A global perspective on Bromine monoxide composition in volcanic plumes derived from three years of S5-P/TROPOMI data

2021 ◽  
Author(s):  
Simon Warnach ◽  
Holger Sihler ◽  
Christian Borger ◽  
Nicole Bobrowski ◽  
Stefan Schmitt ◽  
...  
Keyword(s):  
Global Perspective ◽  
Coefficient Of Determination ◽  
Optical Absorption Spectroscopy ◽  
Polar Regions ◽  
Volcanic Gas ◽  
Volcanic Plumes ◽  
Molar Ratios ◽  
Volcanic Events ◽  
Global Coverage

<p>Bromine monoxide (BrO) is a halogen radical capable of influencing atmospheric chemical processes, in particular the abundance of ozone, e. g. in the troposphere of polar regions, the stratosphere as well as in volcanic plumes. Furthermore, the molar bromine to sulphur ratio in volcanic gas emissions is a proxy for the magmatic composition of a volcano and potentially an eruption forecast parameter.</p><p>The high spatial resolution of the S5-P/TROPOMI instrument (up to 3.5x5.5km<sup>2</sup>) and its daily global coverage offer the potential to detect BrO even during minor eruptions and also to determine BrO/SO<sub>2</sub> ratios during continuous passive degassing.</p><p>Here, we present a global overview of BrO/SO<sub>2</sub> molar ratios in volcanic plumes derived from a systematic long-term investigation of three years of TROPOMI data.</p><p>We retrieved column densities of BrO and SO<sub>2</sub> using Differential Optical Absorption Spectroscopy (DOAS) and calculated mean BrOSO<sub>2</sub> molar ratios for each volcano. As expected, the calculated BrO/SO<sub>2</sub> molar ratios differ strongly between different volcanoes ranging from several 10<sup>-5</sup> up to several 10<sup>-4</sup>. In our study of three years of S5P/TROPOMI data we successfully recorded elevated BrO column densities for more than 100 volcanic events and were able to derive meaningful (coefficient of determination, R<sup>2</sup> exceeding 0.5) BrO/SO<sub>2</sub> ratios for multiple volcanoes.</p>

A global perspective on Bromine monoxide composition in volcanic plumes derived from S5-P/TROPOMI

2020 ◽  
Author(s):  
Simon Warnach ◽  
Holger Sihler ◽  
Christian Borger ◽  
Nicole Bobrowski ◽  
Stefan Schmitt ◽  
...  
Keyword(s):  
High Spatial Resolution ◽  
Systematic Investigation ◽  
Activity Level ◽  
Global Perspective ◽  
Optical Absorption Spectroscopy ◽  
Polar Regions ◽  
Type I ◽  
Volcanic Gas ◽  
Volcanic Plumes ◽  
Molar Ratios

<p>Bromine monoxide (BrO) is a halogen radical altering the atmospheric ozone chemistry, e. g. in polar regions, the stratosphere as well as volcanic plumes. In particular, the molar bromine to sulphur ratio in volcanic gas emissions is characteristic to the magmatic composition of a volcano.</p><p>The high spatial resolution of S5-P/TROPOMI (up to 3.5x5.5km²) and daily coverage offer the potential to detect BrO even during minor eruptions and determine BrO/SO<sub>2</sub> ratios during continuous passive degassing.</p><p>Here, we present a global overview of BrO/SO<sub>2</sub> molar ratios in volcanic plumes derived from a systematic investigation of two years (2018 and 2019) of TROPOMI data.</p><p>We retrieved BrO column densities as well as SO<sub>2</sub> column densities using Differential Optical Absorption Spectroscopy (DOAS) and calculated mean BrO/SO<sub>2</sub> molar ratios for each volcano. The calculated BrO/SO<sub>2</sub> molar ratios differ strongly between different volcanoes ranging between several 10<sup>-5</sup> and 10<sup>-4</sup>. The data are classified and discussed with regard to several volcanic parameters –  more specific the volcanic region, volcano type (i. e. subduction zone, hotspot etc.) as well as activity level.</p>

scholarly journals BrO/SO<sub>2</sub> molar ratios from scanning DOAS measurements in the NOVAC network

