ED2 release notes

Most of this summary is based on the Supporting Information available in Longo et al. (2019).

Developments parallel to ED-2.2, and fully integrated with the main distribution.

Plant hydrodynamics. Internal water from leaves and wood varies over time. Energy changes are also tracked
Liana functional type, and the representation of process specific to lianas (e.g., structural parasitism).
New photosynthesis scheme, which accounts for electron transport rates (aka Jmax) and triode-phosphate utilisation limitation
Updated forestry routines, which allow for selective logging
Basic crop model that allows tracking yield

Improvements in the energy, water, and carbon dioxide:
- Enthalpy definitions update, to ensure it behave as a true state variable. Specifically, latent heat became a function of temperature.
- Transfer of internal energy from soil to leaves during transpiration.
- Enthalpy exchange accounts for mass exchange when vaporisation or condensation occurs.
- Implementation of detailed checks to prevent leaky simulations to continue.
Shared-memory parallelisation of thermodynamics subroutines. Parallel code was written to allow for any number of cores (no need to match the number of patches).
Update of the photosynthesis solver, to ensure the solution always converge to the actual internal carbon and net assimilation rate. Option to use Q10-based functions for photosynthesis.
Updated methods for obtaining leaf and wood boundary layer conductance, and new approaches to obtain ground-to-canopy conductance in forests with complex vertical structure.
Use of GitHub platform for version control and active development.

Improvements in the energy and water cycles:
- Use of leaf internal energy and canopy air space enthalpy as prognostic variables
- Mechanistic representation of heat capacity for vegetation that is linearly related to vegetation biomass.
- Improved representation of the surface layer model, in particular during stable conditions
- Flexible representation of soil hydraulic and thermal characteristics, based on site-specific silt, sand, and clay content.
Implementation of full restart files, so interrupted simulations can continue, with binary reproducibility.

Major restructuring of the ED-2.0 code.
- Translation of nearly the entire code to Fortran 95
- Output files in HDF5 format.
- Option to input parameters through XML files (useful for calibration, sensitivity analyses, and ensemble
Implementation of version control for future ED-2 developments.

Implementation of a biophysical core to solve energy and water cycles at sub-daily scale
Use of 4th order Runge-Kutta solver to improve numerical stability
Prescribed leaf phenology