durant_goldschmidt_20110817x - NILU

kayakjokeΜηχανική

22 Φεβ 2014 (πριν από 3 χρόνια και 6 μήνες)

95 εμφανίσεις

Adam Durant and Fred
Prata



adu@nilu.no


Norsk

institutt

for
luftforskning

(NILU)

Norwegian Institute for Air Research


Nicarnica

Aviation A.S.

17 Aug 2011

1

Advances in understanding of atmospheric impacts of
volcanic ash emissions since
Eyjafjallaj
ö
kull

2010

Volcanic ash clouds

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

2

2

ELEMENTS, VOL. 6, PP. 235

240

Durant, A.J.,
Bonadonna
, C.,
Horwell
, C.J., (2010),
Atmospheric and
Environmental Impacts of Volcanic Particulates.
Elements

6
, 235
-
240.

Airborne ash measurement

3

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

4

AIRS

4 June 2011


15 June 2011

Prata
, A.J., (1989),
Infrared
Radiative
-
Transfer Calculations for Volcanic Ash Clouds.
Geophys
. Res.
Lett
.
16
, 1293
-
1296.

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

5

AIRS

16 June 2011


21 June 2011

Prata
, A.J., (1989),
Infrared
Radiative
-
Transfer Calculations for Volcanic Ash Clouds.
Geophys
. Res.
Lett
.
16
, 1293
-
1296.

Global ash particle fluxes

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

6

Global annual
flux of fine ash
(< 63 µ
m
):


~ 176
-
256
Tg


Durant, A.J.,
Bonadonna
, C.,
Horwell
, C.J., (2010),
Atmospheric and
Environmental Impacts of Volcanic Particulates.
Elements

6
, 235
-
240.

Pinatubo, 1991

Toba, 74 ka

MSH, 1980

Inversion technique to reduce
emission uncertainty


A priori source information


Satellite retrievals


Lagrangian

dispersion model output


Result:
refinement of volcanic ash source
strength as a function of altitude and time



17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

7

Stohl
, A.,
Prata
, A.J.,
Eckhardt
, S., Clarisse, L., Durant, A.,
Henne
, S., Kristiansen, N.I.,
Minikin
, A., Schumann, U., Seibert, P.,
Stebel
, K., Thomas, H.E.,
Thorsteinsson
, T.,
Torseth
, K.,
Weinzierl
, B., (2011)
: Determination of time
-

and height
-
resolved volcanic
ash emissions for quantitative ash dispersion modeling: the 2010
Eyjafjallajokull

eruption.
Atmos. Chem. Phys. Discuss.

11
, 5541
-
5588.

Emission profile refinement

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

8

A priori






A posteriori

Correlation with airborne
in situ

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

9

19 April 2010

DLR FALCON



A posteriori

inversion results (ECMWF data)
reduced root
-
mean
-
square (RMS) error by 28
% compared to satellite ash total columns


Ash lifetime reduced by aggregation

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

10

260
m
m

325
m
m

Particles: 0.6
-
120
m
m

Particles: 2
-
40
m
m

Particles: 1
-
10
m
m

700
m
m

Particles: 1
-
50
m
m

(
courtesy

Costanza
Bonadonna
)

Eyjafjallajokull

5
-
7 May 2010


R.J. Brown, C.
Bonadonna
, A.J. Durant (2011,

sub
judice
)
, A Review of Volcanic Ash
Aggregation,

J. Phys. Chem. Earth

(Ash Special Issue).


W.I. Rose and A.J. Durant (2011, in press),
Fate of volcanic ash: Aggregation and
fallout,
Geology
,
39
(
9
), 895

896,
doi
: 10.1130/focus092011.1.


J.
Taddeucci

et al. (2011, in press),
Aggregation
-
dominated ash settling from the
Eyjafjallajökull

volcanic cloud illuminated by field and laboratory high
-
speed
imaging,

Geology
,
39
(
9
), 891

894, doi:10.1130/G32016.1.


