An automated SO 2 camera system for continuous, real-time monitoring of gas emissions from Kīlauea Volcano's summit Overlook Crater

Kern, Christoph; Sutton, Jeff; Elias, Tamar; Lee, Lopaka; Kamibayashi, Kevan; Antolik, L.; Werner, C. A.

doi:10.1016/j.jvolgeores.2014.12.004

Cited by 45 publications

(49 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the view of extending our methodology toward emission estimates, we will aim at linking the VCD ratios observed in the plume to actual emission ratios by combining our measurements with the monitoring infrastructures at Mt. Etna such as the FLAME SO 2 network (Salerno et al, 2009), by operating a dedicated SO 2 camera system together with the direct-sun spectrometers (e.g., Kern et al, 2015;D'Aleo et al, 2016), or by meteorological modeling of the local wind fields. In the view of volcano monitoring, a few of our spectrometers could be operated in stationary observatories, possibly together with a mobile observatory, to set up a network that allows for monitoring Mt.…”

Section: Discussionmentioning

confidence: 99%

Remote sensing of volcanic CO2, HF, HCl, SO2, and BrO in the downwind plume of Mt. Etna

et al. 2017

View full text Add to dashboard Cite

Abstract. Remote sensing of the gaseous composition of non-eruptive, passively degassing volcanic plumes can be a tool to gain insight into volcano interior processes. Here, we report on a field study in September 2015 that demonstrates the feasibility of remotely measuring the volcanic enhancements of carbon dioxide (CO 2 ), hydrogen fluoride (HF), hydrogen chloride (HCl), sulfur dioxide (SO 2 ), and bromine monoxide (BrO) in the downwind plume of Mt. Etna using portable and rugged spectroscopic instrumentation. To this end, we operated the Fourier transform spectrometer EM27/SUN for the shortwave-infrared (SWIR) spectral range together with a co-mounted UV spectrometer on a mobile platform in direct-sun view at 5 to 10 km distance from the summit craters. The 3 days reported here cover several plume traverses and a sunrise measurement. For all days, intra-plume HF, HCl, SO 2 , and BrO vertical column densities (VCDs) were reliably measured exceeding 5 ×1016 , 2 ×10 17 , 5 ×10 17 , and 1 ×10 14 molec cm −2 , with an estimated precision of 2.2 ×10 15 , 1.3 ×10 16 , 3.6 ×10 16 , and 1.3 ×10 13 molec cm −2 , respectively. Given that CO 2 , unlike the other measured gases, has a large and wellmixed atmospheric background, derivation of volcanic CO 2 VCD enhancements ( CO 2 ) required compensating for changes in altitude of the observing platform and for background concentration variability. The first challenge was met by simultaneously measuring the overhead oxygen (O 2 ) columns and assuming covariation of O 2 and CO 2 with altitude. The atmospheric CO 2 background was found by identifying background soundings via the coemitted volcanic gases. The inferred CO 2 occasionally exceeded 2 × 10 19 molec cm −2 with an estimated precision of 3.7 × 10 18 molec cm −2 given typical atmospheric background VCDs of 7 to 8 × 10 21 molec cm −2 . While the correlations of CO 2 with the other measured volcanic gases confirm the detection of volcanic CO 2 enhancements, correlations were found of variable significance (R 2 ranging between 0.88 and 0.00). The intra-plume VCD ratios CO 2 / SO 2 , SO 2 / HF, SO 2 / HCl, and SO 2 / BrO were in the range 7.1 to 35.4, 5.02 to 21.2, 1.54 to 3.43, and 2.9 × 10 3 to 12.5 × 10 3 , respectively, showing pronounced day-to-day and intra-day variability.

show abstract

Section: Discussionmentioning

confidence: 99%

Remote sensing of volcanic CO2, HF, HCl, SO2, and BrO in the downwind plume of Mt. Etna

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Luckily, the high resolution of the imaging systems allows us to account for these spatial and temporal fluctuations by directly measuring the projected 2-D velocity fields using optical flow (OF) algorithms (e.g. Krueger et al, 2013, Bjornsson et al, 2013, Peters et al, 2015, Lopez et al, 2015, Stebel et al, 2015, Kern et al, 2015.…”

Section: Introductionmentioning

confidence: 99%

“…The problem is less pronounced for OF algorithms using global constraints (e.g. the algorithm by Horn and Schunck, 1981 which is used in Kern et al, 2015), which can propagate reliable motion vectors over larger image areas. However, note that, depending on the optimisation strategy, global regularisers are often more sensitive to noise (e.g.…”

