English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In thermally stratified lakes, the greatest annual methaneemissions typically occur during thermal overturn events. In July of 2012,Greenland experienced significant warming that resulted in substantialmelting of the Greenland Ice Sheet and enhanced runoff events. This unusualclimate phenomenon provided an opportunity to examine the effects ofshort-term natural heating on lake thermal structure and methane dynamicsand compare these observations with those from the following year, whentemperatures were normal. Here, we focus on methane concentrations withinthe water column of five adjacent small lakes on the ice-free margin ofsouthwestern Greenland under open-water and ice-covered conditions from2012–2014. Enhanced warming of the epilimnion in the lakes under open-waterconditions in 2012 led to strong thermal stability and the development ofanoxic hypolimnia in each of the lakes. As a result, during open-waterconditions, mean dissolved methane concentrations in the water column weresignificantly (<i>p</i> < 0.0001) greater in 2012 than in 2013. Inall of the lakes, mean methane concentrations under ice-covered conditionswere significantly (<i>p</i> < 0.0001) greater than underopen-water conditions, suggesting spring overturn is currently the largestannual methane flux to the atmosphere. As the climate continues to warm,shorter ice cover durations are expected, which may reduce the winterinventory of methane and lead to a decrease in total methane flux duringice melt. Under open-water conditions, greater heat income and warming oflake surface waters will lead to increased thermal stratification andhypolimnetic anoxia, which will consequently result in increased watercolumn inventories of methane. This stored methane will be susceptible toemissions during fall overturn, which may result in a shift in greatestannual efflux of methane from spring melt to fall overturn. The results ofthis study suggest that interannual variation in ground-level airtemperatures may be the primary driver of changes in methane dynamicsbecause it controls both the duration of ice cover and the strength of thermalstratification

Exceptional summer warming leads to contrasting outcomes for methane cycling in small Arctic lakes of Greenland