AER seminar

1
GOME HCHO columndata
Dec 1996
1016 molecules cm-2
June 1997
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
Sciences Harvard University
http//www.people.fas.harvard.edu/ppalmer
3
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?

4
O2
hv
O3
STRATOSPHERE
TROPOSPHERE
hv
OH
HNO3
NO
NO2
O3
HO2
OH
H2O2
hv, H2O
CO, hydrocarbons, NOx
HCHO h? ? 2HO2 CO (radical
channel) HCHO OH ? HO2 CO H2O
lifetime few hrs
5
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
ppb
6
Aircraft HCHO profile data
North Atlantic Regional Experiment 1997
Southern Oxidant Study 1995
measurements
GEOS-CHEM model
Altitude km
Altitude km
ppb
Defined background CH4 OH
Surface source (mostly isopreneOH)
Continental outflow
7
Global Ozone Monitoring Experiment

• 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

8
HCHO slant column fitting
Chance et al 2000

• O3
• NO2
• BrO
• O2-O2

3 x 1016 molec cm-2
8 x 1016 molec cm-2
1? fitting uncertainty 4 x 1015 molec cm-2
9
vertical column slant column /AMF
GEOS-CHEM
satellite
?lnIB/??
Sigma coordinate (?)
d?HCHO
1
Earth Surface
HCHO mixing ratio C(?)
Scattering weights
Shape factor
S(?) C(?) ?air/?HCHO
w(?) - 1/AMFG ?lnIB/??
1
AMF AMFG ? w(?) S(?) d?
0
10
AMF example - Tennessee
S?(?) w(?)
AMF 0.71
AMFG 2.08
w(?)
GEOS-CHEM S?(?)
AMF calculation every GOME July 1996 scene...
11
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 AODO3

Dickerson et al, 1997
12
HCHO columns July 1996
GEOS-CHEM
r2 0.7 n 756
Bias 11
1016molec cm-2
GOME
HCHO fitted in UV (340 nm) 1? uncertainty
4 x 1015 molec cm-2
13
GOME
GEOS-CHEM
Isoprene volcano
July 7 1996
July 20 1996
1016 molec cm-2
mm
14
How do we validate satellite observations?
GOME, MOPITT, SCIAMACHY TES, OMI
Global 3d model of chemistry
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Relating HCHO columns to hydrocarbon emissions
Chemical loss kHCHO

• Absence of transport ? ?Yi Ei

HCHO ?
HC oxidation ki (HCHO yield Yi)
i
Emission Ei
kHCHO
HCi
16
HCHO yields from HCs
Total 86
17
Horizontal transport displaces HCHO signal
Displacement length scale
L d,i U
ki
( )
ln
ki -kHCHO
kHCHO
midmorning eg values KHCHO 0.5h-1 U
20kmh-1 OH5E6 mol cm-3 ISOP Ld,i ? 40
km CH4 Ld,i many 1000s km CH3OH Ld,i
100s km
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GEOS-CHEM HCHO columnsJuly 1996
GEIA isoprene emissions

1016 molec cm-2
19
July 1996 (25-50oN, 65-130oW)
NW
NE
Slope S Y/kHCHO
Model HCHO column 1016 molec cm-2
SE
SW
model without isoprene
Isoprene emission 1013 atomC cm-2 s-1
20
Yields consistent with photochemical model
21
GOME
GEOS-CHEM
Isoprene volcano
July 7 1996
July 20 1996
1016 molec cm-2
mm
22
The Ozarks

• Dissected plateau - 129,500 sq km
• Oak forests good isoprene emitters

Cambridge, MA
"Trees cause more pollution than automobiles do."
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Ozark Isoprene Experiment 1998
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
Photos c/o Alex Guenther, NCAR
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HCHO data over the Ozarks
SOS 1999
Aircraft data _at_ 350 m during July 1999
Illinois
Missouri
Kansas
OZARKS
ppb
c/o Y-N. Lee, Brookhaven National Lab.
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GOME
GEOS-CHEM
Isoprene volcano
Temperature dependence of isoprene emission
July 7 1996
Slant column HCHO 1016 mol cm-2
Surface temperature K
July 20 1996
1016 molec cm-2
26
Global 3d model of chemistry
27
GEIA
EPA BEIS2
28
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
ppb
29
Modeling in situ data
GEIA
BEIS2
r2 0.65 Bias -30
r2 0.53 Bias -3
30
Model Transfer functions
NW
NE
Model HCHO column 1016 molec cm-2
SE
SW
model without isoprene
Isoprene emission 1013 atomC cm-2 s-1
31
GOME isoprene emissions July 1996
1012 atom C cm-2 s-1
32
Consistency GOME and in situ data
r2 0.77 Bias -12
33
Global HCHO from GOME July 1996
1016 molec cm-2
34
ATSR Firecounts July 1996
35
Global HCHO from GOME Oct 1996
1016 molec cm-2
36
CONSTRAINING SEASONAL AND INTERANNUAL VARIABILITY
IN BIOGENIC VOC EMISSIONS
HCHO columns, Jun-Aug 1997
GOME
GEOS-CHEM
37
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