Satellite and model analysis of wildfire NOx emissions in Siberia: Links to interannual variabilit

y of surface ozone, 1998–2004

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

Photo: Siberia (courtesy of T. Machida)

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.

150

100

50

0CO

(ppb

v)

20052004200320022001200019991998

Year

Monthly mean anomaly

-10

-5

0

5

10

Ozo

ne (p

pbv)

20052004200320022001200019991998

Year

Monthly mean anomaly

O3 enhancement in “fire plumes” Cheeka Peak (Jaffe et al.), Pico-NAR

E (Val Martin, Honrath, et al.), Rishiri (Tanimoto et al.), etc

O3 “background-levels” Mace Head (Simmonds et al.), Pico-N

ARE (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

Rishiri Island, Japan

Questions & Tools

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%)

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?

Distributions of NOx emissions in GFEDv2

Rishiri Island

KAMFESESWS

+

Target region

1250

1000

750

500

250

0

NO

x em

issi

ons

(Gg)

20052004200320022001200019991998

Year

Whole Siberia WS ES FES KAM

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

1998JAS

2002JAS

2003AMJ

GFEDv2 NOx emis.GOME/SCIA NO2 GEOS-Chem NOx

Locations of NOx enhancement are consistent for satellites and G-C

0.30

0.20

0.10

0.00

-0.10

Tro

p. N

O2 (

101

5m

ole

c/cm

2)

2004200320022001200019991998

Year

0.75

0.50

0.25

0.00

-0.25

NO

x in BL (ppbv)

September

0.30

0.20

0.10

0.00

-0.10

Tro

p. N

O2 (

101

5m

ole

c/cm

2)

2004200320022001200019991998

Year

0.75

0.50

0.25

0.00

-0.25

NO

x in BL (ppbv)

August

0.30

0.20

0.10

0.00

-0.10

Tro

p. N

O2 (

101

5m

ole

c/cm

2)

2004200320022001200019991998

Year

0.75

0.50

0.25

0.00

-0.25

NO

x in BL (ppbv)

July

0.30

0.20

0.10

0.00

-0.10

Tro

p. N

O2 (

101

5m

ole

c/cm

2)

2004200320022001200019991998

Year

0.75

0.50

0.25

0.00

-0.25

NO

x in BL (ppbv)

May

GOME/SCIA vs. GEOS-Chem

Satellites can detect NOx emissions from “large” and “medium” scale fires GEOS-Chem agrees well with satellites in a qualitative manner

Satellites / GEOS-Chem

Anomalies in ozone by G-C, surface level (L=1)Rishiri

20

15

10

5

0

-5

-10

Ozo

ne (

ppb

v)

20052004200320022001200019991998 Year

Surface observations, RIS GEOS-Chem, 45N, 141E

Anomalies in surface ozone, obs vs. G-C

G-C did a good job in reproducing anomalies observed at Rishiri

Rishiri Island, Japan (45N, 141E)

Rishiri Is.

Summary GOME/SCIA can detect NO2 enhancement from boreal fires in Siberia G-C reproduces NOx enhancement – need more quantitative evaluati

ons (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 section120 degE 140 degE (Rishiri) 155 degW (Barrow)

1998

2002

2003

Rishiri Barrow

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

Weak but significant enhancement of NO2 in 1998, 2002, 2003

Locations of NO2 enhancements differ depending on year

1998 summer

2003 spring

2002 summer