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>

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>

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

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 A rapid deployment instrument network for temporarily monitoring volcanic SO<sub>2</sub> emissions – a study case from Telica volcano

2014 ◽  
Vol 4 (1) ◽  
pp. 191-211
Author(s):  
V. Conde ◽  
D. Nilsson ◽  
B. Galle ◽  
R. Cartagena ◽  
A. Muñoz
Keyword(s):  
Measurement Techniques ◽  
Active Volcano ◽  
Optical Absorption Spectroscopy ◽  
So2 Emissions ◽  
Volcanic Gas ◽  
Data Set ◽  
So2 Flux ◽  
Geophysical Processes ◽  
Rapid Deployment ◽  
Short Time

Abstract. Volcanic gas emissions play a crucial role in describing geophysical processes; hence measurements of magmatic gases such as SO2 can be used as tracers prior and during volcanic crises. Different measurement techniques based on optical spectroscopy have provided valuable information when assessing volcanic crises. This paper describes the design and implementation of a network of spectroscopic instruments based on Differential Optical Absorption Spectroscopy (DOAS) for remote sensing of volcanic SO2 emissions, which is robust, portable and can be deployed in relative short time. The setup allows the processing of raw data in situ even in remote areas with limited accessibility, and delivers pre-processed data to end-users in near real time even during periods of volcanic crisis, via a satellite link. In addition, the hardware can be used to conduct short term studies of volcanic plumes in remotes areas. The network was tested at Telica, an active volcano located in western Nicaragua, producing what is so far the largest data set of continuous SO2 flux measurements at this volcano.

scholarly journals Retrieval algorithm for OClO from TROPOMI by Differential Optical Absorption Spectroscopy

2021 ◽  
Author(s):  
Jānis Puķīte ◽  
Christian Borger ◽  
Steffen Dörner ◽  
Myojeong Gu ◽  
Udo Frieß ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Chlorine Dioxide ◽  
Large Scale ◽  
Order Term ◽  
Differential Optical Absorption Spectroscopy ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Polar Regions ◽  
Spectrally Resolved

Abstract. The TROPOspheric Monitoring Instrument (TROPOMI) is a UV-VIS-NIR-SWIR instrument on board of Sentinel-5P satellite developed for monitoring the Earth’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 3.5 x 7.2 km² (3.5 x 5.6 km² 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). 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 dependence of its formation to chlorine oxide (ClO). Here we present a new retrieval algorithm of the slant column densities (SCDs) of chlorine dioxide (OClO) by DOAS. To achieve a substantially improved accuracy, which is especially important for OClO observations, accounting for absorber and pseudo absorber structures in optical depth even of the order of 10−4 is important. Therefore in comparison to existing retrievals, we include several additional fit parameters accounting for spectral effects like the temperature dependency of the Ring effect and Ring absorption effects, higher order term for the OClO SCD dependency on wavelength and account for the BrO absorption. We investigate the performance of different retrieval settings by an error analysis with respect to random variations, large scale systematic variations as function of solar zenith angle and also more localised systematic variations by a novel application of an autocorrelation analysis. The retrieved TROPOMI OClO SCDs show a very good agreement with ground based zenith sky measurements and are correlated well with preliminary data of the opeartional TROPOMI OClO retrieval algorithm currently being developed as part of ESA's S5p+I project.

scholarly journals Linking atmospheric pollution to cryospheric change in the Third Pole region: current progress and future prospects

2019 ◽  
Vol 6 (4) ◽  
pp. 796-809 ◽  
Author(s):  
Shichang Kang ◽  
Qianggong Zhang ◽  
Yun Qian ◽  
Zhenming Ji ◽  
Chaoliu Li ◽  
...  
Keyword(s):  
Atmospheric Pollution ◽  
Environmental Changes ◽  
Temporal Variations ◽  
Global Perspective ◽  
Atmospheric Pollutants ◽  
Future Research ◽  
The Tibetan Plateau ◽  
Polar Regions ◽  
Research Framework ◽  
The Third

ABSTRACTThe Tibetan Plateau and its surroundings are known as the Third Pole (TP). This region is noted for its high rates of glacier melt and the associated hydrological shifts that affect water supplies in Asia. Atmospheric pollutants contribute to climatic and cryospheric changes through their effects on solar radiation and the albedos of snow and ice surfaces; moreover, the behavior and fates within the cryosphere and environmental impacts of environmental pollutants are topics of increasing concern. In this review, we introduce a coordinated monitoring and research framework and network to link atmospheric pollution and cryospheric changes (APCC) within the TP region. We then provide an up-to-date summary of progress and achievements related to the APCC research framework, including aspects of atmospheric pollution's composition and concentration, spatial and temporal variations, trans-boundary transport pathways and mechanisms, and effects on the warming of atmosphere and changing in Indian monsoon, as well as melting of glacier and snow cover. We highlight that exogenous air pollutants can enter into the TP’s environments and cause great impacts on regional climatic and environmental changes. At last, we propose future research priorities and map out an extended program at the global scale. The ongoing monitoring activities and research facilitate comprehensive studies of atmosphere–cryosphere interactions, represent one of China's key research expeditions to the TP and the polar regions and contribute to the global perspective of earth system science.

