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Satellite and model analysis of wildfire NOx emissions in Siberia: Links to interannual variability of surface ozone, 1998–2004. Photo: Siberia (courtesy of T. Machida). Hiroshi Tanimoto National Institute for Environmental Studies, Japan In collaboration with
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Satellite and model analysis of wildfire NOx emissions in Siberia: Links to interannual variability of surface ozone, 1998–2004 Photo: Siberia (courtesy of T. Machida) Hiroshi Tanimoto National Institute for Environmental Studies, Japan In collaboration with K. Folkert Boersma, Ronald van der A, Kiyoshi Matsumoto, Mitsuo Uematsu, Philippe Le Sager, Bob Yantosca
Background & Motivation • Role of boreal forest fires in interannual variations of trop. O3 in N.H. (especially, Rishiri Island, northern Japan) • Impacts on CO is well-known (Yurganov, Edwards, etc), but O3 is less known. Still lots of discussions on magnitude of O3 increase. Rishiri Island, Japan • O3 enhancement in “fire plumes” • Cheeka Peak (Jaffe et al.), Pico-NARE (Val Martin, Honrath, et al.), Rishiri (Tanimoto et al.), etc • O3 “background-levels” • Mace Head (Simmonds et al.), Pico-NARE (Lapina et al.) • O3 enhancements are subtle, “several ppbv” – challenge • NOx is a key species, but not extensively examined, because of limited measurements nearby fires
Questions & Tools • Can satellites see NOx (NO2) enhancement due to boreal fires? • Does the GFED-driven model reproduce the NOx enhancement, and predict O3 enhancement? • Are satellites, model, and surface data consistent with each other? • GEOS-Chem • Version: v8-01-01 • Met. Field: GEOS4 • Horizontal Grid: 4x5 deg • Vertical Layers: 30 layers • Tracers: 43 species • Emissions: GFEDv2, monthly • Period: Apr – Sep, 1998, 1999, 2000, 2001, 2002, 2003, 2004 • GOME • 1998-2002, 10:30LT, 40x320 km • SCIAMACHY • 2002-2004, 10:00LT, 30x60 km • TEMIS (KNMI, The Netherlands) • monthly grid data • cloud-free & nearly cloud-free (cloud radiance <50%)
Distributions of NOx emissions in GFEDv2 Target region WS ES FES KAM + Rishiri Island • FES (Far-Eastern Siberia) & ES (Eastern Siberia) • “low-fire-year”: 1999, 2000, 2001, 2004 = reference • “high-fire-year”: 1998, 2002, 2003
Anomalies in trop. NO2 column GEOS-Chem NOx GOME/SCIA NO2 GFEDv2 NOx emis. 1998 JAS • Locations of NOx enhancement are consistent for satellites and G-C 2002 JAS 2003 AMJ
GOME/SCIA vs. GEOS-Chem Satellites / GEOS-Chem • Satellites can detect NOx emissions from “large” and “medium” scale fires • GEOS-Chem agrees well with satellites in a qualitative manner
Anomalies in surface ozone, obs vs. G-C Rishiri Island, Japan (45N, 141E) Rishiri Is. • G-C did a good job in reproducing anomalies observed at Rishiri • Summary • GOME/SCIA can detect NO2 enhancement from boreal fires in Siberia • G-C reproduces NOx enhancement – need more quantitative evaluations (sampling time, 2x2.5 grid, etc) • G-C well reproduces O3 anomalies at Rishiri Island in BB-years
Anomalies in ozone by G-C, alt.-lat cross section 120 degE 140 degE (Rishiri) 155 degW (Barrow) 1998 Rishiri Barrow 2002 2003
Trop. NO2 column over Siberia viewed from space Mean (summer, 1999, 2000, 2001, 2004) • In general, NO2 is very low over Siberia, due to small anth. activities • Enhancement of NO2 is negligible in “low-fire-year”
Trop. NO2 columns in 1998, 2002, 2003 1998 summer 2002 summer • Weak but significant enhancement of NO2 in 1998, 2002, 2003 • Locations of NO2 enhancements differ depending on year 2003 spring