FOREST FIRE AEROSOLSOptical and microphysical properties from

EARLINET observations

D. BalisLaboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece

Contributions from

E. Giannakaki (AUTH), V. Amiridis (NOA), A. Papayannis, R. Mamouri (NTUA), I. Mattis, D. Mueller (IfT), L. Mona (CNR-IMAA)

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Outline

Fire sources affecting Europe

Tools for smoke identification

Optical properties for smoke from EARLINET observations

Microphysical retrievals for smoke within EARLINET

Effects of ageing of smoke plume

Summary

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Systematic sources affecting Europe

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forest

agricu lture

w etlands

grasslands

other

Thessaloniki

Longitude (degrees)

Latit

ude

(deg

rees

)

In Europe In N. America

In SiberiaRegional scale example (August 2007)

Tools for identification of fire sources and the possibility of advection over a lidar station

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Emission sensitivity obtained from 20-day backward simulations with FLEXPART

MODIS rapid response system

World Fire Atlas (ATSR)

HYSPLIT-backtrajectories

Optical properties for smoke from EARLINET observations

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10 15 20 25 30 35 40 45LO NG ITUDE, d e g re e s

25

30

35

40

45

50

55

60

LATIT

UDE,

de

gre

es

1000

900

800

700

600

500

400

300

200

100

PRES

SURE

, hPa

-96 -72 -48 -24 0TIM E, ho urs

ANALYTIC AL BAC KTRAJ EC TO RIESd a ta p ro vid e d b y the G e rm a n We a the r Se rvic e

THESSALO NIKI, 19 UTC 09.08.01

975 hPa

850 hPa

700 hPa

500 hPa

300 hPa

200 hPa

Thessaloniki, 9 August 2001

Smoke originating mainly from Russia’s Agricultural District and other regional sources

Example of 3+2 lidar retrievals of extinction and backscatter for a smoke case study (Mueller et al., 2004)

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Canadian fires detected overLeipzig June 2003

0

2

4

6

8

10

0.000 0.002 0.004

CNR-IMAA - Potenza, Italy, (40.60°N, 15.73°E) 10 September 2009, 19:12 - 19:42 UTC

355nm 532nm 1064nm

Back. Coeff.

(sr-1km-1)

He

igh

t a

.s.l. (k

m)

0.00 0.10 0.20 0.30Ext. Coeff.

(km-1)

0 60 120Lidar Ratio

(sr)

-2 0 2 4

Angströmexponent

Possible intrusion of forest fires particles coming from East Mediterranean region.

It is also possible a mixture with forest fires particles coming from North US –Canada

Detection very close to the source

Athens27-30 August 2007

0

1

2

3

4

5

6

7

0 200 400 0 2 4 6 80

1

2

3

4

5

6

7

0 40 80 1200

1

2

3

4

5

6

7

-1 0 1 2 3

AOT355=1.04AOT532=0.78

27 AUGUST 2007 22:07- 00:30 UTC

ALTI

TUDE

A.S

.L. [m

]

EXTICNCTION COEFFICIENT [Mm] BACKSCATTER COEFFICIENT [Mm-1sr-1] LIDAR RATIO [sr] ANGSTROEM EXPONENT

1064nm

532nm

355nm

83 ± 11

95 ± 16

Ab [uv-vis] Aa [uv-vis]

1.27 ± 0.33

0.49 ± 0.43

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

0 200 400 600 8000

1

2

3

4

5

6

7

0 3 6 9 120

1

2

3

4

5

6

7

0 1 2 3 4 50

1

2

3

4

5

6

7

0 30 60 90 1200

1

2

3

4

5

6

7

0 1 2 3 4

12 SEP 2005 01 AUG 2005 28 JUL 2005 22 AUG 2002 08 JUL 2002 20 AUG 2001 16 AUG 2001 09 AUG 2001 16 JUL 2001 12 JUL 2001

355 nm

EXT. COEF. [Mm-1

]

HE

IGH

T[k

m]

355 nm

BSC. COEF. [Mm-1

sr-1

]

5 3 2 n m

BSC. COEF. [Mm-1

sr-1

]

3 5 5 n m

LIDAR RATIO [sr]

b355 nm - b532 nm

ANGSTRÖM EXP.

