Global budget of atmospheric acetone

ATMOSPHERIC OBSERVATIONS
OF ACETONE (0.2-3 ppbv)
SONEX
ABLE
-3B
PEM
-WB
PEM-TB
Surface sites

OCEANIC SIGNATURE
IN ATMOSPHERIC ACETONE OBSERVATIONS?
Low winter values
over Europe:
ocean sink?
southern Sweden
[Solberg et al., 1996]
High values over
South Pacific:
ocean source?
South Pacific
[Singh et al., 2001]

ROLE OF OCEAN
IN ATMOSPHERIC BUDGET OF ACETONE
organic microlayer
Organic microlayer
Model sink as adjustable
saturation ratio R
Model source as proportional
To UV-B flux

Observed atmospheric
concentrations
(with “errors”)
Global 3-D model (“forward model”):
defines sensitivity of atmospheric concentrations to global sources/sinks (“state vector”)
INVERSE MODEL ANALYSIS OF ACETONE BUDGET
A posteriori optimized estimate
of sources/sinks
A priori best estimate
of sources/sinks
(with errors)

CONSTRUCTING THE A PRIORI:
SIMULATION OF C3-5 ISOALKANES TO
IMPROVE CONSTRAINT ON EMISSIONS
observed
model
(EDGAR)
model
(Piccot+)
Global propane source of 12 Tg C yr-1, mainly natural gas

CONTRIBUTION OF DIFFERENT SOURCES
TO A PRIORI BUDGET OF ACETONE
(symbols: observations lines: model)

FITTING OF OCEAN SATURATION RATIO R
TO MINIMIZE MODEL vs. OBSERVED CHI-SQUARE
IN A POSTERIORI OPTIMIZED SOURCES
Best fit for
R = 0.7-0.85

OPTIMIZED GLOBAL 3-D MODEL SIMULATION
OF ATMOSPHERIC ACETONE