Summary of the Provided Article:

2.5.3.1. Theory

1. Sensible Heat Flux:
   - The sensible heat flux (H) between the surface and atmosphere is balanced by the sum of sensible heat from the vegetation (Hv) and the ground (Hg).
   - Equations are provided to calculate H, Hv, and Hg in terms of atmospheric and surface temperatures, aerodynamic resistances, and vegetation parameters.

2. Latent Heat Flux:
   - The water vapor flux (E) between the surface and atmosphere is balanced by the sum of the water vapor flux from the vegetation (Ev) and the ground (Eg).
   - Equations are provided to calculate E, Ev, and Eg in terms of atmospheric and surface specific humidities, aerodynamic and surface resistances, and vegetation parameters.

3. Aerodynamic Resistances and Vegetation Parameters:
   - Formulas are given to calculate the aerodynamic resistances (rah', raw') between the ground and canopy air, and the leaf boundary layer resistance (rb).
   - Vegetation parameters, such as roughness lengths (z0m,v, z0h,v, z0w,v), displacement height (d), and others, are defined and their calculations are explained.

4. Partial Derivatives:
   - The partial derivatives of the ground sensible and latent heat fluxes with respect to ground temperature are provided for use in soil temperature calculations and flux updates.

The article presents the theoretical framework and associated equations used in the Community Land Model (CLM) to model the exchange of sensible and latent heat between the land surface, vegetation, and the atmosphere.