Modelling CH 4 emissions from arctic wetlands: effects of hydrological parameterization

• Main Authors: Petrescu, A. M. R., van Huissteden, J. C., Jackowicz-Korczynski, M., Yurova, A., Christensen, T. R., Crill, P. M., Maximov, T. C.
• Other Authors: Faculty of Earth and Life Sciences Amsterdam (FALW), Vrije Universiteit Amsterdam Amsterdam (VU), Lund University Lund, Department of Geology and Geochemistry Stockholm, Stockholm University, Institute of Biological Problems of Cryolithozone, Siberian Branch of the Russian Academy of Sciences (SB RAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Arctic; Abisko; Indigirka; Stordalen; Torneträsk; Northern Sweden; permafrost; Siberia
• Online Access: https://hal.archives-ouvertes.fr/hal-00297919; https://hal.archives-ouvertes.fr/hal-00297919/document; https://hal.archives-ouvertes.fr/hal-00297919/file/bgd-4-3195-2007.pdf

International audience This study compares the CH 4 fluxes from two arctic wetland sites of different annual temperatures during 2004 to 2006. The PEATLAND-VU model was used to simulate the emissions. The CH 4 module of PEATLAND-VU is based on the Walter-Heimann model. The first site is located in northeast Siberia, Indigirka lowlands, Kytalyk reserve (70° N, 147° E) in a continuous permafrost region with mean annual temperatures of ?14.3°C. The other site is Stordalen mire in the eastern part of Lake Torneträsk (68° N, 19° E), ten kilometres east of Abisko, northern Sweden. It is located in a discontinuous permafrost region. Stordalen has a sub arctic climate with a mean annual temperature of ?0.7°C. Model input consisted of observed temperature, precipitation and snow cover data. In all cases, modelled CH 4 emissions show a direct correlation between variations in water table and soil temperature variations. The differences in CH 4 emissions between the two sites are caused by different climate, hydrology, soil physical properties, vegetation type and NPP. For Kytalyk the simulated CH 4 fluxes show similar trends during the growing season, having average values for 2004 to 2006 between 1.29?2.09 mg CH 4 m ?2 h ?1 . At Stordalen the simulated fluxes show a slightly lower average value for the same years (3.52 mg CH 4 m ?2 h ?1 ) than the observed 4.7 mg CH 4 m ?2 h ?1 . The effect of the longer growing season at Stordalen is simulated correctly. Our study shows that modelling of arctic CH 4 fluxes is improved by adding a relatively simple hydrological model that simulates the water table position from generic weather data. We conclude that CH 4 fluxes at these sites are less sensitive to temperature variation than to water table variations. Furthermore, parameter uncertainty at site level in wetland CH 4 process models is an important factor in large scale modelling of CH 4 fluxes.