Volcanic Ash Algorithm Intercomparison
Marco Fulle ‐ www.stromboli.net
Michael PavolonisNOAA/NESDIS
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Before Ash Event During Ash Event
Why is volcanic ash monitoring important?
VAAC Best Practices Meeting (May 2015)
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General consensus: The next generation of GEO satellites (HIMAWARI‐8/9, MSG/MTG, GOES‐R/S, GEO‐KOMPSAT, FY‐4, Electro‐L) will allow the VAAC’S to produce more detailed information, especially at the t+0 timeframe
http://www.wmo.int/aemp/?q=node/65
Motivation for VA IntercomparisonValue of satellite-based volcanic ash products recognized by VAACs and airlines, especially during the eruptions in the last five years, but:
Quantifying volcanic ash parameters is difficult, but in demand;
There is no internationally-agreed validation protocol for such products;
Many products are available, and their strengths and weaknesses are not known or comparable,
Many products are produced on an ad-hoc basis and not sustained or operationally available,
There is no standard for volcanic cloud geophysical parameters endorsed by WMO.
Eyjafjallajokull (Arni Fridriksson, 17 Apr 2010)
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VA Intercomparison: Need for Guidance
Satellite-based VA Intercomparison
WMO SCOPE-Nowcasting
WMO Commission
for Basic Systems
WMO/IUGG VASAG
WMO Commission
for AeronauticalMeteorology
ICAO Met Panel WG 2 Met Information and
Service DevelopmentSub-Group on VA
ICAO Met Panel
ICAO (Contracting States)
WMO (Member States and Territories)
Other users / benefits
WMO Commission
for Atmospheric
Science
GAW/WWRP
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Intercomparison Meeting
29 June – 02 July, 2015
Madison, WI, USA
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http://cimss.ssec.wisc.edu/meetings/vol_ash15/
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http://www.wmo.int/pages/prog/sat/documents/SCOPE-NWC-PP2_VAIntercompWSReport2015.pdf
Algorithm Contributions (Total: 27 (22))Organization Algorithm(s)
NOAA SEVIRI_NOAAMODIS_NOAA
Oxford University IASI_OXFORDTERRA_MODIS_ORACAQUA_MODIS_ORAC
Université Libre de Bruxelles IASI_ULB
CMA SEVIRI_CMA
EUMETSAT METOP-A_PMAPMETOP-B_PMAPSEVIRI_EUMOP
Australian BOM MTSAT2_BOMMODIS_BOM
DLR Germany SEVIRI_VADUGS
SNM Argentina MODIS_CENZARG
INGV Italy MODIS_LUTMODIS_VPR
SRC Planeta, Russia METOP_PLANETA
University of Bristol BRISTOL_IASI
UK MetOffice SEVIRI_MOAVHRR_MO
Organization Algorithm(s)
JMA MTSAT2_JMAMTSATIR_JMA
STFC RAL, UK SEVIRI_ORAC_RALTERRA_MODIS_RALAQUA_MODIS_RAL
FMI AATSR_FMI
NASA MISR
“Validation” Sources• FAAM UK Airborne lidar
• CALIPSO CALIOP
• Ground-based Lidar
• Expert assessment
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Primary Conclusions
The accuracy of satellite-based volcanic ash products is a strong function of the retrieval methodology, satellite sensor capability, and scene complexity.
Additional analyses are required to better understand differences and provide a consensus outlook on end-to-end capabilities for operational applications
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Proposed Actions (12 month effort) Reaffirm commitment from algorithm contributors (contributors will have a
chance to update their data sets) Expand ash detection validation through comparison with expert analyses Gain detailed insight into differences in retrieved ash cloud properties:
Compare all retrieval inputs (satellite measurements and ancillary data) for a select number of common pixels, co-located with validation data, with different background conditions (water background, land background, meteorological cloud background, etc.). For the same common pixels, analyze all retrieval outputs.
Inter-compare volcanic ash products derived from the first of the next generation geostationary satellites (Himawari-8 AHI) for a single event from start to finish
Hold a workshop to document results, formulate best practices, and assess ability to meet demands of aviation community for more quantitative volcanic ash advisories
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Very optically thin(far field)
Semi‐transparent(intermediate field)
Optically thick/Opaque(near field)
Height
PoorSensitivity
SomeSensitivity
GoodSensitivity
SomeSensitivity
PoorSensitivity
(some UV/VIS exceptions)
Mass Loading
More consistent ash detection and characterization capabilities are needed across the spectrum of optical depth (down to detection limit) and height
Very optically thin(far field)
Semi‐transparent(intermediate field)
Optically thick/Opaque(near field)
Height
SomeSensitivity
PoorSensitivity
PoorSensitivity
(some UV/VIS exceptions)
GoodSensitivity
SomeSensitivity