Integrazione di tecniche di osservazione per la caratterizzazione di aerosol di origine vulcanica

Transcription

1 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 amodeo@imaa.cnr.it

2 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

3 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, O 3 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)

4 Main involvements 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) GEOMON (Global Earth Observation and Monitoring of the atmosphere) ESA projects - ESA-ESTEC Aerosols and Clouds: Long Term Database from Spaceborne Lidar Measurements ( ) - ESA-ESRIN VALID MULTI-MISSION QUALITY ANALYSIS BY LIDAR ( ) - ESA-ESRIN CEOS (Committee on Earth Observation Satellites) intercalibration of groundbased spectrometers and lidar ( ) 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

5 Potenza EArlinet Raman Lidar (PEARL) LASER: ND:YAG (Continuum Powerlite Precision II 9050) Max. pulse energy : Max. repetition rate 50Hz Beam divergence 0.25 mrad (beam expander 2X with remixing) RECEIVER: Cassegrain Telescope Diameter of the primary mirror Combined focal length Nighttime field of view Achromatic lens 0.5 m Ø=2, f=50cm 5 m 1 mrad CHANNEL SELECTION Interference filters (FI), bandwidth 0.5 nm Polarizer beam splitter (BK7) a 532 nm (POL) Dichroic mirrors (DM e HT) Selection of high and low altitude channels ACQUISITION Fotomultipliers (PMT) THORN EMI 9202QA 532, 532, 532, 607 nm 9893/350B 355, 386 nm EG&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)

6 CNR-IMAA EARLINET Mobile Reference System LASER: ND:YAG (Continuum Surelite II-20) Max. pulse energy : Max. repetition rate 20Hz Beam divergence 0.6 mrad RECEIVER: Cassegrain Telescope Diameter of the primary mirror Combined focal length Nighttime field of view Achromatic lens 0.3 m 950 mm 1 mrad Ø=9mm, f=100mm CHANNEL SELECTION Interference filters (FI), bandwidth 0.5 nm Polarizer beam splitter (BK7) at 532 nm (POL) Dichroic mirrors (DM e HT) ACQUISITION Fotomultipliers (PMT), Hamamatsu R7400P , 387, 532, 532 nm R7400U nm APD 1064nm Licel Transient recorder (12bit 40 MHz analogic, 250 MHz photoncounting) Operational since April 2009

7 MP3014 Microwave profiler K-band channels = , , , , 30 GHz V-band channels = , , , , , , 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

8 Quota a.s.l. (km) Quota a.s.l. (km) Radiosoudings AS 13 Autosonde system (October 2004) MW 21 manual system (July 2004) PP15 manual system (January 1994) RS92 RS80 RS80corr a) b) RS92 RS Umidità relativa (%) Temperatura ( C)

9 MIRA 36 GHz doppler radar 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 km and 10 s Averaging PRF = 5 khz +/- 11 m/s Operational since February 2009 Hail

10 Ceilometers CT25K 905 nm ceilometer Operational since August 2004 CHM15K 1064 nm ceilometer Operational since July 2009

11 CIMEL CE318 sunphotometer Operational since November 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 AERONET network and the measured radiances are processed at the NASA GSFC. All the data are available at Main AERONET products (quality assured lv2.0) 1. Aerosol optical depth at 340, 380, 440,500, 675, 870, 1020, 1640 nm nm Ångström coefficient 3. Integrated water vapour 4. Single scattering albedo 5. Refractive index 6. Size distribution

12 Irradiance (W/(m 2 nm)) Radiation measurements 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 CH nm (50 % points) 11 μv/w/ m2 Pyrgeometer CG μm 10 μv/w/ m2 2 Pyranometer CM nm (50% points) 10 μv/w/m2 The sensors are automatically managed by a sun tracker. Operational since May Longwave hemispheric radiation net IR / Shortwave hemispheric irradiance Tito Scalo 07/06/ LW SW Time UTC

13 Height a.s.l. (km) Volcanic plume transported from Iceland observed over Potenza 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. 10 PEARL - Potenza, Italy, (40.60 N, E), 20 April 2010, 21:00-23:05 UTC MUSA PEARL Back. Coeff. (sr -1 km -1 ) Ext. Coeff. (km -1 ) Lidar Ratio (sr) Angström exponent Volume Depolarizatio ratio

14 Height a.s.l. (km) Volcanic plume transported from Iceland observed over Potenza 10 PEARL - Potenza, Italy, (40.60 N, E), 20 April 2010, 21:00-23:05 UTC Back. Coeff. (sr -1 km -1 ) Ext. Coeff. (km -1 ) Lidar Ratio (sr) Angström exponent Volcanic layer ( km a.s.l.) MUSA S (lidar PEARL = 37 nm= Volume Depolarizatio ratio 6 sr Lower altitude layer ( km a.s.l.) = 49 3 sr = 43 3sr Ångström 355/532nm = PBL (2.2 km a.s.l.) = 58 8 sr = 50 7sr Ångström 355/532nm =

15 Height a.s.l. (km) Volcanic plume transported from Iceland observed over Potenza The temporal evolution of nm shows that the volcanic layer goes down in altitude mixing with the underlying local aerosol layer. PEARL - Potenza, Italy, (40.60 N, E), April 19:06-03:09 UTC Back. Coeff. (sr -1 km -1 ) Ext. Coeff. (km -1 ) Lidar Ratio (sr) Angström exponent Volcanic-local mixed layer ( km a.s.l.) = sr = 80 12sr Ångström 355/532nm = Volume Depolarization ratio PBL (1.9 km a.s.l.) = 71 2 sr = 78 3 sr Ångström 355/532nm =

16 dv(r)/dln(r) [ m 3 / m 2 ] AERONET data 2.0 Angstrom nm Fine Mode Fraction 500nm 0.05 April20 April April 18 April 22 April Julian Day Radius [ m] 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 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.

17 Microwave radiometer data 20 April 21 April 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 km (~20%) when the pure volcanic ash layer was observed.

18 Comparison of the co-located measurements performed using the radar and the lidar 19:00-22:00 UTC, 19 April 2010 Radar MIRA-36 time series of the vertical profile of the linear depolarization ratio Lidar time series of the lidar rangecorrected signal at 1064 nm F. Madonna, et al.,, GRL (accepted, 2010)

19 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)

20 ACKNOWLEDGMENTS European Commission grant RICA EARLINET-ASOS NOAA Air Resources Laboratory (ARL) Barcelona Supercomputing Center for DREAM forecasts