Inside Volcanic Clouds: Remote Sensing of Ash Plumes Using Microwave Weather Radars

Microphysical and dynamical features of volcanic tephra due to Plinian and sub-Plinian eruptions can be quantitatively monitored by using ground-based microwave weather radars. The methodological rationale and unique potential of this remote-sensing technique are illustrated and discussed. Volume data, acquired by ground-based weather radars, are processed to automatically classify and estimate ash particle concentration and fallout. The physical– statistical retrieval algorithm is based on a backscattering microphysical model of fine, coarse, and lapilli ash particles, used within a Bayesian classification and optimal estimation methodology. The experimental evidence of the usefulness and limitations of radar acquisitions for volcanic ash monitoring is supported by describing several case studies of volcanic eruptions all over the world. The radar sensitivity due to the distance and the system noise, as well as the various radar bands and configurations (i.e., Doppler and dual polarized), are taken into account. The discussed examples of radar-derived ash concentrations refer to the case studies of the Augustine volcano eruption in 2002, observed in Alaska by an S-band radar; the Grímsvötn volcano eruptions in 2004 and 2011, observed in Iceland by C- and X-band weather radars and compared with in situ samples; and the Mount Etna volcano eruption in 2011, observed by an X-band polarimetric radar. These applications demonstrate the variety of radar-based products that can be derived and exploited for the study of explosive volcanism.

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Remote Sensing of Volcanic Processes and Risk

Remote Sensing ◽

10.3390/rs12162567 ◽

2020 ◽

Vol 12 (16) ◽

pp. 2567

Author(s):

Francesca Cigna ◽

Deodato Tapete ◽

Zhong Lu

Keyword(s):

Remote Sensing ◽

Case Studies ◽

Wavelet Transforms ◽

Ground Deformation ◽

Volcanic Eruptions ◽

Added Value ◽

Landsat 8 ◽

Magnetic Survey ◽

Special Issue ◽

Volcanic Processes

Remote sensing data and methods are increasingly being embedded into assessments of volcanic processes and risk. This happens thanks to their capability to provide a spectrum of observation and measurement opportunities to accurately sense the dynamics, magnitude, frequency, and impacts of volcanic activity in the ultraviolet (UV), visible (VIS), infrared (IR), and microwave domains. Launched in mid-2018, the Special Issue “Remote Sensing of Volcanic Processes and Risk” of Remote Sensing gathers 19 research papers on the use of satellite, aerial, and ground-based remote sensing to detect thermal features and anomalies, investigate lava and pyroclastic flows, predict the flow path of lahars, measure gas emissions and plumes, and estimate ground deformation. The strong multi-disciplinary character of the approaches employed for volcano monitoring and the combination of a variety of sensor types, platforms, and methods that come out from the papers testify the current scientific and technology trends toward multi-data and multi-sensor monitoring solutions. The research advances presented in the published papers are achieved thanks to a wealth of data including but not limited to the following: thermal IR from satellite missions (e.g., MODIS, VIIRS, AVHRR, Landsat-8, Sentinel-2, ASTER, TET-1) and ground-based stations (e.g., FLIR cameras); digital elevation/surface models from airborne sensors (e.g., Light Detection And Ranging (LiDAR), or 3D laser scans) and satellite imagery (e.g., tri-stereo Pléiades, SPOT-6/7, PlanetScope); airborne hyperspectral surveys; geophysics (e.g., ground-penetrating radar, electromagnetic induction, magnetic survey); ground-based acoustic infrasound; ground-based scanning UV spectrometers; and ground-based and satellite Synthetic Aperture Radar (SAR) imaging (e.g., TerraSAR-X, Sentinel-1, Radarsat-2). Data processing approaches and methods include change detection, offset tracking, Interferometric SAR (InSAR), photogrammetry, hotspots and anomalies detection, neural networks, numerical modeling, inversion modeling, wavelet transforms, and image segmentation. Some authors also share codes for automated data analysis and demonstrate methods for post-processing standard products that are made available for end users, and which are expected to stimulate the research community to exploit them in other volcanological application contexts. The geographic breath is global, with case studies in Chile, Peru, Ecuador, Guatemala, Mexico, Hawai’i, Alaska, Kamchatka, Japan, Indonesia, Vanuatu, Réunion Island, Ethiopia, Canary Islands, Greece, Italy, and Iceland. The added value of the published research lies on the demonstration of the benefits that these remote sensing technologies have brought to knowledge of volcanoes that pose risk to local communities; back-analysis and critical revision of recent volcanic eruptions and unrest periods; and improvement of modeling and prediction methods. Therefore, this Special Issue provides not only a collection of forefront research in remote sensing applied to volcanology, but also a selection of case studies proving the societal impact that this scientific discipline can potentially generate on volcanic hazard and risk management.

