Accumulation in multiple phases

Diffusion

Advection

Chemical and biogeochemical reactions

Accumulation in three phases

Diffusion

Advection

Chemical and biogeochemical reactions

Accumulation in three phases

Diffusion

Advection

Chemical and biogeochemical reactions

Accumulation in three phases

Diffusion

Advection

Chemical and biogeochemical reactions

• Upstream discretization (Tremback et al. 1987) • Transpiration fluxes • Horizontal fluxes with surface runoff: assume in equilibrium with top 2 soil

layers

• Comparable to aerosols for accumulation and melt (Oleson et al. 2010) • Allows tracer movement through advection and diffusion; fast equilibration

FSR = Surface CO2 Flux SR = Subsurface CO2 Production

C14 surface flux vs C14 respiration

CO2 flux vs soil respiration

Radio-carbon simulation in CLM4-BeTR

Development, Evaluation, and Application of a BGC Transport and Reaction Capability for CLM4.5 (CLM4-BeTR)OutlineMotivationModel Structure and ImplementationModel Structure and ImplementationModel Structure and ImplementationModel Structure and ImplementationModel Structure and ImplementationModel Structure and ImplementationModel TestingHarvard Forest SimulationsHarvard Forest SimulationsSoil-Gas CO2Slide Number 14Slide Number 15Slide Number 16Belowground Flux PartitioningUsing 14C to Characterize CO2 SourcesUsing 14C to Characterize CO2 SourcesSummary, Etc.Slide Number 21Slide Number 22Slide Number 23