High carbon emissions from thermokarst lakes and their determinants in the Tibet Plateau.

Thermokarst lakes are potentially important sources of methane (CH ) and carbon dioxide (CO ). However, considerable uncertainty exists regarding carbon emissions from thermokarst lakes owing to a limited understanding of their patterns and motivators. In this study, we measured CH and CO diffusive fluxes in 163 thermokarst lakes in the Qinghai-Tibet Plateau (QTP) over 3 years from May to October.

Carbon and mercury export from the Arctic rivers and response to permafrost degradation.

Arctic rivers export a large amount of organic carbon (OC) and mercury (Hg) to Arctic oceans. Because there are only a few direct calculations of OC and Hg exports from these large rivers, very little is known about their response to changes in the active layer in northern permafrost-dominated areas. In this study, multiyear data sets from the Arctic Great Rivers Observatory (ArcticGRO) are used to estimate the export of dissolved organic carbon (DOC), particulate organic carbon (POC), total mercury (THg) and methylmercury (MeHg) from the six largest rivers (Yenisey, Lena, Ob, Mackenzie, Yukon and Kolyma) draining to the Arctic Ocean.