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This publication delves into the innovative techniques and technologies behind microwave remote sensing of volcanic plumes and clouds. Explore the utilization of ground-based microwave radar, space-based radiometric sensing, and case studies like Grímsvötn 2011 eruption. Learn about the radar equation, Volcanic Ash Radar Retrieval (VARR), and the potential synergy between ground and satellite observations. Follow the author, Frank S. Marzano, as he presents the rationale, principles, and sensitivity of microwave radar observations in quantitatively estimating ash plumes from explosive eruptions.
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Outline • Introduction • Remote sensing of volcanic plumes and clouds • Volcanic plumes and tephra • Microwave remote sensing of volcanic plumes • Ground-based microwave radar remote sensing • Microwave weather radars • Radar equation and Volcanic Ash Radar Retrieval (VARR) technique • Space-based microwave radiometric remote sensing • Microwave radiative transfer from space • Spaceborne microwave radiometers • Case studies and sensor synergy studies • Grímsvötn 2011 eruption: polarimetric radar and spaceborne radiometric monitoring • Calbuco 2015 eruption: microwave and infrared radiometric synergy from space • Conclusions Microwave remote sensing of volcanic plumes – Frank S. Marzano
What do we want to measure? Tephra at ground and on air from explosive eruptions • Fragments of volcanic rocks and lava injected into the air by explosions or carried upward by hot gases • Product of volcanic eruption columns or lava fountains Tephra: block Tephra ash & pumice Tephra reticulate Microwave remote sensing of volcanic plumes – Frank S. Marzano
How can wemeasure(estimate) it? MODIS Aquasat. VIIRS NPP sat. SEVIRI METEOSAT sat. CALIOP CALIPSO sat. SSMIS, DMSP sat. ATMS, NPP sat. L-C-X-Ka band Doppler dual-pol weather Radar Ashsieving, drilling, spectrometry Microwave remote sensing of volcanic plumes – Frank S. Marzano
Microwave rationale: motivation and goals • Volcanic plumes • Develop fast • Cover large areas • Particle sizes from [mm] to [mm] • Microwave (MW) observations • Observation requirements • High repetition cycle (sec to min) • Large coverage ~1000 km • Fine spatial resolution ~100 m Additional • 3D volume scans • All weather conditions • (Night Day, Cloudy) 5 - 10 min Hours - days ~100 km ~1000 km ~100 m >10 km Can we exploit MW observations from ground and satellite to QUANTITATIVELY estimate ashplumes due to explosiveeruptions? YES NO Ground weather RADAR LEO Satellite RADIOMETER YES YES Microwave remote sensing of volcanic plumes – Frank S. Marzano
Outline • Introduction • Remote sensing of volcanic plumes and clouds • Volcanic plumes and tephra • Microwave remote sensing of volcanic plumes • Ground-based microwave radar remote sensing • Microwave weather radars • Radar equation and Volcanic Ash Radar Retrieval (VARR) technique • Space-based microwave radiometric remote sensing • Microwave radiative transfer from space • Spaceborne microwave radiometers • Case studies and sensor synergy studies • Grímsvötn 2011 eruption: polarimetric radar and spaceborne radiometric monitoring • Calbuco 2015 eruption: microwave and infrared radiometric synergy from space • Conclusions Microwave remote sensing of volcanic plumes – Frank S. Marzano 2
Microwave radar observation principles Spatial sampling of WR Weather radar WR DH Sampling volume DD DD Dmax DH = 0.25 km = 120 km = variable [0.1 - 2] km H: PPI D: Dual polarization WR Temporal sampling of WR • Hmax • TR • = 30 km • = 5 – 15 min D q H T0+TR T0 Microwave remote sensing of volcanic plumes – Frank S. Marzano 2