scholarly journals Enhanced tropospheric BrO over Antarctic sea ice in mid winter observed by MAX-DOAS on board the research vessel Polarstern

2007 ◽  
Vol 7 (12) ◽  
pp. 3129-3142 ◽  
Author(s):  
T. Wagner ◽  
O. Ibrahim ◽  
R. Sinreich ◽  
U. Frieß ◽  
R. von Glasow ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Sea Ice ◽  
Vertical Mixing ◽  
Satellite Observations ◽  
Research Vessel ◽  
Optical Absorption Spectroscopy ◽  
Back Trajectory ◽  
First Year ◽  
Polar Regions ◽  
Near Surface

Abstract. We present Multi AXis-Differential Optical Absorption Spectroscopy (MAX-DOAS) observations of tropospheric BrO carried out on board the German research vessel Polarstern during the Antarctic winter 2006. Polarstern entered the area of first year sea ice around Antarctica on 24 June 2006 and stayed within this area until 15 August 2006. For the period when the ship cruised inside the first year sea ice belt, enhanced BrO concentrations were almost continuously observed. Outside the first year sea ice belt, typically low BrO concentrations were found. Based on back trajectory calculations we find a positive correlation between the observed BrO differential slant column densities (ΔSCDs) and the duration for which the air masses had been in contact with the sea ice surface prior to the measurement. While we can not completely rule out that in several cases the highest BrO concentrations might be located close to the ground, our observations indicate that the maximum BrO concentrations might typically exist in a (possibly extended) layer around the upper edge of the boundary layer. Besides the effect of a decreasing pH of sea salt aerosol with altitude and therefore an increase of BrO with height, this finding might be also related to vertical mixing of air from the free troposphere with the boundary layer, probably caused by convection over the warm ocean surface at polynyas and cracks in the ice. Strong vertical gradients of BrO and O3 could also explain why we found enhanced BrO levels almost continuously for the observations within the sea ice. Based on our estimated BrO profiles we derive BrO mixing ratios of several ten ppt, which is slightly higher than many existing observations. Our observations indicate that enhanced BrO concentrations around Antarctica exist about one month earlier than observed by satellite instruments. From detailed radiative transfer simulations we find that MAX-DOAS observations are up to about one order of magnitude more sensitive to near-surface BrO than satellite observations. In contrast to satellite observations the MAX-DOAS sensitivity hardly decreases for large solar zenith angles and is almost independent from the ground albedo. Thus this technique is very well suited for observations in polar regions close to the solar terminator. For large periods of our measurements the solar elevation was very low or even below the horizon. For such conditions, most reactive Br-compounds might exist as Br2 molecules and ozone destruction and the removal of reactive bromine compounds might be substantially reduced.

scholarly journals Early in-flight detection of SO<sub>2</sub> via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

2011 ◽  
Vol 4 (3) ◽  
pp. 2827-2881 ◽  
Author(s):  
L. Vogel ◽  
B. Galle ◽  
C. Kern ◽  
H. Delgado Granados ◽  
V. Conde ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Volcanic Ash ◽  
Lower Troposphere ◽  
Differential Optical Absorption Spectroscopy ◽  
Cumulative Exposure ◽  
Optical Absorption Spectroscopy ◽  
Volcanic Plumes ◽  
Volcanic Clouds ◽  
Volcanic Cloud

Abstract. Volcanic ash constitutes a risk to aviation, mainly due to its ability to cause jet engines to fail. Other risks include the possibility of abrasion of windshields and potentially serious damage to avionic systems. These hazards have been widely recognized since the early 1980s, when volcanic ash provoked several incidents of engine failure in commercial aircraft. In addition to volcanic ash, volcanic gases also pose a threat. Prolonged and/or cumulative exposure to sulphur dioxide (SO2) or sulphuric acid (H2SO4) aerosols potentially affects e.g. windows, air frame and may cause permanent damage to engines. SO2 receives most attention among the gas species commonly found in volcanic plumes because its presence above the lower troposphere is a clear proxy for a volcanic cloud and indicates that fine ash could also be present. Up to now, remote sensing of SO2 via Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet spectral region has been used to measure volcanic clouds from ground based, airborne and satellite platforms. Attention has been given to volcanic emission strength, chemistry inside volcanic clouds and measurement procedures were adapted accordingly. Here we present a set of experimental and model results, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO2 in two spatial dimensions. In order to prove our new concept, simultaneous airborne and ground-based measurements of the plume of Popocatépetl volcano, Mexico, were conducted in April 2010. The plume extended at an altitude around 5250 m above sea level and was approached and traversed at the same altitude with several forward looking DOAS systems aboard an airplane. These DOAS systems measured SO2 in the flight direction and at ± 40 mrad (2.3°) angles relative to it in both, horizontal and vertical directions. The approaches started at up to 25 km distance to the plume and SO2 was measured at all times well above the detection limit. In combination with radiative transfer studies, this study indicates that an extended volcanic cloud with a concentration of 1012 molecules cm−3 at typical flight levels of 10 km can be detected unambiguously at distances of up to 80 km away. This range provides enough time (approx. 5 min) for pilots to take action to avoid entering a volcanic cloud in the flight path, suggesting that this technique can be used as an effective aid to prevent dangerous aircraft encounters with potentially ash rich volcanic clouds.

