Abstract


SPATIAL AND TEMPORAL ANALYSIS OF THE ROLE OF HARDWATER AND SALINE LAKES IN ATMOSPHERIC CO2 EXCHANGE

Contrasting research suggests that hardwater and saline lakes are either substantial sources or sinks of CO2. On one hand, meta-analyses show that the rate of CO2 evasion from saline lakes greatly exceeds that of boreal lakes, whereas analysis of decadal time series demonstrates that hardwater lakes are large CO2 sinks, in part due to global warming. To resolve this discrepancy, we surveyed ~200 hardwater lakes in two lake districts of western Canada using a geographically-stratified design over a period of two decades to quantify the spatial patterns and temporal variability of pCO2 and chemically-enhanced CO2 flux during late summer. Analysis revealed that >65% of prairie lakes (mean +/- SD, 113+/-135 mg DIC/L, pH 9.0+/-0.4) were under-saturated with CO2 (411+/-392 uatm) and were modest sinks of atmospheric CO2 in late-summer 2014 (-6+/- 38 mmol CO2/m2/d), whereas British Columbia lakes (47,411+/-98387 mg DIC/L, pH 9.0+/-0.6) were supersaturated (776+/-734 uatm) and often released CO2 (24.8+/-45.3 mmol CO2/m2/d). We conclude that spatial variation in relationship between pH and DIC regulate differences in atmospheric CO2 exchange among hardwater lake districts.

http://bit.ly/peterleavitt

Authors

Leavitt, P. R., University of Regina, Canada, Peter.Leavitt@uregina.ca

Haig, H. A., University of Regina, Canada, haig.a.heather@gmail.com

Wiik, E., University of Regina, Canada, emma.wiik@uregina.ca

Finlay, K., University of Regina, Canada, Kerri.Finlay@uregina.ca

Pham, S. V., University of Regina, Canada, info@cannorth.com

Simpson, G. L., University of Regina, Canada, gavin.simpson@uregina.ca

Wissel, B., University of Regina, Canada, bjoern.wissel@uregina.ca

Cumming, B. F., Queen's University, Canada, cummingb@queensu.ca

laird, K. R., Queen's University, Canada, lairdk@queensu.ca

Smol, J. P., Queen's University, Canada, smolj@queensu.ca

Hodder, K. R., University of Regina, Canada, kyle.hodder@uregina.ca

Details

Oral presentation

Session #:SS08
Date: 06/07/2016
Time: 08:30
Location: Sweeney Ballroom A

Presentation is given by student: No