Microwave radar retrieval and sensitivity Tephra Weather radar (GWR) Sampling volume Tephraparticle size distribution Gamma or Weibull • (Marzano et al., BAMS 2013) De=0.1 mm Coarse Ash Intense Concentration Minimum detectable Reflectivity Sensitivity to ash particles Ca=5 [g/m3] MDZ Fine Ash Intense Concentration De=0.01 mm Ca=5 [g/m3] MDS MDS Signal [dBZ] DETECTED NOT DETECTED t: pulse length Lf : filter loss Pt: transmitted power q,f: beam width. MDZ MDZ: Minimum detectable Reflectivity MDS: Minimum detectable signal Distance [km] Microwave remote sensing of volcanic plumes – Frank S. Marzano 8
VARR: radar-based retrieval algorithm • Volcanic Ash Radar Retrieval (VARR) Marzano F.S., E. Picciotti, G. Vulpiani and M. Montopoli, "Inside Volcanic clouds: Remote Sensing of Ash Plumes Using Microwave Weather Radars", Bullettin Am. Met. Soc. (BAMS), pp. 1567-1586, DOI: 10.1175/BAMS-D-11-00160.1, October 2013 Microwave remote sensing of volcanic plumes – Frank S. Marzano
Satellite microwave radiometers SSMIS BT • SSMIS (Special Sensor MicrowaveImagerSounder) aboard DSMP sat. • Conical scan at 50°(Brewster) • Swath: 1700 km • ATMS (Adv. Tech. MicrowaveSounder) abourSuomi NPP sat. • Linear cross-track scanning • Swath: 1500 km • Aboard LEO satellites • Channels above 100 GHz are used for volcanic applications (13x 16 km res.) with wavelengths less than 3 mm; • MW emission/scatt./ extinction as Brightness Temperature (K) from the volcanic plume and scene. • Repetition: 2 or 3 overpasses/day Microwave remote sensing of volcanic plumes – Frank S. Marzano
Satellite microwave radiometric retrieval Mesoscalevolcanic model ATHAM Radiative transfer model SNEM: Eddington model Brightness Temperature BT [K] Syntheticplume 183 GHz MW Sensor 19 GHz BTup Plume height and Total ash content estimator Layer > Ash > Meteo Earth’s surface Microwave remote sensing of volcanic plumes – Frank S. Marzano
Outline • Introduction • Remote sensing of volcanic plumes and clouds • Volcanic plumes and tephra • Microwave remote sensing of volcanic plumes • Ground-based microwave radar remote sensing • Microwave weather radars • Radar equation and Volcanic Ash Radar Retrieval (VARR) technique • Space-based microwave radiometric remote sensing • Microwave radiative transfer from space • Spaceborne microwave radiometers • Case studies and sensor synergy studies • Grímsvötn 2011 eruption: polarimetric radar and spaceborne radiometric monitoring • Calbuco 2015 eruption: microwave and infrared radiometric synergy from space • Conclusions Microwave remote sensing of volcanic plumes – Frank S. Marzano 2
Microwave remote sensing of volcanic plumes Brightness temperature@ [ 90 – 183] GHz BT: [K](wavelength: 3 mm < l < 1.5 mm) Microwave Satellite RADIOMETER Lost contributions Microwaves (mm-wave to cm-wave) sensitive to coarse ash and lapilli: look INSIDE the erupted plume …! Microwave Ground weather RADAR BT Earth’s surface Radar observables at [5.6 – 10] GHz (wavelength: 3 mm < l< 60 mm) ZHH : Reflectivity factor [dBZ] ZDR : Differential Reflectivity KDP: differential phase shift [deg/km] rHV : cross- polar correlation coefficient • Microwaves as NEAR-SOURCE probes? • Concentration and mass loading • Height and mass eruption rate • Particle size spectrum Microwave remote sensing of volcanic plumes – Frank S. Marzano
Grímsvötn2011: MW data intercomparison SSMIS RADAR ZHH [dBZ] BTH [K] 183 ±6GHz Radar ZHH 30 dBZ isoline BTH<240 K matches to ZHH >30dBZ Microwave remote sensing of volcanic plumes – Frank S. Marzano
2015 Calbuco volcaniceruption • Calbuco(2003 m) Southern Chile (41.326◦ S, 72.614◦ W) • Three phases started on April 22, 2015 • pulse • 22.4.2015 21:08 UTC • huge explosion • 23.4.2015 at 4:00 UTC • smaller explosion • 24.4.2015 02:30 UTC TA [K] TA [K] TIR Sensor MW Sensor Sub-Plinian volcanic eruption VEI = 4 (max is 5) Microwave remote sensing of volcanic plumes – Frank S. Marzano
2015 Calbuco volcaniceruption – weather radar Vidal L., S.W. Nesbitt, P. Salio, C. Farias, M.G. Nicora, M.S. Osores, L. Mereu, F.S. Marzano, “C-band Dual-Polarization Radar Observations of a Massive Volcanic Eruption in South America”, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 10, n. 3, pp. 960-974, March 2017) Microwave remote sensing of volcanic plumes – Frank S. Marzano
