1. Modeling of microscale variations in methane fluxes Anu Kettunen Jan 17th, 2003

2. 2 Solar energy and cycling of elements

3. 3 Natural green house phenomenon Atmosphere  surface temperature of Earth ca 30 o C higher than without atmosphere Green house gases prevent Solar energy from escaping from Earth H 2 O, CO 2, CH 4, N 2 O, CFC compounds

4. 4 Human activities Use of fossil fuel etc. human actions increase green house gas concentrations = enhances green house phenomenon  climate change Robert T. Watson, IPCC chair

5. 5 Future climate On average warmer Regional differences Precipitation patterns Likelihood for extreme events (drought, storms) increases

6. 6 Mires Northern mires carbon sinks during last millenia, huge amount of carbon in peat Sources of green house gases (CO 2 ja CH 4 ) Important to understand role of mires in carbon cycle

7. 7 Methane CH 4 important green house gas Concentration increases ca 1% per year Wetlands (20-30 %), rice paddies, ruminants, landfills, artificial lakes

8. 8 Research problem Previously no satisfactory description of spatial and seasonal variations in methane fluxes Growing season measurument: CH 4, T, WT etc. from different mire surfaces Methane production and oxidaton potentials Process model connects methane flux to vegetation cover, photosynthetic cycle and peat thermal and moisture conditions

9. 9 Process model

10. 10 Model predictions

11. 11 Fresh carbon, NPP and T Model sensitive to fresh carbon If T ja CO 2   NPP   substrate   CH 4  If only T  CH 4  less

12. 12 Transport of oxygen to peat The more sedges transport oxygen to peat, the lower the CH 4 flux If methane oxidation   CH 4  Change in transport capacity of sedges

13. 13 The effect of drought Long dry periods  methanogens   CH 4  If > 4-6 week drought, no recovery even after rains come

14. 14 Main contribution of the thesis Simulation model for CH 4 fluxes from different mire surfaces  CH 4 fluxes from boreal mires can be predicted under current and future climate Increased understanding Connection to general circulation models