2013 ◽  
Vol 5 (2) ◽  
pp. 1845-1870 ◽  
Author(s):  
P. Lübcke ◽  
N. Bobrowski ◽  
S. Arellano ◽  
B. Galle ◽  
G. Garzón ◽  
...  
Keyword(s):  
Molar Ratio ◽  
Optical Absorption Spectroscopy ◽  
Short Term ◽  
Dynamic Changes ◽  
Volcanic System ◽  
Molar Ratios ◽  
Remote Sensing Technique ◽  
Field Campaigns ◽  
Term Field

Abstract. The molar ratio of BrO to SO2 is, like other halogen/sulphur ratios, a~possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique Differential Optical Absorption Spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given and the influence of co-adding spectra on the retrieval error will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia encompassing almost four years of measurements between November 2009 and end of June 2013. This dataset shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

scholarly journals Multicopter measurements of volcanic gas emissions at Masaya (Nicaragua), Turrialba (Costa Rica) and Stromboli (Italy) volcanoes: Applications for volcano monitoring and insights into halogen speciation

2017 ◽  
Author(s):  
Julian Rüdiger ◽  
Lukas Tirpitz ◽  
J. Maarten de Moor ◽  
Nicole Bobrowski ◽  
Alexandra Gutmann ◽  
...  
Keyword(s):  
Costa Rica ◽  
Atmospheric Chemistry ◽  
Optical Absorption Spectroscopy ◽  
Stromboli Volcano ◽  
Volcanic Gas ◽  
Airborne Measurements ◽  
Volcanic Plumes ◽  
Custom Made ◽  
Reactive Gases

Abstract. Volcanoes are a natural source of several reactive gases (e.g. sulfur and halogen containing species), as well as non-reactive gases (e.g. carbon dioxide). Besides that, halogen chemistry in volcanic plumes might have important impacts on atmospheric chemistry, carbon to sulfur ratios and sulfur dioxide fluxes are important established parameters to gain information on subsurface processes. In this study we demonstrate the successful deployment of a multirotor UAV (quadcopter) system with custom-made lightweight payloads on board for the compositional analysis and gas flux estimation of volcanic plumes. The various applications and their potential with such new measurement strategy are presented and discussed on example studies at three volcanoes encompassing flight heights of 450 m to 3300 m and various states of volcanic activity. Field applications were performed at Stromboli Volcano (Italy), Turrialba Volcano (Costa Rica) and Masaya Volcano (Nicaragua). Two in-situ gas-measuring systems adapted for autonomous airborne measurements, based on electrochemical and optical detection principles, as well as an airborne sampling unit, are introduced. We show volcanic gas composition results including, abundances of CO2, SO2 and halogen species. The new instrumental set-ups were compared with established instruments during ground-based measurements. For total SO2 flux estimations a small differential optical absorption spectroscopy (DOAS) system measured SO2 column amounts on transversal flights below the plume, showing the potential to replace ground-based manned operations. At Stromboli volcano, short-term fluctuation of the CO2 / SO2 ratios could be determined and confirm an increased CO2 / SO2 ratio in spatial and temporal proximity to explosions by airborne in-situ measurements. Reactive bromine to sulfur ratios of 0.19 × 10−4 to 9.8 × 10−4 were measured in-situ in the plume of Stromboli volcano downwind of the vent.

scholarly journals BrO/SO<sub>2</sub> molar ratios from scanning DOAS measurements in the NOVAC network

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 409-424 ◽  
Author(s):  
P. Lübcke ◽  
N. Bobrowski ◽  
S. Arellano ◽  
B. Galle ◽  
G. Garzón ◽  
...  
Keyword(s):  
Molar Ratio ◽  
Optical Absorption Spectroscopy ◽  
Dynamic Changes ◽  
Data Set ◽  
Volcanic System ◽  
Molar Ratios ◽  
Remote Sensing Technique ◽  
Field Campaigns ◽  
Term Field

