape had a significant effect on the wind speed-k relationship. Although these new models did not fit the global dataset significantly better than previous k models, they generate overall less biased predictions for global lakes. We further provide explicit estimates of prediction errors that integrate methodological and lake-specific uncertainties. Our results highlight the potential limits when using wind-based models to predict k across lakes and urge scientists to properly account for prediction errors, or measure k directly in the field whenever possible.
@article{klaus_challenges_2020,
	title = {Challenges of predicting gas transfer velocity from wind measurements over global lakes},
	volume = {82},
	issn = {1420-9055},
	url = {https://doi.org/10.1007/s00027-020-00729-9},
	doi = {10.1007/s00027-020-00729-9},
	abstract = {Estimating air–water gas transfer velocities (k) is integral to understand biogeochemical and ecological processes in aquatic systems. In lakes, k is commonly predicted using wind-based empirical models, however, their predictive performance under conditions that differ from their original calibration remains largely unassessed. Here, we collected 2222 published k estimates derived from various methods in 46 globally distributed lakes to (1) evaluate the predictions of a selection of six available wind-speed based k models for lakes and (2) explore and develop new empirical models to predict k over global lakes. We found that selected k models generally performed poorly in predicting k in lakes. Model predictions were more accurate than simply assuming a mean k in only 2–39\% of all lakes, however, we could not identify with confidence the specific conditions in which some models outperformed others. We developed new wind-based models in which additional variables describing the spatial coverage of k estimates and the lake size and shape had a significant effect on the wind speed-k relationship. Although these new models did not fit the global dataset significantly better than previous k models, they generate overall less biased predictions for global lakes. We further provide explicit estimates of prediction errors that integrate methodological and lake-specific uncertainties. Our results highlight the potential limits when using wind-based models to predict k across lakes and urge scientists to properly account for prediction errors, or measure k directly in the field whenever possible.},
	language = {en},
	number = {3},
	urldate = {2024-03-26},
	journal = {Aquatic Sciences},
	author = {Klaus, Marcus and Vachon, Dominic},
	month = may,
	year = {2020},
	keywords = {\#nosource, Air–water gas exchange, Lake gas flux, Model assessment, Reaeration, Wind speed, k 600},
	pages = {53},
}

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