Reactive bromine chemistry in the Rann of Kachchh salt desert

2020 ◽  
Author(s):  
Jonas Kuhn ◽  
Vinod Kumar ◽  
Thomas Wagner ◽  
Simon Warnach ◽  
Ulrich Platt
Keyword(s):  
Transport Processes ◽  
Pollution Level ◽  
Ambient Atmosphere ◽  
Polar Regions ◽  
Ozone Monitoring Instrument ◽  
Volcanic Plumes ◽  
Heterogeneous Processes ◽  
Southern Border ◽  
Short Time ◽  
Salt Desert

&lt;p&gt;The Rann of Kachchh is a salt desert in the southern border area of India and Pakistan. Recently, high amounts of bromine monoxide (BrO) were observed there in satellite measurements of the Ozone Monitoring Instrument (OMI). Release mechanisms of reactive bromine, dominating chemical processes, the influence of the ambient atmosphere and transport processes, etc. are not well understood in general. Furthermore, due to their short time scales these processes are difficult to assess with satellite instruments, which only offer a single measurement per day with limited spatial resolution.&lt;/p&gt;&lt;p&gt;Here, we present BrO, HCHO and nitrogen dioxide (NO&lt;sub&gt;2&lt;/sub&gt;) measurements from ground-based MAX DOAS performed at two different locations in the Rann of Kachchh salt desert in Gujarat, India during three weeks in March and April 2019. We observe large amounts of BrO building up during daytime reaching maxima of several tens of ppt in the late afternoon. Additional mobile measurements performed directly over the salt gave similar results to the measurements at 5-15 km distance from the salt surface, suggesting that the BrO formation time scale and effective life times during daytime are at least of the order of several minutes to a few hours. Additional in-situ ozone measurements indicate ozone depletion events linked to the episodes of high BrO abundance. This indicates that BrO is formed by bromine atoms reacting with ozone and then being recycled via BrO self-reaction and heterogeneous processes involving aerosol surfaces, as proposed for other environments (Polar Regions, volcanic plumes).&lt;/p&gt;&lt;p&gt;While we found high but steady HCHO levels, the observed NO&lt;sub&gt;2&lt;/sub&gt; levels showed a distinct anti-correlation to BrO, indicating coupling of bromine- and NO&lt;sub&gt;x&lt;/sub&gt;-chemistry and thereby the influence of the pollution level of the ambient atmosphere. Formation of bromine nitrate probably delays the formation of large BrO amounts, but might also support the recycling of bromine atoms through heterogeneous chemistry.&lt;/p&gt;

Bio-oil as Substitute of Phenol for Synthesis of Resol-type Phenolic Resin as Wood Adhesive

2017 ◽  
Vol 16 (3) ◽  
Author(s):  
Fangjia Dong ◽  
Mingcun Wang ◽  
Zhehui Wang
Keyword(s):  
Weight Ratio ◽  
Wood Adhesive ◽  
Exothermic Peak ◽  
Molar Ratio ◽  
Type I ◽  
Thermal Cure ◽  
Molar Ratios ◽  
Comprehensive Properties ◽  
Bio Oil ◽  
Resol Resin

AbstractThe bio-oil from fast pyrolysis of cornstalks was used as substitute of phenol to synthesize resol resin as an ideal wood adhesive. The effects of formaldehyde/phenol (F/P) molar ratios and oil/phenol (O/P) weight ratios on rehology, thermal cure, thermal resistance and adhension of plywoods were investigated. With the increase of bio-oil used in bio-resol, the gel time of the prepared bio-oil modified resol resin (bio-resol resin) increased gradually, and the exothermic peak temperature of thermal cure shifted slightly higher. It was found that the bio-resin with bio-oil/phenol = 0.5 (weight ratio) and F/P = 1.5 (molar ratio) had the best comprehensive properties. The plywoods made with the bio-resol resins fulfilled the standards of E0and type I plywood, implying the bio-resol resins was a new environment-friendly adhesive.

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