C.
Bonadonna

et al. (2011,
sub
judice
)
,
Tephra

sedimentation during the 2010
Eyjafjallajökull

eruption (Iceland) from deposit, radar and satellite observations,
J.
Geophys
. Res.


Ash impacts microphysical processes

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

11

Thanks to:

IMO, Iceland

Sigrún

Karlsdóttir
,
Þórarinn

H.
Harðarson

University of Iceland

Magnús

Tumi

Guðmundsson

May 2011
Grímsvötn

eruption (
www.visir.is
)

Mammatus

= water/ice and
turbulent clustering

Grímsvötn

Volcanogenic hailstones

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

12

Grimsvotn

2011 (<20 km)


Durant, A.J., Shaw, R.A., Rose, W.I., Mi, Y., Ernst, G.G.J. (
2008
),
Ice nucleation and
overseeding

of ice in volcanic clouds,

J.
Geophys
. Res.
-
Atmos
.
113
,

doi
:
10.1029
/
2007
JD
009064
.


H.
Bingemer

et al. (
2011
),
Atmospheric ice nuclei in the
Eyjafjallajokull

volcanic ash
plume,
Atmos. Chem. Phys. Discuss
.,
11
,
2733

2748
.


I. Steinke et al. (
2011
),

Ice nucleation properties of fine ash particles from the
Eyjafjallajö
kull

eruption in April
2010
,
Atmos. Chem. Phys. Discuss.
,
11
,
17665

17698
,
2011
.


Outstanding questions

1.
What are the mechanisms that drive
aggregation? What controls the rate of fine ash
aggregation?


changes in aggregate morphology with distance


fraction of external water


1.
What is the role in cloud microphysical
processes?


locally (ash lifetime, sedimentation)


globally (ash fluxes, cloud hydrometeor formation, e.g.,
impact on Earth
albedo
?)

17 Aug 2011

Durant and
Prata

|
adu@nilu.no

| Goldschmidt 2011

13

Summary


Global annual flux of volcanic particulates is
poorly known


Eruption source term has high uncertainty


Inversion methodology (
Stohl

et al. 2011)
improves quantification of ash particle fluxes


Microphysics and aggregation strongly
influence fine ash sedimentation and
atmospheric lifetime (not currently
modelled
)

17
Aug
2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

14

NILU Volcanic Ash Cloud Group



NILU


Inversion methodology
:

Andreas
Stohl
,

Sabine Eckhart,

Fred
Prata
, Nina Kristiansen


A
irborne
V
olcanic
O
bject
I
dentifier
D
etector
:

Fred
Prata
,
Cirilo

Bernardo



easyJet

Ian Davies


17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

15


17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

16

Ice nucleation by ash

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt
2011

17

253.1 K (σ = 2.1)

Steinke et al., ACPD 11, 2011

(immersion < 252 K)

(deposition < 242 K)

Durant, A.J., Shaw, R.A., Rose, W.I., Mi, Y., Ernst, G.G.J., 2008
J.
Geophys
. Res.
-
Atmos
. 113,
doi
: 10.1029/2007JD009064

Correlation with space
-
borne
lidar

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt
2011

18

03:00
-
04:00 UTC


03:00
-
04:00 UTC



10:00
-
13:00 UTC

Contours
(model):


black


20
µ

gm
-
3


white


200
µ

gm
-
3

Attenuated backscatter at 532 nm

Error reduction (%)

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

19

Satellite retrieval

17 Aug 2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

20

SEVIRI

5 June 2011


6 June 2011

Prata
, A.J., (1989),
Infrared
Radiative
-
Transfer Calculations for Volcanic Ash Clouds.
Geophys
. Res.
Lett
.
16
, 1293
-
1296.

Inversion methodology

17
Aug
2011

Durant and Prata | adu@nilu.no | Goldschmidt 2011

21

Source
-
receptor matrix calculation with a
Lagrangian

particle dispersion
model in backward mode, P. Seibert and A. Frank, ACP, 4, 51
-
63, 2004.

3840 Images

SEVIRI

IASI

122 Images

FLEXPART

6232 Runs