Atmospheric CO2 budget over the Amazon basin: the role of convective systems

• Main Author: Herrmann,Valdir
• Publication Date: 2011
• Other Authors: Freitas,Saulo Ribeiro de
• Format: Article
• Language: eng
• Source: Revista Brasileira de Meteorologia (Online)
• Download full: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-77862011000400003
• topic: carbon budget; Amazon basin; convective transport; CO2 flux

This work studies the atmospheric CO2 budget in the Amazon basin, focusing on the role of shallow and deep convective systems. The vertical redistribution of CO2 is numerically simulated using an Eulerian transport model coupled to the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS). The transport model includes grid-scale advection, diffusion in the PBL (Planetary Boundary Layer) and convective transport by sub-grid shallow and deep moist convection. In the simulation, the mass conservation equation is solved for six tracers, including or not the shallow and deep moist convection terms. The rectifier effect is also showed through simulation of the transport to the free troposphere of PBL air masses with low CO2 concentrations due to assimilation by vegetation during the afternoon, when both CO2 fixation and convection are at their peak. The model is applied to simulate July 2001 with a 30 km grid resolution covering the northwest part of South America. We compare the model results with airborne CO2 observations collected in the Amazon basin during the 2001 CLAIRE field campaign.