Presentation is loading. Please wait.

Presentation is loading. Please wait.

Distribution of formaldehyde over North America:

Published byOpal Hicks Modified over 6 years ago

Similar presentations

Presentation on theme: "Distribution of formaldehyde over North America:"— Presentation transcript:

1 Distribution of formaldehyde over North America:
Implications for satellite retrievals and mapping of precursor emissions Dylan Millet D.J. Jacob, D.R. Blake, K. Chance, A. Fried, B.G. Heikes, R.C. Hudman, T.P. Kurosu, H.B. Singh, S. Turquety, S. Wu ACCESS VIII Yellowstone National Park September 1-4, 2005

2 Can we use WHCHO as a proxy for VOC emissions?
Volatile organic compunds (VOCs): Precursors of ozone Precursors of organic aerosol Sinks of OH OH, hu, O3 VOC HCHO

3 Key Questions: Measurement: Interpretation
HCHO slant columns measured by GOME (K. Chance, T.P. Kurosu et al.) Key Questions: Measurement: 1) What is the uncertainty and bias in HCHO columns measured from satellites? Interpretation 2) What are the main precursors contributing to HCHO columns and variability over North America? 3) What are the implications for retrieving VOC emissions from space?  Address using aircraft measurements -0.5 0.5 1 1.5 2 2.5 LOD 1016 molecules/cm2 HCHO slant columns measured by OMI (K. Chance, T.P. Kurosu et al.)

4 Uncertainty in solar backscatter retrievals of HCHO
1) Fitting uncertainty (~ 4 x 1015 molec/cm2) 2) Relating slant columns to vertical columns Air mass factor (AMF) AMF depends on Atmospheric Scattering Cloud effects Aerosol effects HCHO vertical profile HCHO Model

5 AMF: approach Calculate measured and modeled AMFs using aircraft profiles
Viewing geometry & SZA scattering HCHO vertical distribution measured vs. modeled [HCHO], aerosol DC-8 flight tracks (ICARTT, summer 2004) measured vs. ‘satellite’ clouds

6 AMF: results Mean: 1.2 – 1.3 Range: 0.11 - 2.42 Model bias:
-5% over continents (-57+70%) +13% over ocean (-14+72%) 25% uncertainty for a single scene What drives the variability?

7 Errors in satellite retrievals of HCHO due to clouds & aerosols
Mean Individual profiles Model HCHO vertical profile: -4% mean bias over land +7% over ocean Aerosols: Increase the AMF (i.e. sensitivity to HCHO) by ~16% Clouds: Can ↑ or ↓ AMF Major source of error 2X uncertainty for a single scene Recommend cloud cutoff: AMF error of 40% cloud fraction

8 Interpreting HCHO columns
OH, hu, O3 VOC HCHO Methane, anthro. & biogenic VOCs What drives variability in WHCHO?

9 WHCHO sources & variability
isoprene OVOCs NMHCs methane terpenes WHCHO sources & variability Methane & OVOCs main HCHO precursors in most of the atmosphere But variability in column production rate is low Satellite LOD / tHCHO: ~ 5x1011 molec/cm2 /s Probability Measured column HCHO production rate

10 Relating HCHO columns to precursor emissions
NMHCs methane terpenes OVOCs isoprene Isoprene dominant source when WHCHO is high Variability in WHCHO over N. America driven by isoprene Column HCHO Measured column HCHO production rate

11 HCHO production yield from isoprene
HCHO column mass balance: MOD MOD From measured (WHCHO vs. Wi) & modeled (ki/kHCHO): Y = 1.61 MOD (flighttrack) OBS

12 Conclusions Uncertainty in HCHO columns measured from space
Clouds major source of error Increase AMF uncertainty by ~ 2x  Uncertainty in satellite HCHO columns due to the AMF: Mean bias ~ -5% over continents Uncertainty ~ 25% (1s) for individual scene (less for time averages) Mapping VOC emissions Variability in WHCHO over N. America driven by isoprene  Satellite retrievals of WHCHO can be used as a proxy for isoprene emissions over N. America Estimated average HCHO yield from isoprene oxidation: 1.61 Upper end of GEOS-Chem ( ) NOx-dependent yield

13 Jakarta Chongqing

Download ppt "Distribution of formaldehyde over North America:"

Similar presentations

Formaldehyde columns from GOME as a proxy for biogenic emissions over Europe Università degli Studi dellAquila – CETEMPS LAquila, ITALY

Formaldehyde columns from GOME as a proxy for biogenic emissions over Europe Università degli Studi dellAquila – CETEMPS LAquila, ITALY
Dylan Millet Harvard University with

Dylan Millet Harvard University with
Dec 1996 June 1997 GOME HCHO column data 10 16 molecules cm -2.

Dec 1996 June 1997 GOME HCHO column data molecules cm -2.
GEOS-CHEM Meeting 2005 Dylan Millet Variability of CH 2 O during ICARTT: Implications for GOME/OMI Dylan Millet GEOS-CHEM Users’ Meeting April 2005.

GEOS-CHEM Meeting 2005 Dylan Millet Variability of CH 2 O during ICARTT: Implications for GOME/OMI Dylan Millet GEOS-CHEM Users’ Meeting April 2005.
Page 1 OMI Science Team Meeting, Helsinki, Finland, 24 – 27 June 2008M. Van Roozendael et al. On the usability of space nadir UV-visible observations for.

