Japan Geoscience Union Meeting 2018

Presentation information

[EE] Evening Poster

A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG35] Global Carbon Cycle Observation and Analysis

Tue. May 22, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Kazuhito Ichii(Chiba University), Prabir Patra(Research Institute for Global Change, JAMSTEC), Toshinobu Machida(国立環境研究所, 共同), David Crisp(Jet Propulsion Laboratory)

[ACG35-P05] Northern boreal methane emission estimates from CTDAS-CH4 data assimilation system

*Aki Tsuruta1, Tuula Aalto1, Leif Backman1, Sebastian Lienert2, Fortunat Joos2, Edward Dlugokencky9, Tuomas Laurila1, Juha Hatakka1, Martin Heimann8, Doug Worthy10, Mika Aurela1, Annalea Lohila1, Joshua F. Dean3, Thomas Friborg5, Jutta Holst4, Elyn Humphreys7, Järvi Järveoja6, Mats B Nilsson6, Matthias Peichl6 (1.Finnish Meteorological Institute, Climate Research Programme, 2.University of Bern, Climate and Environmental Physics, Physics Institute & Oeschger Centre for Climate Change Research, 3.Vrije Universiteit Amsterdam, Faculty of Science, Department of Earth Sciences, 4. Lund University, Institutionen för Naturgeografi och ekosystemvetenskap (INES), Department of Physical Geography and Ecosystem Science, 5.University of Copenhagen, Department of Geosciences and Natural Resource Management, 6.Swedish University of Agricultural Sciences, Department of Forest Ecology & Management, 7.Carleton University, Department of Geography and Environmental Studies, 8.Max Planck Institute for Biogeochemistry, 9.NOAA Earth System Research Laboratory, Global Monitoring Division, 10.Environment and Climate Change Canada)

Keywords:methane, atmospheric inverse model, northen boreal region, peatland

Boreal and arctic terrestrial land is covered by a large areas of peatlands, where about one fifth of global terrestrial carbon is stored. The region is very sensitive to the changes in temperature and water balance; the annual average temperate increase is nearly twice the global mean change, plus it is expected to release soil carbon into the atmosphere due to the warming. The largest sources of methane (CH4) emissions from the boreal and arctic regions are natural biospheric sources, such as peatlands, wetlands and permafrost. However, their magnitude and spatial distribution still vary greatly in the process model estimates, mainly due to the heterogeneity of CH4 fluxes, and the uncertainty in wetland extent. In this study, we estimate CH4 fluxes in northern Fennoscandia, north west Russia and west Canada for 2004-2015 using the CTDAS-CH4 data assimilation system. Continuous and discrete atmospheric CH4 observations from in situ stations are assimilated, and CH4 fluxes are optimized at 1ox1o horizontal resolution in those regions. In addition, atmospheric CH4 observations from the global in situ stations are assimilated to constrain the global budget. The estimated fluxes will be compared with the process model estimates and flux observations, such as those based on the eddy covariance method, to better identify the spatial distribution and magnitude of CH4 emissions in boreal and arctic regions.