Integrazione di tecniche di osservazione per la...

Società Italiana di Fisica , XCVI Congresso Nazionale 20-24 settembre 2010, Bologna, Italia

Integrazione di tecniche di osservazione per la

caratterizzazione di aerosol di origine vulcanica

Amodeo Aldo, Boselli Antonella, D'Amico Giuseppe, Giunta Aldo,

Madonna Fabio, Mona Lucia, Pappalardo Gelsomina

Consiglio Nazionale delle Ricerche – Istituto di Metodologie per l’Analisi

Ambientale (CNR-IMAA), Potenza, Italy

[email protected]


Summary

CNR-IMAA Atmospheric Observatory

The lidar observations for the volcanic aerosol study

The synergy of instruments in the observation of the volcanic aerosol

Conclusions and future work


CNR-IMAA Atmospheric Observatory

PEARL multi-wavelength Raman lidar (EARLINET)

Mobile aerosol multi-wavelength Raman lidar (EARLINET QA

reference system)

Cloud-radar (METEK MIRA-36)

Microwave profiler 12 channels (Radiometrics MP3014)

Radiosounding systems (P,T, RH, O3

and wind) RS92-Vaisala

CIMEL sunphotometer (AERONET)

Ceilometer (Jenoptik CHM15k)

Ceilometer (VAISALA CT25K)

Automatic surface radiation station (2Pyranometers, 1pyrgeometer,

1perieliometer)

Automatic weather stations

GPS antenna/receiver (for precipitable water vapor)


Networks

–EARLINET (European Aerosol Research LIdar NETwork)

–AERONET (Aerosol Robotic Network)

–Cloudnet (Development of a European pilot network of stations for observing cloud profiles)

EC projects

- EARLINET-ASOS (Advanced Sustainable Observation System) 2006-2011

- GEOMON (Global Earth Observation and Monitoring of the atmosphere) 2007-2011

ESA projects

- ESA-ESTEC “Aerosols and Clouds: Long Term Database from Spaceborne Lidar

Measurements” (2008-2010)

- ESA-ESRIN VALID “MULTI-MISSION QUALITY ANALYSIS BY LIDAR” (2008-2013)

- ESA-ESRIN CEOS (Committee on Earth Observation Satellites) intercalibration of

groundbased spectrometers and lidar (2008 – 2013)

CAL/VAL programs

- ENVISAT

- CALIPSO

- Next: ADM-Aeolus and EarthCARE

WMO

- GAW-GALION (Global Atmospheric Watch - LIdar Observation Network)

- WMO Sand and Dust Storm Warning System (SDSWS)

Special Measurement Campaigns: ICARTT, EAQUATE, LAUNCH-2005, COPS-2007, LUAMI-2008,

EARLI2009

Main involvements


LASER: ND:YAG (Continuum Powerlite Precision II 9050)Max. pulse energy : 1200mJ @1064nm

600mJ @532nm350mJ @355nm

Max. repetition rate 50HzBeam divergence 0.25 mrad(beam expander 2X with remixing)

RECEIVER: Cassegrain TelescopeDiameter of the primary mirror 0.5 mCombined focal length 5 mNighttime field of view 1 mradAchromatic lens Ø=2”, f=50cm

CHANNEL SELECTIONInterference filters (FI), bandwidth 0.5 nmPolarizer beam splitter (BK7) a 532 nm (POL)Dichroic mirrors (DM e HT)Selection of high and low altitude channels

ACQUISITIONFotomultipliers (PMT) THORN EMI9202QA 532, 532, 532, 607 nm9893/350B 355, 386 nmEG&G MCS – PCI (100ns min dwell time, 150MHz photon counting)APD 1064 nm Licel Transient recorder (12bit 20 MHz analogic, 250 MHz photoncounting)

Operational since 2000 (upgrade in 2005 of a pre-existing lidar system)

Potenza EArlinet Raman Lidar (PEARL)


CNR-IMAA EARLINET Mobile Reference System

LASER: ND:YAG (Continuum Surelite II-20)Max. pulse energy : 550mJ @1064nm

250mJ @532nm120mJ @355nm

Max. repetition rate 20HzBeam divergence 0.6 mrad

RECEIVER: Cassegrain TelescopeDiameter of the primary mirror 0.3 mCombined focal length 950 mmNighttime field of view 1 mradAchromatic lens Ø=9mm, f=100mm

CHANNEL SELECTIONInterference filters (FI), bandwidth 0.5 nmPolarizer beam splitter (BK7) at 532 nm (POL)Dichroic mirrors (DM e HT)

