5252 Long-term data set (2007 to 2017) of eddy covariance CO2 and energy fluxes at High Arctic Bayelva site, Svalbard

• Main Authors: Jentzsch, Katharina, Schulz, Alexander, Lüers, Johannes, Boike, Julia
• Format: Conference Object
• Language: unknown
• Published: 2019
• Subjects: Arctic; Svalbard; Ny-Ålesund; Bayelva; Global warming; north atlantic current; North Atlantic; Ny Ålesund; permafrost
• Online Access: https://epic.awi.de/id/eprint/50756/; https://www.forskningsradet.no/contentassets/f464e19d364c40b59170a1956a98e747/book-of-abstracts-ssc2019.pdf; https://hdl.handle.net/10013/epic.d187ce3b-7530-4915-b091-833f93a3767f

The Arctic is warming at an unprecedented pace. Within the last 25 years an increase of near-surface air temperature exceeding the global warming by a factor of two has been observed. One effect of this amplified warming is the thawing of permafrost and associated changes in surface gas and energy fluxes. Increasing permafrost greenhouse gas emission might even trigger further warming, resulting in a positive feedback loop. This highlights the need to reasonably estimate future greenhouse gas emissions and uptake by permafrost regions. This can only be achieved by incorporating permafrost dynamics into global modelling efforts. Currently there is a large spread between outputs of different Earth System Models. Since model results are useless without information about their uncertainty, in situ measurements of surface carbon fluxes are invaluable for their evaluation. Furthermore they allow an access to an urgently needed deeper understanding of the microscale gas exchange processes taking place. However in the Arctic region there are still very few measurement sites providing long time series of observational data. Here we present one of these few long-term data sets, recorded by an eddy-covariance tower at the Bayelva site close to Ny-Ålesund, Svalbard. The comparatively warm permafrost site is characterized by the influence of the North Atlantic current leading to a maritime climate with average temperatures of 5 °C in July, relatively high winter temperatures of –13 °C in January and an annual mean temperature of -2.5 °C. About 400 mm of precipitation are observed per year and the snow free period amounts to typically three months. Carbon dioxide concentration, humidity, wind velocity, temperature and snow depth have been measured at the station from 2007 to 2017. Therefrom we derived half-hourly net ecosystem exchange of CO2 as well as sensible and latent heat fluxes using the eddy covariance software TK3.