학술논문
Diel, seasonal, and inter-annual variation in carbon dioxide effluxes from lakes and reservoirs
Document Type
article
Author
Malgorzata Golub; Nikaan Koupaei-Abyazani; Timo Vesala; Ivan Mammarella; Anne Ojala; Gil Bohrer; Gesa A Weyhenmeyer; Peter D Blanken; Werner Eugster; Franziska Koebsch; Jiquan Chen; Kevin Czajkowski; Chandrashekhar Deshmukh; Frederic Guérin; Jouni Heiskanen; Elyn Humphreys; Anders Jonsson; Jan Karlsson; George Kling; Xuhui Lee; Heping Liu; Annalea Lohila; Erik Lundin; Tim Morin; Eva Podgrajsek; Maria Provenzale; Anna Rutgersson; Torsten Sachs; Erik Sahlée; Dominique Serça; Changliang Shao; Christopher Spence; Ian B Strachan; Wei Xiao; Ankur R Desai
Source
Environmental Research Letters, Vol 18, Iss 3, p 034046 (2023)
Subject
Language
English
ISSN
1748-9326
Abstract
Accounting for temporal changes in carbon dioxide (CO _2 ) effluxes from freshwaters remains a challenge for global and regional carbon budgets. Here, we synthesize 171 site-months of flux measurements of CO _2 based on the eddy covariance method from 13 lakes and reservoirs in the Northern Hemisphere, and quantify dynamics at multiple temporal scales. We found pronounced sub-annual variability in CO _2 flux at all sites. By accounting for diel variation, only 11% of site-months were net daily sinks of CO _2 . Annual CO _2 emissions had an average of 25% (range 3%–58%) interannual variation. Similar to studies on streams, nighttime emissions regularly exceeded daytime emissions. Biophysical regulations of CO _2 flux variability were delineated through mutual information analysis. Sample analysis of CO _2 fluxes indicate the importance of continuous measurements. Better characterization of short- and long-term variability is necessary to understand and improve detection of temporal changes of CO _2 fluxes in response to natural and anthropogenic drivers. Our results indicate that existing global lake carbon budgets relying primarily on daytime measurements yield underestimates of net emissions.