sylvia generoso, isabelle bey evaluation of aerosol and co distributions from boreal fires in...
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Sylvia Generoso, Isabelle Bey
Evaluation of aerosol and CO distributions from boreal fires in GEOS-Chem using satellite products
Preliminary results using the CALIPSO products
LMCA , ,École Polytechnique Fédérale de Lausanne, Switzerland
Matthieu Labonne, François-Marie BréonLSCE / IPSL, CEA - CNRS, Gif-sur-Yvette, France
Contact: [email protected]
Jean-Luc Attié
LA, Toulouse, France
Model and satellite observations used
GEOS-Chem version v07-02-03- resolution 2°x2.5°, 30 vertical levels, 50 tracers, GEOS-4 meteorological fields
- biomass burning emissions for 2003 : interannual and seasonal variations based on AATSR fire counts [Generoso et al, 2003]
- AOT of the fine mode (AOTfine) including carbonaceous aerosols, sulfates and sea salt
- CO columns applying MOPITT averaging kernel
NASA / MODIS May 2003
Aerosol satellite products
- POLDER AOTfine_865 (r<0.5 µm)
Polarization and Directionality of the Earth Reflectance aboard ADEOS
Data in 1996/1997, 2003
PARASOL (similar sensor) currently flying on PARASOL (A train)
- MODIS AOTfine_550 (r<0.5 µm)
CO satellite products
- MOPITT
Spring and summer 2003 in RussiaSpring and summer 2003 in Russia
POLDER MODIS MOPITT
(May-June-July-August 2003 seasonal mean)
R : 0.65
B:-10±66%
R : 0.72
B:-29±61%
R : 0.78
B:-9±9%
Simulations conductedSimulations conducted
Russian fire sourcesRussian fire sources
Biomass Burning EmissionBiomass Burning Emission
Injection Height (EIH)Injection Height (EIH)
Deposition processesDeposition processes
S standard
a BB emission x 1.5
b BB emission x 3
c BB emission daily
d EIH up to 3 km
e EIH up to 4.5 km
f EIH up to 6.5 km
g e-folding time = 2
h no scavenging
i no rainout/washout Results show :
- aerosol distributions : highly sensitive to daily resolution of BB emission inventories and to injection above the PBL in the late fire season (July and August)
- CO distributions : sensitive to injection above the PBL in the late fire season (July and August)
- Biomass Burning source strenght : underestimate of our emissions in May 2003
Standard simulation:
from July 2002, and analyzed from May to August 2003
Sensitivity simulations: from April 2003, and analyzed from May to August 2003
• MODIS AOTfine_550
∆ GEOS-Chem BE∆ GEOS-Chem Standard
• POLDER AOTfine_865
∆ GEOS-Chem BE∆ GEOS-Chem Standard
• MOPITT CO column∆ GEOS-Chem BE∆ GEOS-Chem Standard
Set-up for the “Best Estimate” (BE) simulation
Fire emissions are
(i) increased by a factor 3 in May
(ii) prescribed on a daily-basis
(iii) Injected up to 4.5 km in July and August
Daily results averaged over the
North Pacific
Contribution of the 2003 Russian fires
to the Northern Hemisphere
AOT
BC deposition
Ratio between the Best Estimate (BE) and a simulation with the Russian fire sources turned off (woBB)
Contribution of the 2003 Russian fires to the “Arctic Haze” eventsevents
Number of days (during MJJA 03) for which the AOT550> 0.094 = threshold to define Arctic haze events [Herber
et al, J. Geophys. Res., 2002]
Contribution of the 2003 Russian fires to the AOT during the days
of Arctic Haze events
Ratio between the Best Estimate (BE) and the standard Ratio between the Best Estimate (BE) and the standard (STD) simulations(STD) simulations
AOT
BC deposition
Preliminary evaluation of the aerosol vertical distribution
in GEOS-Chem using CALIPSO lidar products
The CALIPSO missionCloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation
Quick overview
In this study
We use CALIOP attenuated backscatter at 550 nm (Level 1 products)
- CALIPSO is a joint U.S. (NASA) and French (Centre National d’Etudes Spatiales/CNES) satellite mission with an expected 3 years lifetime.
- Launched on April 28, 2006 aboard CloudSat satellite
- Data available since mid-June 2006
- Part of the A-train constellation
- Includes 3 instruments, which measure aerosol and cloud properties :
Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP)
Imaging Infrared Radiometer (IIR)
Wide Field Camera (WFC)
CALIOP measures attenuated backscatter :
- giving information on the vertical structure of the atmosphere
- including information from from aerosols and clouds
- depending on the extinction and the phase function
GEOS-Chem attenuated backscatter calculated :
- from the AOT : include aerosol information only
- with an estimated fixed phase function : only qualitative comparisons possible so far
(GEOS-Chem version v07-03-06)
Conclusions- In the standard configuration, the model significantly underestimates the MOPITT CO columns, POLDER and MODIS AOT over the north Pacific during May to August 2003.
- Increasing the amount of the biomass burning emissions does not necessarily result in significant improvements (except in May).
- In contrast, the use of daily biomass burning emission inventories improved significantly the aerosol simulations, without any significant effect on the CO columns.
-The injection of particles up to 4.5 km also impacts our simulation but only in the late fire season (July and August).
- According to our improved simulation, the 2003 Russian fires contribute to 16-33% to the monthly mean AOT averaged north of 75°N and to 40-56% to the mass of BC deposited. They contribute to more than 30% of the AOT during the days of Arctic haze events in spring and summer.
- Very encouraging preliminary results from the comparisons between GEOS-Chem
and CALIOP data !
Surface CO simulated by the BE Surface CO simulated by the BE compared to measurements (CMDL)compared to measurements (CMDL)
months
ppbv
Injection ModeInjection Mode
50%25%
12.5%
6.25%...
grid cell
% remaining
n
level
n-1n-2n-3
1
David Lavoué, personnal communication
A summary of the A summary of the sensitive analysissensitive analysis
Label Description
S standard
a BB emission x 1.5
b BB emission x 3
c BB emission daily
d EIH up to 3 km
e EIH up to 4.5 km
f EIH up to 6.5 km
g e-folding time = 2
h no scavenging
i no rainout/washout
BE Best Estimate
)1()1(
)1(4
02 R
RS
ff
ATSR fire count and emission inventoriesATSR fire count and emission inventories
ATSR fire counts for 2000
Available from July 96 to Oct 06
The seasonal cycle, inter-annual variations
and spatial distributions are based on satellite
observations
Definition of “homogeneous” regions
An emission constant computed as the ratio between :
1/ an initial emission estimate (climatology)
2/ATSR fire count averaged over the region and a long observation period (1999-2004)
The emission constant is applied to the monthly ATSR fire count
Generoso et al, ACP, 2003
ATSR versus other satellite productsATSR versus other satellite products
Although all products do have uncertainties, the ATSR night time restriction does not appear to be significant and show a seasonal
cycle that is consistent with the other proxies. Generoso et al, ACP, 2003
ATSR AVHRR TRMM
GLOBSCAR GBA2000
POLDER(Polarization and Directionality of the Earth Reflectance)
POLDER-1 : Nov 96 to Jun 97
POLDER-2 : Apr 03 to Oct 03
Total AOT(Aerosol Optical Thickness)
(over ocean only)
Fine mode AOT
(over ocean and land)
(aboard ADEOS)
Retrieved from polarized lightRetrieved from reflectance
May2003
(local over pass time ~ 10:30 am)