ACQUISITIONFotomultipliers (PMT), HamamatsuR7400P-06 355, 387, 532, 532 nmR7400U-20 607nmAPD 1064nmLicel Transient recorder (12bit 40 MHz analogic, 250 MHz photoncounting)

Operational since April 2009


K-band channels = 22.235, 23.0335,

23.835, 26.235, 30 GHz

V-band channels = 51.250, 52.280,

53.850, 54.940, 56.660, 57.290,

58.800 GHz

Rate: > 12 s

Accuracy: 0.5 K

Resolution: 0.25 K

Output products (Neural network

retrieval)

Temperature, water vapour, relative

humidity and

cloud liquid water profiles up to 10 km

above the ground

Operational since February 2004

MP3014 Microwave profiler


0

2

4

6

8

10

12

14

16

18

20

0 20 40 60 80 100

Umidità relativa (%)

Qu

ota

a.s

.l.

(km

)

RS92

RS80

RS80corr

0

2

4

6

8

10

12

14

16

18

20

-80 -60 -40 -20 0 20 40

Temperatura (°C)

Qu

ota

a.s

.l.

(km

)

RS92

RS80

a) b)

Radiosoudings

AS 13 Autosonde system (October 2004)

MW 21 manual system (July 2004)

PP15 manual system (January 1994)


Hail

•Vertically pointing (ground based,

scanning unit)

• Ka-Band 35.5 GHz 8.6 mm

• Magnetron based, 30 kW Pulse Power

• Range resolution 30 m (w.o. pulse comp.)

• Dual polarization receiver

• -45 dBZ @ 10 km and 10 s Averaging

• PRF = 5 kHz +/- 11 m/s

Operational since February 2009

MIRA 36 GHz doppler radar


CT25K 905 nm ceilometer

Operational since August 2004

CHM15K 1064 nm ceilometer

Operational since July 2009

Ceilometers


Specifications• Multi-channel sun photometer operating at 340, 380, 440, 675, 870, 1020, 1640 nm

•Optical head with 2 collimators

•FOV: Solar collimator: 1.2°

Sky collimator: 1.2°

•Bandwidth: 10 nm at full width at half maximum

•Detector: UV enhanced silicon detector for the sun radiance

•Silicon detector for the sky radiance

•Automatic operations and fully autonomous (power supply from solar panels)

The sun phtometer is operating within AERONETnetwork and the measured radiances are processed atthe NASA GSFC. All the data are available athttp://aeronet.gsfc.nasa.gov

Operational since November 2004.

CIMEL CE318 sunphotometer

Main AERONET products (quality assured lv2.0)

1. Aerosol optical depth at 340, 380, 440,500, 675, 870, 1020, 1640 nm

2. 870-440 nm Ångström coefficient

3. Integrated water vapour

4. Single scattering albedo

5. Refractive index

6. Size distribution


Automatic surface radiation station. The station is designed according to the BSRN requirements

and it is equipped with the following sensors:

Instrument Spectral Range Sensitivity_

Pyrheliometer CH1 200 - 4000 nm (50 % points) 11 μV/W/ m2

Pyrgeometer CG4 4.5 - 42 μm 10 μV/W/ m2

2 Pyranometer CM22 200 - 3600 nm (50% points) 10 μV/W/m2

The sensors are automatically managed by a sun tracker.

Operational since May 2005.

Radiation measurements

1500 1600 1700 1800

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

LW

Longwave hemispheric radiation net IR / Shortwave hemispheric irradiance

Tito Scalo 07/06/2005

Irra

dia

nce

(W

/(m

2 n

m))

Time UTC

-10

0

10

20

30

40

50

SW


Volcanic plume transported from Iceland observed over Potenza

0

2

4

6

8

10

0.000 0.002 0.004 0.006

PEARL - Potenza, Italy, (40.60°N, 15.73°E), 20 April 2010, 21:00 - 23:05 UTC

355

532

1064

Back. Coeff.

(sr-1km

-1)

He

igh

t a

.s.l. (k

m)

0.00 0.05 0.10 0.15 0.20

Ext. Coeff.

(km-1)

0 60 120

Lidar Ratio(sr)

-2 0 2 4

Angströmexponent

0.00 0.05 0.10

MUSA PEARL

Volume Depolarizatio ratio

The most intense

aerosol return

above the PBL is

observed on 20

April around 22:20

UT at about 4 km

a.s.l. Ancillary

information confirm

the volcanic origin

of the selected

layer.



