GENIE:Land

Documentation converted across from genie/genie-land/doc/genie_land_v01.tex by J Hughes (hence incomplete at present).

Introduction
This document is the equations that make up the forst version of the land-surface scheme in (REF). This scheme is based on Pete Cox's Interactive Vegetation Model (IVM), which is itself a (very) reduced version of the tiled UM land-surface scheme MOSES2. As a result, some of this text has been grafted from Hadley Centre Technial Notes 24 (TRIFFID) and 30 (MOSES2).

Structure
In each gridbox, the energy, water and carbon balance is calculated for seven tile types (broadleaf tree, needleleaf tree, C3 grass, C4 grass, shrub, bare soil, land ice) under the same forcing. Gridbox means (GBMs) of a particular quantity are calculated by weighting tile values by the fractional coverage of each tile in the gridbox. e.g. for a quantity $$Q$$ the GBM is calculated as,

$$Q = \sum_{i=1}^{ntiles} f_i Q_i$$

where $$f_i$$ is the fraction of the gridbox covered by tile type $$i$$. For much of this document the subscript $$i$$ is not explicitly written to make the equations easier to read. Unless stated otherwise, assume that an equation is solved for each tile separately.