Page 1 OMI Science Team Meeting, Helsinki, Finland, 24 – 27 June 2008M. Van Roozendael et al. On the usability of space nadir UV-visible observations for.
GEOS-CHEM Near-Real Time Full-Chemistry Simulations S. Turquety, D. J. Jacob, R. M. Yantosca, R. C. Hudman, L. Jaeglé, S. Wu Objectives : 1.ICARTT campaign.

GEOS-CHEM Near-Real Time Full-Chemistry Simulations S. Turquety, D. J. Jacob, R. M. Yantosca, R. C. Hudman, L. Jaeglé, S. Wu Objectives : 1.ICARTT campaign.
Integrating satellite observations for assessing air quality over North America with GEOS-Chem Mark Parrington, Dylan Jones University of Toronto

Integrating satellite observations for assessing air quality over North America with GEOS-Chem Mark Parrington, Dylan Jones University of Toronto
Dylan Millet, Daniel Jacob, and May Fu Harvard University Thomas Kurosu and Kelly Chance Harvard-Smithsonian Astrophysical Observatory Alex Guenther NCAR.

Dylan Millet, Daniel Jacob, and May Fu Harvard University Thomas Kurosu and Kelly Chance Harvard-Smithsonian Astrophysical Observatory Alex Guenther NCAR.
INITIAL COMPARISONS OF TES TROPOSPHERIC OZONE WITH GEOS-CHEM Lin Zhang, Daniel J. Jacob, Solene Turquety, Shiliang Wu, Qinbin Li (JPL)

INITIAL COMPARISONS OF TES TROPOSPHERIC OZONE WITH GEOS-CHEM Lin Zhang, Daniel J. Jacob, Solene Turquety, Shiliang Wu, Qinbin Li (JPL)
Formaldehyde columns over Europe as a proxy for biogenic emissions Università degli Studi dell’Aquila – CETEMPS L’Aquila, ITALY

Formaldehyde columns over Europe as a proxy for biogenic emissions Università degli Studi dell’Aquila – CETEMPS L’Aquila, ITALY
GEOS-CHEM GLOBAL 3-D MODEL OF TROPOSPHERIC CHEMISTRY Assimilated NASA/DAO meteorological observations for 1988-2001 1 o x1 o to 4 o x5 o horizontal resolution,

GEOS-CHEM GLOBAL 3-D MODEL OF TROPOSPHERIC CHEMISTRY Assimilated NASA/DAO meteorological observations for o x1 o to 4 o x5 o horizontal resolution,
Detection of anthropogenic formaldehyde over North America by oversampling of OMI data: Implications for TEMPO Lei Zhu and Daniel J. Jacob.

Detection of anthropogenic formaldehyde over North America by oversampling of OMI data: Implications for TEMPO Lei Zhu and Daniel J. Jacob.
AQUA AURA The Berkeley High Spatial Resolution(BEHR) OMI NO2 Retrieval: Recent Trends in NO2 Ronald C. Cohen University of California, Berkeley $$ NASA.

AQUA AURA The Berkeley High Spatial Resolution(BEHR) OMI NO2 Retrieval: Recent Trends in NO2 Ronald C. Cohen University of California, Berkeley $$ NASA.
Isoprene emissions in Africa inferred from OMI HCHO ACKNOWLEDGEMENTS: This work was funded by the NASA ACMAP program and the South African National Research.

Isoprene emissions in Africa inferred from OMI HCHO ACKNOWLEDGEMENTS: This work was funded by the NASA ACMAP program and the South African National Research.
Validation of a Satellite Retrieval of Tropospheric Nitrogen Dioxide Randall Martin Dalhousie University Smithsonian Astrophysical Observatory Daniel Jacob.

Validation of a Satellite Retrieval of Tropospheric Nitrogen Dioxide Randall Martin Dalhousie University Smithsonian Astrophysical Observatory Daniel Jacob.
Mapping isoprene emissions from space Dylan Millet with

Mapping isoprene emissions from space Dylan Millet with
North American Isoprene Emissions Measured from Space Paul Palmer Harvard University ACD seminar series, NCAR, January 14, 2002.

North American Isoprene Emissions Measured from Space Paul Palmer Harvard University ACD seminar series, NCAR, January 14, 2002.
Using Satellite Data to Infer Surface Emissions and Boundary Layer Concentrations of NO x (and SO 2 ) Randall Martin With contributions from: Xiong Liu,

Using Satellite Data to Infer Surface Emissions and Boundary Layer Concentrations of NO x (and SO 2 ) Randall Martin With contributions from: Xiong Liu,
CHEMICAL CHARACTERISTICS OF NORTH AMERICAN OUTFLOW: INSIGHTS FROM CHEBOGUE POINT, NOVA SCOTIA Allen Goldstein, Dylan Millet, James Allan, Eben Cross, Rupert.

CHEMICAL CHARACTERISTICS OF NORTH AMERICAN OUTFLOW: INSIGHTS FROM CHEBOGUE POINT, NOVA SCOTIA Allen Goldstein, Dylan Millet, James Allan, Eben Cross, Rupert.
CHEMISTRY-CLIMATE INTERACTIONS: science questions, science needs Daniel J. Jacob THE BROAD QUESTIONS: How do chemical processes in the troposphere affect.

CHEMISTRY-CLIMATE INTERACTIONS: science questions, science needs Daniel J. Jacob THE BROAD QUESTIONS: How do chemical processes in the troposphere affect.

Similar presentations

Ads by Google