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Sulphur mass balance and radiative forcing estimation for a moderate volcanic eruption using new sulphate aerosols retrievals based on IASI observations

10.5194/amt-2019-341 ◽

2019 ◽

Cited By ~ 2

Author(s):

Henda Guermazi ◽

Pasquale Sellitto ◽

Juan Cuesta ◽

Maxim Eremenko ◽

Mathieu Lachatre ◽

...

Keyword(s):

Mass Balance ◽

Radiative Forcing ◽

Eastern Mediterranean ◽

Volcanic Eruptions ◽

Mount Etna ◽

Retrieval Algorithm ◽

Volcanic Plume ◽

Total Uncertainty ◽

Sulphate Aerosols ◽

Crucial Information

Abstract. We developed a new retrieval algorithm based on the Infrared Atmospheric Sounding Interferometer (IASI) observations, called AEROIASI-Sulphates, to measure vertically-resolved sulphate aerosols (SA) extinction and mass concentration profiles, with limited theoretical uncertainties (typically ~25 % total uncertainty for SA mass column estimations). The algorithm, based on a self-adapting Tikhonov-Phillips regularization method, is applied to a medium-sized-intensity eruption of Mount Etna volcano (18 March 2012). Comparisons with simultaneous and independent SO2 plume observations and simulations show that AEROIASI-Sulphates correctly identifies the volcanic plume morphology both horizontally and vertically. This method provided, for the first time, crucial information pieces to describe the gaseous-to-particulate volcanic sulphur mass balance (60 % of the injected sulphur mass is converted to particulate matter, after ~24 hours) and to estimate the regional shortwave direct radiative forcing (a regional forcing of −0.8 W/m2 is exerted in the eastern Mediterranean) for moderate volcanic eruptions.

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Tephrostratigraphic studies on a sediment core from Lake Prespa in the Balkans

Climate of the Past ◽

10.5194/cp-9-267-2013 ◽

2013 ◽

Vol 9 (1) ◽

pp. 267-287 ◽

Cited By ~ 33

Author(s):

M. Damaschke ◽

R. Sulpizio ◽

G. Zanchetta ◽

B. Wagner ◽

A. Böhm ◽

...

Keyword(s):

Volcanic Eruptions ◽

Explosive Volcanism ◽

Mount Etna ◽

Campi Flegrei ◽

Central Mediterranean ◽

Major Element Composition ◽

The Balkans ◽

Lake Prespa ◽

Balkan Region ◽

Microscopic Inspection

Abstract. A detailed tephrostratigraphic record, which dates back to Marine Isotope Stage (MIS) 5b (ca. 91 kyr), has been established from a 17.76 m long core (Co1215) from Lake Prespa (Macedonia, Albania and Greece). A total of eleven tephra and cryptotephra layers (PT0915-1 to PT0915-11) were identified, using XRF scanning, magnetic susceptibility measurements, and macro- and microscopic inspection of the sediments. The major element composition of glass shards and/or micro-pumice fragments indicates that the tephras and cryptotephras originate from the explosive volcanism of Italy. Eight tephra and cryptotephra layers were correlated with specific volcanic eruptions: the AD 512 eruption of Somma-Vesuvius (1438 cal yr BP), the Mercato eruption of Somma-Vesuvius (8890 ± 90 cal yr BP), the Tufi Biancastri/LN1-LN2 eruption of the Campi Flegrei (14 749 ± 523 cal yr BP and 15 551 ± 621 cal yr BP), the SMP1-e/Y-3 eruption of the Campi Flegrei (30 000–31 000 cal yr BP), the Campanian Ignimbrite/Y-5 eruption of the Campi Flegrei (39 280 ± 110 cal yr BP), the SMP1-a event of Ischia Island (around 44 000 cal yr BP) and the Green Tuff/Y-6 eruption of Pantelleria Island (around 45 000 cal yr BP). One tephra could be attributed to the volcanic activity of Mount Etna, but probably represents an unknown eruption at ca. 60 000 cal yr BP. Cryptotephras PT0915-6 and PT0915-10 remain unclassified so far, but according to the presented age-depth model these would have been deposited around 35 000 and 48 500 cal yr BP, respectively. Some of the tephras and cryptotephras are recognised for the first time in the Balkan region. The tephrostratigraphic work provides important information about ash dispersal and explosion patterns of source volcanoes and can be used to correlate and date geographically distant paleoenvironmental and archaeological archives in the central Mediterranean region. Moreover, the tephrostratigraphic work in combination with radiocarbon and electron spin resonance (ESR) dating is a precondition for paleoclimatic reconstructions inferred from the sediment succession Co1215.

