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Title: Contribution of gas concentration and transfer velocity to CO2 flux variability in northern lakes
Abstract The CO2flux () from lakes to the atmosphere is a large component of the global carbon cycle and depends on the air–water CO2concentration gradient (ΔCO2) and the gas transfer velocity (k). Both ΔCO2andkcan vary on multiple timescales and understanding their contributions to is important for explaining variability in fluxes and developing optimal sampling designs. We measured and ΔCO2and derivedkfor one full ice‐free period in 18 lakes using floating chambers and estimated the contributions of ΔCO2andkto variability. Generally,kcontributed more than ΔCO2to short‐term (1–9 d) variability. With increased temporal period, the contribution ofkto variability decreased, and in some lakes resulted in ΔCO2contributing more thankto variability over the full ice‐free period. Increased contribution of ΔCO2to variability over time occurred across all lakes but was most apparent in large‐volume southern‐boreal lakes and in deeper (> 2 m) parts of lakes, whereaskwas linked to variability in shallow waters. Accordingly, knowing the variability of bothkand ΔCO2over time and space is needed for accurate modeling of from these variables. We conclude that priority in assessments should be given to direct measurements of at multiple sites when possible, or otherwise from spatially distributed measurements of ΔCO2combined withk‐models that incorporate spatial variability of lake thermal structure and meteorology.  more » « less
Award ID(s):
1753856
PAR ID:
10540419
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
Limnology and Oceanography
Volume:
69
Issue:
4
ISSN:
0024-3590
Page Range / eLocation ID:
818 to 833
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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