edoc

Spatiotemporal patterns in methane flux and gas transfer velocity at low wind speeds: Implications for upscaling studies on small lakes

Schilder, J. and Bastviken, D. and van Hardenbroek, M. and Heiri, O.. (2016) Spatiotemporal patterns in methane flux and gas transfer velocity at low wind speeds: Implications for upscaling studies on small lakes. JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES, 121 (6). pp. 1456-1467.

Full text not available from this repository.

Official URL: https://edoc.unibas.ch/67694/

Downloads: Statistics Overview

Abstract

Lakes contribute significantly to the global natural emissions of methane (CH4) and carbon dioxide. However, to accurately incorporate them into the continental carbon balance more detailed surveys of lacustrine greenhouse gas emissions are needed, especially in respect to spatiotemporal variability and to how this affects the upscaling of results. We investigated CH4 flux from a small, wind-shielded lake during 10 field trips over a 14month period. We show that floating chambers may be used to calibrate the relationship between gas transfer velocity (k) and wind speed at 10m height (U-10) to the local system, in order to obtain more accurate estimates of diffusive CH4 flux than by applying general models predicting k based on U-10. We confirm earlier studies indicating strong within-lake spatial variation in this relationship and in ebullitive CH4 flux within the lake basin. However, in contrast to the pattern reported in other studies, ebullitive CH4 flux was highest in the central parts of the lake. Our results indicate positive relationships between k and U-10 at very low U-10 (0-3ms(-1)), which disagrees with earlier suggestions that this relationship may be negligible at low U-10 values. We estimate annually averaged open water CH4 emission from Lake Gerzensee to be 3.6-5.8mmolm(-2)d(-1). Our data suggest that estimates of greenhouse gas emissions from aquatic systems to the atmosphere based on the upscaling of short-term and small-scale measurements can be improved if both spatial and temporal variabilities of emissions are taken into account.
Faculties and Departments:05 Faculty of Science > Departement Umweltwissenschaften > Geowissenschaften > Geoƶkologie (Heiri)
UniBasel Contributors:Heiri, Oliver
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:AMER GEOPHYSICAL UNION
ISSN:2169-8953
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
Last Modified:18 May 2020 19:16
Deposited On:18 May 2020 19:16

Repository Staff Only: item control page