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ISAC-CNR, Rome , Italy f.barnaba@isac.cnr.it. CNR - Area Ricerca Tor Vergata 12 January 2010. An important fingerprint of wildfires on the European aerosol load. CETEMPS - Dip. Fisica Università dell’Aquila, Italy gabriele.curci@aquila.infn.it. CNR - Area Ricerca Tor Vergata
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ISAC-CNR, Rome, Italy f.barnaba@isac.cnr.it CNR - Area Ricerca Tor Vergata 12 January 2010 An important fingerprint of wildfires on the European aerosol load CETEMPS - Dip. Fisica Università dell’Aquila, Italy gabriele.curci@aquila.infn.it CNR - Area Ricerca Tor Vergata 14 January 2010 Francesca Barnaba, Federico Angelini, Gabriele Curci, Gian Paolo Gobbi [Barnaba et al., ACPD 2011] EGU 2011, 4 April, Vienna
AEROSOL OPTICAL THICKNESS (AOT) IN ROME DOES NOT PERFECTLY FOLLOW A “SINUSOIDAL” YEARLY CYCLE … ROME http://aeronet.gsfc.nasa.gov/ … but a “bimodal” cycle is observed AOT is expected to have a “sinusoidal” yearly cycle AOT anomaly AOT Data Counts [Yu et al., JGR 2003 ]
AOT “BIMODALITY” IS A MORE GENERAL FEATURE OVER EUROPE 2002-2007 average AOT and FFAOT @ 550 nm from MISR satellite instrument also shows significant deviation from “sinusoidal” yearly cycle. AOT max: April & Jul-Aug
WILDFIRES IN EASTERN EUROPE ARE MOSTLY CONCENTRATED INEARLY SPRING & SUMMER Example: MODIS Fire Counts 2006 Spring These fires are mostly related to human activities (crops, forestry, …) Summer
FRPn1 Tn1 n1 q FRPn2 n2 Target Region Tn2 WE COMBINE SATELLITE DATA AND TRAJECTORY MODEL TO ESTIMATE THE IMPACT OF WILDFIRES ON EUROPEAN AOT • MISR AOT & Fine Fraction AOT (< 0.35 µm), λ = 550 nm, 0.5° x 0.5° Level 3 Monthly • MODIS, 0.5° x 0.5° Level 3 Monthly mean: • Fire Counts, FC (counts/km2/day) • Fire Radiative Power, FRP (MW) • HYSPLIT Lagrangian trajectory model (http://ready.arl.noaa.gov) 5 days Combining 2 and 3 we derive a Fire Weighted Trajectory Density (FWTD)
MONTHLY FIRE WEIGHTED TRAJECTORY DENSITY (FWTD) 2002-2007 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
FWTD YEARLY CYCLE IN PHASE WITH AOT & FFAOT 2002-2007 average MISR AOT MISR FFAOT (~ no dust/sea salt) FWTD LARGER INTER-ANNUAL VARIABILITY @ MAX
IMPACT OF EASTERN EUROPE FIRES IS UBIQUITOUS.PORTUGAL FIRES LIMITED TO SOUTH-WESTERN EUROPE Q3 Q4 Q1 Q2 Eastern Europe (Q3) Fires WMed (Q1) Fires
CONTRIBUTION OF WILDFIRES TO FINE FRACTION AOT (FFAOT):ESTIMATED FROM DIFFERENCE WITH “SINUSOIDAL” FIT OBSERVED MISR FFAOT “Reconstructed” FFAOT FFAOT_RB (fit) FFAOT_WF = FFAOT – FFAOT_RB
CONTAMINATION FROM INTERCONTINENTAL TRANSPORT FROM NORTH AMERICA SIGNIFICANT ONLY IN SOUTH-WESTERN EUROPE IN SPRING MISR FFAOT JULY 2002-2007 average MISR FFAOT FFAOT_RB (fit) FFAOT – FFAOT_RB
CONCLUDING REMARKS • A step forward toward a comprehensive long-term (2002-2007) evaluation of wildfires impact (mostly from agricultural & forestry practices) on European aerosol load: previous studies focused on episodic events. • A combination of satellite observations and trajectory modelling show that fires (mostly from Eastern EU and European Russia) contribute to a continent-wide haze. • In spring and summer, 10-30% of Fine Fraction AOT over Europe is related to wildfires. • Clear target for mitigation: biomass energyproduction and air quality • To be done: Evaluation of the impact on PM at the ground (air quality) – Preliminary estimate on PM10: WF Fine Fraction AOT = 0.04 Mass-to-extinction = 4 m2/g Column Mass = 0.01 g/m2 Monthly mean WF related PM10 = 10 µg/m3 If PBL Height = 1000 m and Uniform distribution