Abstract. The molar ratio of BrO to SO2 is, like other halogen/sulfur ratios, a possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique differential optical absorption spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns, this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given. The influence of co-adding spectra on the retrieval error and influences of radiative transfer will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia, encompassing almost 4 years of measurements between November 2009 and end of June 2013. This data set shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

OClO as observed by TROPOMI on Sentinel 5P

2020 ◽  
Author(s):  
Janis Pukite ◽  
Christian Borger ◽  
Steffen Dörner ◽  
Thomas Wagner
Keyword(s):  
Chlorine Dioxide ◽  
Meteorological Data ◽  
Trace Gas ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Polar Regions ◽  
Arctic Regions ◽  
Halogen Chemistry ◽  
Global Coverage ◽  
Spectrally Resolved

&lt;p&gt;The TROPOspheric Monitoring Instrument (TROPOMI) is an UV-VIS-NIR-SWIR instrument on board of Sentinel-5P satellite developed for monitoring the Earth&amp;#8217;s atmosphere. It was launched on 13 October 2017 in a near polar orbit. It measures spectrally resolved earthshine radiances at an unprecedented spatial resolution of around 3.5x7.2 km&lt;sup&gt;2&lt;/sup&gt; (3.5x5.6 km&lt;sup&gt;2 &lt;/sup&gt;starting from 6 Aug 2019) (near nadir) with a total swath width of ~2600 km on the Earth's surface providing daily global coverage. From the measured spectra high resolved trace gas distributions can be retrieved by means of differential optical absorption spectroscopy (DOAS).&lt;/p&gt;&lt;p&gt;Chlorine dioxide (OClO) is a by-product of the ozone depleting halogen chemistry in the stratosphere. Although being rapidly photolysed at low solar zenith angles (SZAs) it plays an important role as an indicator of the chlorine activation in polar regions during polar winter and spring at twilight conditions because of the nearly linear relation of its formation to chlorine oxide (ClO).&lt;/p&gt;&lt;p&gt;Here we present a new DOAS retrieval algorithm of the slant column densities (SCDs) of chlorine dioxide (OClO) and correlate this TROPOMI OClO signal with meteorological data for both Antarctic and Arctic regions.&lt;/p&gt;

OClO as observed by TROPOMI on Sentinel 5P

2021 ◽  
Author(s):  
Janis Pukite ◽  
Christian Borger ◽  
Steffen Dörner ◽  
Myojeong Gu
Keyword(s):  
Meteorological Data ◽  
Trace Gas ◽  
Optical Absorption Spectroscopy ◽  
Polar Regions ◽  
Chlorine Oxide ◽  
Arctic Regions ◽  
Halogen Chemistry ◽  
Global Coverage ◽  
Spectrally Resolved ◽  
Temporal Coverage

&lt;p&gt;Chlorine dioxide (OClO) is a by-product of the ozone depleting halogen chemistry in the stratosphere. Although being rapidly photolysed at low solar zenith angles (SZAs) it plays an important role as an indicator of the chlorine activation in polar regions during polar winter and spring at twilight conditions because of the nearly linear relation of its formation to chlorine oxide (ClO).&lt;/p&gt;&lt;p&gt;The TROPOspheric Monitoring Instrument (TROPOMI) is an UV-VIS-NIR-SWIR instrument on board the Sentinel-5P satellite developed for monitoring the composition of the Earth&amp;#8217;s atmosphere. It was launched on 13 October 2017 in a near polar orbit. It measures spectrally resolved earthshine radiances at an unprecedented spatial resolution of around 3.5x7.2 km&lt;sup&gt;2&lt;/sup&gt; (3.5x5.6 km&lt;sup&gt;2 &lt;/sup&gt;starting from 6 Aug 2019) (near nadir) with a total swath width of ~2600 km on the Earth's surface providing daily global coverage and even higher temporal coverage in polar regions. From the measured spectra high resolved trace gas distributions can be retrieved by means of differential optical absorption spectroscopy (DOAS).&lt;/p&gt;&lt;p&gt;Here we present retrieved time series of OClO slant column densities (SCDs) for the period 2017 - 2020, compare them with ground based zenith sky measurements and correlate them with meteorological data for both Antarctic and Arctic regions.&lt;/p&gt;

scholarly journals The Infrared Absolute Radiance Interferometer (ARI) for CLARREO