Wide range of optical properties for 10 smoke cases (identified with FLEXPART ) over Thessaloniki (Amiridis et al., 2009)

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Microphysical retrievals for smoke within EARLINET

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Muller et al. JGR, 2005Muller et al. JGR, 2005

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Balis et al., JGR, 2010

Variation of microphysical properties for smoke cases studied within EARLINET

The wide range of the values could be attributed on the source type or on ageing of the source plumes

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Mueller et al. personal communication)

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Date RegionLidar Ratio

SSAAerosol

IndexAOD @ 355nm

Ångstromexponent

Color Index

12 Jul 2001 RAD 95 - 0.27 - - 0.61

16 Jul 2001 RAD 75 0.96 -0.35 0.85 1.6 1.26

09 Aug 2001 RAD 57 - 0.86 1.52 1.3 1.33

16 Aug 2001 RAD 87 0.95 -0.53 0.62 1.3 1.29

20 Aug 2001 RAD 67 0.95 0.49 0.99 1.43 0.29

08 Jul 2002 RAD 72 0.99 0.29 0.51 1.1 0.26

22 Aug 2002 Portugal 46 - -0.18 0.52 2.2 2.12

28 Jul 2005 RAD 55 0.98 -0.78 0.93 1.3 1.82

01 Aug 2005 RAD 85 0.95 -0.3 0.85 1.5 1.26

12 Sep 2005 Portugal 58 0.96 -1.51 0.7 1.2 1.57

Possible differences in optical and microphysical propertiesdue to the source?

RegionRegion Lidar RatioLidar Ratio SSASSA AODAOD ÅngstromÅngstrom Color Color IndexIndex

RADRAD 74 ± 14 0.96 ± 0.01 0.89 ± 0.32 1.36 ± 0.16 1.26 ± 0.36

PortugalPortugal 52 ± 8 0.96 0.61 ± 0.12 1.7 ± 0.7 1.84 ± 0.38

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Smoke plumes can travel for many days in the free troposphere(e.g. Damoah et al. ACP, 2004)

Simulated total CO columns (ECMWF and GFS)

0 2 4 80

1

2

3

4

5

6

7

8

9

10

C O M ixing R atio [ppb]

Age [days]

Thessaloniki, 20/08/2001

0 2 4 6 8 10 12 14 16 18 20

Hei

ght

, asl

[m]

6

For the same source (e.g. Eastern Europe). The age of the travelling smoke plume should be the reason for the wide range of values.

Use of CO age from FLEXPART to estimate the age of the smoke plume. Model calculations were performed considering CO emissions only from fire hotspots detected by ATSR.

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0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 10 20 30 40 50 60 70 80 90 100 110 120

Correlation Coefficient = -0.84

Lidar Ratio @ 355 nm (sr)

Bsc

. An

gst

rom

Exp

. [3

55

/ 53

2 n

m]

Vertical mean values of the backscatter related Ångström exponent calculated from the backscatter coefficients at 355 and 532 nm versus vertical mean values of the lidar ratio at 355 nm, calculated for the same height ranges of smoke presence

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5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 200.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Correlation Coefficient = -0.85

Bsc

. Ang

stro

m E

xp. [

355

/ 532

nm

]

Age of Carbon Monoxide from fire emissions [days]

Vertical mean values of the backscatter related Ångström exponent calculated from the backscatter coefficients at 355 and 532 nm versus weighted mean age of the carbon monoxide tracer, calculated for height ranges of smoke presence

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Mueller et al., JGR 2007

Summary

• EARLINET stations are systematically affected by forest fires (Russia, Siberia, N. Canada, Portugal, regional ones)

• Smoke plumes can travel for many days in the free troposphere and can result to very high optical depths and extinction coefficients (1.7 and 400 Mm-1 respectively)

• Estimated optical and microphysical properties for smoke show a wide range of values (lr355=30-90 sr, lr532=40-100sr, lr355/lr532<1,

Åa(355/532)=0.5-1.5, reff=0.2-0.4 μm, ssa: the majority of cases 0.9-0.95)

• The ageing of the smoke plume and/or different source type can explain part of the observed variability

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Thank you for your attention!

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