sea salt: Gong et al. (1997) - GEMS

Emissions in GEMS
Data on emissions are needed for the 4 sub-systems GHG, GRG, AER and RAQ
GEMS Project has dedicated tasks for emissions and surface fluxes parameterization
- GHG-Task 1.3
- GRG-Task 2.9
- AER-Task 2
- RAQ-Task 2.4
Consistent data sets (between GHG, GRG and AER) are needed for emissions of
common source origin (Anthropogenic, Biomass Burning)
Consistency should also be observed between emission inventories used at a global and
regional scale (between GRG-AER and RAQ systems)
Different inventories exist for the same species
Define criteria on temporal and spatial resolution but also on the quality of the
data sets (accuracy, documentation, accessibility)

Current CO 2
surface fluxes in GEMS
• Anthropogenic emissions : Fossil Fuel burning, Cement Production and Gas Flaring
Estimates for 1995 (total 6.17 PgC/year), data base developed by the CDIAC
Based on national statistics databases, density of population used to distribute the emissions
ref. (Brenkert, 1998 ; Andres et al., 1996)
• Air-Sea CO2 exchange : Fluxes are based on Takahashi et al. (2002) climatology
Estimates are based on measurements of pCO2 in surface waters between 1960 and 1995
The annual oceanic uptake estimate is about -2.2 PgC/year
• Exchange with terrestrial ecosystem : NEP Estimates are taken from Randerson et al. 1997
using CASA (links remote sensing data, meteorological data and surface observations)
The Net Ecosystem Production NEP = GPP - AR – HR
Photosynthesis
Annually balanced terrestrial biosphere
NPP
Plant respiration
Soil components
respiration
Biomass burning disturbances are not taken into account (4PgC/year = 7% of annual NPP)
Note : Oxidation of reduced carbon species are taken into account implicitly in some of these
estimations ; they are released at the surface rather than distributed in the atmosphere

Aerosol sources
• For the introduction of aerosol processes in the ECMWF IFS, the initial
emission fluxes and sources are taken from:
– sea salt: Gong et al. (1997)
– desert dust: INCA, Schulz et al. (1998), Guelle et al. (2000)
– And other constituents from AEROCOM intercomparison data sets
Organic matter: Bond and Streets (1996)
Black carbon: Bond and Streets (1996), GFED
Sulfate: IIASA, dGEIA, Guenter et al. (1994)
• Within GEMS-Aerosols, refinement of aerosol emission sources is dealt with in
WP_AER2
> update and assimilation of the anthropogenic emission inventories of aerosol and
its precursors
> assimilation of information on wild fires
> quantification of the wind-blown dust emission from desert areas
> quantification of the wind-blown sea salt emission
> sources of stratospheric aerosols

Emissions for GRG
Many species (VOC)
Different inventories exist at regional or global scale based on
different methodologies or statistical data
Inventories may overlap in space and time and may include similar data
sets
A compiled list of global and regional inventories is needed with a
detailed content, reference years, space and time resolution
starting base : - HALO paper on emissions (J. Flemming)
- Finnish Meteorological Institute initiative
VOC break down ?
Discussion is needed for the datasets to be implemented

Emission inventory for Regional Air Quality
across Europe
Decide on a common emissions inventory for anthropogenic
emissions, gases and particulate matter
EMEP/CORINAIR inventory will be the basis for yearly totals and
their historical evolution
- Downscaling for a resolution of ~ 5 km
-Temporal profiles on the diurnal, weekly and seasonal timescales

How important are emissions from Biomass Burning?
Only in the two past decades have researchers realized the important
contributions of biomass burning to the global budgets of many radiatively
and chemically active gases, and elemental carbon particulates
Fossil fuel
6.2 Pg C/yr
Biomass burning 4 Pg C/yr (Andreae and Merlet 2001)
Net effect uncertain
Estimates vary but biomass burning contributes up to:
10 % of CH 4
38% of tropospheric O 3
42% of BC (Bond et al., 2004)
74% of OC

Biomass Burning emissions in GEMS
Biomass burning is a major source for greenhouse gases, reactive
gases and aerosols
Biomass burning can be observed from space
Emissions from biomass burning are subject to high uncertainties,
some investment is required to improve the quality of estimations
Time resolution required for GRG and AER sub-projects have to
be considered for the choice of data sets
It is also important to prepare emission data supply for the
operational phase of the assimilation system

Emissions in GEMS - Outline
Consistency in emission data sets should be achieved between
the 4 sub-systems within GEMS
A compiled list of emission inventories (present species, time
and space coverage, resolution, quality) as a base for decisions
Biomass burning emissions in GEMS ?
Temporal resolution for GRG and AER
What else?