2020 ◽  
Vol 12 (12) ◽  
pp. 1915
Author(s):  
Joe K. Taylor ◽  
Henry E. Revercomb ◽  
Fred A. Best ◽  
David C. Tobin ◽  
P. Jonathan Gero
Keyword(s):  
Brightness Temperature ◽  
New Technologies ◽  
Spectral Radiance ◽  
Overall Design ◽  
Societal Challenges ◽  
Ideal System ◽  
Uncertainty Estimates ◽  
Infrared Spectrometer ◽  
Global Coverage

The Absolute Radiance Interferometer (ARI) is an infrared spectrometer designed to serve as an on-orbit radiometric reference with the ultra-high accuracy (better than 0.1 K 3‑σ or k = 3 brightness temperature at scene brightness temperature) needed to optimize measurement of the long-term changes of Earth’s atmosphere and surface. If flown in an orbit that frequently crosses sun-synchronous orbits, ARI could be used to inter-calibrate the international fleet of infrared (IR) hyperspectral sounders to similar measurement accuracy, thereby establishing an observing system capable of achieving sampling biases on high-information-content spectral radiance products that are also < 0.1 K 3‑σ. It has been shown that such a climate observing system with <0.1 K 2‑σ overall accuracy would make it possible to realize times to detect subtle trends of temperature and water vapor distributions that closely match those of an ideal system, given the limit set by the natural variability of the atmosphere. This paper presents the ARI sensor's overall design, the new technologies developed to allow on-orbit verification and test of its accuracy, and the laboratory results that demonstrate its capability. In addition, we describe the techniques and uncertainty estimates for transferring ARI accuracy to operational sounders, providing economical global coverage. Societal challenges posed by climate change suggest that a Pathfinder ARI should be deployed as soon as possible.

scholarly journals Consistent Long-Term Monthly Coastal Wetland Vegetation Monitoring Using a Virtual Satellite Constellation

2021 ◽  
Vol 13 (3) ◽  
pp. 438
Author(s):  
Subrina Tahsin ◽  
Stephen C. Medeiros ◽  
Arvind Singh
Keyword(s):  
Vegetation Index ◽  
Coastal Wetland ◽  
Thermal Emission ◽  
Mean Squared Error ◽  
Wetland Vegetation ◽  
Coefficient Of Determination ◽  
Landsat 8 ◽  
Vegetation Monitoring ◽  
Time Space

Long-term monthly coastal wetland vegetation monitoring is the key to quantifying the effects of natural and anthropogenic events, such as severe storms, as well as assessing restoration efforts. Remote sensing data products such as Normalized Difference Vegetation Index (NDVI), alongside emerging data analysis techniques, have enabled broader investigations into their dynamics at monthly to decadal time scales. However, NDVI data suffer from cloud contamination making periods within the time series sparse and often unusable during meteorologically active seasons. This paper proposes a virtual constellation for NDVI consisting of the red and near-infrared bands of Landsat 8 Operational Land Imager, Sentinel-2A Multi-Spectral Instrument, and Advanced Spaceborne Thermal Emission and Reflection Radiometer. The virtual constellation uses time-space-spectrum relationships from 2014 to 2018 and a random forest to produce synthetic NDVI imagery rectified to Landsat 8 format. Over the sample coverage area near Apalachicola, Florida, USA, the synthetic NDVI showed good visual coherence with observed Landsat 8 NDVI. Comparisons between the synthetic and observed NDVI showed Root Mean Squared Error and Coefficient of Determination (R2) values of 0.0020 sr−1 and 0.88, respectively. The results suggest that the virtual constellation was able to mitigate NDVI data loss due to clouds and may have the potential to do the same for other data. The ability to participate in a virtual constellation for a useful end product such as NDVI adds value to existing satellite missions and provides economic justification for future projects.

