Spatial distribution of methane over Lake Baikal surface

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Geochemistry

Background:

• Methane is a potent greenhouse gas with significant atmospheric implications.
• Understanding methane sources and fluxes is crucial for climate change research.
• Lake Baikal, a unique ecosystem, may be a notable source of atmospheric methane.

Purpose of the Study:

• To investigate atmospheric methane concentrations over Lake Baikal.
• To quantify methane emissions from Lake Baikal's water surface into the atmosphere.
• To identify and characterize localized methane emission hotspots.

Main Methods:

• Utilized a high-sensitivity methane laser detector for atmospheric measurements.
• Conducted field research from a stationary station and the research vessel "Vereschagin".
• Performed measurements during two summer expeditions in 2003 and 2004.

Main Results:

• Mean background atmospheric methane concentrations were measured at approximately 2.00 ppm (August 2003) and 1.90 ppm (June 2004).
• Distinct, localized areas of methane emission through the water surface were identified, ranging from 150-300 m in diameter.
• Methane concentrations within these emission centers reached up to approximately 27 ppm, indicating significant localized flux.

Conclusions:

• Lake Baikal exhibits localized methane emissions into the atmosphere.
• The high-sensitivity laser detector is effective for mapping methane hotspots and quantifying fluxes.
• Further research is warranted to understand the drivers and overall contribution of these emissions to the regional methane budget.