scholarly journals Review of 'Satellite-derived SO2 flux time-series and magmatic processes during the 2015 Calbuco eruptions'

2017 ◽  
Author(s):  
Anonymous
Keyword(s):  
Time Series ◽  
So2 Flux ◽  
Magmatic Processes

scholarly journals Satellite-derived SO<sub>2</sub> flux time-series and magmatic processes during the 2015 Calbuco eruptions

2017 ◽  
Author(s):  
Federica Pardini ◽  
Mike Burton ◽  
Fabio Arzilli ◽  
Giuseppe La Spina ◽  
Margherita Polacci
Keyword(s):  
Time Series ◽  
Melt Inclusion ◽  
Computational Cost ◽  
High Temporal Resolution ◽  
Climatic Impact ◽  
So2 Emissions ◽  
Plume Height ◽  
So2 Flux ◽  
Magmatic Processes ◽  
Average Flux

Abstract. Quantifying time-series of sulphur dioxide (SO2) emissions during explosive eruptions provides insight into volcanic processes, assists in volcanic hazard mitigation, and permits quantification of the climatic impact of major eruptions. While volcanic SO2 is routinely detected from space during eruptions, the retrieval of plume injection height and SO2 flux time-series remains challenging. Here we present a new numerical method based on forward- and backward-trajectory analyses which enable such time-series to be robustly determined. The method is applied to satellite images of volcanic eruption clouds through the integration of the HYSPLIT software with custom-designed Python routines in a fully automated manner. Plume injection height and SO2 flux time-series are computed with a period of ~ 10 minutes with low computational cost. Using this technique, we investigated the SO2 emissions from two sub-Plinian eruptions of Calbuco, Chile, produced in April 2015. We found a mean injection height above the vent of ~ 15 km for the two eruptions, with overshooting tops reaching ~ 20 km. We calculated a total of 300 ± 46 kt of SO2 released almost equally during both events, with 160 ± 30 kt produced by the first event and 140 ± 35 kt by the second. The retrieved SO2 flux time-series show an intense gas release during the first eruption (average flux of 2560 kt day−1), while a lower SO2 flux profile was seen for the second (average flux 560 kt day−1), suggesting that the first eruption was richer in SO2. This result is exemplified by plotting SO2 flux against retrieved plume height above the vent, revealing distinct trends for the two events. We propose that a pre-erupted exsolved volatile phase was present prior to the first event, which could have led to the necessary overpressure to trigger the eruption. The second eruption, instead, was mainly driven by syneruptive degassing. This hypothesis is supported by melt inclusion measurements of sulfur concentrations in plagioclase phenocrysts and groundmass glass of tephra samples through electron microprobe analysis. This work demonstrates that detailed interpretations of sub-surface magmatic processes during eruptions are possible using satellite SO2 data. Quantitative comparisons of high temporal resolution plume height and SO2 flux time-series offer a powerful tool to examine processes triggering and controlling eruptions. These novel tools open a new frontier in space-based volcanological research, and will be of great value when applied to remote, poorly monitored volcanoes, and to major eruptions that can have regional and global climate implications through, for example, influencing ozone depletion in the stratosphere and light scattering from stratospheric aerosols.

New insights into magmatic processes from integrated satellite observation, trajectory analysis and magma ascent modelling

2021 ◽  
Author(s):  
Mike Burton ◽  
Giuseppe La Spina ◽  
Catherine Hayer ◽  
Benjamin Esse
Keyword(s):  
Time Series ◽  
Trajectory Analysis ◽  
High Spatial Resolution ◽  
Satellite Observation ◽  
Magma Ascent ◽  
Satellite Monitoring ◽  
Plume Height ◽  
So2 Flux ◽  
Magmatic Processes ◽  
Global Coverage

&lt;p&gt;Analysis of TROPOMI data with plume trajectory tools opens the possibility of new insights into volcanic / magmatic processes from two data sources: SO2 flux time series and plume height time series. In this paper we investigate results from explosive eruptions and attempt to explain the results with a magma ascent conduit model. The combination of plume height and gas flux data with a model of the magma ascent process provides a toolkit which allows us to constrain magma reservoir processes from satellite monitoring data. The combination of modelling and observations opens a new volcanological research frontier, because the TROPOMI sensor has daily global coverage, a high spatial resolution and is sensitive enough to detect many small-medium explosions globally, so that a large inventory of explosive activity can be characterised.&amp;#160;&lt;/p&gt;

scholarly journals Plume propagation direction determination with SO<sub>2</sub> cameras

