dec 1996
DESCRIPTION
GOME HCHO columndata. Dec 1996. 10 16 molecules cm -2. June 1997. North American Hydrocarbon Emissions Measured from Space. Paul Palmer , Daniel Jacob, Arlene Fiore, Randall Martin, Dorian Abbot, Kelly Chance, Thomas Kurosu Division of Engineering and Applied Sciences - PowerPoint PPT PresentationTRANSCRIPT
Dec 1996
June 1997
GOME HCHO columndata
10
16 m
ole
cu
les c
m-2
North American Hydrocarbon Emissions Measured from Space
Paul Palmer, Daniel Jacob, Arlene Fiore, Randall Martin, Dorian Abbot, Kelly Chance,
Thomas Kurosu
Division of Engineering and Applied SciencesHarvard University
http://www.people.fas.harvard.edu/~ppalmer
Overview
• Why are accurate hydrocarbon emissions important?
•Relating measured HCHO columns to specific hydrocarbon emissions
•Are satellite observations consistent with in situ data?
•The future?
CO, hydrocarbons, NOx
STRATOSPHERE
TROPOSPHERE
HO2OH
NONO2
H2O2
O3
O3
O2
hv, H2O
hv
hvHNO3
OH
HCHO + h 2HO2 + CO (radical channel)
HCHO + OH HO2 + CO + H2O lifetime = few hrs
ppb
Summertime in situ HCHO datasets
Fried et al 1997
Harris et al 1989
Kleindienst et al 1988
Lee et al 1995, 1998
Martin et al 1991
McKeen et al 1997
OZIE -Guenther
Reimer et al 1998
Shepson et al 1991
Aircraft HCHO profile data
Southern Oxidant Study 1995
North Atlantic Regional Experiment 1997
[ppb]
Surface source (mostly isoprene+OH)
Continental outflow
Alt
itu
de
[km
]
Alt
itu
de
[km
]
measurements GEOS-CHEM model
Defined background CH4 + OH
• Nadir-viewing SBUV instrument
• Launched April 1995
• Pixel 320 x 40 km2
• 10.30 am cross-equator time
• Global coverage in 3 days
• O3, NO2, BrO, OClO, SO2, HCHO, H2O, & cloud coverage
Global Ozone Monitoring Experiment
HCHO slant column fitting
3 x 1016 molec cm-2
8 x 1016 molec cm-2
1 fitting uncertainty 4 x 1015 molec cm-2
Chance et al [2000]
O3
NO2
BrO
O2-O2
vertical column = slant column /AMF
satellite
dHCHO
Earth Surface
HCHO mixing ratio C()
lnIB/
Scattering weights
Shape factorw() = - 1/AMFG lnIB/
Sig
ma c
oord
inate
(
)
S() = C() air/HCHO
AMF = AMFG w() S() d1
1
0
GEOS-CHEM
AMF example - Tennessee
GEOS-CHEM S()
w()
S()
w() AMF
G
2.08
AMF
0.71
AMF calculation every GOME July 1996 scene...
GEOS-CHEM global 3D model:
101
•Driven by DAO GEOS met data
•2x2.5o resolution/26 vertical levels
•O3-NOx-VOC chemistry
•GEIA isoprene emissions
•Aerosol scattering: AOD:O3
Dickerson et al, [1997]
[1016molec cm-2]
GEOS-CHEM
GOME
HCHO columns – July 1996
r2 = 0.7 n = 756
Bias = 11%
HCHO fitted in UV (~340 nm)
1 uncertainty: 4 x 1015 molec cm-2
[1016 molec cm-
2]
GOME GEOS-CHEM
July 7 1996
July 20 1996
Isoprene “volcano”
mm
Global 3d model of chemistry
How do we validate satellite observations?
