Open AccessImpact of atmospheric pressure variations on methane ebullition and lake turbidity during ice‐cover
Author(s) -
Zhao Kai,
Tedford Edmund W.,
Zare Marjan,
Lawrence Gregory A.
Publication year - 2021
Publication title -
limnology and oceanography letters
Language(s) - English
Resource type - Journals
ISSN - 2378-2242
DOI - 10.1002/lol2.10201
Subject(s) - turbidity , environmental science , methane , atmospheric sciences , atmosphere (unit) , oceanography , water column , melt pond , atmospheric pressure , climatology , sea ice , hydrology (agriculture) , arctic ice pack , geology , antarctic sea ice , chemistry , meteorology , geography , geotechnical engineering , organic chemistry
Methane ebullition (bubbling) from lake sediments is an important methane flux into the atmosphere. Previous studies have focused on the open‐water season, showing that temperature variations, pressure fluctuations, and wind‐induced currents can affect ebullition. However, ebullition surveys during the ice‐cover are rare despite the prevalence of seasonally ice‐covered lakes, and the factors controlling ebullition are poorly understood. Here, we present a month‐long, high frequency record of acoustic ebullition data from an ice‐covered lake. The record shows that ebullition occurs almost exclusively when atmospheric pressure drops below a threshold that is approximately equal to the long‐term average pressure. The intensity of ebullition is proportional to the amount by which the pressure drops below this threshold. In addition, field measurements of turbidity, in conjunction with laboratory experiments, provide evidence that ebullition is responsible for previously unexplained elevated levels of turbidity during ice‐cover.