2017 ◽  
Vol 10 (3) ◽  
pp. 979-987 ◽  
Author(s):  
Angelika Klein ◽  
Peter Lübcke ◽  
Nicole Bobrowski ◽  
Jonas Kuhn ◽  
Ulrich Platt
Keyword(s):  
Time Series ◽  
Wind Direction ◽  
Column Density ◽  
Image Plane ◽  
Propagation Direction ◽  
Volcanic Plume ◽  
High Temporal Resolution ◽  
Good Precision ◽  
So2 Flux ◽  
Flux Measurements

Abstract. SO2 cameras are becoming an established tool for measuring sulfur dioxide (SO2) fluxes in volcanic plumes with good precision and high temporal resolution. The primary result of SO2 camera measurements are time series of two-dimensional SO2 column density distributions (i.e. SO2 column density images). However, it is frequently overlooked that, in order to determine the correct SO2 fluxes, not only the SO2 column density, but also the distance between the camera and the volcanic plume, has to be precisely known. This is because cameras only measure angular extents of objects while flux measurements require knowledge of the spatial plume extent. The distance to the plume may vary within the image array (i.e. the field of view of the SO2 camera) since the plume propagation direction (i.e. the wind direction) might not be parallel to the image plane of the SO2 camera. If the wind direction and thus the camera–plume distance are not well known, this error propagates into the determined SO2 fluxes and can cause errors exceeding 50 %. This is a source of error which is independent of the frequently quoted (approximate) compensation of apparently higher SO2 column densities and apparently lower plume propagation velocities at non-perpendicular plume observation angles.Here, we propose a new method to estimate the propagation direction of the volcanic plume directly from SO2 camera image time series by analysing apparent flux gradients along the image plane. From the plume propagation direction and the known location of the SO2 source (i.e. volcanic vent) and camera position, the camera–plume distance can be determined. Besides being able to determine the plume propagation direction and thus the wind direction in the plume region directly from SO2 camera images, we additionally found that it is possible to detect changes of the propagation direction at a time resolution of the order of minutes. In addition to theoretical studies we applied our method to SO2 flux measurements at Mt Etna and demonstrate that we obtain considerably more precise (up to a factor of 2 error reduction) SO2 fluxes. We conclude that studies on SO2 flux variability become more reliable by excluding the possible influences of propagation direction variations.

scholarly journals Plume Propagation Direction Determination with SO<sub>2</sub> Cameras

2016 ◽  
Author(s):  
Angelika Klein ◽  
Peter Lübcke ◽  
Nicole Bobrowski ◽  
Jonas Kuhn ◽  
Ulrich Platt
Keyword(s):  
Time Series ◽  
Wind Direction ◽  
Column Density ◽  
Image Plane ◽  
Propagation Direction ◽  
Volcanic Plume ◽  
High Temporal Resolution ◽  
Good Precision ◽  
So2 Flux ◽  
Flux Measurements

Abstract. SO2 cameras are becoming an established tool for measuring sulphur dioxide (SO2) fluxes in volcanic plumes with good precision and high temporal resolution. The primary result of SO2 camera measurements are time series of two-dimensional SO2 column density distributions (i.e. SO2 column density images). However it is frequently overlooked that in order to determine the correct SO2 fluxes, not only the SO2 column density, but also the distance between the camera and the volcanic plume have to be precisely known. This is because cameras only measure angular extensions of objects while flux measurements require knowledge of the spatial plume extension. The distance to the plume may vary within the image array (i.e. the field of view of the SO2 camera) since the plume propagation direction (i.e. the wind direction) might not be parallel to the image plane of the SO2 camera. If the wind direction and thus the camera-plume distance is not well known, this error propagates into the determined SO2 fluxes and can cause errors exceeding 50 %. This is a source of error which is independent of the frequently quoted (approximate) compensation of apparently higher SO2 column densities and apparently lower plume propagation velocities at non-perpendicular plume observation angles. Here, we propose a new method to estimate the propagation direction of the volcanic plume directly from SO2 camera image time series by analysing apparent flux gradients along the image plane. From the plume propagation direction and the known location of the SO2 source (i.e. volcanic vent) and camera position the camera-plume distance can be determined. Besides being able to determine the plume propagation direction, and thus the wind direction in the plume region, directly from SO2 camera images, we additionally found, that it is possible to detect changes of the propagation direction at a time resolution on the order of minutes. In addition to theoretical studies we applied our method to SO2 flux measurements at Mt. Etna and demonstrate that we obtain considerably more precise (up to a factor of 2 error reduction) SO2 fluxes. We conclude that studies on SO2 flux variability become more reliable by excluding the possible influences of propagation direction variations.

