@article{33bddcbbf3cd416c80375fa40b5b66e8,
title = "Global carbon dioxide efflux from rivers enhanced by high nocturnal emissions",
abstract = "Carbon dioxide (CO2) emissions to the atmosphere from running waters are estimated to be four times greater than the total carbon (C) flux to the oceans. However, these fluxes remain poorly constrained because of substantial spatial and temporal variability in dissolved CO2 concentrations. Using a global compilation of high-frequency CO2 measurements, we demonstrate that nocturnal CO2 emissions are on average 27% (0.9 gC m−2 d−1) greater than those estimated from diurnal concentrations alone. Constraints on light availability due to canopy shading or water colour are the principal controls on observed diel (24 hour) variation, suggesting this nocturnal increase arises from daytime fixation of CO2 by photosynthesis. Because current global estimates of CO2 emissions to the atmosphere from running waters (0.65–1.8 PgC yr−1) rely primarily on discrete measurements of dissolved CO2 obtained during the day, they substantially underestimate the magnitude of this flux. Accounting for night-time CO2 emissions may elevate global estimates from running waters to the atmosphere by 0.20–0.55 PgC yr−1.",
author = "Llu{\'i}s G{\'o}mez-Gener and Gerard Rocher-Ros and Tom Battin and Cohen, {Matthew J.} and Dalmagro, {Higo J.} and Dinsmore, {Kerry J.} and Drake, {Travis W.} and Cl{\'e}ment Duvert and Alex Enrich-Prast and {\AA}sa Horgby and Johnson, {Mark S.} and Lily Kirk and Fausto Machado-Silva and Marzolf, {Nicholas S.} and McDowell, {Mollie J.} and McDowell, {William H.} and Heli Miettinen and Ojala, {Anne K.} and Hannes Peter and Jukka Pumpanen and Lishan Ran and Riveros-Iregui, {Diego A.} and Santos, {Isaac R.} and Johan Six and Stanley, {Emily H.} and Wallin, {Marcus B.} and White, {Shane A.} and Sponseller, {Ryan A.}",
note = "Funding Information: We thank S. Blackburn, J. Crawford, the Krycklan Catchment study and the Swedish Infrastructure for Ecosystem Science for sharing data used in this study. This study was largely supported by a Formas grant to R.A.S. Datasets provided by the StreamPULSE Network were funded by the National Science Foundation Macrosystems program (NSF Grant EF-1442439). D.A.R.-I. acknowledges support from the National Science Foundation (Grant EAR-1847331). Publisher Copyright: {\textcopyright} 2021, The Author(s), under exclusive licence to Springer Nature Limited. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",
year = "2021",
month = may,
doi = "10.1038/s41561-021-00722-3",
language = "English",
volume = "14",
pages = "289--294",
journal = "Nature Geoscience",
issn = "1752-0894",
publisher = "Nature Publishing Group",
}