correlation of co-hcn-c 2 h 2 -c 2 h 6 : global constraints on combustion sources
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Correlation of CO-HCN-C2H2-C2H6: Global Constraints on Combustion Sources
Biomass burning Biofuels
Natural gas/coal
C2H6
~2 mon
CO
Fossil fuel combustion
Auto combustion
C2H2
~2 mon
~2 wks
uptake
HCN
~5 mon
ocean
Yaping XiaoAtmospheric Chemistry Modeling Group
Harvard University
Observed correlation of CO-HCN-C2H2-C2H6
FTIR column measurements Ship cruises
Key questions: What do the correlations imply? Are they consistent with our
current understanding of sources? How can we use them to constrain source terms? What constraints can C2H2-CO correlation provide on OH
concentration?
Model analysis of CO-HCN-C2H2-C2H6 system
Tasks: Improve understanding of global C2H2 budget
Constrain regional OH concentration using C2H2/CO relationship
Improve understanding of HCN oceanic sink with the new column data in Southern Hemisphere
Interpret column and aircraft data in terms of constraining sources using forward model analysis of CO-HCN-C2H2-C2H6 system
C2H2 preliminary emission inventory
total ff bf bb oceanicEDGAR 3.2 4
Gupta et al.[1998] 3.1
Gautrois et al.[2003] 8.8
Blake et al.[1996] 2.1/2.8
Kanikiou et al.[1988] 0.2~1.4
Plass et al.[1992] Very small
Plass-Dulmer et al.[1993] 0.16~0.54
This work 4.2 1.1 1.5 1.6 ?0.53
Asia
Streets et al.[2003] 0.9 1.3
This work 0.25 0.88 0.45
Evaluation of C2H2 with seasonal variationNA bf & Streets in Asia With NA bfPreliminary
Arctic
Europe
NA
Tropical Pacifc
C2H2: Tropical pacific
Pem-TA (Sep)
Pem-TB(Mar)
Constrain sources using C2H2 /CO
Trace-P
China Coast S ChinaCoast SJapan
CO
C2H2
Constrain OH using C2H2 /CO correlation
Trace-P
Pemw-a
HCN: Two different oceanic sink parameterizations
constant seawater conctr. (xyp)uniform saturation ratio (qli)
Lauder Antarctic
The model with constant seawater HCN conctr. improves comparison in SH
Southern Ocean is not a sink for HCN?
HCN CO
AntarcticObsModel
LauderObsModel
CO yield from CH4 oxidation in tagged CO model
Mean yields in austral winter at SH mid and high latitudes are 0.81-0.86, otherwise about 0.95
With modified yield, mean bias in tagged CO at southern high latitudes decreases from 9 to 6 ppb in May-Aug.
C2H6 emission inventory: Streets vs. standard
Standard GEOS-CHEM:
ff scaled from CH4
Streets: Streets ff/bf in Asia, elsewhere increased by 30%
C2H6 (Tg/yr) ff bf bb
Standard 8.4 (2.4)
2.0(1.5)
2.0
Streets10.1(0.8)
2.0(1.5)
CO: SH mid/high latitude problem
Model CO at 45S-90S is overestimated by ~15 ppb in full chem
Mean yields in austral winter at SH mid and high latitudes are 0.81-0.86
With yield update in tagged CO model, bias decreases from 9 to 6 ppb in May-Aug.
How can this be accounted for in full chemistry simulation?
CO yield from CH4
amf v4-33mje v5-07-08
xyp tagged v4-33 OHrvm v4-26 1997
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