scholarly journals Exploiting Sentinel-5P TROPOMI and Ground Sensor Data for the Detection of Volcanic SO2 Plumes and Activity in 2018–2021 at Stromboli, Italy

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 6991
Author(s):  
Alessandra Cofano ◽  
Francesca Cigna ◽  
Luigi Santamaria Santamaria Amato ◽  
Mario Siciliani de Siciliani de Cumis ◽  
Deodato Tapete
Keyword(s):  
Time Series ◽  
Short Wave ◽  
Mount Etna ◽  
Sensor Data ◽  
Test Case ◽  
So2 Emissions ◽  
Vertical Column ◽  
Activity Intensity ◽  
So2 Flux ◽  
Sentinel 2

Sulfur dioxide (SO2) degassing at Strombolian volcanoes is directly associated with magmatic activity, thus its monitoring can inform about the style and intensity of eruptions. The Stromboli volcano in southern Italy is used as a test case to demonstrate that the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Copernicus Sentinel-5 Precursor (Sentinel-5P) satellite has the suitable spatial resolution and sensitivity to carry out local-scale SO2 monitoring of relatively small-size, nearly point-wise volcanic sources, and distinguish periods of different activity intensity. The entire dataset consisting of TROPOMI Level 2 SO2 geophysical products from UV sensor data collected over Stromboli from 6 May 2018 to 31 May 2021 is processed with purposely adapted Python scripts. A methodological workflow is developed to encompass the extraction of total SO2 Vertical Column Density (VCD) at given coordinates (including conditional VCD for three different hypothetical peaks at 0–1, 7 and 15 km), as well as filtering by quality in compliance with the Sentinel-5P Validation Team’s recommendations. The comparison of total SO2 VCD time series for the main crater and across different averaging windows (3 × 3, 5 × 5 and 4 × 2) proves the correctness of the adopted spatial sampling criterion, and practical recommendations are proposed for further implementation in similar volcanic environments. An approach for detecting SO2 VCD peaks at the volcano is trialed, and the detections are compared with the level of SO2 flux measured at ground-based instrumentation. SO2 time series analysis is complemented with information provided by contextual Sentinel-2 multispectral (in the visible, near and short-wave infrared) and Suomi NPP VIIRS observations. The aim is to correctly interpret SO2 total VCD peaks when they either (i) coincide with medium to very high SO2 emissions as measured in situ and known from volcanological observatory bulletins, or (ii) occur outside periods of significant emissions despite signs of activity visible in Sentinel-2 data. Finally, SO2 VCD peaks in the time series are further investigated through daily time lapses during the paroxysms in July–August 2019, major explosions in August 2020 and a more recent period of activity in May 2021. Hourly wind records from ECMWF Reanalysis v5 (ERA5) data are used to identify local wind direction and SO2 plume drift during the time lapses. The proposed analysis approach is successful in showing the SO2 degassing associated with these events, and warning whenever the SO2 VCD at Stromboli may be overestimated due to clustering with the plume of the Mount Etna volcano.

