GEOS-5 GMI Configuration for PIESA: Difference between revisions

Trace gas emissions from fossil fuels, biofuels, and biomass burning are based on inventories and routines provided by the Harvard University GEOS-Chem group.  Individual sources are described below.  The general approach for fossil fuel and biofuel emissions is to begin with a global inventory and overwrite particular regions where regional inventory data is available.  Fossil fuel emissions are scaled from the inventory base year to the simulation year using scaling factors from the Harvard University GEOS-Chem group (''van Donkelaar et al.'', 2008).  Biomass burning emissions use emission factors for boreal forest, tropical forest, and savanna/herb/other vegetation types, to convert Global Fire Emissions Database version 2 (GFEDv2) (Randerson, 2007; Van der Werf, 2006) carbon emissions to emissions of NOx, CO, or VOCs, using a carbon to dry matter ratio of 0.45.

===NOx sources===

*Aircraft NOx: Steven Baughcum provided aircraft emissions of NOx for 1995 on a 1x1 degree grid with 1 km vertical resolution.  We then vertically regridded the aircraft data to the GEOS5 vertical grid using a routine from the Harvard GEOS-Chem group.

**EPA/NEI 2005 over the United States, with seasonality from the VISTAS inventory

**CAC 2002 and 2005 over Canada: 2002 for years 2002 and earlier, 2005 for years 2005 and later, and interpolated between the 2002 and 2005 inventory for 2003 and 2004

*Global biofuel NOx emissions are from Yevich et al. (2003).  These are overwritten with EPA/NEI 1999 biofuels over the United States.  For years 2006 and later, biofuel emissions are zeroed over southeast Asia to avoid double counting because the 2006 inventory for southeast Asia does not separate fossil fuels and biofuels.

*NOx is emitted as NO.

===CO sources===

*Global CO emissions from fossil fuels are from the EDGAR inventory for 2000.  We impose a seasonal cycle north of 36 degrees N (except over China, where the inventory is already monthly), with emissions 10% higher during winter and 10% lower during summer, following Duncan et al. (2007).

*The following regional inventories overwrite the global inventory for fossil fuel CO:

===VOC sources===

*Global fossil fuel emissions of MEK, PRPE, C2H6, C3H8, and ALK4 come from GEOS-Chem's inventory for 1985 (Wang et al. 1998), based on speciation information from EPA.  Annual scaling of VOC's uses the same scaling factors as CO.

*The following regional inventories overwrite the global VOC emissions:

**For 2006 and later, Zhang et al. (2009) inventory for 2006 over southeast Asia

*Biofuel emissions of MEK, PRPE, C2H6, C3H8, ALK4, CH2O, and ALD2 come from Yevich et al. (2003).  All species except CH2O are overwritten with EPA/NEI1999 biofuels over the US. For years 2006 and later, biofuel emissions are zeroed over southeast Asia to avoid double counting because the 2006 inventory for southeast Asia does not separate fossil fuels and biofuels.

== References ==

EPA/NEI: http://www.epa.gov/air/data/neidb.html

Randerson, J. T., G. R. van der Werf, L. Giglio, G. J. Collatz, and P. S. Kasibhatla, Global Fire Emissions Da tabase, Version 2 (GFEDv2.1), Data set, Available on-line from [http://daac.ornl.gov/ Oak Ridge National Laboratory]