Abstract. Lakes in permafrost regions are dynamic landscape
components and play an important role for climate change feedbacks. Lake
processes such as mineralization and flocculation of dissolved organic
carbon (DOC), one of the main carbon fractions in lakes, contribute to the
greenhouse effect and are part of the global carbon cycle. These processes
are in the focus of climate research, but studies so far are limited to specific
study regions. In our synthesis, we analyzed 2167 water samples from 1833
lakes across the Arctic in permafrost regions of Alaska, Canada, Greenland,
and Siberia to provide first pan-Arctic insights for linkages between DOC
concentrations and the environment. Using published data and unpublished
datasets from the author team, we report regional DOC differences linked to
latitude, permafrost zones, ecoregions, geology, near-surface soil organic
carbon contents, and ground ice classification of each lake region. The lake
DOC concentrations in our dataset range from 0 to
1130 mg L−1 (10.8 mg L−1 median DOC concentration). Regarding the
permafrost regions of our synthesis, we found median lake DOC concentrations
of 12.4 mg L−1 (Siberia), 12.3 mg L−1 (Alaska),
10.3 mg L−1 (Greenland), and 4.5 mg L−1 (Canada). Our synthesis
shows a significant relationship between lake DOC concentration and lake
ecoregion. We found higher lake DOC concentrations at boreal permafrost
sites compared to tundra sites. We found significantly higher DOC
concentrations in lakes in regions with ice-rich syngenetic permafrost
deposits (yedoma) compared to non-yedoma lakes and a weak but significant
relationship between soil organic carbon content and lake DOC concentration
as well as between ground ice content and lake DOC. Our pan-Arctic dataset
shows that the DOC concentration of a lake depends on its environmental
properties, especially on permafrost extent and ecoregion, as well as
vegetation, which is the most important driver of lake DOC in this study.
This new dataset will be fundamental to quantify a pan-Arctic lake DOC pool
for estimations of the impact of lake DOC on the global carbon cycle and
climate change.