Biosphere-atmosphere interactions over West Africa. I: Development and validation of a coupled dynamic model

In this study we develop a zonally symmetric, synchronously coupled biosphe re-atmosphere model including ecosystem dynamics, and apply this model to s tudy biosphere-atmosphere interactions in the region of West Africa. The at mospheric model is zonally symmetric, and includes representation of atmosp heric dynamics, a radiation scheme, a moist convection scheme, a boundary-l ayer scheme, and a cloud-parametrization scheme. The biospheric model is th e Integrated BIosphere Simulator (IBIS), which includes representation of t he water, energy, momentum, and carbon balance, vegetation phenology, and v egetation dynamics. We modified the representation of canopy hydrology in I BIS to account for the impact of rainfall subgrid variability. The biospher ic model and atmospheric model are separately tested against observations. The synchronously coupled model is then used to simulate the biosphere-atmo sphere: 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.