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Tephrostratigraphic studies on a sediment core from Lake Prespa in the Balkans

Climate of the Past Discussions ◽

10.5194/cpd-8-4443-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 4443-4492 ◽

Cited By ~ 2

Author(s):

M. Damaschke ◽

R. Sulpizio ◽

G. Zanchetta ◽

B. Wagner ◽

A. Böhm ◽

...

Keyword(s):

Volcanic Eruptions ◽

Explosive Volcanism ◽

Mount Etna ◽

Campi Flegrei ◽

Central Mediterranean ◽

Major Element Composition ◽

The Balkans ◽

Lake Prespa ◽

Balkan Region ◽

Microscopic Inspection

Abstract. A detailed tephrostratigraphic record, which dates back to Marine Isotope Stage (MIS) 5, has been established from a 17.76 m long core (Co1215) from Lake Prespa (Macedonia, Albania and Greece). A total of eleven tephra and cryptotephra layers (PT0915-1 to PT0915-11) were identified, using XRF scanning, magnetic susceptibility measurements, and macro- and microscopic inspection of the sediments. The major element composition of glass shards and/or micro-pumice fragments indicates that the tephras and cryptotephras originate from the explosive volcanism of Italy. Eight tephra and cryptotephra layers were correlated with specific volcanic eruptions: cryptotephra PT0915-1 with the 512 AD eruption of Somma-Vesuvius (1438 cal yr BP), tephra PT0915-2 with the Mercato eruption of Somma-Vesuvius (8890 ± 90 cal yr BP), cryptotephras PT0915-3 and PT0915-4 with Tufi Biancastri/LN1-LN2 of the Campi Flegrei (14 749 ± 523 cal yr BP and 15 551 ± 621 cal yr BP), tephra PT0915-5 with the SMP1-e/Y-3 eruption of the Campi Flegrei (30 000–31 000 cal yr BP), tephra PT0915-7 with the Campanian Ignimbrite/Y-5 of the Campi Flegrei (39 280 ± 110 cal yr BP), cryptotephra PT0915-8 with the SMP1-a event of Ischia Island (around 44 000 cal yr BP) and tephra PT0915-9 with the Green Tuff/Y-6 eruption of Pantelleria Island (around 45 000 cal yr BP). Tephra PT0915-11 could be attributed to the volcanic activity of Mount Etna, but probably represents a hitherto unknown eruption at ca. 60 000 cal yr BP. Cryptotephras PT0915-6 and PT0915-10 remain unclassified so far, but according to the presented age-depth model these would have been deposited around 35 000 and 48 500 cal yr BP, respectively. Some of the tephras and cryptotephras are recognised for the first time in the Balkan region. The tephrostratigraphic work provides important information about ash dispersal and explosion patterns of source volcanoes and can be used to correlate and date geographically distant paleoenvironmental and archaeological archives in the central Mediterranean region. Moreover, the tephrostratigraphic work in combination with radiocarbon and electron spin resonance (ESR) dating is a precondition for paleoclimatic reconstructions inferred from the sediment succession Co1215.

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Best Practices In Multilanguage Satellite Remote Sensing Training: Case Studies In Spanish-Speaking Countries [Education]

IEEE Geoscience and Remote Sensing Magazine ◽

10.1109/mgrs.2021.3060777 ◽

2021 ◽

Vol 9 (2) ◽

pp. 105-111

Author(s):

Ana Prados ◽

Erika Podest ◽

David G Barbato ◽

Annelise Carleton-Hug ◽

Brock Blevins ◽

...

