Post on 05-Jan-2016
Reconstructing ozone chemistry from Asian fires using satellite and aircraft
measurements (Spring ARCTAS 2008)
Richard Dupont 1, John Worden 1, Brad Pierce 2, Johnathan Hair 3, Marta Fenn 3, Paul Hamer 1, Murali Natarajan 3, Todd Schaack 4, Allen Lenzen 4, Eric Apel 5, Jack Dibb 6, Glenn Diskin 3 and Andrew Weinheimer 5
1. Jet Propulsion Laboratory/Caltech, Pasadena, CA, USA2. NOAA/NESDIS/STAR, Madison, WI, USA3. NASA Langley Research Center, Hampton, VI, USA4. Space Science and Engineering Center, University of Wisconsin, Madison, WI, USA 5. National Center for Atmospheric Research, Boulder, CO, USA 6. University of New Hampshire - EOS, Durham, NH, USA
Ozone (O3)
O3 + hv O1D
CO/CH4/VOC
O2
H2OOH HO2/RO2
NO
NO2hv
O(3P)
O2
HOx
HONO
HONO2
HO2NO2
H2O2
ROOH
The third most important greenhouse gas in the atmosphere (IPCC, 2007).
An important source of hydroxyl radicals (HOx), the “detergent” of the atmosphere;
Wildfire emissions affect atmospheric composition at a global scale (Andreae, 1983; Reichle et al, 1986, Fishman et al., 1990, Soja et al., 2006);
Biomass burning emissions appear to be comparable to fossil fuel emissions (Seiler and Crutzen, 1980; Crutzen and Andreae, 1990);
Global biomass burning emissions
Asian biomass burning emissions
Asian fires = 10% of global bb C emissions (Van der Werf et al., 2006);Important role in tropospheric CO variability and magnitude in the Northern Hemisphere (Novelli et al., 2003; Edwards et al., 2004; Kasischke et al., 2005; Pfister et al., 2005; Nedelec et al., 2005);Influence tropospheric O3 concentrations over North America (Jaffe et al., 2004;
Bertschi and Jaffe, 2005; Morris et al., 2006), the Arctic (Warnecke et al., 2008) and even Europe (Simmonds et al., 2005).
Fires impact on tropospheric O3 concentrations is challenging to estimate. O3 production depends on aerosols (photochemical production) as well as highly variable PAN and NOx emissions and the cycling between these species (Mauzerall et al., 1996; Lapina et al., 2006; Val Martin et al., 2006; Real et al., 2007; Verma et al., 2009).
Quantifying the impact of Asian fires on O3 concentrations over North America during the Spring ARCTAS 2008 campaign;
Identifying the chemical and dynamical processes involved during the transport of biomass burning plumes over the Pacific ocean.
Goals
MODIS fire count
Spring ARCTAS: April 2008
High fire activity over Asian boreal region in April 2008 (Fisher et al., 2010)
3 regions of major fire activity in the mid-northern latitudes:- Kazakhstan- Siberia- South East Asia (Thailand)
ARCTASARCTAS
Warm conveyor belt
Multiple types of measurement platforms:- Aircraft (NASA DC8, …)- Satellites (TES, OMI, MODIS, …- Ground-based measurements- Sondes (ARCIONS)
CO2H2O, N2O O3
TES
TES = infrared Fourier Transform SpectrometerSpectral range = 650-2250 cm-1
Nadir footprint = 5.3 km (across-track) × 8.5 km (along track) (Beer et al., 2001)O3 vertical resolution = about 6 kmMain sensitivity = middle troposphere
NASA/DC8 aircraft data
Ozone (O3) and Aerosol Scattering Ratio (ASR) = Differential Absorption LidarCarbon monoxide (CO) = Spectrometer and photometerSulfur dioxide (SO2) = Chemical Ionization Mass Spectrometer Black Carbon (BC) = Particle photometerNitrogen Oxides (NOx) + PeroxyAcetyl Nitrate (PAN) = NCAR NOxyO3Hydrogen CyaNide (HCN) = Chemical Ionization Mass Spectrometer
RAQMS (Pierce et al., JGR, 2007)
Developed by UW-Madison and NASA LangleyGlobal 3D modelAssimilation and forecast of chemistry and aerosols including STESpatial resolution : 2°×2°35 vertical levels (max 60km)Temporal resolution : 6h
Long range transport
Kazakhstan/Siberianplume
Thailandplume
ASR O3
Chemistry
The lower/middle tropospheric plume has a biomass burning origin;
Kazakhstan/Siberian plume trajectory (RAQMS)
Kazakhstan/Siberian plume trajectory (RAQMS)
Kazakhstan/Siberian plume trajectory (RAQMS)
Kazakhstan and Siberian fires increase background concentrations of CC, CO and O3 respectively by 4 ppbv, 50 ppbv and nearly 9 ppbv in the lower troposphere;
Thailand fires increase background concentrations of CC, CO and O3 respectively by 2 ppbv, 70 ppbv and nearly 10 ppbv in the upper troposphere;
Fires impact over Northwestern America
Conclusion
The stratosphere appears to be the main contributor of O3 concentrations in Asian biomass burning plumes during spring. However, photochemistry also plays an important role;
After transport over the Pacific, Thailand and Kazakhstan fires increase tropospheric O3 concentrations of about 10 ppbv relative to background levels;
The Asian fires can contribute to about 10-15% of the tropospheric O3 concentrations measured over the west coast of North America.