Biosphere–atmosphere interactions over West Africa. II: Multiple climate equilibria. Quaternary

In this study we develop a zonally symmetric, synchronously coupled biosphere-atmosphere model including ecosystem dynamics, and apply this model to study biosphere-atmosphere interactions in the region of West Africa. The atmospheric model is zonally symmetric, and includes representation of atmospheric dynamics, a radiation scheme, a moist convection scheme, a boundary-layer scheme, and a cloud-parametrization scheme. The biospheric model is the Integrated BIosphere Simulator (IBIS), which includes representation of the water, energy, momentum, and carbon balance, vegetation phenology, and vegetation dynamics. We modified the representation of canopy hydrology in IBIS to account for the impact of rainfall subgrid variability. The biospheric model and atmospheric model are separately tested against observations. The synchronously coupled model is then used to simulate the biosphere-atmosphere system of West Africa. A study on the role of biosphere-atmosphere interactions, including ecosystem dynamics, in the climate variability over West Africa using this model will be presented in a companion paper