Keyword(s):

Remote Sensing ◽

Best Practices ◽

Case Studies ◽

Satellite Remote Sensing ◽

Spanish Speaking ◽

Training Case

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Remote Sensing of Ecosystem Water Use Efficiency: A Review of Direct and Indirect Estimation Methods

Remote Sensing ◽

10.3390/rs13122393 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2393

Author(s):

Wanyuan Cai ◽

Sana Ullah ◽

Lei Yan ◽

Yi Lin

Keyword(s):

Remote Sensing ◽

Water Use Efficiency ◽

Analytical Model ◽

Water Use ◽

Estimation Methods ◽

Retrieval Algorithm ◽

Canopy Conductance ◽

Coupling Mechanism ◽

Indirect Methods ◽

Use Efficiency

Water use efficiency (WUE) is a key index for understanding the ecosystem of carbon–water coupling. The undistinguishable carbon–water coupling mechanism and uncertainties of indirect methods by remote sensing products and process models render challenges for WUE remote sensing. In this paper, current progress in direct and indirect methods of WUE estimation by remote sensing is reviewed. Indirect methods based on gross primary production (GPP)/evapotranspiration (ET) from ground observation, processed models and remote sensing are the main ways to estimate WUE in which carbon and water cycles are independent processes. Various empirical models based on meteorological variables and remote sensed vegetation indices to estimate WUE proved the ability of remotely sensed data for WUE estimating. The analytical model provides a mechanistic opportunity for WUE estimation on an ecosystem scale, while the hypothesis has yet to be validated and applied for the shorter time scales. An optimized response of canopy conductance to atmospheric vapor pressure deficit (VPD) in an analytical model inverted from the conductance model has been also challenged. Partitioning transpiration (T) and evaporation (E) is a more complex phenomenon than that stated in the analytic model and needs a more precise remote sensing retrieval algorithm as well as ground validation, which is an opportunity for remote sensing to extrapolate WUE estimation from sites to a regional scale. Although studies on controlling the mechanism of environmental factors have provided an opportunity to improve WUE remote sensing, the mismatch in the spatial and temporal resolution of meteorological products and remote sensing data, as well as the uncertainty of meteorological reanalysis data, add further challenges. Therefore, improving the remote sensing-based methods of GPP and ET, developing high-quality meteorological forcing datasets and building mechanistic remote sensing models directly acting on carbon–water cycle coupling are possible ways to improve WUE remote sensing. Improvement in direct WUE remote sensing methods or remote sensing-driven ecosystem analysis methods can promote a better understanding of the global ecosystem carbon–water coupling mechanisms and vegetation functions–climate feedbacks to serve for the future global carbon neutrality.

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Imaging Spectroscopy for Conservation Applications

Remote Sensing ◽

10.3390/rs13020292 ◽

2021 ◽

Vol 13 (2) ◽

pp. 292

Author(s):

Megan Seeley ◽

Gregory P. Asner

Keyword(s):

Remote Sensing ◽

Decision Making ◽

Case Studies ◽

Spatial Scales ◽

Imaging Spectroscopy ◽

Remote Sensing Data ◽

Decision Makers ◽

High Spectral Resolution ◽

Conservation Areas ◽

Broad Array

As humans continue to alter Earth systems, conservationists look to remote sensing to monitor, inventory, and understand ecosystems and ecosystem processes at large spatial scales. Multispectral remote sensing data are commonly integrated into conservation decision-making frameworks, yet imaging spectroscopy, or hyperspectral remote sensing, is underutilized in conservation. The high spectral resolution of imaging spectrometers captures the chemistry of Earth surfaces, whereas multispectral satellites indirectly represent such surfaces through band ratios. Here, we present case studies wherein imaging spectroscopy was used to inform and improve conservation decision-making and discuss potential future applications. These case studies include a broad array of conservation areas, including forest, dryland, and marine ecosystems, as well as urban applications and methane monitoring. Imaging spectroscopy technology is rapidly developing, especially with regard to satellite-based spectrometers. Improving on and expanding existing applications of imaging spectroscopy to conservation, developing imaging spectroscopy data products for use by other researchers and decision-makers, and pioneering novel uses of imaging spectroscopy will greatly expand the toolset for conservation decision-makers.

