GEIA Document bccooke.txt 29 Oct 97

Inventory file antbc84yr1.1a
Fossil fuel black carbon annual metric tons 1

Inventory file biobc87mn1.1a
Biomass burning black carbon monthly metric tons 1

Contact: William F. Cooke, Geophysical Fluid Dynamics Laboratory,
Forrestal Campus, Princeton, NJ, 08542-0308, U.S.A
Julian J.N. Wilson, Environment Institute,
Joint Research Centre, Ispra (VA), I-21020, Italy

This document explains the proposed black carbon emission fields. The emissions are compiled in two files.

FOSSIL FUEL BLACK CARBON EMISSIONS

The fossil fuel emissions, contained in file antbc84yr1.1a, are compiled from 23 fuel types of which coal, lignite brown and diesel form the majority of the emissions. The data are representative of 1984 emissions. The data is given in tonnes per 1 degree grid.

BIOMASS BURNING BLACK CARBON (BC) EMISSIONS

The biomass burning emissions are compiled from various sources of deforestation amounts and estimates of savanna burning.

The method used to calculate these emissions is presented in Cooke and Wilson (1996)

The seasonality of the biomass emissions is a combination of a modified version of Hao et al. (1991) and some assumptions for extra-tropical forest fires. In addition seasonality as estimated by satellite observations are used to modify the seasonality of vegetation fires in Africa. This modification is discussed in Cooke et al. (1996) The modifications to the Hao et al. data is as follows

1) The same dry season is assumed as Hao et. al. but the fraction of biomass burnt in each of the five months is modified so that the fractions are now 5%, 25%, 40%, 25% and 5% for the appropriate five months of the dry season. A sharper peak has been observed in the seasonality of the fire season (Cooke et al. 1996) so this would appear to be The forest fires in extra-tropical regions has been assumed to occur in the summer-time.

2) For Africa, satellite observations over a five year period have been used to estimate the seasonality of vegetation fires. Where fires have been detected the seasonality of Hao et al. (1991) has been replaced by the seasonality as estimated by the satellite data.

REFERENCES:

Cooke W.F. and J.J.N. Wilson (1996) A global black carbon aerosol model. J. Geophys. Res., 101, 14, 19395-19409.

Cooke W.F., B. Koffi and J.-M. Gregoire (1996) Seasonality of vegetation fires in Africa from remote sensing data and application to a global chemistry model. J. Geophys. Res., 101, 15, 21051-21065.

Hao W.M., M.H. Liu and P.J. Crutzen (1991) Estimates of Annual and Regional releases of CO2 and other trace gases to the atmosphere from fires in the tropics, based on FAO statisitics for the period 1975-1980. In "Fire in the tropical biota-Ecosystems processes and global challenges" editor J.G. Goldammer, Springer-Verlag.