2015 Calbuco volcaniceruption – weather radar Vidal L., S.W. Nesbitt, P. Salio, C. Farias, M.G. Nicora, M.S. Osores, L. Mereu, F.S. Marzano, “C-band Dual-Polarization Radar Observations of a Massive Volcanic Eruption in South America”, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 10, n. 3, pp. 960-974, March 2017) Microwave remote sensing of volcanic plumes – Frank S. Marzano
Satellite-based data for 2015 Calbuco • No specific passive sensors are designed for volcanic ash clouds • Thermal InfraRed (TIR)radiometers are most used for estimations at large scales • Ash absorbs more radiation than water and ice at 10.8 mm. The opposite is true at 12 mm. • MicroWave (MW) radiometers (f> 90 GHz) are sensitive to coarser particles close to vent • Scattering effects of coarse ash particles Satellite data availability for 2015 Calbuco case study Microwave remote sensing of volcanic plumes – Frank S. Marzano
VIIRS infrareddetectionsaturationnearvent BTD < BTDth(0 K) BTD=BTM15(10.76 μm)-BTM16 (12.01 μm) 10.8 micron 12.0 micron VIIRS (05:09 UTC, 23 April 2015) over the Calbuco volcanic area TIR BTD (d) Ash cloud mask based on BTD (blue is no ash). S-NPP image at 05:09 UTC: VIIRS BTD mask values at TIR Microwave remote sensing of volcanic plumes – Frank S. Marzano
ATMS microwavevolcaniccolumndetection MSDW <MSDWth(0 K) NPP-ATMS brightness temperatures at 05:09 UTC on 23 April 2015 MW detection:Microwave Spectral Difference GHz 23.8 51.76 52.8 54.94 MSDW =BTBQH(165.0GHz)-BTBQV(88.2GHz) 57.290.22 57.290.32 88.2 165.0 183.3 +/- 1.0 183.3 +/- 1.8 183.3 +/- 3.0 183.3 +/- 4.5 Microwave remote sensing of volcanic plumes – Frank S. Marzano
ATMS and VIIRS complementarydetection VIIIRS BTD ATMS MSDW MW and TIR spaceborne radiometric observations from the same platform Complementarityin the retrieval of near-source plume (MW) and distal ash cloud (TIR) Microwave remote sensing of volcanic plumes – Frank S. Marzano
ATMS-basedmicrowavenear-source retrievals ESTIMATES FROM ATMS on 23 Apr. 2015 at 05:09 Total Columnar Content (TCC): 9.0 kg/m2 (max) Cloud top altitude (Ht):21 km (max); 17 km (ave) Mass Flow rate (QM):2.2 x 107 kg/s (max) Total Ash mass: 36.5 Tg Htop (km) QM (kg/s) TCC (kg/m2) Microwave remote sensing of volcanic plumes – Frank S. Marzano
Comparison with ground data Romero et al, Journal of Volcanology and Geothermal Research, 2016 Field campaign in 2015-16 within the Calbuco eruption area The eruption is not usually constant over time and ATMS only provides a snapshot 69 min after the first pulse. However, if we assume that the eruption rate is constant and the ATMS snapshot contains the tephra emitted during these 69 min, then ATMS-based estimate can be proportionally extrapolated to 360 min Empirical formula Satellite obs (MW) Ground deposit Marzano et al., TGRS (Trans. Geosci. Rem. Sens.), 2018 Microwave remote sensing of volcanic plumes – Frank S. Marzano
Conclusions on MW remote sensing of plumes • Microwave RADAR remote sensing of tephra: feasible …! • Radar VARR: physically-based retrieval scheme, rigorous and flexible • Radar VARR retrieval sensitivity • Good sensitivity for coarse ash and lapilli (> 100 micron radius) • Finer ash detectable down to 25-micron radius ONLY using X-band radar close (less 30 km) to the vent is used (high sensitivity) • Radar VARR radar products • Availability: within 240x240 km2 area and every 5 minutes! • Ash concentration and fallout rate (and a realistic estimate of VEI) • Particle size spectrum parameters (and its vertical profile) • Mass flow rate from volcano vent (and its vertical profile) • Ash mass loading at ground • Satellite microwave RADIOMETRY of plumes: appealing …! • Spaceborne microwave radiometry potential • Current spatial resolution inadequate for optically thin plumes • Near-source/thick plumes can be detected where IR BTD saturates • Synergy with GEO/LEO satellite infrared radiometric retrievals Grazie. Microwave remote sensing of volcanic plumes – Frank S. Marzano, frank.marzano@uniroma1.it