A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

Rationalizing Burned Carbon with Carbon Monoxide Exported from South AmericaR. Chatfield 1 , S. R. Freitas 2 , M. A. Silva Dias 2, and P. L. Silva Dias 22NASA Ames Research Center, Bldg. 245-5, Moffett Field, CA, 94035, USA, E-mail: chatfield@clio.arc.nasa.gov,2Rua do Matão, 1226, Departamento de Ciências Atmosféricas, Universidade de São Paulo, São Paulo, BrazilE-mail: sfreitas@model.iag.usp.br; mafdsdia@model.iag.usp.br; pldsdias@model.iag.usp.br;We present several estimates cross-checking the fluxes of carbon to the atmosphere from burning,comparing models that are based on simple land-surface parameterizations and atmospheric transportdynamics. Both estimates made by NASA Ames and USP modeling techniques are quite highcompared to some detailed satellite/land-use studies of emissions. The flux of carbon liberated to theatmosphere via biomass burning is important for several reasons. This flux is a fundemental statisticfor the parameterization of the large-scale flux of gases controlling the reactive greenhouse gasesmethane and ozone. Similarly, it is central to the estimation of the translocation of nitrogen andpyrodenitrification in the tropics. Thirdly, CO 2 emitted from rainforest clearing contributes directly tocarbon lost from the rainforest system as it contributes to greenhouse gas forcing. While CO 2 frompasturage, agriculture, etc, is considered to be reabsorbed seasonally, and so “off budget” for thecarbon cycle, it must also be accounted. CO 2 anomalies related to daily weather and interannualclimatic variation are strong enough to perturb our scientific perception of long-term carbon storagetrends. We compare fluxes deduced from land-use statistics (originally, W.M. Hao) and from satellitehot pixels (A. Setzer) with atmospheric fluxes determined by the mescoscale/continental scale modelsRAMS and MM5, and point to some new work with highly resolved global models (the NASA DataAssimilation Office’s GEOS4). Our simulations are tied to events, so that measured tracers like COtie the models directly to the burning and meteorology of a specific period. We point out a particularsensitivity in estimates based on CO, and indicate how analysis of CO 2 along with other biomassburningtracers may lead to an improved multi-species estimator of carbon burned.