Bridging the gap from caldera unrest to resurgence

2020 ◽  
Author(s):  
Valerio Acocella
Keyword(s):  
Time Series ◽  
Causal Relationships ◽  
Short Term ◽  
Caldera Unrest ◽  
Magmatic Processes ◽  
Incremental Growth ◽  
Magma Emplacement

&lt;p&gt;Calderas often inflate up to a few metres for weeks to years, which is evidence of short-term unrest. Some calderas also show larger uplift (up to a thousand metres), achieved over the long-term (hundreds to thousands of years), manifest by a resurgent dome or block. How the short-term inflation relates to long-term resurgence is still poorly understood, even though established views consider the two processes distinct. This study exploits the longer deformation time series now available for several calderas, as well as the better understanding of magmatic processes and their evolution, to try to bridge the gap between these two scales of uplift. Available data challenge established views, suggesting that resurgence, rather than being produced by constant or continuous uplift, is the net cumulated result of tens to thousands distinct episodes of inflation, even interrupted by deflation episodes, as observed on short-term unrest. These inflation episodes are ascribed to distinct pulses of shallow magma emplacement, with most of the magma remaining intruded, especially in felsic calderas. This supports an incremental growth of magmatic systems, consistently with that observed below resurgent calderas and what is inferred for plutons. Comparing the uplift (as expression of the intrusive record) and eruptive histories or resurgent calderas opens new exciting research paths to understand the causal relationships between intruded and erupted magma at a given caldera, thus enhancing its long-term eruptive forecast.&lt;/p&gt;

scholarly journals Satellite-derived sulfur dioxide (SO<sub>2</sub>) emissions from the 2014–2015 Holuhraun eruption (Iceland)

2019 ◽  
Vol 19 (7) ◽  
pp. 4851-4862 ◽  
Author(s):  
Elisa Carboni ◽  
Tamsin A. Mather ◽  
Anja Schmidt ◽  
Roy G. Grainger ◽  
Melissa A. Pfeffer ◽  
...  
Keyword(s):  
Time Series ◽  
Sulfur Dioxide ◽  
Large Scale ◽  
Climate Model ◽  
Time Series Data ◽  
Series Data ◽  
Data Set ◽  
Model Simulations ◽  
So2 Flux ◽  
Erupted Mass

Abstract. The 6-month-long 2014–2015 Holuhraun eruption was the largest in Iceland for 200 years, emitting huge quantities of sulfur dioxide (SO2) into the troposphere, at times overwhelming European anthropogenic emissions. Weather, terrain and latitude made continuous ground-based or UV satellite sensor measurements challenging. Infrared Atmospheric Sounding Interferometer (IASI) data are used to derive the first time series of daily SO2 mass present in the atmosphere and its vertical distribution over the entire eruption period. A new optimal estimation scheme is used to calculate daily SO2 fluxes and average e-folding time every 12 h. For the 6 months studied, the SO2 flux was observed to be up to 200 kt day−1 and the minimum total SO2 erupted mass was 4.4±0.8 Tg. The average SO2 e-folding time was 2.4±0.6 days. Where comparisons are possible, these results broadly agree with ground-based near-source measurements, independent remote-sensing data and values obtained from model simulations from a previous paper. The results highlight the importance of using high-resolution time series data to accurately estimate volcanic SO2 emissions. The SO2 mass missed due to thermal contrast is estimated to be of the order of 3 % of the total emission when compared to measurements by the Ozone Monitoring Instrument. A statistical correction for cloud based on the AVHRR cloud-CCI data set suggested that the SO2 mass missed due to cloud cover could be significant, up to a factor of 2 for the plume within the first kilometre from the vent. Applying this correction results in a total erupted mass of 6.7±0.4 Tg and little change in average e-folding time. The data set derived can be used for comparisons to other ground- and satellite-based measurements and to petrological estimates of the SO2 flux. It could also be used to initialise climate model simulations, helping to better quantify the environmental and climatic impacts of future Icelandic fissure eruptions and simulations of past large-scale flood lava eruptions.

scholarly journals Supplementary material to "Satellite-derived SO<sub>2</sub> flux time-series and magmatic processes during the 2015 Calbuco eruptions"

2017 ◽  
Author(s):  
Federica Pardini ◽  
Mike Burton ◽  
Fabio Arzilli ◽  
Giuseppe La Spina ◽  
Margherita Polacci
Keyword(s):  
Time Series ◽  
Magmatic Processes ◽  
Supplementary Material

The LDE-Type Flare Occurrence (1969-1993)

1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová
Keyword(s):  
Time Series ◽  
Fourier Analysis ◽  
Sunspot Cycle ◽  
List Type ◽  
Type Number ◽  
Solar Cycles ◽  
Type Iv ◽  
Long Duration ◽  
Cycle Maximum ◽  
Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

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