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Remote Sensing Applications for Landslide Monitoring and Investigation in Western Canada

Remote Sensing ◽

10.3390/rs13030366 ◽

2021 ◽

Vol 13 (3) ◽

pp. 366

Author(s):

Renato Macciotta ◽

Michael T. Hendry

Keyword(s):

Remote Sensing ◽

Case Studies ◽

Slope Failure ◽

Landslide Monitoring ◽

Western Canada ◽

Extensive Literature ◽

Sensing Applications ◽

Remote Sensing Techniques ◽

Definition Of ◽

River Valleys

Transportation infrastructure in mountainous terrain and through river valleys is exposed to a variety of landslide phenomena. This is particularly the case for highway and railway corridors in Western Canada that connect towns and industries through prairie valleys and the Canadian cordillera. The fluidity of these corridors is important for the economy of the country and the safety of workers, and users of this infrastructure is paramount. Stabilization of all active slopes is financially challenging given the extensive area where landslides are a possibility, and monitoring and minimization of slope failure consequences becomes an attractive risk management strategy. In this regard, remote sensing techniques provide a means for enhancing the monitoring toolbox of the geotechnical engineer. This includes an improved identification of active landslides in large areas, robust complement to in-place instrumentation for enhanced landslide investigation, and an improved definition of landslide extents and deformation mechanisms. This paper builds upon the extensive literature on the application of remote sensing techniques and discusses practical insights gained from a suite of case studies from the authors’ experience in Western Canada. The review of the case studies presents a variety of landslide mechanisms and remote sensing technologies. The aim of the paper is to transfer some of the insights gained through these case studies to the reader.

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A Computational Methodology for the Calibration of Tephra Transport Nowcasting at Sakurajima Volcano, Japan

Atmosphere ◽

10.3390/atmos12010104 ◽

2021 ◽

Vol 12 (1) ◽

pp. 104

Author(s):

Alexandros P. Poulidis ◽

Atsushi Shimizu ◽

Haruhisa Nakamichi ◽

Masato Iguchi

Keyword(s):

Remote Sensing ◽

High Resolution ◽

Remote Sensing Data ◽

Volcanic Eruptions ◽

Weather Research And Forecasting ◽

Sakurajima Volcano ◽

Observation Network ◽

Complementary Strategy ◽

Physical Quantities ◽

Do So

Ground-based remote sensing equipment have the potential to be used for the nowcasting of the tephra hazard from volcanic eruptions. To do so raw data from the equipment first need to be accurately transformed to tephra-related physical quantities. In order to establish these relations for Sakurajima volcano, Japan, we propose a methodology based on high-resolution simulations. An eruption that occurred at Sakurajima on 16 July 2018 is used as the basis of a pilot study. The westwards dispersal of the tephra cloud was ideal for the observation network that has been installed near the volcano. In total, the plume and subsequent tephra cloud were recorded by 2 XMP radars, 1 lidar and 3 optical disdrometers, providing insight on all phases of the eruption, from plume generation to tephra transport away from the volcano. The Weather Research and Forecasting (WRF) and FALL3D models were used to reconstruct the transport and deposition patterns. Simulated airborne tephra concentration and accumulated load were linked, respectively, to lidar backscatter intensity and radar reflectivity. Overall, results highlight the possibility of using such a high-resolution modelling-based methodology as a reliable complementary strategy to common approaches for retrieving tephra-related quantities from remote sensing data.

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Evaluating the accuracy of C- and X-band weather radars and their application for stream flow simulation

Journal of Hydroinformatics ◽

10.2166/hydro.2012.120 ◽

2012 ◽

Vol 15 (4) ◽

pp. 1121-1136 ◽

Cited By ~ 7

Author(s):

N. K. Shrestha ◽

T. Goormans ◽

P. Willems

Keyword(s):

Conceptual Model ◽

Stream Flow ◽

Flow Simulation ◽

Winter Storms ◽

Weather Radars ◽

X Band ◽

Rainfall Estimates

This paper investigates the accuracy of rainfall estimates from C- and X-band weather radars and their application for stream flow simulation. Different adjustment procedures are applied to raw radar estimates using gauge readings from a network of 12 raingauges. The stream flow is simulated for the 48.17 km2 Molenbeek/Parkbeek catchment located in the Flemish region of Belgium based on a lumped conceptual model. Results showed that raw radar estimates can be greatly improved using adjustment procedures. The gauge-radar residuals however, remain large even after adjustments. The adjusted X-band radar estimates are observed to be better estimates than corresponding C-band estimates. Their application for stream flow simulation showed that raingauges and radars can simulate spatially more uniform winter storms with almost the same accuracy, whereas differences are more evident on summer events.

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