Gas transfer rate and CO₂ flux between an unproductive lake and the atmosphere in northern Sweden

Abstract

[1] Measurements of the gas transfer rate of CO 2 between lake water and the atmosphere present a critical problem for the understanding of lake ecosystem carbon balances and landscape carbon budgets. We present calculations of the gas transfer rate of CO 2 from direct measurements of the CO 2 flux using an eddy covariance system and concurrent measurements of the concentration of CO 2 in the surface water in a lake in boreal zone of northern Sweden. The measured gas transfer rate was different, and in general larger than, rates obtained with the most commonly used models for prediction of the gas transfer rate in lakes. The normalized gas transfer rate (k 600 EC) was well predicted from the wind speed at 10 m height if data were bin classed into wind classes of 1 m/s for winds above 1 m/s. Unbinned data were also correlated to wind speed but also to water temperature, water temperature/air temperature ratio and to incoming photosynthetic active radiation (PAR). These relationships could reflect effects of both physico-chemical reactions and biological activity.Citation: Jonsson, A., J. Å berg, A. Lindroth, and M. Jansson (2008), Gas transfer rate and CO 2 flux between an unproductive lake and the atmosphere in northern Sweden,

The relationship between near‐surface turbulence and gas transfer velocity in freshwater systems and its implications for floating chamber measurements of gas exchange

“…These may include thermocline depth, fetch, lake depth, and chemical factors such as surfactants. Nevertheless, we contend that turbulence variables have the advantage of taking into account the modulating effects of such factors on the turbulence generated by a given wind speed itself (Jonsson et al 2008).…”

Small Boreal Lake Ecosystem Evolution under the Influence of Natural and Anthropogenic Factors: Results of Multidisciplinary Long-Term Study

“…In addition to low molecular weight (LMW, <1 kDa) phytoplankton exometabolites, important process responsible for the production of LMW organic ligands in the surface layers may be the photooxidation of DOM (e.g., refs. [29][30][31]). In a humic boreal lake, photooxidation is responsible for at least 10% of total OM degradation [32], although the relative importance of this process for the production of LMW complexes of DOC and TEs in Lake Svyatoe cannot be evaluated.…”

Continuous measurement of air–water gas exchange by underwater eddy covariance

“…A common approach for smaller reservoirs and lakes relies on additions of inert tracers, e.g., SF 6 (Wanninkhof, 1985;Cole et al, 2010), whereas floating chambers are often deployed in larger rivers, reservoirs, lakes, and estuaries (Marino and Howarth, 1993). In a limited number of studies of large reservoirs and lakes, tower-mounted atmospheric eddy covariance systems have been used to measure air-water exchange, and from that, k values were derived (Anderson et al, 1999;Jonsson et al, 2008;Mammarella et al, 2015). Partly motivated by the substantial and often methodologically challenging effort required to measure k at specific sites with any of these approaches, many studies have simply relied on general empirical correlations for k produced by fitting k values measured for other similar aquatic systems (Raymond and Cole, 2001;Borges et al, 2004;Cole et al, 2010).…”