Impacts of tropical deforestation. Part II: The role of large-scale dynamics

This is the second in a pair of papers in which the possible impacts of tropical deforestation are examined using a version of the NCAR CCM1. The emphasis in this paper is on the influence of tropical deforestation on the large-scale climate system. This influence is explored through the examination of the regional moisture budget and through an analysis of the Hadley and Walker circulations. Modification of the model surface parameters to simulate tropical deforestation produces significant modifications of both Hadley and Walker circulations, which result in changes distant from the region of deforestation. A mechanism for propagation to middle and high latitudes of disturbances arising from tropical deforestation is proposed based on Rossby wave propagation mechanisms. These mechanisms, which have also been associated with the extratropical influences of ENSO events, provide a pathway for the dispersion of the tropical disturbances to high latitudes.