README

Skeleton of pyAPES -multi-layer soil-plant-atmosphere model. Original version used for simplified model: pyAPES_kersti master (v. 12.11.2019).

Samuli Launiainen 20.01.2020:

• new canopy.forestfloor and more outputs to ncf
• changes in canopy.canopy, canopy.interception (units)
• canopy.canopy forcing['precipitation'] now in [kg m-2 s-1] as are water flux outputs

SoilProfile

Water flow:

• Equilibrium within vertical column during each timestep
• OR Richards 1D equation ! problem with infiltration (pF curves and unsaturated hydraulic conductivity) ! description of preferential flow?

Heat flow:

• solves heat conduction -> soil temperature and ice content ! neglects heat convection (heat transfer with water flow)

Canopy

Multilayer canopy description

• Radiation model: canopy SW (PAR&NIR) and LW including multiple scattering in horizontally homogenous porous media Zhao & Qualls (2005, 2006), sunlit/shade leaves ! range of zenith angle?
• Interception model: interception of rainfall and snow following approach by Tanaka (2002, Ecol. Mod.) -> solves wet leaf temperature ! restrict to snow surface level? sublimation of snow from canopy should be checked
• Leaf gas-exchange: Photosynthesis calculated based on biochemical model of Farquhar et al. (1980) coupled with various stomatal control schemes (Medlyn, Ball-Woodrow-Berry, Hari, Katul-Vico et al.) -> solves dry leaf temperature
• Momentum, H2O, CO2 and T within canopy: 1st-order closure model (sources/sinks: evaporation, transpiration, photosynthesis, respiration, sensible heat etc.)

Forest floor and snowpack:

• Moss cover (present during snow free periods): Interceps rainfall and evaporates interception storage, CO2 exchange differs if 'byophyte' or 'litter' ! capillary flux not included
• Bare soil surface energy balance -> solves soil surface temperature: NOT IMPLEMENTED
• Soil respiration ! improve and check units
• Snow model: Temperature-based snow accumulation and melt In future two layer energy balance snow scheme

Forcing

Lettosuo (2010-2018) Hyytiälä (1997-2016) see tools/dataprocessing_scripts

Todos..

• Documentation!
• Updating bryophyte model (energy and water)
• Description of soil respiration? branches etc..
• Feedbacks from soil to canopy + trunk water storage dynamics