GOME,
MOPITT,
SCIAMACHY
TES, OMI
Relating HCHO columns to hydrocarbon emissions
•Absence of
transport = Yi Ei
i
kHCHO
HCi
HCHO
Chemical loss kHCHO
Emission Ei
HC oxidation ki (HCHO yield Yi)
HCHO yields from HCsSpecies
Emission[TgC month-
1]
HCHO Yield[C-1]
Potential HCHO production [%]
CH4 2.6 1.0 28.5
ISOP 7.3 0.45 32.0
-pinenes
1.1 0.8
0.019 0.045
0.23 0.39
MBO 0.8 0.06 0.53
HCHO 0.15 1.0 1.64
CH3OH 2.1 1.0 23.0 Total: 86%
L d,i = U
Horizontal transport displaces HCHO signalDisplacement length scale
ki -kHCHOln( )ki
kHCHO
midmorning eg values KHCHO = 0.5h-1; U = 20kmh-1; [OH]=5E6 mol cm-3
ISOP Ld,i 40 km
CH4 Ld,i = many 1000s km
CH3OH Ld,i =100s km
GEOS-CHEM HCHO columnsJuly 1996
[1016 molec cm-2]
GEIA isoprene emissions
NW NE
SESW
Isoprene emission [1013 atomC cm-2 s-1]
Mod
el H
CH
O c
olu
mn
[101
6 m
ole
c c
m-2
] July 1996 (25-50oN, 65-130oW)
Slope S = Y/kHCHO
model without isoprene
n S[103 s]
r2 lifetime[hours]
Y[C-1]
NW 1810
2.04 0.51 1.67 0.34
NE 2193
1.90 0.43 1.76 0.30
SE 1913
2.09 0.65 1.48 0.39
SW 1750
1.27 0.49 1.48 0.24
Yields consistent with photochemical model
[1016 molec cm-
2]
GOME GEOS-CHEM
July 7 1996
July 20 1996
Isoprene “volcano”
mm
The Ozarks• Dissected plateau - 129,500 sq km
• Oak forests – good isoprene emitters
"Trees cause more pollution than automobiles do."
Cambridge, MA
Ozark Isoprene Experiment 1998
Photos c/o Alex Guenther, NCAR
Result Summary
Type Spec ppb Alt [m] Local time
Balloon Isop 1-7 400-1000 0830-1930
Plane Isop 3-6 450-900 1800-2000
Surface HCHO 7-15(11) 0830-1930
Plane HCHO 3-11(7) 1300-1800
HCHO data over the Ozarks
Missouri Illinois
Kansas
[ppb]
Aircraft data @ 350 m during July 1999
c/o Y-N. Lee, Brookhaven National Lab.
OZARKS
SOS 1999
[1016 molec cm-
2]
GOME GEOS-CHEM
July 7 1996
July 20 1996
Surface temperature [K]
Sla
nt
colu
mn
HC
HO
[1
016 m
ol
cm
-2]
Temperature dependence of isoprene emission
Isoprene “volcano”
Global 3d model of chemistry
EPA BEIS2
GEIA
ppb
Summertime in situ HCHO datasets
Fried et al 1997
Harris et al 1989
Kleindienst et al 1988
Lee et al 1995, 1998
Martin et al 1991
McKeen et al 1997
OZIE -Guenther
Reimer et al 1998
Shepson et al 1991
Modeling in situ dataGEIA BEIS2
r2 = 0.53
Bias -3%
r2 = 0.65
Bias -30%
NW NE
SESW
Isoprene emission [1013 atomC cm-2 s-1]
Mod
el H
CH
O c
olu
mn
[101
6 m
ole
c c
m-2
]Model Transfer functions
model without isoprene
[1012 atom C cm-2 s-
1]
GOME isoprene emissions – July 1996
Consistency: GOME and in situ data
r2 = 0.77
Bias -12%
Global HCHO from GOME: July 1996
[1016 molec cm-2]
ATSR Firecounts – July 1996
[1016 molec cm-2]
Global HCHO from GOME: Oct 1996
CONSTRAINING SEASONAL AND INTERANNUAL VARIABILITY IN BIOGENIC
VOC EMISSIONSHCHO columns, Jun-Aug 1997GOME GEOS-CHEM
Summary
New methodology for HC emission from space-based HCHO columns
Isoprene is dominant HC for North American summertime
GOME shows Ozarks isoprene volcano
GOME data consistent with in situ data
Future work will include global mapping