Tracking the emission and transport of pollution from wildfires using the IASI CO retrievals: analysis of the summer 2007 Greek fires 1UPMC Univ. Paris 06; Université Versailles St.-Quentin; CNRS/INSU, LATMOS-IPSL, Paris, France
2Spectroscopie de l'atmosphère, Chimie Quantique et Photophysique, Université Libre de Bruxelles, Brussels, Belgium
*now at: Laboratoire de Météorologie Dynamique/IPSL, UPMC Univ. Paris 06, Paris, France
Received: 16 February 2009 – Published in Atmos. Chem. Phys. Discuss.: 20 March 2009 Abstract. In this paper, we analyze the performance of the Infrared Atmospheric
Sounding Interferometer (IASI), launched in October 2006 on board METOP-A,
for the monitoring of carbon monoxide (CO) during extreme fire events,
focusing on the record-breaking fires which devastated thousands of square
kilometers of forest in Greece during the last week (23–30) of August 2007.
After an assessment of the quality of the profiles retrieved using the Fast
Optimal Retrievals on Layers for IASI (FORLI) algorithm, the information
provided on fire emissions and subsequent pollution outflow is discussed.
Large CO plumes were observed above the Mediterranean Basin and North
Africa, with total CO columns exceeding 24×1018 molecules/cm2
and absolute volume mixing ratios up to 4 ppmv on the 25
August. Up to 30×1018 molecules/cm2 and 22 ppmv in the
lower troposphere are retrieved close to the fires above the Peloponnese,
but with larger uncertainty. The average root-mean-square (RMS) difference
between simulated and observed spectra is close to the estimated radiometric
noise level, slightly increasing (by ~14%) in the fresh fire
plumes. CO profiles are retrieved with a vertical resolution of about 8 km,
with ~1.7 pieces of independent information on the vertical in the
region considered and a maximum sensitivity in the free troposphere (~4–5 km).
Using the integrated total amount, the increase in CO burden due to
these fires is estimated to 0.321 Tg, ~40% of the total annual
anthropogenic emissions in Greece. The patterns of these CO enhancements are
in good agreement with the aerosol optical depth (AOD) retrieved from the
MODIS measurements, highlighting a rapid transport of trace gases and
aerosols across the Mediterranean Basin (less than one day). While the
coarse vertical resolution will not allow the location of the exact plume
height, the large CO enhancements observed in the lower troposphere are
consistent with the maximum aerosol backscatter coefficient at ~2 km
detected by the CALIPSO lidar in space (CALIOP).
Revised: 02 July 2009 – Accepted: 14 July 2009 – Published: 24 July 2009
Citation: Turquety, S., Hurtmans, D., Hadji-Lazaro, J., Coheur, P.-F., Clerbaux, C., Josset, D., and Tsamalis, C.: Tracking the emission and transport of pollution from wildfires using the IASI CO retrievals: analysis of the summer 2007 Greek fires, Atmos. Chem. Phys., 9, 4897-4913, doi:10.5194/acp-9-4897-2009, 2009.