scholarly journals Satellite-Derived Protein Concentration of Phytoplankton in the Southwestern East/Japan Sea

2021 ◽  
Vol 9 (2) ◽  
pp. 189
Author(s):  
Hyeonji Bae ◽  
Dabin Lee ◽  
Jae Joong Kang ◽  
Jae Hyung Lee ◽  
Naeun Jo ◽  
...  
Keyword(s):  
Protein Concentration ◽  
Japan Sea ◽  
Biological Properties ◽  
Measured Data ◽  
Trophic Levels ◽  
Coefficient Of Determination ◽  
P Value ◽  
Chl A ◽  
Major Factors

The cellular macromolecular contents and energy value of phytoplankton as primary food source determine the growth of higher trophic levels, affecting the balance and sustainability of oceanic food webs. Especially, proteins are more directly linked with basic functions of phytoplankton biosynthesis and cell division and transferred through the food chains. In recent years, the East/Japan Sea (EJS) has been changed dramatically in environmental conditions, such as physical and chemical characteristics, as well as biological properties. Therefore, developing an algorithm to estimate the protein concentration of phytoplankton and monitor their spatiotemporal variations on a broad scale would be invaluable. To derive the protein concentration of phytoplankton in EJS, the new regional algorithm was developed by using multiple linear regression analyses based on field-measured data which were obtained from 2012 to 2018 in the southwestern EJS. The major factors for the protein concentration were identified as chlorophyll-a (Chl-a) and sea surface nitrate (SSN) in the southwestern EJS. The coefficient of determination (r2) between field-measured and algorithm-derived protein concentrations was 0.55, which is rather low but reliable. The satellite-derived estimation generally follows the 1:1 line with the field-measured data, with Pearson’s correlation coefficient, which was 0.40 (p-value < 0.01, n = 135). No remarkable trend in the long-term annual protein concentration of phytoplankton was found in the study area during our observation period. However, some seasonal difference was observed in winter protein concentration between the 2003–2005 and 2017–2019 periods. The algorithm is developed for the regional East/Japan Sea (EJS) and could contribute to long-term monitoring for climate-associated ecosystem changes. For a better understanding of spatiotemporal variation in the protein concentration of phytoplankton in the EJS, this algorithm should be further improved with continuous field surveys.

scholarly journals Development and Verification of the Available Number of Water Intake Days in Ungauged Local Water Source Using the SWAT Model and Flow Recession Curves

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1511
Author(s):  
Jung-Ryel Choi ◽  
Il-Moon Chung ◽  
Se-Jin Jeung ◽  
Kyung-Su Choo ◽  
Cheong-Hyeon Oh ◽  
...  
Keyword(s):  
Water Supply ◽  
Water Intake ◽  
Water Resource Management ◽  
Assessment Tool ◽  
Swat Model ◽  
High Water ◽  
Coefficient Of Determination ◽  
Severe Drought ◽  
Regional Government

Climate change significantly affects water supply availability due to changes in the magnitude and seasonality of runoff and severe drought events. In the case of Korea, despite high water supply ratio, more populations have continued to suffer from restricted regional water supplies. Though Korea enacted the Long-Term Comprehensive Water Resources Plan, a field survey revealed that the regional government organizations limitedly utilized their drought-related data. These limitations present a need for a system that provides a more intuitive drought review, enabling a more prompt response. Thus, this study presents a rating curve for the available number of water intake days per flow, and reviews and calibrates the Soil and Water Assessment Tool (SWAT) model mediators, and found that the coefficient of determination, Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS) from 2007 to 2011 were at 0.92, 0.84, and 7.2%, respectively, which were “very good” levels. The flow recession curve was proposed after calculating the daily long-term flow and extracted the flow recession trends during days without precipitation. In addition, the SWAT model’s flow data enables the quantitative evaluations of the number of available water intake days without precipitation because of the high hit rate when comparing the available number of water intake days with the limited water supply period near the study watershed. Thus, this study can improve drought response and water resource management plans.

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