Diel Variability of CO2 Emissions From Northern Lakes. Rudberg, D., Duc, N. T., Schenk, J., Sieczko, A. K., Pajala, G., Sawakuchi, H. O., Verheijen, H. A., Melack, J. M., MacIntyre, S., Karlsson, J., & Bastviken, D. Journal of Geophysical Research: Biogeosciences, 126(10):e2021JG006246, 2021. _eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021JG006246
Diel Variability of CO2 Emissions From Northern Lakes [link]Paper  doi  abstract   bibtex   
Lakes are generally supersaturated in carbon dioxide (CO2) and emitters of CO2 to the atmosphere. However, estimates of CO2 flux () from lakes are seldom based on direct flux measurements and usually do not account for nighttime emissions, yielding risk of biased assessments. Here, we present direct measurements from automated floating chambers collected every 2–3 hr and spanning 115 24 hr periods in three boreal lakes during summer stratification and before and after autumn mixing in the most eutrophic lake of these. We observed 40%–67% higher mean in daytime during periods of surface water CO2 supersaturation in all lakes. Day-night differences in wind speed were correlated with the day-night differences in the two larger lakes, but in the smallest and most wind-sheltered lake peaks of coincided with low-winds at night. During stratification in the eutrophic lake, CO2 was near equilibrium and diel variability of insignificant, but after autumn mixing was high with distinct diel variability making this lake a net CO2 source on an annual basis. We found that extrapolating daytime measurements to 24 hr periods overestimated by up to 30%, whereas extrapolating measurements from the stratified period to annual rates in the eutrophic lake underestimated by 86%. This shows the importance of accounting for diel and seasonal variability in lake CO2 emission estimates.
@article{rudberg_diel_2021,
	title = {Diel {Variability} of {CO2} {Emissions} {From} {Northern} {Lakes}},
	volume = {126},
	copyright = {© 2021. The Authors.},
	issn = {2169-8961},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JG006246},
	doi = {10.1029/2021JG006246},
	abstract = {Lakes are generally supersaturated in carbon dioxide (CO2) and emitters of CO2 to the atmosphere. However, estimates of CO2 flux () from lakes are seldom based on direct flux measurements and usually do not account for nighttime emissions, yielding risk of biased assessments. Here, we present direct measurements from automated floating chambers collected every 2–3 hr and spanning 115 24 hr periods in three boreal lakes during summer stratification and before and after autumn mixing in the most eutrophic lake of these. We observed 40\%–67\% higher mean in daytime during periods of surface water CO2 supersaturation in all lakes. Day-night differences in wind speed were correlated with the day-night differences in the two larger lakes, but in the smallest and most wind-sheltered lake peaks of coincided with low-winds at night. During stratification in the eutrophic lake, CO2 was near equilibrium and diel variability of insignificant, but after autumn mixing was high with distinct diel variability making this lake a net CO2 source on an annual basis. We found that extrapolating daytime measurements to 24 hr periods overestimated by up to 30\%, whereas extrapolating measurements from the stratified period to annual rates in the eutrophic lake underestimated by 86\%. This shows the importance of accounting for diel and seasonal variability in lake CO2 emission estimates.},
	language = {en},
	number = {10},
	urldate = {2023-07-20},
	journal = {Journal of Geophysical Research: Biogeosciences},
	author = {Rudberg, D. and Duc, N. T. and Schenk, J. and Sieczko, A. K. and Pajala, G. and Sawakuchi, H. O. and Verheijen, H. A. and Melack, J. M. and MacIntyre, S. and Karlsson, J. and Bastviken, D.},
	year = {2021},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021JG006246},
	keywords = {\#nosource, automated flux chambers, autumn mixing, carbon dioxide fluxes, diel variability, lake greenhouse gas emissions},
	pages = {e2021JG006246},
}

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