Organic carbon quality changes in response to altered hydrological regime and rapid climate warming of an arid, permafrost environment (Kangerlussuaq, SW Greenland)
Abstract
Land-water interactions across arctic landscapes are changing rapidly in response to regional warming, melting permafrost and altered precipitation regimes. The interplay of seasonal active layer dynamics and precipitation type and amount can strongly influence the source, transfer and fate of organic carbon in permafrost landscapes: process interactions that have important implications for regional GHG emissions. Understanding these processes and how they are changing in response to multiple drivers is difficult because of the scarcity of long-term data series. The Kangerlussuaq area of SW Greenland close to the present ice-sheet margin is characterized by continuous permafrost, low annual precipitation (<200 mm/yr) and a strong landscape-morphometric control on surface water movement and availability. The area has thousands of lakes and only began to warm recently, so much so that it has been possible to track hydrological and carbon quality responses to recent warming in real time. Using a 20-year stable isotope dataset (δ18O and δ13C) from multiple lakes we consider the effect of altered landscape-scale hydrological linkages (increased evaporation, reduced seasonal hydrological connectivity) on surface water dissolved organic carbon (DOC) dynamics. We show that as well as changes in the aquatic storage pools and variable terrestrial carbon inputs, there have also been significant changes in DOC quality as indicated by stable isotope and fluorescence analyses. The results are indicative of the fate of organic carbon in a future, warmer and importantly, drier Arctic.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B42B..07A
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCES;
- 0708 Thermokarst;
- CRYOSPHERE;
- 0793 Biogeochemistry;
- CRYOSPHERE;
- 1823 Frozen ground;
- HYDROLOGY;
- 1865 Soils;
- HYDROLOGY