AUTHOR=Zhao Kai , Tedford Edmund W. , Lawrence Gregory A. 

TITLE=Ebullition Regulated by Pressure Variations in a Boreal Pit Lake

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2022.850652

DOI=10.3389/feart.2022.850652

ISSN=2296-6463

ABSTRACT=Methane ebullition from lakes is an important contributor to atmospheric greenhouse gases. However, ebullition is typically sampled at intervals greater than the duration of ebullition events, limiting our understanding of the factors controlling this flux. Here, we present high-frequency ebullition data from a single site in a boreal pit lake during open-water season between June 24 and October 21, 2018. We record ebullition every 30 minutes for the first two months, and then every minute for the next two months. During the four-month period, 24 ebullition events were recorded. These events generally lasted 2-4 days in response to low atmospheric pressure systems. The peaks in ebullition corresponded to troughs in atmospheric pressure. We provide empirical equations that incorporate a pressure threshold to model the time-series of ebullition events. Minor and gradual variations in mud temperature had no apparent effects on the observed ebullition events.