use of high temporal resolution data to characterize ch 4 emission pathways in a temperate peatland...

Use of high temporal resolution Use of high temporal resolution data to characterize CHdata to characterize CH44 emission emission

pathways in a temperate pathways in a temperate peatlandpeatland

Jordan GoodrichJordan GoodrichAdvisors: Ruth Varner,Advisors: Ruth Varner,

Steve Frolking,Steve Frolking,

Bryan DuncanBryan Duncan

Uncertainty in Emission Estimates

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WetlandsEnergy

RuminantsLandfills

Rice AgricultureBiomass Burning

TermitesOcean

Hydrates

Waste Treatment

OtherSoil Sink

Stratospheric Loss

OH Sink

Total SourceTotal Sink

Global Methane Flux (Tg CH4/yr)

Minimum Maximum

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Background• CH4 flux measurements

– Most seasonal estimates are based on weekly flux measurements

– Focus primarily on growing season dynamics

– Manual measurements tend to be restricted to stable atmospheric

conditions

• Emission Pathways

– Diffusion

– Plant Mediated

– Ebullition

Wetland CH4 Flux at Sallie’s Fen

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Month of Year

mg CH

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Monthly mean CH4 flux for 19 years for 9 collars, binned by dominant species. Green squares are collars dominated by Carex and Sphagnum while blue triangles are shrub dominated collars.

Research Questions

• What is the temporal variability of CH4 flux?– What are the controls?

• Can ebullition be observed with autochambers?– Partition other processes?

• Will higher resolution measurements change annual estimates of CH4 emissions from this wetland?

CH4 flux time series with 1-day running mean (April 4 - July 22)

- Ideal diffusive flux curves are common at this resolution

4:16pm 4:18pm 4:20pm 4:22pm 4:24pm 4:26pm

- Ebullitive fluxes seem to be well captured: new

processing method is needed

∆ [CH4] due to bubble

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Time

NASA Chem-Climate Model CH4

Questions?

• Acknowledgements – Research & Discover

– Tuula Larmola– Eduardo Miranda

Model EmissionsGlobal Methane Trends

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