0

2

4

6

8

10

0.000 0.002 0.004 0.006

PEARL - Potenza, Italy, (40.60°N, 15.73°E), 20 April 2010, 21:00 - 23:05 UTC

355

532

1064

Back. Coeff.

(sr-1km

-1)

He

igh

t a

.s.l. (k

m)

0.00 0.05 0.10 0.15 0.20

Ext. Coeff.

(km-1)

0 60 120

Lidar Ratio(sr)

-2 0 2 4

Angströmexponent

0.00 0.05 0.10

MUSA PEARL

Volume Depolarizatio ratio

Volcanic layer (3.25-4.97 km a.s.l.)

S (lidar ratio) @355nm = 37 6 sr

AOD @355 nm= 0.07

Lower altitude layer (2.3 - 3.2 km

a.s.l.)

S @532nm = 49 3 sr

S @355nm = 43 3sr

AOD @532nm= 0.03

AOD @355nm= 0.06

Ångström 355/532nm = 1.3 0.2

PBL (2.2 km a.s.l.)

S @532nm = 58 8 sr

S @355nm = 50 7sr

AOD @532nm= 0.19

AOD @355nm= 0.25

Ångström 355/532nm = 1.3

0.3



The temporal

evolution of RCS

@1064 nm shows

that the volcanic

layer goes down in

altitude mixing with

the underlying local

aerosol layer.

0

2

4

6

8

10

12

14

0.000 0.002 0.004

PEARL - Potenza, Italy, (40.60°N, 15.73°E), 21-22 April 19:06-03:09 UTC

355

532

1064

Back. Coeff.

(sr-1km

-1)

He

igh

t a

.s.l. (k

m)

0.00 0.05 0.10 0.15 0.20

Ext. Coeff.

(km-1)

0 60 120

Lidar Ratio(sr)

-2 0 2 4

Angströmexponent

0.0 0.1

Volume Depolarizationratio

Volcanic-local mixed layer

(1.9 -3.8 km a.s.l.)

S @532nm = 81 14 sr

S @355nm = 80 12sr

AOD @532nm= 0.05

AOD @355nm= 0.08

Ångström 355/532nm = 1.0 0.3

PBL (1.9 km a.s.l.)

S @532nm = 71 2 sr

S @355nm = 78 3 sr

AOD @532nm= 0.12

AOD @355nm= 0.18

Ångström 355/532nm = 1.3

0.1


0.1 1 10

0.00

0.01

0.02

0.03

0.04

0.05

dV

(r)/

dln

(r)

[m

3/

m2]

Radius [m]

April20 April21

AERONET data

104 105 106 107 108 109 110 111 112

0.0

0.5

1.0

1.5

2.0

14 April 18 April 22 April

Julian Day

Angstrom 380-500 nm

Fine Mode Fraction 500nm

AERONET Sun-photometer data show an increase in columnar Angstrom exponent starting

from 20 April , i.e. corrispondence of arrival of volcanic plume over Potenza. The size

distributions, resulting from the Level 1.5 inversion on daily product, for 20-21 April 2010,

show that on 21 April the fine mode is less populated respect to 20 April in agreement with

the increase in particle size observed with lidar on 21 April evening.


Microwave radiometer data

This increase in particle size could be related to the hygroscopicity of the ash particles and to

the fact that, on 21 April evening, the volcanic + local aerosols are located between 1.9 and

3.8 km asl where the atmosphere is more humid (~60%) than on 20 April at 3.2-5 km (~20%)

when the pure volcanic ash layer was observed.

20 April 21 April


Comparison of the co-located measurements

performed using the radar and the lidar

Radar MIRA-36

time series of the vertical

profile of the linear

depolarization ratio

Lidar

time series of the lidar range-

corrected signal at 1064 nm

19:00 - 22:00 UTC , 19 April 2010

F. Madonna, et al.,, GRL (accepted, 2010)


Conclusions and future activities

The synergy of a variety of atmospheric observation instruments

can give a more complete characterization of volcanic aerosol

(optical and microphysical properties, igroscopicity)

Next

Complete the analysis

Integration of lidar/sunphotometric observations and

improvement of the retrieval of microphysical properties

Mass conversion, model evaluation, integration with in-situ

observations, satellite (CALIPSO and not only)


ACKNOWLEDGMENTS

European Commission grant RICA-025991 EARLINET-ASOS

NOAA Air Resources Laboratory (ARL)

Barcelona Supercomputing Center for DREAM forecasts

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