Section: Introductionmentioning

confidence: 99%

Improved optical flow velocity analysis in SO2 camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

et al. 2018

View full text Add to dashboard Cite

Abstract. Accurate gas velocity measurements in emission plumes are highly desirable for various atmospheric remote sensing applications. The imaging technique of UV SO 2 cameras is commonly used to monitor SO 2 emissions from volcanoes and anthropogenic sources (e.g. power plants, ships). The camera systems capture the emission plumes at high spatial and temporal resolution. This allows the gas velocities in the plume to be retrieved directly from the images. The latter can be measured at a pixel level using optical flow (OF) algorithms. This is particularly advantageous under turbulent plume conditions. However, OF algorithms intrinsically rely on contrast in the images and often fail to detect motion in low-contrast image areas. We present a new method to identify ill-constrained OF motion vectors and replace them using the local average velocity vector. The latter is derived based on histograms of the retrieved OF motion fields. The new method is applied to two example data sets recorded at Mt Etna (Italy) and Guallatiri (Chile). We show that in many cases, the uncorrected OF yields significantly underestimated SO 2 emission rates. We further show that our proposed correction can account for this and that it significantly improves the reliability of optical-flow-based gas velocity retrievals.In the case of Mt Etna, the SO 2 emissions of the northeastern crater are investigated. The corrected SO 2 emission rates range between 4.8 and 10.7 kg s −1 (average of 7.1 ± 1.3 kg s −1 ) and are in good agreement with previously reported values. For the Guallatiri data, the emissions of the central crater and a fumarolic field are investigated. The retrieved SO 2 emission rates are between 0.5 and 2.9 kg s −1 (average of 1.3 ± 0.5 kg s −1 ) and provide the first report of SO 2 emissions from this remotely located and inaccessible volcano.

show abstract

“…To date, the targets covered by permanent network installations have been rather few, e.g., Etna and Stromboli in Italy and Kīlauea in Hawaii [33][34][35][36][37], potentially as a consequence of the requirement to image the plume, e.g., without cloud cover between the camera and summit area. There is, of course, meteorological cloud cover at the top of volcanoes, which can occlude observations.…”

Section: Improving the Spatio-temporal Resolution Of Volcanic Degassingmentioning

confidence: 99%

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

et al. 2017

View full text Add to dashboard Cite

Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at ≈1 Hz, expediting more holistic investigations of volcanic source-process behaviour. Secondly, there has been the combination of surface observations of gas release with fluid dynamic models (numerical, mathematical, and laboratory) for gas flow in conduits, in attempts to link subterranean driving flow processes to surface activity types. There has also been considerable research and development concerning the technique itself, covering error analysis and most recently the adaptation of smartphone sensors for this application, to deliver gas fluxes at a significantly lower instrumental price point than possible previously. At this decadal juncture in the application of UV imaging in volcanology, this article provides an overview of what has been achieved to date as well as a forward look to possible future research directions.

show abstract

An automated SO 2 camera system for continuous, real-time monitoring of gas emissions from Kīlauea Volcano's summit Overlook Crater

Cited by 45 publications

References 37 publications

Remote sensing of volcanic CO<sub>2</sub>, HF, HCl, SO<sub>2</sub>, and BrO in the downwind plume of Mt. Etna

Remote sensing of volcanic CO<sub>2</sub>, HF, HCl, SO<sub>2</sub>, and BrO in the downwind plume of Mt. Etna

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

Contact Info

Product

Resources

About

An automated SO 2 camera system for continuous, real-time monitoring of gas emissions from Kīlauea Volcano's summit Overlook Crater

Cited by 45 publications

References 37 publications

Remote sensing of volcanic CO&lt;sub&gt;2&lt;/sub&gt;, HF, HCl, SO&lt;sub&gt;2&lt;/sub&gt;, and BrO in the downwind plume of Mt. Etna

Remote sensing of volcanic CO&lt;sub&gt;2&lt;/sub&gt;, HF, HCl, SO&lt;sub&gt;2&lt;/sub&gt;, and BrO in the downwind plume of Mt. Etna

Improved optical flow velocity analysis in SO&lt;sub&gt;2&lt;/sub&gt; camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

Contact Info

Product

Resources

About

Remote sensing of volcanic CO<sub>2</sub>, HF, HCl, SO<sub>2</sub>, and BrO in the downwind plume of Mt. Etna

Remote sensing of volcanic CO<sub>2</sub>, HF, HCl, SO<sub>2</sub>, and BrO in the downwind plume of Mt. Etna

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile