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Sample records for volcanic so2 measurements

  1. Re-processing TOMS UV Measurements to Retrieve SO2 Emissions From Volcanic Eruptions

    Science.gov (United States)

    Fisher, B. L.; Krotkov, N. A.; Bhartia, P. K.; Li, C.; Haffner, D. P.; Leonard, P.; Carn, S. A.; Telling, J. W.

    2015-12-01

    The SO2 Monitoring Group at the NASA Goddard Space Flight Center is producing a new multi-satellite long term data set of volcanic SO2 column amounts and heights (MSVOLSO2L4) as part of the NASA MEaSUREs Program. Here we present re-analysis of the UV measurements (BUV) from the NASA Nimbus 7 Total Ozone Mapping Spectrometer (N7 TOMS: 1978-1993). Ozone is the dominant atmospheric absorber in the BUV spectrum, but volcanic eruptions can produce enough SO2 to be distinguished from ozone background. Quantitative retrieval of volcanic SO2 requires:1) Separation of the O3 and SO2 absorption in BUV radiances;2) Close to zero mean SO2 background;3) RT forward model that accounts for the presence of volcanic ash in the plume; 4) A priori knowledge of the ozone and SO2 vertical profiles.Our iterative retrieval algorithm returns O3 and SO2 column amounts, effective reflectivity and its spectral slope. The retrieval model also generates a 4 x 4 gain matrix for the SO2 free regions that is used to soft calibrate the measured 340 nm BUV radiance. The spectral slope implicitly accounts for the interference of volcanic ash, but more explicit ash treatment is required to better quantify SO2 errors in volcanic plumes heavily loaded with ash. This presentation will discuss the methods used to characterize the error sources and assess the quality of this unique long-term SO2 data set.

  2. A decade of global volcanic SO2 emissions measured from space

    Science.gov (United States)

    Carn, S. A.; Fioletov, V. E.; McLinden, C. A.; Li, C.; Krotkov, N. A.

    2017-03-01

    The global flux of sulfur dioxide (SO2) emitted by passive volcanic degassing is a key parameter that constrains the fluxes of other volcanic gases (including carbon dioxide, CO2) and toxic trace metals (e.g., mercury). It is also a required input for atmospheric chemistry and climate models, since it impacts the tropospheric burden of sulfate aerosol, a major climate-forcing species. Despite its significance, an inventory of passive volcanic degassing is very difficult to produce, due largely to the patchy spatial and temporal coverage of ground-based SO2 measurements. We report here the first volcanic SO2 emissions inventory derived from global, coincident satellite measurements, made by the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite in 2005-2015. The OMI measurements permit estimation of SO2 emissions from over 90 volcanoes, including new constraints on fluxes from Indonesia, Papua New Guinea, the Aleutian Islands, the Kuril Islands and Kamchatka. On average over the past decade, the volcanic SO2 sources consistently detected from space have discharged a total of ~63 kt/day SO2 during passive degassing, or ~23 ± 2 Tg/yr. We find that ~30% of the sources show significant decadal trends in SO2 emissions, with positive trends observed at multiple volcanoes in some regions including Vanuatu, southern Japan, Peru and Chile.

  3. Multi-decadal satellite measurements of passive and eruptive volcanic SO2 emissions

    Science.gov (United States)

    Carn, Simon; Yang, Kai; Krotkov, Nickolay; Prata, Fred; Telling, Jennifer

    2015-04-01

    Periodic injections of sulfur gas species (SO2, H2S) into the stratosphere by volcanic eruptions are among the most important, and yet unpredictable, drivers of natural climate variability. However, passive (lower tropospheric) volcanic degassing is the major component of total volcanic emissions to the atmosphere on a time-averaged basis, but is poorly constrained, impacting estimates of global emissions of other volcanic gases (e.g., CO2). Stratospheric volcanic emissions are very well quantified by satellite remote sensing techniques, and we report ongoing efforts to catalog all significant volcanic SO2 emissions into the stratosphere and troposphere since 1978 using measurements from the ultraviolet (UV) Total Ozone Mapping Spectrometer (TOMS; 1978-2005), Ozone Monitoring Instrument (OMI; 2004 - present) and Ozone Mapping and Profiler Suite (OMPS; 2012 - present) instruments, supplemented by infrared (IR) data from HIRS, MODIS and AIRS. The database, intended for use as a volcanic forcing dataset in climate models, currently includes over 600 eruptions releasing a total of ~100 Tg SO2, with a mean eruption discharge of ~0.2 Tg SO2. Sensitivity to SO2 emissions from smaller eruptions greatly increased following the launch of OMI in 2004, but uncertainties remain on the volcanic flux of other sulfur species other than SO2 (H2S, OCS) due to difficulty of measurement. Although the post-Pinatubo 1991 era is often classified as volcanically quiescent, many smaller eruptions (Volcanic Explosivity Index [VEI] 3-4) since 2000 have injected significant amounts of SO2 into the upper troposphere - lower stratosphere (UTLS), peaking in 2008-2011. We also show how even smaller (VEI 2) tropical eruptions can impact the UTLS and sustain above-background stratospheric aerosol optical depth, thus playing a role in climate forcing on short timescales. To better quantify tropospheric volcanic degassing, we use ~10 years of operational SO2 measurements by OMI to identify the

  4. Comparison of Low Cost Miniature Spectrometers for Volcanic SO2 Emission Measurements

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    Euripides P. Kantzas

    2009-04-01

    Full Text Available Miniature ultraviolet USB coupled spectrometers have become ubiquitously applied over the last decade for making volcanic SO2 emission rate measurements. The dominantly applied unit has recently been discontinued however, raising the question of which currently available devices should now be implemented. In this paper, we consider, and make recommendations on this matter, by studying a number of inexpensive compact spectrometers in respect of measurement performance and thermal behaviour. Of the studied units, the Avaspec demonstrated the best prospects for the highest time resolution applications, but in the majority of cases, we anticipate users likely preferring the less bulky USB2000+s.

  5. Comparison of Low Cost Miniature Spectrometers for Volcanic SO2 Emission Measurements

    Science.gov (United States)

    Kantzas, Euripides P.; McGonigle, Andrew J. S.; Bryant, Robert G.

    2009-01-01

    Miniature ultraviolet USB coupled spectrometers have become ubiquitously applied over the last decade for making volcanic SO2 emission rate measurements. The dominantly applied unit has recently been discontinued however, raising the question of which currently available devices should now be implemented. In this paper, we consider, and make recommendations on this matter, by studying a number of inexpensive compact spectrometers in respect of measurement performance and thermal behaviour. Of the studied units, the Avaspec demonstrated the best prospects for the highest time resolution applications, but in the majority of cases, we anticipate users likely preferring the less bulky USB2000+s. PMID:22412310

  6. Vulcamera: a program for measuring volcanic SO2 using UV cameras

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    Alessandro Aiuppa

    2011-06-01

    Full Text Available We report here on Vulcamera, a stand-alone program for the determination of volcanic SO2  fluxes using ultraviolet cameras. The code enables field image acquisition and all the required post-processing operations.

  7. A Low-Cost Smartphone Sensor-Based UV Camera for Volcanic SO2 Emission Measurements

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    Thomas Charles Wilkes

    2017-01-01

    Full Text Available Recently, we reported on the development of low-cost ultraviolet (UV cameras, based on the modification of sensors designed for the smartphone market. These units are built around modified Raspberry Pi cameras (PiCams; ≈USD 25, and usable system sensitivity was demonstrated in the UVA and UVB spectral regions, of relevance to a number of application areas. Here, we report on the first deployment of PiCam devices in one such field: UV remote sensing of sulphur dioxide emissions from volcanoes; such data provide important insights into magmatic processes and are applied in hazard assessments. In particular, we report on field trials on Mt. Etna, where the utility of these devices in quantifying volcanic sulphur dioxide (SO2 emissions was validated. We furthermore performed side-by-side trials of these units against scientific grade cameras, which are currently used in this application, finding that the two systems gave virtually identical flux time series outputs, and that signal-to-noise characteristics of the PiCam units appeared to be more than adequate for volcanological applications. Given the low cost of these sensors, allowing two-filter SO2 camera systems to be assembled for ≈USD 500, they could be suitable for widespread dissemination in volcanic SO2 monitoring internationally.

  8. Retrieval of SO2 from thermal infrared satellite measurements: correction procedures for the effects of volcanic ash

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    S. Corradini

    2009-05-01

    Full Text Available The simultaneous presence of SO2 and ash in a volcanic plume can lead to a significant error in the SO2 column abundance retrieval when multispectral Thermal InfraRed (TIR data are used. The ash particles within the plume with effective radii from 1 to 10 μm reduce the Top Of Atmosphere (TOA radiance in the entire TIR spectral range, including the channels used for SO2 retrieval. The net effect is a significant SO2 overestimation. In this work the interference of ash is discussed and two correction procedures for satellite SO2 volcanic plume retrieval in the TIR spectral range are developed to achieve an higher computational speed and a better accuracy. The ash correction can be applied when the sensor spectral range includes the 7.3 and/or 8.7 μm SO2 absorption bands, and the split window bands centered around 11 and 12 μm required for ash retrieval. This allows the possibility of simultaneous estimation of both volcanic SO2 and ash in the same data set. The proposed ash correction procedures have been applied to the Moderate Resolution Imaging Spectroradiometer (MODIS and the Spin Enhanced Visible and Infrared Imager (SEVIRI measurements. Data collected during the 24 November 2006 Mt. Etna eruption have been used to illustrate the technique. The SO2 and ash estimation is carried out by using a best weighted least squares fit method and the Brightness Temperature Difference (BTD procedures, respectively. The simulated TOA radiance Look-Up Table (LUT needed for the SO2 column abundance and the ash retrievals have been computed using the MODTRAN 4 Radiative Transfer Model. The results show the importance of the ash correction on SO2 retrievals at 8.7 μm, where the corrected SO2 column abundance values are less than 50% of the uncorrected values. The ash correction on SO2 retrieval at 7.3 μm is much less important and only significant for low SO2 column abundances. Results also show that the simplified and faster correction procedure

  9. Retrieval of SO2 from thermal infrared satellite measurements: correction procedures for the effects of volcanic ash

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    A. J. Prata

    2009-02-01

    Full Text Available The simultaneous presence of SO2 and ash in a volcanic plume can lead to a significant error in the SO2 columnar abundance retrieval when multispectral Thermal InfraRed (TIR data are used. The ash particles within the plume with effective radii (from 1 to 10 μm reduce the Top Of Atmosphere (TOA radiance in the entire TIR spectral range, including the channels used for SO2 retrieval. The net effect is a significant SO2 overestimation. In this work the interference of ash is discussed and two correction procedures for satellite SO2 volcanic plume retrieval in the TIR spectral range are developed to achieve an higher computation speed and a better accuracy. The ash correction can be applied when the sensor spectral range includes the 7.3 and/or 8.7 μm SO2 absorption bands, and the split window bands centered around 11 and 12 μm required for ash retrieval. This allows the possibility of a simultaneous estimation of both volcanic SO2 and ash in the same data set. The proposed ash correction procedures have been applied to the Moderate Resolution Imaging Spectroradiometer (MODIS and the Spin Enhanced Visible and Infrared Imager (SEVIRI measurements. Data collected during the 24 November 2006 Mt. Etna eruption have been used to illustrate the technique. The SO2 and ash estimations are carried out by using a least squares fit method and the Brightness Temperature Difference (BTD procedures, respectively. The simulated TOA radiance Look-Up Table (LUT needed for the SO2 columnar abundance and the ash retrievals have been computed using the MODTRAN 4 Radiative Transfer Model. The results show the importance of the ash correction on SO2 retrieval at 8.7 μm – the SO2 columnar abundance corrected by the ash influence is less than one half of the values retrieved without the correction. The ash correction on SO2 retrieval at 7.3 μm is much less important and only significant for low SO2 columnar abundances. Results also show that the simplified and

  10. Early in-flight detection of SO2 via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

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    U. Platt

    2011-09-01

    Full Text Available 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

  11. Early in-flight detection of SO2 via Differential Optical Absorption Spectroscopy: A feasible aviation safety measure to prevent potential encounters with volcanic plumes

    Science.gov (United States)

    Vogel, L.; Galle, B.; Kern, C.; Delgado, Granados H.; Conde, V.; Norman, P.; Arellano, S.; Landgren, O.; Lubcke, P.; Alvarez, Nieves J.M.; Cardenas, Gonzales L.; Platt, U.

    2011-01-01

    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 5 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 10 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 vol- 15 canic 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 Popocatepetl 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 25 the plume and SO2 was measured at all times well above the detection

  12. Simulated Radiative Transfer DOAS - A new method for improving volcanic SO2 emissions retrievals from ground-based UV-spectroscopic measurements of scattered solar radiation

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    Kern, C.; Deutschmann, T.; Vogel, L.; Bobrowski, N.; Hoermann, C.; Werner, C. A.; Sutton, A. J.; Elias, T.

    2011-12-01

    Passive Differential Optical Absorption Spectroscopy (DOAS) has become a standard tool for measuring SO2 at volcanoes. More recently, ultra-violet (UV) cameras have also been applied to obtain 2D images of SO2-bearing plumes. Both techniques can be used to derive SO2 emission rates by measuring SO2 column densities, integrating these along the plume cross-section, and multiplying by the wind speed. Recent measurements and model studies have revealed that the dominating source of uncertainty in these techniques often originates from an inaccurate assessment of radiative transfer through the volcanic plume. The typical assumption that all detected radiation is scattered behind the volcanic plume and takes a straight path from there to the instrument is often incorrect. We recently showed that the straight path assumption can lead to column density errors of 50% or more in cases where plumes with high SO2 and aerosol concentrations are measured from several kilometers distance, or where the background atmosphere contains a large amount of scattering aerosols. Both under- and overestimation are possible depending on the atmospheric conditions and geometry during spectral acquisition. Simulated Radiative Transfer (SRT) DOAS is a new evaluation scheme that combines radiative transfer modeling with spectral analysis of passive DOAS measurements in the UV region to derive more accurate SO2 column densities than conventional DOAS retrievals, which in turn leads to considerably more accurate emission rates. A three-dimensional backward Monte Carlo radiative transfer model is used to simulate realistic light paths in and around the volcanic plume containing variable amounts of SO2 and aerosols. An inversion algorithm is then applied to derive the true SO2 column density. For fast processing of large datasets, a linearized algorithm based on lookup tables was developed and tested on a number of example datasets. In some cases, the information content of the spectral data is

  13. Satellite Observations of Atmospheric SO2 from Volcanic Eruptions

    Science.gov (United States)

    Khokhar, M. F.; Platt, U.; Wagner, T.

    Volcanoes are an important source of various atmospheric trace gases. Volcanic eruptions and their emissions are sporadic and intermittent and often occur in uninhabited regions. Therefore assessing the amount and size of the gaseous and particulate emission from volcanoes is difficult. Satellite remote sensing measurements provide one well suited opportunity to overcome this difficulty. Onboard ERS-2, GOME's moderate spectral resolution enables us to apply the Differential Optical Absorption Spectroscopy (DOAS) algorithm to retrieve SO2 column densities from radiance/irradiance measurements in UV spectral region. Volcanic emissions can cause significant variations of climate on a variety of time scales; just one very large eruption can cause a measurable change in the Earth's climate with a time scale of a few years. Stratospheric aerosols produced by volcanic eruptions can influence stratospheric chemistry both through chemical reactions that take place on the surface of the aerosols and through temperature changes induced by their presence in the stratosphere. In this work we give a comprehensive overview on several volcanoes and the retrieval of SO2 column densities from GOME data for the years 1996 - 2002. The focus is on both eruption and out gassing scenarios from different volcanic eruptions in Italy, Iceland, Congo/ Zaire, Ecuador and Mexico.

  14. Observations of Volcanic SO2 and HCl from Aura MLS

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    Read, W. G.; Froidevaux, L.; Santee, M. L.; Livesey, N. J.

    2009-12-01

    The Microwave Limb Sounder (MLS) on board the Aura satellite has been taking composition measurements of the Earth's upper troposphere, stratosphere and mesosphere for the past 5 years. During this time period, MLS has observed volcanic emissions from Manam, Anatahan, Soufriere Hills, Okmok, Kasatochi, Redoubt,and Sarychev eruptions. The eruptions from these volcanoes injected SO2 and HCl into the lower stratosphere. MLS makes vertically resolved measurements of these gases and therefore can determine the injection height of these volcanoes. We will provide a survey of the eruptions MLS has observed to date and compare results to SO2 columns seen by the Ozone Monitoring Instrument (OMI), also on the Aura satellite. Aura MLS however, can only make measurements along its orbit track twice daily which limits its usefulness for hazards detection or determining the amount of injected SO2. The utility of these measurements for hazard detection will be greatly enhanced in the next generation MLS instrument envisioned for the third tier decadal survey Global Atmospheric Composition Mission (GACM). The future mission will provide 50 km^2 near global coverage with 4--6 observations per day.

  15. Observations of volcanic SO2 from MLS on Aura

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    H. C. Pumphrey

    2014-07-01

    Full Text Available Sulphur dioxide (SO2 is an important atmospheric constituent, particularly in the aftermath of volcanic eruptions. These events can inject large amounts of SO2 into the lower stratosphere, where it is oxidised to form sulphate aerosols; these in turn have a significant effect on the climate. The MLS instrument on the Aura satellite has observed the SO2 mixing ratio in the upper troposphere and lower stratosphere from August 2004 to the present, during which time a number of volcanic eruptions have significantly affected those regions of the atmosphere. We describe the MLS SO2 data and how various volcanic events appear in the data. As the MLS SO2 data are currently not validated we take some initial steps towards their validation. First we establish the level of internal consistency between the three spectral regions in which MLS is sensitive to SO2. We compare SO2 column values calculated from MLS data to total column values reported by the OMI instrument. The agreement is good in cases where the SO2 is clearly at altitudes above 147 hPa.

  16. Observations of volcanic SO2 from MLS on Aura

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    H. C. Pumphrey

    2015-01-01

    Full Text Available Sulfur dioxide (SO2 is an important atmospheric constituent, particularly in the aftermath of volcanic eruptions. These events can inject large amounts of SO2 into the lower stratosphere, where it is oxidised to form sulfate aerosols; these in turn have a significant effect on the climate. The MLS instrument on the Aura satellite has observed the SO2 mixing ratio in the upper troposphere and lower stratosphere from August 2004 to the present, during which time a number of volcanic eruptions have significantly affected those regions of the atmosphere. We describe the MLS SO2 data and how various volcanic events appear in the data. As the MLS SO2 data are currently not validated we take some initial steps towards their validation. First we establish the level of internal consistency between the three spectral regions in which MLS is sensitive to SO2. We compare SO2 column values calculated from MLS data to total column values reported by the OMI instrument. The agreement is good (within about 1 DU in cases where the SO2 is clearly at altitudes above 147 hPa.

  17. Monitoring of volcanic SO2 emissions using the GOME-2 instrument

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    Hedelt, Pascal; Valks, Pieter; Loyola, Diego

    2014-05-01

    This contribution focusses on the GOME-2 SO2 column products from the METOP-A and B satellites. The GOME-2 SO2 column product has been developed in the framework of EUMETSAT's Satellite Application Facility on Ozone and Atmospheric Chemistry Monitoring (O3M-SAF). Satellite-based remote sensing measurements of volcanic SO2 provide critical information for reducing volcanic hazards. Volcanic eruptions may bring ash and gases (e.g. SO2) high up into the atmosphere, where a long-range transport can occur. SO2 is an important indicator for volcanic activity and an excellent tracer for volcanic eruption clouds, especially if ash detection techniques fail. SO2 can affect aviation safety: In the cabin it can cause disease and respiratory symptoms, whereas in its hydrogenated form H2SO4 it is highly corrosive and can cause damage to jet engines as well as pitting of windscreens. We will present results for volcanic events retrieved from GOME-2 solar backscattered measurements in the UV wavelength region around 320nm using the Differential Optical Absorption Spectroscopy (DOAS) method. SO2 columns are generated operationally by DLR with the GOME Data Processor (GDP) version 4.7 and are available in near-real-time, i.e. within two hours after sensing. Using data from both MetOp satellites allows for a daily global coverage. We will furthermore present current improvements to the GOME-2 SO2 column product.

  18. SO2 flux and the thermal power of volcanic eruptions

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    Henley, Richard W.; Hughes, Graham O.

    2016-09-01

    A description of the dynamics, chemistry and energetics governing a volcanic system can be greatly simplified if the expansion of magmatic gas can be assumed to be adiabatic as it rises towards the surface. The conditions under which this assumption is valid are clarified by analysis of the transfer of thermal energy into the low conductivity wallrocks traversed by fractures and vents from a gas phase expanding over a range of mass flux rates. Adiabatic behavior is predicted to be approached typically within a month after perturbations in the release of source gas have stabilized, this timescale being dependent upon only the characteristic length scale on which the host rock is fractured and the thermal diffusivity of the rock. This analysis then enables the thermal energy transport due to gas release from volcanoes to be evaluated using observations of SO2 flux with reference values for the H2O:SO2 ratio of volcanic gas mixtures discharging through high temperature fumaroles in arc and mantle-related volcanic systems. Thermal power estimates for gas discharge are 101.8 to 104.1 MWH during quiescent, continuous degassing of arc volcanoes and 103.7 to 107.3 MWH for their eruptive stages, the higher value being the Plinean Pinatubo eruption in 1991. Fewer data are available for quiescent stage mantle-related volcanoes (Kilauea 102.1 MWH) but for eruptive events power estimates range from 102.8 MWH to 105.5 MWH. These estimates of thermal power and mass of gas discharges are commensurate with power estimates based on the total mass of gas ejected during eruptions. The sustained discharge of volcanic gas during quiescent and short-lived eruptive stages can be related to the hydrodynamic structure of volcanic systems with large scale gaseous mass transfer from deep in the crust coupled with episodes of high level intrusive activity and gas release.

  19. Volcanic SO2, BrO and plume height estimations using GOME‐2 satellite measurements during the eruption of Eyjafjallajökull in May 2010

    National Research Council Canada - National Science Library

    Rix, M; Valks, P; Hao, N; Loyola, D; Schlager, H; Huntrieser, H; Flemming, J; Koehler, U; Schumann, U; Inness, A

    2012-01-01

    ... plume heights are important for aviation safety. This paper describes the observations of SO 2 and BrO columns in the eruption plume and the determination of the SO 2 plume height using the GOME...

  20. High frequency SO2 flux measurements at Semeru volcano, Indonesia, using the SO2 camera

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    Smekens, J.; Burton, M. R.; Clarke, A. B.; Harijoko, A.; Wibowo, H.; Sawyer, G.

    2013-12-01

    SO2 monitoring is a common technique at many volcanic centers. Recently, automated networks of scanning spectrometers have led to great improvement in frequency and accuracy of measurements. Simultaneously a new instrument has been proposed to acquire 2D images of volcanic plumes in the UV spectrum. This imaging technique (hereafter referred to as the SO2 camera) provides additional contextual information, as well as a quantitative way of determining plume velocity from a single remote location, without relying on weather reports. These advantages are to be balanced against a loss of spectroscopic information associated with using band-pass filters that reduce precision in the measurements. We have developed a custom-built acquisition and processing software to be used with the SO2 camera developed by INGV-Pisa for monitoring of Etna and Stromboli, which consists of two Quantum Scientific Imaging CCD cameras equipped with UV filters and a USB2000+ spectrometer. We have tested the instrument at two power plants in Arizona, USA. We were able to successfully measure SO2 fluxes as low as 1-2 tons/day. We also validated our method by comparing the SO2 camera measurements against high-frequency in-situ measurements (1 data point every minute) obtained from chemical sensors within the stacks. We have also used the SO2 camera during a field campaign at Semeru volcano, Indonesia, in May and June of 2013. Semeru is a persistently active explosive volcano, whose latest eruption began in 1967. Its eruptive behavior can be characterized by cyclic dome growth and collapse in the active crater and frequent small magnitude explosions occurring at periods of minutes to hours. We found that the majority of SO2 at Semeru is released during the explosive phases (instantaneous peaks of up to 40 kg/s), with passive emission levels between explosions fluctuating from 0-5 kg/s. After the initial explosive release, emission returns to background levels following an exponential decline over

  1. Intercomparison of SO2 camera systems for imaging volcanic gas plumes

    Science.gov (United States)

    Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-François; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

    2015-07-01

    SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

  2. Intercomparison of SO2 camera systems for imaging volcanic gas plumes

    Science.gov (United States)

    Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-Francois; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

    2015-01-01

    SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

  3. Recent advances in ground-based ultraviolet remote sensing of volcanic SO2 fluxes

    Directory of Open Access Journals (Sweden)

    Euripides P. Kantzas

    2011-06-01

    Full Text Available Measurements of volcanic SO2 emission rates have been the mainstay of remote-sensing volcanic gas geochemistry for almost four decades, and they have contributed significantly to our understanding of volcanic systems and their impact upon the atmosphere. The last ten years have brought step-change improvements in the instrumentation applied to these observations, which began with the application of miniature ultraviolet spectrometers that were deployed in scanning and traverse configurations, with differential optical absorption spectroscopy evaluation routines. This study catalogs the more recent empirical developments, including: ultraviolet cameras; wide-angle field-of-view differential optical absorption spectroscopy systems; advances in scanning operations, including tomography; and improved understanding of errors, in particular concerning radiative transfer. Furthermore, the outcomes of field deployments of sensors during the last decade are documented, with respect to improving our understanding of volcanic dynamics and degassing into the atmosphere.

  4. Applying UV cameras for SO2 detection to distant or optically thick volcanic plumes

    Science.gov (United States)

    Kern, Christoph; Werner, Cynthia; Elias, Tamar; Sutton, A. Jeff; Lübcke, Peter

    2013-01-01

    Ultraviolet (UV) camera systems represent an exciting new technology for measuring two dimensional sulfur dioxide (SO2) distributions in volcanic plumes. The high frame rate of the cameras allows the retrieval of SO2 emission rates at time scales of 1 Hz or higher, thus allowing the investigation of high-frequency signals and making integrated and comparative studies with other high-data-rate volcano monitoring techniques possible. One drawback of the technique, however, is the limited spectral information recorded by the imaging systems. Here, a framework for simulating the sensitivity of UV cameras to various SO2 distributions is introduced. Both the wavelength-dependent transmittance of the optical imaging system and the radiative transfer in the atmosphere are modeled. The framework is then applied to study the behavior of different optical setups and used to simulate the response of these instruments to volcanic plumes containing varying SO2 and aerosol abundances located at various distances from the sensor. Results show that UV radiative transfer in and around distant and/or optically thick plumes typically leads to a lower sensitivity to SO2 than expected when assuming a standard Beer–Lambert absorption model. Furthermore, camera response is often non-linear in SO2 and dependent on distance to the plume and plume aerosol optical thickness and single scatter albedo. The model results are compared with camera measurements made at Kilauea Volcano (Hawaii) and a method for integrating moderate resolution differential optical absorption spectroscopy data with UV imagery to retrieve improved SO2 column densities is discussed.

  5. Volcanic SO2 fluxes derived from satellite data: a survey using OMI, GOME-2, IASI and MODIS

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    N. Theys

    2013-06-01

    Full Text Available Sulphur dioxide (SO2 fluxes of active degassing volcanoes are routinely measured with ground-based equipment to characterize and monitor volcanic activity. SO2 of unmonitored volcanoes or from explosive volcanic eruptions, can be measured with satellites. However, remote-sensing methods based on absorption spectroscopy generally provide integrated amounts of already dispersed plumes of SO2 and satellite derived flux estimates are rarely reported. Here we review a number of different techniques to derive volcanic SO2 fluxes using satellite measurements of plumes of SO2 and investigate the temporal evolution of the total emissions of SO2 for three very different volcanic events in 2011: Puyehue-Cordón Caulle (Chile, Nyamulagira (DR Congo and Nabro (Eritrea. High spectral resolution satellite instruments operating both in the ultraviolet-visible (OMI/Aura and GOME-2/MetOp-A and thermal infrared (IASI/MetOp-A spectral ranges, and multispectral satellite instruments operating in the thermal infrared (MODIS/Terra-Aqua are used. We show that satellite data can provide fluxes with a sampling of a day or less (few hours in the best case. Generally the flux results from the different methods are consistent, and we discuss the advantages and weaknesses of each technique. Although the primary objective of this study is the calculation of SO2 fluxes, it also enables us to assess the consistency of the SO2 products from the different sensors used.

  6. piscope - A Python based software package for the analysis of volcanic SO2 emissions using UV SO2 cameras

    Science.gov (United States)

    Gliss, Jonas; Stebel, Kerstin; Kylling, Arve; Solvejg Dinger, Anna; Sihler, Holger; Sudbø, Aasmund

    2017-04-01

    UV SO2 cameras have become a common method for monitoring SO2 emission rates from volcanoes. Scattered solar UV radiation is measured in two wavelength windows, typically around 310 nm and 330 nm (distinct / weak SO2 absorption) using interference filters. The data analysis comprises the retrieval of plume background intensities (to calculate plume optical densities), the camera calibration (to convert optical densities into SO2 column densities) and the retrieval of gas velocities within the plume as well as the retrieval of plume distances. SO2 emission rates are then typically retrieved along a projected plume cross section, for instance a straight line perpendicular to the plume propagation direction. Today, for most of the required analysis steps, several alternatives exist due to ongoing developments and improvements related to the measurement technique. We present piscope, a cross platform, open source software toolbox for the analysis of UV SO2 camera data. The code is written in the Python programming language and emerged from the idea of a common analysis platform incorporating a selection of the most prevalent methods found in literature. piscope includes several routines for plume background retrievals, routines for cell and DOAS based camera calibration including two individual methods to identify the DOAS field of view (shape and position) within the camera images. Gas velocities can be retrieved either based on an optical flow analysis or using signal cross correlation. A correction for signal dilution (due to atmospheric scattering) can be performed based on topographic features in the images. The latter requires distance retrievals to the topographic features used for the correction. These distances can be retrieved automatically on a pixel base using intersections of individual pixel viewing directions with the local topography. The main features of piscope are presented based on dataset recorded at Mt. Etna, Italy in September 2015.

  7. Massive Volcanic SO2 Oxidation and Sulphate Aerosol Deposition in Cenozoic North America

    Science.gov (United States)

    Volcanic eruptions release a large amount of sulphur dioxide (SO2) into the atmosphere. SO2 is oxidized to sulphate and can subsequently form sulphate aerosol, which can affect the Earth's radiation balance, biologic productivity and high-altitude ozone co...

  8. SO2-flux measurements and BrO/SO2 ratios at Guallatiri volcano, Altiplano, northern Chile

    Science.gov (United States)

    Gliss, Jonas; Stebel, Kerstin; Thomas, Helen

    2015-04-01

    Sulphur dioxide (SO2) fluxes were measured recently at Guallatiri volcano using two UV SO2-cameras and one IR SO2-camera. Furthermore, measurements of reactive halogens (e.g. BrO, OClO) were investigated using a high performance DOAS (Differential Optical Absorption Spectroscopy) instrument. Guallatiri (18° 25' 00″ S, 69° 5' 30″ W, 6.071 m a.s.l.) is situated in the Altiplano in northern Chile, close to the Bolivian border. The last known eruption of Guallatiri was in 1960. The measurements were performed during a short-term field trip on three days in November 2014 (20.11.-22.11.2014). During that time, the volcano showed a quiescent degassing behaviour from the summit crater and from a fumarolic field on the southern flank. A preliminary evaluation of the spectra recorded with the DOAS instruments showed SO2 column amounts (SCDs) up to 3 - 1017 molec/cm2 and BrO-SCDs of the order of several 1013 molec/cm2. This corresponds to BrO/SO2-ratios of the order of 10-4 which is a typical order of magnitude for volcanic emissions. We will present SO2-flux estimates for Guallatiri volcano during these three days as well as BrO/SO2-ratio estimates in dependence of different plume ages. Furthermore, we will compare the results retrieved with the two UV-cameras with the data recorded simultaneously with the IR-camera.

  9. Retrieval of volcanic SO2 from HIRS/2 using optimal estimation

    Science.gov (United States)

    Miles, Georgina M.; Siddans, Richard; Grainger, Roy G.; Prata, Alfred J.; Fisher, Bradford; Krotkov, Nickolay

    2017-07-01

    We present an optimal-estimation (OE) retrieval scheme for stratospheric sulfur dioxide from the High-Resolution Infrared Radiation Sounder 2 (HIRS/2) instruments on the NOAA and MetOp platforms, an infrared radiometer that has been operational since 1979. This algorithm is an improvement upon a previous method based on channel brightness temperature differences, which demonstrated the potential for monitoring volcanic SO2 using HIRS/2. The Prata method is fast but of limited accuracy. This algorithm uses an optimal-estimation retrieval approach yielding increased accuracy for only moderate computational cost. This is principally achieved by fitting the column water vapour and accounting for its interference in the retrieval of SO2. A cloud and aerosol model is used to evaluate the sensitivity of the scheme to the presence of ash and water/ice cloud. This identifies that cloud or ash above 6 km limits the accuracy of the water vapour fit, increasing the error in the SO2 estimate. Cloud top height is also retrieved. The scheme is applied to a case study event, the 1991 eruption of Cerro Hudson in Chile. The total erupted mass of SO2 is estimated to be 2300 kT ± 600 kT. This confirms it as one of the largest events since the 1991 eruption of Pinatubo, and of comparable scale to the Northern Hemisphere eruption of Kasatochi in 2008. This retrieval method yields a minimum mass per unit area detection limit of 3 DU, which is slightly less than that for the Total Ozone Mapping Spectrometer (TOMS), the only other instrument capable of monitoring SO2 from 1979 to 1996. We show an initial comparison to TOMS for part of this eruption, with broadly consistent results. Operating in the infrared (IR), HIRS has the advantage of being able to measure both during the day and at night, and there have frequently been multiple HIRS instruments operated simultaneously for better than daily sampling. If applied to all data from the series of past and future HIRS instruments, this

  10. Continuous SO2 flux measurements for Vulcano Island, Italy

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    Fabio Vita

    2012-06-01

    Full Text Available The La Fossa cone of Vulcano Island (Aeolian Archipelago, Italy is a closed conduit volcano. Today, Vulcano Island is characterized by sulfataric activity, with a large fumarolic field that is mainly located in the summit area. A scanning differential optical absorption spectroscopy instrument designed by the Optical Sensing Group of Chalmers University of Technology in Göteborg, Sweden, was installed in the framework of the European project "Network for Observation of Volcanic and Atmospheric Change", in March 2008. This study presents the first dataset of SO2 plume fluxes recorded for a closed volcanic system. Between 2008 and 2010, the SO2 fluxes recorded showed average values of 12 t.d–1 during the normal sulfataric activity of Vulcano Island, with one exceptional event of strong degassing that occurred between September and December, 2009, when the SO2 emissions reached up to 100 t.d–1.

  11. Theoretical description of functionality, applications, and limitations of SO2 cameras for the remote sensing of volcanic plumes

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    U. Platt

    2010-02-01

    Full Text Available The SO2 camera is a novel technique for the remote sensing of volcanic emissions using solar radiation scattered in the atmosphere as a light source for the measurements. The method is based on measuring the ultra-violet absorption of SO2 in a narrow wavelength window around 310 nm by employing a band-pass interference filter and a 2-D UV-sensitive CCD detector. The effect of aerosol scattering can be eliminated by additionally measuring the incident radiation around 325 nm where the absorption of SO2 is no longer significant, thus rendering the method applicable to optically opaque plumes. The ability to deliver spatially resolved images of volcanic SO2 distributions at a frame rate on the order of 1 Hz makes the SO2 camera a very promising technique for volcanic monitoring and for studying the dynamics of volcanic plumes in the atmosphere. This study gives a theoretical basis for the pertinent aspects of working with SO2 camera systems, including the measurement principle, instrument design, data evaluation and technical applicability. Several issues are identified that influence camera calibration and performance. For one, changes in the solar zenith angle lead to a variable light path length in the stratospheric ozone layer and therefore change the spectral distribution of scattered solar radiation incident at the Earth's surface. The thus varying spectral illumination causes a shift in the calibration of the SO2 camera's results. Secondly, the lack of spectral resolution inherent in the measurement technique leads to a non-linear relationship between measured weighted average optical density and the SO2 column density. In addition, as is the case with all remote sensing techniques that use scattered solar radiation as a light source, the radiative transfer between the sun and the instrument is variable, with both radiative dilution as well as multiple scattering occurring. These effects can lead to both, over or underestimation of the SO2

  12. Retrieval and intercomparison of volcanic SO2 injection height and eruption time from satellite maps and ground-based observations

    Science.gov (United States)

    Pardini, Federica; Burton, Mike; de'Michieli Vitturi, Mattia; Corradini, Stefano; Salerno, Giuseppe; Merucci, Luca; Di Grazia, Giuseppe

    2017-02-01

    Syneruptive gas flux time series can, in principle, be retrieved from satellite maps of SO2 collected during and immediately after volcanic eruptions, and used to gain insights into the volcanic processes which drive the volcanic activity. Determination of the age and height of volcanic plumes are key prerequisites for such calculations. However, these parameters are challenging to constrain using satellite-based techniques. Here, we use imagery from OMI and GOME-2 satellite sensors and a novel numerical procedure based on back-trajectory analysis to calculate plume height as a function of position at the satellite measurement time together with plume injection height and time at a volcanic vent location. We applied this new procedure to three Etna eruptions (12 August 2011, 18 March 2012 and 12 April 2013) and compared our results with independent satellite and ground-based estimations. We also compare our injection height time-series with measurements of volcanic tremor, which reflects the eruption intensity, showing a good match between these two datasets. Our results are a milestone in progressing towards reliable determination of gas flux data from satellite-derived SO2 maps during volcanic eruptions, which would be of great value for operational management of explosive eruptions.

  13. SO2 camera measurements at Lastarria volcano and Lascar volcano in Chile

    Science.gov (United States)

    Lübcke, Peter; Bobrowski, Nicole; Dinger, Florian; Klein, Angelika; Kuhn, Jonas; Platt, Ulrich

    2015-04-01

    The SO2 camera is a remote-sensing technique that measures volcanic SO2 emissions via the strong SO2 absorption structures in the UV using scattered solar radiation as a light source. The 2D-imagery (usually recorded with a frame rate of up to 1 Hz) allows new insights into degassing processes of volcanoes. Besides the large advantage of high frequency sampling the spatial resolution allows to investigate SO2 emissions from individual fumaroles and not only the total SO2 emission flux of a volcano, which is often dominated by the volcanic plume. Here we present SO2 camera measurements that were made during the CCVG workshop in Chile in November 2014. Measurements were performed at Lastarria volcano, a 5700 m high stratovolcano and Lascar volcano, a 5600 m high stratovolcano both in northern Chile on 21 - 22 November, 2014 and on 26 - 27 November, 2014, respectively. At both volcanoes measurements were conducted from a distance of roughly 6-7 km under close to ideal conditions (low solar zenith angle, a very dry and cloudless atmosphere and an only slightly condensed plume). However, determination of absolute SO2 emission rates proves challenging as part of the volcanic plume hovered close to the ground. The volcanic plume therefore is in front of the mountain in our camera images. An SO2 camera system consisting of a UV sensitive CCD and two UV band-pass filters (centered at 315 nm and 330 nm) was used. The two band-pass filters are installed in a rotating wheel and images are taken with both filter sequentially. The instrument used a CCD with 1024 x 1024 pixels and an imaging area of 13.3 mm x 13.3 mm. In combination with the focal length of 32 mm this results in a field-of-view of 25° x 25°. The calibration of the instrument was performed with help of a DOAS instrument that is co-aligned with the SO2 camera. We will present images and SO2 emission rates from both volcanoes. At Lastarria gases are emitted from three different fumarole fields and we will attempt

  14. Theoretical description of functionality, applications, and limitations of SO2 cameras for the remote sensing of volcanic plumes

    Directory of Open Access Journals (Sweden)

    U. Platt

    2010-06-01

    Full Text Available The SO2 camera is a novel device for the remote sensing of volcanic emissions using solar radiation scattered in the atmosphere as a light source for the measurements. The method is based on measuring the ultra-violet absorption of SO2 in a narrow wavelength window around 310 nm by employing a band-pass interference filter and a 2 dimensional UV-sensitive CCD detector. The effect of aerosol scattering can in part be compensated by additionally measuring the incident radiation around 325 nm, where the absorption of SO2 is about 30 times weaker, thus rendering the method applicable to optically thin plumes. For plumes with high aerosol optical densities, collocation of an additional moderate resolution spectrometer is desirable to enable a correction of radiative transfer effects. The ability to deliver spatially resolved images of volcanic SO2 distributions at a frame rate on the order of 1 Hz makes the SO2 camera a very promising technique for volcanic monitoring and for studying the dynamics of volcanic plumes in the atmosphere. This study gives a theoretical basis for the pertinent aspects of working with SO2 camera systems, including the measurement principle, instrument design, data evaluation and technical applicability. Several issues are identified that influence camera calibration and performance. For one, changes in the solar zenith angle lead to a variable light path length in the stratospheric ozone layer and therefore change the spectral distribution of scattered solar radiation incident at the Earth's surface. The varying spectral illumination causes a shift in the calibration of the SO2 camera's results. Secondly, the lack of spectral resolution inherent in the measurement technique leads to a non-linear relationship between measured weighted average optical density and the SO2 column density. Thirdly, as is the case with all remote sensing techniques that use scattered solar radiation as a light source, the radiative transfer

  15. Volcanic SO2 and SiF4 visualization and their ratio monitored using 2-D thermal emission spectroscopy

    Science.gov (United States)

    Stremme, W.; Krueger, A.; Harig, R.; Grutter, M.

    2011-09-01

    The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a save distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006-2009 using a Scanning Infrared Gas Imaging System (SIGIS). The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm-1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume, animation and determination of its propagation speed. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 which was confirmed from the strong ash emission registered around 01:00 a.m. LST (Local Standard Time) and a pronounced SO2 cloud was registered. Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential imagees is used to calculate the emission rates at different distances from the crater.

  16. Measuring SO2 ship emissions with an ultraviolet imaging camera

    Science.gov (United States)

    Prata, A. J.

    2014-05-01

    Over the last few years fast-sampling ultraviolet (UV) imaging cameras have been developed for use in measuring SO2 emissions from industrial sources (e.g. power plants; typical emission rates ~ 1-10 kg s-1) and natural sources (e.g. volcanoes; typical emission rates ~ 10-100 kg s-1). Generally, measurements have been made from sources rich in SO2 with high concentrations and emission rates. In this work, for the first time, a UV camera has been used to measure the much lower concentrations and emission rates of SO2 (typical emission rates ~ 0.01-0.1 kg s-1) in the plumes from moving and stationary ships. Some innovations and trade-offs have been made so that estimates of the emission rates and path concentrations can be retrieved in real time. Field experiments were conducted at Kongsfjord in Ny Ålesund, Svalbard, where SO2 emissions from cruise ships were made, and at the port of Rotterdam, Netherlands, measuring emissions from more than 10 different container and cargo ships. In all cases SO2 path concentrations could be estimated and emission rates determined by measuring ship plume speeds simultaneously using the camera, or by using surface wind speed data from an independent source. Accuracies were compromised in some cases because of the presence of particulates in some ship emissions and the restriction of single-filter UV imagery, a requirement for fast-sampling (> 10 Hz) from a single camera. Despite the ease of use and ability to determine SO2 emission rates from the UV camera system, the limitation in accuracy and precision suggest that the system may only be used under rather ideal circumstances and that currently the technology needs further development to serve as a method to monitor ship emissions for regulatory purposes. A dual-camera system or a single, dual-filter camera is required in order to properly correct for the effects of particulates in ship plumes.

  17. BrO/SO2 molar ratios from scanning DOAS measurements in the NOVAC network

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    P. Lübcke

    2014-06-01

    Full Text Available 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.

  18. Using CATS Near-Real-time Lidar Observations to Monitor and Constrain Volcanic Sulfur Dioxide (SO2) Forecasts

    Science.gov (United States)

    Hughes, E. J.; Yorks, J.; Krotkov, N. A.; da Silva, A. M.; Mcgill, M.

    2016-01-01

    An eruption of Italian volcano Mount Etna on 3 December 2015 produced fast-moving sulfur dioxide (SO2) and sulfate aerosol clouds that traveled across Asia and the Pacific Ocean, reaching North America in just 5 days. The Ozone Profiler and Mapping Suite's Nadir Mapping UV spectrometer aboard the U.S. National Polar-orbiting Partnership satellite observed the horizontal transport of the SO2 cloud. Vertical profiles of the colocated volcanic sulfate aerosols were observed between 11.5 and 13.5 km by the new Cloud Aerosol Transport System (CATS) space-based lidar aboard the International Space Station. Backward trajectory analysis estimates the SO2 cloud altitude at 7-12 km. Eulerian model simulations of the SO2 cloud constrained by CATS measurements produced more accurate dispersion patterns compared to those initialized with the back trajectory height estimate. The near-real-time data processing capabilities of CATS are unique, and this work demonstrates the use of these observations to monitor and model volcanic clouds.

  19. Modeling of 2008 Kasatochi volcanic sulfate direct radiative forcing: assimilation of OMI SO2 plume height data and comparison with MODIS and CALIOP observations

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    A. H. Omar

    2012-10-01

    Full Text Available Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI with the Extended Iterative Spectral Fitting (EISF technique are used to initialize a global chemistry transport model (GEOS-Chem to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS and Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP, and (b a e-folding time for volcanic SO2 that is consistent with OMI measurements, reflecting SO2 oxidation in the upper troposphere and stratosphere is reliably represented in the model However, a consistent (~25% low bias is found in the GEOS-Chem simulated SO2 burden, and is likely due to a high (~20% bias of cloud liquid water amount (as compared to the MODIS cloud product and the resultant stronger SO2 oxidation in the GEOS meteorological data during the first week after eruption when part of SO2 underwent aqueous-phase oxidation in clouds. Radiative transfer calculations show that the forcing by Kasatochi volcanic sulfate aerosol becomes negligible 6 months after the eruption, but its global average over the first month is −1.3 W m−2 with the majority of the forcing-influenced region located north of 20° N, and with daily peak values up to −2 W m−2 on days 16–17. Sensitivity experiments show that every 2 km decrease of SO2 injection height in the GEOS-Chem simulations will result in a ~25% decrease in volcanic sulfate forcing; similar sensitivity but opposite sign also holds for a 0.03 μm increase of geometric radius of the

  20. Modeling of 2008 Kasatochi volcanic sulfate direct radiative forcing: assimilation of OMI SO2 plume height data and comparison with MODIS and CALIOP observations

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    N. Krotkov

    2013-02-01

    Full Text Available Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI with the Extended Iterative Spectral Fitting (EISF technique are used to initialize a global chemistry transport model (GEOS-Chem to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS and Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP, and (b an e-folding time for volcanic SO2 that is consistent with OMI measurements, reflecting SO2 oxidation in the upper troposphere and stratosphere is reliably represented in the model. However, a consistent (~25% low bias is found in the GEOS-Chem simulated SO2 burden, and is likely due to a high (~20% bias of cloud liquid water amount (as compared to the MODIS cloud product and the resultant stronger SO2 oxidation in the GEOS meteorological data during the first week after eruption when part of SO2 underwent aqueous-phase oxidation in clouds. Radiative transfer calculations show that the forcing by Kasatochi volcanic sulfate aerosol becomes negligible 6 months after the eruption, but its global average over the first month is −1.3 Wm−2, with the majority of the forcing-influenced region located north of 20° N, and with daily peak values up to −2 Wm−2 on days 16–17. Sensitivity experiments show that every 2 km decrease of SO2 injection height in the GEOS-Chem simulations will result in a ~25 % decrease in volcanic sulfate forcing; similar sensitivity but opposite sign also holds for a 0.03 μm increase of geometric radius of

  1. Modeling of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation of OMI SO2 Plume Height Data and Comparison with MODIS and CALIOP Observations

    Science.gov (United States)

    Wang, J.; Park, S.; Zeng, J.; Ge, C.; Yang, K.; Carn, S.; Krotkov, N.; Omar, A. H.

    2013-01-01

    Volcanic SO2 column amount and injection height retrieved from the Ozone Monitoring Instrument (OMI) with the Extended Iterative Spectral Fitting (EISF) technique are used to initialize a global chemistry transport model (GEOS-Chem) to simulate the atmospheric transport and lifecycle of volcanic SO2 and sulfate aerosol from the 2008 Kasatochi eruption, and to subsequently estimate the direct shortwave, top-of-the-atmosphere radiative forcing of the volcanic sulfate aerosol. Analysis shows that the integrated use of OMI SO2 plume height in GEOS-Chem yields: (a) good agreement of the temporal evolution of 3-D volcanic sulfate distributions between model simulations and satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP), and (b) an e-folding time for volcanic SO2 that is consistent with OMI measurements, reflecting SO2 oxidation in the upper troposphere and stratosphere is reliably represented in the model. However, a consistent (approx. 25 %) low bias is found in the GEOS-Chem simulated SO2 burden, and is likely due to a high (approx.20 %) bias of cloud liquid water amount (as compared to the MODIS cloud product) and the resultant stronger SO2 oxidation in the GEOS meteorological data during the first week after eruption when part of SO2 underwent aqueous-phase oxidation in clouds. Radiative transfer calculations show that the forcing by Kasatochi volcanic sulfate aerosol becomes negligible 6 months after the eruption, but its global average over the first month is -1.3W/sq m, with the majority of the forcing-influenced region located north of 20degN, and with daily peak values up to -2W/sq m on days 16-17. Sensitivity experiments show that every 2 km decrease of SO2 injection height in the GEOS-Chem simulations will result in a approx.25% decrease in volcanic sulfate forcing; similar sensitivity but opposite sign also holds for a 0.03 m increase of geometric radius of

  2. Validation of a novel Multi-Gas sensor for volcanic HCl alongside H2S and SO2 at Mt. Etna

    Science.gov (United States)

    Roberts, T. J.; Lurton, T.; Giudice, G.; Liuzzo, M.; Aiuppa, A.; Coltelli, M.; Vignelles, D.; Salerno, G.; Couté, B.; Chartier, M.; Baron, R.; Saffell, J. R.; Scaillet, B.

    2017-05-01

    Volcanic gas emission measurements inform predictions of hazard and atmospheric impacts. For these measurements, Multi-Gas sensors provide low-cost in situ monitoring of gas composition but to date have lacked the ability to detect halogens. Here, two Multi-Gas instruments characterized passive outgassing emissions from Mt. Etna's (Italy) three summit craters, Voragine (VOR), North-east Crater (NEC) and Bocca Nuova (BN) on 2 October 2013. Signal processing (Sensor Response Model, SRM) approaches are used to analyse H2S/SO2 and HCl/SO2 ratios. A new ability to monitor volcanic HCl using miniature electrochemical sensors is here demonstrated. A "direct-exposure" Multi-Gas instrument contained SO2, H2S and HCl sensors, whose sensitivities, cross-sensitivities and response times were characterized by laboratory calibration. SRM analysis of the field data yields H2S/SO2 and HCl/SO2 molar ratios, finding H2S/SO2 = 0.02 (0.01-0.03), with distinct HCl/SO2 for the VOR, NEC and BN crater emissions of 0.41 (0.38-0.43), 0.58 (0.54-0.60) and 0.20 (0.17-0.33). A second Multi-Gas instrument provided CO2/SO2 and H2O/SO2 and enabled cross-comparison of SO2. The Multi-Gas-measured SO2-HCl-H2S-CO2-H2O compositions provide insights into volcanic outgassing. H2S/SO2 ratios indicate gas equilibration at slightly below magmatic temperatures, assuming that the magmatic redox state is preserved. Low SO2/HCl alongside low CO2/SO2 indicates a partially outgassed magma source. We highlight the potential for low-cost HCl sensing of H2S-poor HCl-rich volcanic emissions elsewhere. Further tests are needed for H2S-rich plumes and for long-term monitoring. Our study brings two new advances to volcano hazard monitoring: real-time in situ measurement of HCl and improved Multi-Gas SRM measurements of gas ratios.

  3. Analysis of gaseous SO2, CO2 and halogen species in volcanic plumes using a multirotor Unmanned Aerial Vehicle (UAV).

    Science.gov (United States)

    Rüdiger, J.; de Moor, M. J.; Tirpitz, L.; Bobrowski, N.; Gutmann, A.; Hoffmann, T.

    2016-12-01

    Volcanoes are a large source for several reactive atmospheric trace gases including sulfur and halogen containing species. The detailed understanding of volcanic plume chemistry is needed to draw information from gas measurements on subsurface processes. This knowledge is essential for using gas measurements as a monitoring tool for volcanic activity. The reactive bromine species bromine monoxide (BrO) is of particular interest, because BrO as well as SO2 are readily measurable from safe distance by spectroscopic remote sensing techniques. BrO is not directly emitted, but is formed in the plume by a multiphase reaction mechanism. The abundance of BrO changes as a function of the distance from the vent as well as the spatial position in the plume. The precursor substance for the formation of BrO is HBr with Br2 as an intermediate product. In this study we present the application of a UAV as a carrier for a remote-controlled sampling system for halogen species (Br2, HBr, BrCl, etc), based on the gas diffusion denuder technique, which allows speciation and enrichment by selective organic reactions. For the analysis of gaseous SO2 and CO2 an in-situ gas monitoring system was additionally mounted. This setup was deployed into the gas plumes of Stromboli Volcano (Italy) and Masaya Volcano (Nicaragua) in 2016, to investigate the halogen chemistry at distant locations in the plume further downwind to the emission source, which are in most cases not accessible by other approaches. The used quadrocopter (0.75 m in diameter) weighs 2.45 kg and lifts a payload of 1.3 kg. Flights into the plume were conducted with ascents of up to 900 m, starting at 500 to 800 m altitude. From telemetrically transmitted SO2 mixing ratios, areas of dense plume were localized to keep the UAV stationary for up to 10 minutes of sampling time. Herein we will present time and spatial resolved gas mixing ratio data for SO2, CO2 and halogen species for a downwind plume age of about 3 to 5 minutes.

  4. Satellite observations of atmospheric SO 2 from volcanic eruptions during the time-period of 1996-2002

    Science.gov (United States)

    Khokhar, M. F.; Frankenberg, C.; Van Roozendael, M.; Beirle, S.; Kühl, S.; Richter, A.; Platt, U.; Wagner, T.

    In this article, we present satellite observations of atmospheric sulfur dioxide (SO 2) from volcanic eruptions. Global ozone monitoring experiment (GOME) data for the years 1996-2002 is analyzed using a DOAS based algorithm with the aim of retrieving SO 2 slant column densities (SCD). The retrieval of SO 2 SCD in the UV spectral region is difficult due to strong and interfering ozone absorptions. It is also likely affected by instrumental effects. We investigated these effects in detail to obviate systematic biases in the SO 2 retrieval. A quantitative study of about 20 volcanoes from Italy, Iceland, Congo/Zaire, Ecuador, Japan, Vanuatu Island and Mexico is presented. The focus is on both eruption and out gassing scenarios. We prepared a 7-year mean map (1996-2002) of SO 2 SCD observed by GOME and tabulated the ratios of the maximum SO 2 SCD observed to the average SO 2 SCD as seen in the 7-year mean map. The further aim of this study is to provide information about unknown volcanic eruptions, e.g., Bandai Honshu Japan, Central Islands Vanuatu, Piton de la Fournaise Réunion Island France, Kamchatka region of Russia and from Indonesia especially. The results demonstrate a high sensitivity of the GOME instrument towards SO 2 emissions during both eruption and degassing episodes.

  5. Compositional variation in aging volcanic plumes - Analysis of gaseous SO2, CO2 and halogen species in volcanic emissions using an Unmanned Aerial Vehicle (UAV).

    Science.gov (United States)

    Rüdiger, Julian; Lukas, Tirpitz; Bobrowski, Nicole; Gutmann, Alexandra; Liotta, Marcello; de Moor, Maarten; Hoffmann, Thorsten

    2017-04-01

    Volcanoes are a large source for several reactive atmospheric trace gases including sulfur and halogen containing species. The detailed understanding of volcanic plume chemistry is needed to draw information from gas measurements on subsurface processes. This knowledge is essential for using gas measurements as a monitoring tool for volcanic activity. The reactive bromine species bromine monoxide (BrO) is of particular interest, because BrO as well as SO2 are readily measurable from safe distance by spectroscopic remote sensing techniques. BrO is not directly emitted, but is formed in the plume by a multiphase reaction mechanism. The abundance of BrO changes as a function of the distance from the vent as well as the spatial position in the plume. The precursor substance for the formation of BrO is HBr with Br2as an intermediate product. In this study we present the application of a UAV as a carrier for a remote-controlled sampling system for halogen species (Br2, HBr, BrCl, etc), based on the gas diffusion denuder technique, which allows speciation and enrichment by selective organic reactions. For the analysis of gaseous SO2 and CO2 an in-situ gas monitoring system was additionally mounted. This setup was deployed into the gas plumes of Stromboli Volcano (Italy), Masaya Volcano (Nicaragua) and Turrialba Volcano (Costa Rica) in 2016, to investigate the halogen chemistry at distant locations in the plume further downwind to the emission source, which are in most cases not accessible by other approaches. Flights into the plume were conducted with ascents of up to 1000 m. From telemetrically transmitted SO2 mixing ratios, areas of dense plume where localized to keep the UAV stationary for up to 10 minutes of sampling time. Additionally, ground based samples were taken at the crater rim (at Masaya and Turrialba) using alkaline traps, denuder and gas sensors for comparison with airborne-collected data. Herein we will present time and spatial resolved gas mixing ratio

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

    Science.gov (United States)

    Butz, André; Solvejg Dinger, Anna; Bobrowski, Nicole; Kostinek, Julian; Fieber, Lukas; Fischerkeller, Constanze; Giuffrida, Giovanni Bruno; Hase, Frank; Klappenbach, Friedrich; Kuhn, Jonas; Lübcke, Peter; Tirpitz, Lukas; Tu, Qiansi

    2017-01-01

    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 (CO2), hydrogen fluoride (HF), hydrogen chloride (HCl), sulfur dioxide (SO2), 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, SO2, and BrO vertical column densities (VCDs) were reliably measured exceeding 5 × 1016, 2 × 1017, 5 × 1017, and 1 × 1014 molec cm-2, with an estimated precision of 2.2 × 1015, 1.3 × 1016, 3.6 × 1016, and 1.3 × 1013 molec cm-2, respectively. Given that CO2, unlike the other measured gases, has a large and well-mixed atmospheric background, derivation of volcanic CO2 VCD enhancements (ΔCO2) 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 (O2) columns and assuming covariation of O2 and CO2 with altitude. The atmospheric CO2 background was found by identifying background soundings via the co-emitted volcanic gases. The inferred ΔCO2 occasionally exceeded 2 × 1019 molec cm-2 with an estimated precision of 3.7 × 1018 molec cm-2 given typical atmospheric background VCDs of 7 to 8 × 1021 molec cm-2. While the correlations of ΔCO2 with the other measured volcanic gases confirm the detection of volcanic CO2 enhancements, correlations were found of variable

  7. Comparison between OMI-TOMS and OMI-DOAS Ozone Columns over High SO2 regions: Volcanic and Chinese Industrial Region

    Science.gov (United States)

    Choi, Wonei; Hong, Hyunkee; Lee, Hanlim

    2017-04-01

    In this present study, we identified the SO2 effect on O3 retrieval from the Ozone Monitoring Instrument (OMI) measurement. The difference between OMI-Total Ozone Mapping Spectrometer (TOMS) and OMI-Differential Optical Absorption Spectrometer (DOAS) total O3 is calculated in high SO2 volcanic regions (Anatahan, La Cumbre, Sierra Negra, and Piton) and Chinese industrial region from 2005 through 2008. In volcanic plumes, OMI-TOMS total O3 column increases with middle and upper troposphere and stratosphere (TRM-STL) SO2, showing high correlation (R = 0.54) between TRM-STL SO2 and TOMS O3 while there is negligible correlation (R = 0.11) between TRM-STL SO2 and OMI- DOAS O3. There is a certain correlation (R = 0.54) between TRM-STL SO2 and the difference between OMI-TOMS and OMI-DOAS O3 (T-D). The T-D reaches its maximum up to 90 DU. T-D has a dependence on planetary boundary layer (PBL) SO2 (R = 0.36) even though T-D in the Chinese industrial region increases more slowly with SO2 than at the volcanic sites. Thus, the altitude at which SO2 exists has an effect on T-D, which could be due to reduced absolute radiance sensitivity in the boundary layer at 317.5 nm (the wavelength used to retrieve OMI-TOMS ozone in boundary layer). In addition, T-D shows a seasonal tendency on PBL SO2. In Turkey and Western USA, where PBL SO2 concentrations are low, |T-D| shows its positive maximum in summer and negative maximum in winter. However, no seasonal variation of T-D was found in the Chinese industrial region due to the effect of low and high PBL SO2 in summer and winter, respectively. The reason for the seasonal characteristics of T-D in the Chinese industrial region will be discussed.

  8. DOAS evaluation of volcanic SO2 using a modeled background spectrum: Examples from the NOVAC stations at Nevado del Ruiz (Colombia) and Tungurahua (Ecuador)

    Science.gov (United States)

    Lübcke, Peter; Lampel, Johannes; Bobrowski, Nicole; Arellano, Santiago; Galle, Bo; Garzón, Gustavo; Hidalgo, Silvana; Vogel, Leif; Warnach, Simon; Platt, Ulrich

    2015-04-01

    SO2 emission rates are monitored using Differential Optical Absorption Spectroscopy (DOAS) in the UV at an increasing number of volcano observatories. The Network for Observation of Volcanic and Atmospheric Change (NOVAC) has currently installed 80 scanning DOAS instruments at 30 volcanoes world-wide. One important question for the evaluation of spectra using DOAS is the availability of background spectra that are not influenced by volcanic gas emissions. An SO2 contaminated background spectrum would lead to a negative offset of the retrieved SO2 column densities, and thus to an underestimation of the volcanic SO2 emission rate. In NOVAC this problem is approached by performing a scan, e.g. through a plane from one horizon to the other horizon, and defining the average of the 20% spectra with the lowest SO2 content as the zero-baseline value, which is assumed to be gas free. To verify this assumption we revisit the idea of evaluating spectra using the DOAS method with a modeled background spectrum based on a high-resolution solar atlas. One challenge when evaluating spectra with a modeled background spectrum is properly accounting for instrumental effects that are usually removed when calculating the measured optical density relative to a measured background spectrum. We present our approach to handle these instrumental effects, showing that we gain a similar fit quality to the method using a measured reference spectrum. For example, wavelength dependent structures in the spectrum due to the spectrometer (e.g., quantum efficiency of the detector and grating efficiency) were identified with help of a principal component analysis of an SO2 free subset of the residual spectra. These structures were included in a second iteration of the fit in order to improve the evaluation. We further discuss influences like strong ozone absorption and the instrument temperature on the quality of the SO2 fit using a modeled background spectrum. The new evaluation scheme was applied

  9. Ozone variations related to volcanic activity and disappearance of SO2

    Science.gov (United States)

    Roldugin, V. C.; Henriksen, K.

    The long-term trend analysis of the total ozone data for the period 1973-1989 was made for three regions of the USSR. A common negative trend is explained by the eruptions of Fuego and El Chichon as one of two considered reasons, and comparison of the ozone and sulphur dioxide data for Murmansk gives further evidence to the study of De Muer and De Backer, finding that an ozone decrease vanishes when correction for tropospheric SO2 decrease is carried out. The well-known hypothesis about anthropogenic induced depletion of the ozone layer is not confirmed by these data.

  10. Measuring the complex behavior of the SO2 oxidation reaction

    Directory of Open Access Journals (Sweden)

    Muhammad Shahzad

    2015-09-01

    Full Text Available The two step reversible chemical reaction involving five chemical species is investigated. The quasi equilibrium manifold (QEM and spectral quasi equilibrium manifold (SQEM are used for initial approximation to simplify the mechanisms, which we want to utilize in order to investigate the behavior of the desired species. They show a meaningful picture, but for maximum clarity, the investigation method of invariant grid (MIG is employed. These methods simplify the complex chemical kinetics and deduce low dimensional manifold (LDM from the high dimensional mechanism. The coverage of the species near equilibrium point is investigated and then we shall discuss moving along the equilibrium of ODEs. The steady state behavior is observed and the Lyapunov function is utilized to study the stability of ODEs. Graphical results are used to describe the physical aspects of measurements.

  11. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy – Part 1: Slant-columns and their ratios

    Directory of Open Access Journals (Sweden)

    M. Grutter

    2012-02-01

    Full Text Available The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a safe distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006–2009 using a Scanning Infrared Gas Imaging System (SIGIS. The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm−1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume and its animation. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 and strong ash emission together with a pronounced SO2 cloud was registered around 01:00 a.m. LST (Local Standard Time. Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential images is used in a subsequent paper (Part 2 to calculate the emission rates at different distances from the crater.

  12. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy - Part 1: Slant-columns and their ratios

    Science.gov (United States)

    Stremme, W.; Krueger, A.; Harig, R.; Grutter, M.

    2012-02-01

    The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a safe distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006-2009 using a Scanning Infrared Gas Imaging System (SIGIS). The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm-1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume and its animation. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 and strong ash emission together with a pronounced SO2 cloud was registered around 01:00 a.m. LST (Local Standard Time). Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential images is used in a subsequent paper (Part 2) to calculate the emission rates at different distances from the crater.

  13. Intercomparison of Metop-A SO2 measure- ments during the 2010- 2011 Icelandic eruptions

    Directory of Open Access Journals (Sweden)

    Maria Elissavet Koukouli

    2015-03-01

    Full Text Available The European Space Agency project Satellite Monitoring of Ash and Sulphur Dioxide for the mitigation of Avi­ ation Hazards, was introduced after the eruption of the Icelandic volcano Eyjafjallajökull in the spring of 2010 to facilitate the development of an optimal End­to­End System for Volcanic Ash Plume Monitoring and Predic­ tion. The Eyjafjallajökull plume drifted towards Europe and caused major disruptions of European air traffic for several weeks affecting the everyday life of millions of people. The limitations in volcanic plume monitoring and prediction capabilities gave birth to this observational system which is based on comprehensive satellite­derived ash plume and sulphur dioxide [SO2] level estimates, as well as a widespread validation using supplementary satellite, aircraft and ground­based measurements. Inter­comparison of the volcanic total SO2 column and plume height observed by GOME­2/Metop­A and IASI/Metop­A are shown before, during and after the Eyjaf­ jallajökull 2010 eruptions as well as for the 2011 Grímsvötn eruption. Co­located ground­based Brewer Spectro­ photometer data extracted from the World Ozone and Ultraviolet Radiation Data Centre for de Bilt, the Nether­ lands, are also compared to the different satellite estimates. Promising agreement is found for the two different types of instrument for the SO2 columns with linear regression coefficients ranging around from 0.64 when comparing the different instruments and 0.85 when comparing the two different IASI algorithms. The agree­ ment for the plume height is lower, possibly due to the major differences between the height retrieval part of the GOME2 and IASI algorithms. The comparisons with the Brewer ground­based station in de Bilt, The Nether­ lands show good qualitative agreement for the peak of the event however stronger eruptive signals are required for a longer quantitative comparison. 

  14. Ground-based remote sensing of volcanic CO2 and correlated SO2, HF, HCl, and BrO, in safe-distance from the crater

    Science.gov (United States)

    Butz, Andre; Solvejg Dinger, Anna; Bobrowski, Nicole; Kostinek, Julian; Fieber, Lukas; Fischerkeller, Constanze; Giuffrida, Giovanni Bruno; Hase, Frank; Klappenbach, Friedrich; Kuhn, Jonas; Lübcke, Peter; Tirpitz, Lukas; Tu, Qiansi

    2017-04-01

    Remote sensing of CO2 enhancements in volcanic plumes can be a tool to estimate volcanic CO2 emissions and thereby, to gain insight into the geological carbon cycle and into volcano interior processes. However, remote sensing of the volcanic CO2 is challenged by the large atmospheric background concentrations masking the minute volcanic signal. Here, we report on a demonstrator study conducted in September 2015 at Mt. Etna on Sicily, where we deployed an EM27/SUN Fourier Transform Spectrometer together with a UV spectrometer on a mobile remote sensing platform. The spectrometers were operated in direct-sun viewing geometry collecting cross-sectional scans of solar absorption spectra through the volcanic plume by operating the platform in stop-and-go patterns in 5 to 10 kilometers distance from the crater region. We successfully detected correlated intra-plume enhancements of CO2 and volcanic SO2, HF, HCl, and BrO. The path-integrated volcanic CO2 enhancements amounted to about 0.5 ppm (on top of the ˜400 ppm background). Key to successful detection of volcanic CO2 was A) the simultaneous observation of the O2 total column which allowed for correcting changes in the CO2 column caused by changes in observer altitude and B) the simultaneous measurement of volcanic species co-emitted with CO2 which allowed for discriminating intra-plume and extra-plume observations. The latter were used for subtracting the atmospheric CO2 background. The field study suggests that our remote sensing observatory is a candidate technique for volcano monitoring in safe distance from the crater region.

  15. Recent SO2 camera and OP-FTIR field measurements in Mexico and Guatemala

    Science.gov (United States)

    La Spina, Alessandro; Salerno, Giuseppe; Burton, Michael

    2013-04-01

    Between 22 and 30 November 2012 a field campaign was carried out at Mexico and Guatemala with the objectives of state the volcanic gas composition and flux fingerprints of Popocatepetl, Santiaguito, Fuego and Pacaya by exploiting simultaneously UV-camera and FTIR measurements. Gases were measured remotely using instruments sensitive to ultraviolet and infrared radiation (UV spectrometer, SO2-camera and OP-FTIR). Data collection depended on the requirements of the methodology, weather condition and eruptive stage of the volcanoes. OP-FTIR measurements were carried out using the MIDAC interferometer with 0.5 cm-1 resolution. Spectra were collected in solar occultation mode in which the Sun acts as an infrared source and the volcanic plume is interposed between the Sun and the spectrometer. At Santiaguito spectra were also collected in passive mode using the lava flow as a radiation source. The SO2-camera used for this study was a dual camera system consisting of two QS Imaging 640s cameras. Each of the two cameras was outfitted with two quartz 25mm lens, coupled with two band-pass filters centred at 310nm and at 330nm. The imaging system was managed by a custom-made software developed in LabView. The UV-camera system was coupled with a USB2000+ spectrometer connected to a QP1000-2-SR 1000 micron optical fiber with a 74-UV collimating lens. For calibration of plume imagery, images of five quartz cells containing known concentration path-lengths of SO2 were taken at the end of each sampling. Between 22 and 23 November 2012 UV-camera and FTIR observations were carried out at Popocatepetl. During the time of our observation, the volcano was characterised by pulsing degassing from the summit crater forming a whitish plume that dispersed rapidly in the atmosphere according to wind direction and speed. Data were collected from the Observatorio Atmosférico Altzomoni (Universidad Nacional Autónoma de México) at 4000 metre a.s.l. and at a distance of ~12 km from the volcano

  16. Atmospheric processes affecting the separation of volcanic ash and SO2 in volcanic eruptions: inferences from the May 2011 Grímsvötn eruption

    Science.gov (United States)

    Prata, Fred; Woodhouse, Mark; Huppert, Herbert E.; Prata, Andrew; Thordarson, Thor; Carn, Simon

    2017-09-01

    The separation of volcanic ash and sulfur dioxide (SO2) gas is sometimes observed during volcanic eruptions. The exact conditions under which separation occurs are not fully understood but the phenomenon is of importance because of the effects volcanic emissions have on aviation, on the environment, and on the earth's radiation balance. The eruption of Grímsvötn, a subglacial volcano under the Vatnajökull glacier in Iceland during 21-28 May 2011 produced one of the most spectacular examples of ash and SO2 separation, which led to errors in the forecasting of ash in the atmosphere over northern Europe. Satellite data from several sources coupled with meteorological wind data and photographic evidence suggest that the eruption column was unable to sustain itself, resulting in a large deposition of ash, which left a low-level ash-rich atmospheric plume moving southwards and then eastwards towards the southern Scandinavian coast and a high-level predominantly SO2 plume travelling northwards and then spreading eastwards and westwards. Here we provide observational and modelling perspectives on the separation of ash and SO2 and present quantitative estimates of the masses of ash and SO2 that erupted, the directions of transport, and the likely impacts. We hypothesise that a partial column collapse or sloughing fed with ash from pyroclastic density currents (PDCs) occurred during the early stage of the eruption, leading to an ash-laden gravity intrusion that was swept southwards, separated from the main column. Our model suggests that water-mediated aggregation caused enhanced ash removal because of the plentiful supply of source water from melted glacial ice and from entrained atmospheric water. The analysis also suggests that ash and SO2 should be treated with separate source terms, leading to improvements in forecasting the movement of both types of emissions.

  17. Atmospheric processes affecting the separation of volcanic ash and SO2 in volcanic eruptions: inferences from the May 2011 Grímsvötn eruption

    Directory of Open Access Journals (Sweden)

    F. Prata

    2017-09-01

    Full Text Available The separation of volcanic ash and sulfur dioxide (SO2 gas is sometimes observed during volcanic eruptions. The exact conditions under which separation occurs are not fully understood but the phenomenon is of importance because of the effects volcanic emissions have on aviation, on the environment, and on the earth's radiation balance. The eruption of Grímsvötn, a subglacial volcano under the Vatnajökull glacier in Iceland during 21–28 May 2011 produced one of the most spectacular examples of ash and SO2 separation, which led to errors in the forecasting of ash in the atmosphere over northern Europe. Satellite data from several sources coupled with meteorological wind data and photographic evidence suggest that the eruption column was unable to sustain itself, resulting in a large deposition of ash, which left a low-level ash-rich atmospheric plume moving southwards and then eastwards towards the southern Scandinavian coast and a high-level predominantly SO2 plume travelling northwards and then spreading eastwards and westwards. Here we provide observational and modelling perspectives on the separation of ash and SO2 and present quantitative estimates of the masses of ash and SO2 that erupted, the directions of transport, and the likely impacts. We hypothesise that a partial column collapse or sloughing fed with ash from pyroclastic density currents (PDCs occurred during the early stage of the eruption, leading to an ash-laden gravity intrusion that was swept southwards, separated from the main column. Our model suggests that water-mediated aggregation caused enhanced ash removal because of the plentiful supply of source water from melted glacial ice and from entrained atmospheric water. The analysis also suggests that ash and SO2 should be treated with separate source terms, leading to improvements in forecasting the movement of both types of emissions.

  18. Early Mars volcanic sulfur storage in the cryosphere and formation of transient SO2-rich atmospheres during the Hesperian

    CERN Document Server

    Schmidt, F; Tian, F; Dartois, E; Herri, J -M; Mousis, O

    2016-01-01

    In a previous paper (Chassefi\\`ere et al., Icarus 223, 878-891, 2013), we have shown that most volcanic sulfur released to early Mars atmosphere could have been trapped in the cryosphere under the form of CO2-SO2 clathrates. Huge amounts of sulfur, up to the equivalent of a ~1 bar atmosphere of SO2, would have been stored in the Noachian cryosphere, then massively released to the atmosphere during Hesperian due to rapidly decreasing CO2 pressure. It would have resulted in the formation of the large sulfate deposits observed mainly in Hesperian terrains, whereas no or little sulfates are found at the Noachian. In the present paper, we first clarify some aspects of our previous work. We discuss the possibility of a smaller cooling effect of sulfur particles, or even of a net warming effect. We point out the fact that CO2-SO2 clathrates formed through a progressive enrichment of a preexisting reservoir of CO2 clathrates and discuss processes potentially involved in the slow formation of a SO2-rich upper cryosphe...

  19. OMI measurements of SO2 pollution over Eastern China in 2005-2008

    Science.gov (United States)

    Krotkov, N.; Pickering, K.; Witte, J.; Carn, S.; Yang, K.; Carmichael, G.; Streets, D.; Zhang, Q.; Wei, C.

    2009-05-01

    The Ozone Monitoring Instrument (OMI) on NASA Aura satellite makes global daily measurements of the total column of sulfur dioxide (SO2), a short-lived trace gas produced by fossil fuel combustion, smelting, and volcanoes. OMI seasonal to multi-year average images clearly show the world-highest consistent SO2 pollution in northeast China. China is the world's largest SO2 emitter, mostly due to the burning of high-sulfur coal in its many coal-fired power plants, which lack the technology used in many other countries to remove sulfur from smoke stack emissions. China's government has instituted nationwide measures to control SO2 emissions through the adoption of flue-gas desulfurization technology on new power plants; and even greater measures were adopted in the Beijing area in anticipation of the Olympic Games. To study the environmental effects of the emission controls we compared OMI SO2 time series over eastern China for 2005 through 2008. The time series have been done as 7-day running means of the cloud-free daily observations. By mid-March we started to see substantial periods of lower SO2 values in 2008 compared to 2007, and by mid June the 2008 values were consistently lower than 2007 and prior years. The decline is widespread with highest SO2 typically located to the south and southwest of Beijing in regions with large clusters of power plants and also around Shanghai. The decline also lasted beyond the Olympic season. We do not yet know to what extent the economic downturn in China (and reduced industrial production) contributed to lower SO2 levels in the fall of 2008. We have also compared the observed and modeled fields using University of Iowa STEM model for the period June - September 2008. The model provided SO2 vertical distributions as well as aerosol vertical profiles that were used to correct OMI operational SO2 retrievals and improve the comparisons. The OMI SO2 changes in 2008 have also been compared with the estimated changes in SO2 emissions

  20. Exploring Io's atmospheric composition with APEX: first measurement of 34SO2 and tentative detection of KCl

    CERN Document Server

    Moullet, A; Moreno, R; Gurwell, M; Black, J; Butler, B

    2013-01-01

    The composition of Io's tenuous atmosphere is poorly constrained. Only the major species SO2 and a handful of minor species have been positively identified, but a variety of other molecular species should be present, based on thermochemical equilibrium models of volcanic gas chemistry and the composition of Io's environment. This paper focuses on the spectral search for expected yet undetected molecular species (KCl, SiO, S2O) and isotopes (34SO2). We analyze a disk-averaged spectrum of a potentially line-rich spectral window around 345 GHz, obtained in 2010 at the APEX-12m antenna (Atacama Pathfinder EXperiment). Using different models assuming either extended atmospheric distributions or a purely volcanically-sustained atmosphere, we tentatively measure the KCl relative abundance with respect to SO2 and derive a range of 4x10^{-4}-8x10^{-3}. We do not detect SiO or S2O and present new upper limits on their abundances. We also present the first measurement of the 34S/32S isotopic ratio in gas phase on Io, wh...

  1. A new simplified approach for simultaneous retrieval of SO2 and ash content of tropospheric volcanic clouds: an application to the Mt Etna volcano

    Directory of Open Access Journals (Sweden)

    S. Pugnaghi

    2013-05-01

    Full Text Available A new procedure is presented for simultaneous estimation of SO2 and ash abundance in a volcanic plume, using thermal infrared (TIR MODIS data. Plume altitude and temperature are the only two input parameters required to run the procedure, while surface emissivity, temperature, atmospheric profiles, ash optical properties, and radiative transfer models are not necessary to perform the atmospheric corrections. The procedure gives the most reliable results when the surface under the plume is uniform, for example above the ocean, but still produces fairly good estimates in more challenging and not easily modelled conditions, such as above land or meteorological cloud layers. The developed approach was tested on the Etna volcano. By linearly interpolating the radiances surrounding a detected volcanic plume, the volcanic plume removal (VPR procedure described here computes the radiances that would have been measured by the sensor in the absence of a plume, and reconstructs a new image without plume. The new image and the original data allow computation of plume transmittance in the TIR-MODIS bands 29, 31, and 32 (8.6, 11.0 and 12.0 μm by applying a simplified model consisting of a uniform plume at a fixed altitude and temperature. The transmittances are then refined with a polynomial relationship obtained by means of MODTRAN simulations adapted for the geographical region, ash type, and atmospheric profiles. Bands 31 and 32 are SO2 transparent and, from their transmittances, the effective ash particle radius (Re, and aerosol optical depth at 550 nm (AOD550 are computed. A simple relation between the ash transmittances of bands 31 and 29 is demonstrated and used for SO2 columnar content (cs estimation. Comparing the results of the VPR procedure with MODTRAN simulations for more than 200 000 different cases, the frequency distribution of the differences shows the following: the Re error is less than ±0.5 μm in more than 60% of cases; the AOD550 error

  2. Evaluation of tropospheric SO2 retrieved from MAX-DOAS measurements in Xianghe, China

    Directory of Open Access Journals (Sweden)

    T. Wang

    2014-03-01

    Full Text Available Ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS measurements of sulfur dioxide (SO2 have been performed at the Xianghe station (39.75° N, 116.96° E located at ~50 km southeast of Beijing from March 2010 to February 2013. Tropospheric SO2 vertical profiles and corresponding vertical column densities (VCDs, retrieved by applying the Optimal Estimation Method to the MAX-DOAS observations, have been used to study the seasonal and diurnal cycles of SO2, in combination to correlative measurements from in situ instruments, as well as meteorological data. A marked seasonality was observed in both SO2 VCD and surface concentration, with a maximum in winter (February and a minimum in summer (July. This can be explained by the larger emissions in winter due to the domestic heating and more favorable meteorological conditions for the accumulation of SO2 close to the ground during this period. Wind speed and direction are also found to be two key factors in controlling the level of the SO2-related pollution at Xianghe. In the case of east or southwest wind, the SO2 concentration rises with the increase of the wind speed, since heavy polluting industries are located to the east and southwest of the station. In contrast, when wind comes from other directions, the stronger the wind, the less SO2 is observed. Regarding the diurnal cycle, the SO2 amount is larger in the early morning and late evening and lower at noon, in line with the diurnal variation of pollutant emissions and atmospheric stability. The observed diurnal cycles of MAX-DOAS SO2 surface concentration are also in very good agreement (correlation coefficient close to 0.9 with those from collocated in-situ data, demonstrating the reliability and robustness of our retrieval.

  3. Volcanic Plume Measurements with UAV (Invited)

    Science.gov (United States)

    Shinohara, H.; Kaneko, T.; Ohminato, T.

    2013-12-01

    Volatiles in magmas are the driving force of volcanic eruptions and quantification of volcanic gas flux and composition is important for the volcano monitoring. Recently we developed a portable gas sensor system (Multi-GAS) to quantify the volcanic gas composition by measuring volcanic plumes and obtained volcanic gas compositions of actively degassing volcanoes. As the Multi-GAS measures variation of volcanic gas component concentrations in the pumped air (volcanic plume), we need to bring the apparatus into the volcanic plume. Commonly the observer brings the apparatus to the summit crater by himself but such measurements are not possible under conditions of high risk of volcanic eruption or difficulty to approach the summit due to topography etc. In order to overcome these difficulties, volcanic plume measurements were performed by using manned and unmanned aerial vehicles. The volcanic plume measurements by manned aerial vehicles, however, are also not possible under high risk of eruption. The strict regulation against the modification of the aircraft, such as installing sampling pipes, also causes difficulty due to the high cost. Application of the UAVs for the volcanic plume measurements has a big advantage to avoid these problems. The Multi-GAS consists of IR-CO2 and H2O gas analyzer, SO2-H2O chemical sensors and H2 semiconductor sensor and the total weight ranges 3-6 kg including batteries. The necessary conditions of the UAV for the volcanic plumes measurements with the Multi-GAS are the payloads larger than 3 kg, maximum altitude larger than the plume height and installation of the sampling pipe without contamination of the exhaust gases, as the exhaust gases contain high concentrations of H2, SO2 and CO2. Up to now, three different types of UAVs were applied for the measurements; Kite-plane (Sky Remote) at Miyakejima operated by JMA, Unmanned airplane (Air Photo Service) at Shinomoedake, Kirishima volcano, and Unmanned helicopter (Yamaha) at Sakurajima

  4. Dynamics and Evolution of SO2 Gas Condensation Around Prometheus-like Volcanic Plumes on Io as Seen by the Near Infrared Mapping Spectrometer

    Science.gov (United States)

    Doute, S.; Lopes-Gautier, R.; Smythe, W. D.; Kamp, L. W.; Carlson, R.

    2001-01-01

    Near Infrared Mapping Spectrometer data acquired during the I24, 25, and 27 Io's Fly-bys by Galileo are analyzed to map the SO2 frost abundance and granularity. This allows a better understanding of the dynamics and evolution of gas condensation around volcanic plumes. Additional information is contained in the original extended abstract.

  5. Field test of available methods to measure remotely SO2 and NOx emissions from ships

    Science.gov (United States)

    Balzani Lööv, J. M.; Alfoldy, B.; Beecken, J.; Berg, N.; Berkhout, A. J. C.; Duyzer, J.; Gast, L. F. L.; Hjorth, J.; Jalkanen, J.-P.; Lagler, F.; Mellqvist, J.; Prata, F.; van der Hoff, G. R.; Westrate, H.; Swart, D. P. J.; Borowiak, A.

    2013-11-01

    Methods for the determination of ship fuel sulphur content and NOx emission factors from remote measurements have been compared in the harbour of Rotterdam and compared to direct stack emission measurements on the ferry Stena Hollandica. The methods were selected based on a review of the available literature on ship emission measurements. They were either optical (LIDAR, DOAS, UV camera), combined with model based estimates of fuel consumption, or based on the so called "sniffer" principle, where SO2 or NOx emission factors are determined from simultaneous measurement of the increase of CO2 and SO2 or NOx concentrations in the plume of the ship compared to the background. The measurements were performed from stations at land, from a boat, and from a helicopter. Mobile measurement platforms were found to have important advantages compared to the landbased ones because they allow to optimize the sampling conditions and to sample from ships on the open sea. Although optical methods can provide reliable results, it was found that at the state of the art, the "sniffer" approach is the most convenient technique for determining both SO2 and NOx emission factors remotely. The average random error on the determination of SO2 emission factors comparing two identical instrumental set-ups was 6%. However, it was found that apparently minor differences in the instrumental characteristics, such as response time, could cause significant differences between the emission factors determined. Direct stack measurements showed that about 14% of the fuel sulphur content was not emitted as SO2. This was supported by the remote measurements and is in agreement with the results of other field studies.

  6. Inverting for volcanic SO2 flux at high temporal resolution using spaceborne plume imagery and chemistry-transport modelling: the 2010 Eyjafjallajökull eruption case study

    Directory of Open Access Journals (Sweden)

    M. Boichu

    2013-09-01

    Full Text Available Depending on the magnitude of their eruptions, volcanoes impact the atmosphere at various temporal and spatial scales. The volcanic source remains a major unknown to rigorously assess these impacts. At the scale of an eruption, the limited knowledge of source parameters, including time variations of erupted mass flux and emission profile, currently represents the greatest issue that limits the reliability of volcanic cloud forecasts. Today, a growing number of satellite and remote sensing observations of distant plumes are becoming available, bringing indirect information on these source terms. Here, we develop an inverse modelling approach combining satellite observations of the volcanic plume with an Eulerian regional chemistry-transport model (CHIMERE to characterise the volcanic SO2 emissions during an eruptive crisis. The May 2010 eruption of Eyjafjallajökull is a perfect case study to apply this method as the volcano emitted substantial amounts of SO2 during more than a month. We take advantage of the SO2 column amounts provided by a vast set of IASI (Infrared Atmospheric Sounding Interferometer satellite images to reconstruct retrospectively the time series of the mid-tropospheric SO2 flux emitted by the volcano with a temporal resolution of ~2 h, spanning the period from 1 to 12 May 2010. We show that no a priori knowledge on the SO2 flux is required for this reconstruction. The initialisation of chemistry-transport modelling with this reconstructed source allows for reliable simulation of the evolution of the long-lived tropospheric SO2 cloud over thousands of kilometres. Heterogeneities within the plume, which mainly result from the temporal variability of the emissions, are correctly tracked over a timescale of a week. The robustness of our approach is also demonstrated by the broad similarities between the SO2 flux history determined by this study and the ash discharge behaviour estimated by other means during the phases of high

  7. Measuring SO2 ship emissions with an ultra-violet imaging camera

    Science.gov (United States)

    Prata, A. J.

    2013-11-01

    Over the last few years fast-sampling ultra-violet (UV) imaging cameras have been developed for use in measuring SO2 emissions from industrial sources (e.g. power plants; typical fluxes ~1-10 kg s-1) and natural sources (e.g. volcanoes; typical fluxes ~10-100 kg s-1). Generally, measurements have been made from sources rich in SO2 with high concentrations and fluxes. In this work, for the first time, a UV camera has been used to measure the much lower concentrations and fluxes of SO2 (typical fluxes ~0.01-0.1 kg s-1) in the plumes from moving and stationary ships. Some innovations and trade-offs have been made so that estimates of the fluxes and path concentrations can be retrieved in real-time. Field experiments were conducted at Kongsfjord in Ny Ålesund, Svalbard, where emissions from cruise ships were made, and at the port of Rotterdam, Netherlands, measuring emissions from more than 10 different container and cargo ships. In all cases SO2 path concentrations could be estimated and fluxes determined by measuring ship plume speeds simultaneously using the camera, or by using surface wind speed data from an independent source. Accuracies were compromised in some cases because of the presence of particulates in some ship emissions and the restriction of single-filter UV imagery, a requirement for fast-sampling (>10 Hz) from a single camera. Typical accuracies ranged from 10-30% in path concentration and 10-40% in flux estimation. Despite the ease of use and ability to determine SO2 fluxes from the UV camera system, the limitation in accuracy and precision suggest that the system may only be used under rather ideal circumstances and that currently the technology needs further development to serve as a method to monitor ship emissions for regulatory purposes.

  8. Continuous measurements of SiF4 and SO2 by thermal emission spectroscopy: Insight from a 6-month survey at the Popocatépetl volcano

    Science.gov (United States)

    Taquet, N.; Meza Hernández, I.; Stremme, W.; Bezanilla, A.; Grutter, M.; Campion, R.; Palm, M.; Boulesteix, T.

    2017-07-01

    The processes linked with the emplacement and growth/destruction of a lava dome are of prime importance to understand the stability of such extrusions and assess the associated risks for local populations. During the last couple of decades, ground and space-based spectroscopic techniques have been developed to monitor such processes from a safe distance. Such approaches significantly improved our knowledge about the relationship between the chemical composition of the volcanic gas plumes and both the deep and shallow volcanic processes leading to the different types of explosive activity. The potential of the ground-based thermal emission Fourier Transform Infrared spectroscopy (FTIR) remained under-exploited due to the difficulty to properly handle the radiative-transfer phenomena. Despite the drawbacks in the complex analytical requirements, this method enables to continuously monitor (day and night) with a high temporal resolution (1 meas/3 min), relevant gas species such as SO2 and SiF4 in the volcanic plumes. Previous studies have related the temporal variations of the SiF4/SO2 ratio in volcanic plumes to the onset of vulcanian explosions. This study reports a 6-month SO2, SiF4, and SiF4/SO2 time series (from January to June 2015) of the Popocatepetl's gas plume obtained from FTIR thermal emission spectroscopic measurements. The infrared spectra were analyzed using the SFIT4 radiative transfer and inverse model, which we have adapted for this application. We obtained highly variable SiF4/SO2 ratios with a mean value of 3.6 × 10- 4, with the highest values (around 3 × 10- 3) measured during the final phase of a lava dome growth (February-March 2015). The rapid SiF4/SO2 variations were more carefully explored and compared for the first time with the seismic activity. A remarkable coincidence between sharp SiF4/SO2 rises and the seismic events are evidenced here.

  9. Real time retrieval of volcanic cloud particles and SO2 by satellite using an improved simplified approach

    Science.gov (United States)

    Pugnaghi, Sergio; Guerrieri, Lorenzo; Corradini, Stefano; Merucci, Luca

    2016-07-01

    Volcanic plume removal (VPR) is a procedure developed to retrieve the ash optical depth, effective radius and mass, and sulfur dioxide mass contained in a volcanic cloud from the thermal radiance at 8.7, 11, and 12 µm. It is based on an estimation of a virtual image representing what the sensor would have seen in a multispectral thermal image if the volcanic cloud were not present. Ash and sulfur dioxide were retrieved by the first version of the VPR using a very simple atmospheric model that ignored the layer above the volcanic cloud. This new version takes into account the layer of atmosphere above the cloud as well as thermal radiance scattering along the line of sight of the sensor. In addition to improved results, the new version also offers an easier and faster preliminary preparation and includes other types of volcanic particles (andesite, obsidian, pumice, ice crystals, and water droplets). As in the previous version, a set of parameters regarding the volcanic area, particle types, and sensor is required to run the procedure. However, in the new version, only the mean plume temperature is required as input data. In this work, a set of parameters to compute the volcanic cloud transmittance in the three quoted bands, for all the aforementioned particles, for both Mt. Etna (Italy) and Eyjafjallajökull (Iceland) volcanoes, and for the Terra and Aqua MODIS instruments is presented. Three types of tests are carried out to verify the results of the improved VPR. The first uses all the radiative transfer simulations performed to estimate the above mentioned parameters. The second one makes use of two synthetic images, one for Mt. Etna and one for Eyjafjallajökull volcanoes. The third one compares VPR and Look-Up Table (LUT) retrievals analyzing the true image of Eyjafjallajökull volcano acquired by MODIS aboard the Aqua satellite on 11 May 2010 at 14:05 GMT.

  10. New-generation NASA Aura Ozone Monitoring Instrument (OMI) volcanic SO2 dataset: algorithm description, initial results, and continuation with the Suomi-NPP Ozone Mapping and Profiler Suite (OMPS)

    Science.gov (United States)

    Li, Can; Krotkov, Nickolay A.; Carn, Simon; Zhang, Yan; Spurr, Robert J. D.; Joiner, Joanna

    2017-02-01

    Since the fall of 2004, the Ozone Monitoring Instrument (OMI) has been providing global monitoring of volcanic SO2 emissions, helping to understand their climate impacts and to mitigate aviation hazards. Here we introduce a new-generation OMI volcanic SO2 dataset based on a principal component analysis (PCA) retrieval technique. To reduce retrieval noise and artifacts as seen in the current operational linear fit (LF) algorithm, the new algorithm, OMSO2VOLCANO, uses characteristic features extracted directly from OMI radiances in the spectral fitting, thereby helping to minimize interferences from various geophysical processes (e.g., O3 absorption) and measurement details (e.g., wavelength shift). To solve the problem of low bias for large SO2 total columns in the LF product, the OMSO2VOLCANO algorithm employs a table lookup approach to estimate SO2 Jacobians (i.e., the instrument sensitivity to a perturbation in the SO2 column amount) and iteratively adjusts the spectral fitting window to exclude shorter wavelengths where the SO2 absorption signals are saturated. To first order, the effects of clouds and aerosols are accounted for using a simple Lambertian equivalent reflectivity approach. As with the LF algorithm, OMSO2VOLCANO provides total column retrievals based on a set of predefined SO2 profiles from the lower troposphere to the lower stratosphere, including a new profile peaked at 13 km for plumes in the upper troposphere. Examples given in this study indicate that the new dataset shows significant improvement over the LF product, with at least 50 % reduction in retrieval noise over the remote Pacific. For large eruptions such as Kasatochi in 2008 (˜ 1700 kt total SO2) and Sierra Negra in 2005 (> 1100 DU maximum SO2), OMSO2VOLCANO generally agrees well with other algorithms that also utilize the full spectral content of satellite measurements, while the LF algorithm tends to underestimate SO2. We also demonstrate that, despite the coarser spatial and

  11. New-Generation NASA Aura Ozone Monitoring Instrument (OMI) Volcanic SO2 Dataset: Algorithm Description, Initial Results, and Continuation with the Suomi-NPP Ozone Mapping and Profiler Suite (OMPS)

    Science.gov (United States)

    Li, Can; Krotkov, Nickolay A.; Carn, Simon; Zhang, Yan; Spurr, Robert J. D.; Joiner, Joanna

    2017-01-01

    Since the fall of 2004, the Ozone Monitoring Instrument (OMI) has been providing global monitoring of volcanic SO2 emissions, helping to understand their climate impacts and to mitigate aviation hazards. Here we introduce a new-generation OMI volcanic SO2 dataset based on a principal component analysis (PCA) retrieval technique. To reduce retrieval noise and artifacts as seen in the current operational linear fit (LF) algorithm, the new algorithm, OMSO2VOLCANO, uses characteristic features extracted directly from OMI radiances in the spectral fitting, thereby helping to minimize interferences from various geophysical processes (e.g., O3 absorption) and measurement details (e.g., wavelength shift). To solve the problem of low bias for large SO2 total columns in the LF product, the OMSO2VOLCANO algorithm employs a table lookup approach to estimate SO2 Jacobians (i.e., the instrument sensitivity to a perturbation in the SO2 column amount) and iteratively adjusts the spectral fitting window to exclude shorter wavelengths where the SO2 absorption signals are saturated. To first order, the effects of clouds and aerosols are accounted for using a simple Lambertian equivalent reflectivity approach. As with the LF algorithm, OMSO2VOLCANO provides total column retrievals based on a set of predefined SO2 profiles from the lower troposphere to the lower stratosphere, including a new profile peaked at 13 km for plumes in the upper troposphere. Examples given in this study indicate that the new dataset shows significant improvement over the LF product, with at least 50% reduction in retrieval noise over the remote Pacific. For large eruptions such as Kasatochi in 2008 (approximately 1700 kt total SO2/ and Sierra Negra in 2005 (greater than 1100DU maximum SO2), OMSO2VOLCANO generally agrees well with other algorithms that also utilize the full spectral content of satellite measurements, while the LF algorithm tends to underestimate SO2. We also demonstrate that, despite the

  12. High solubility of SO2: evidence in an intensive fog event measured in the NCP region, China

    Directory of Open Access Journals (Sweden)

    X. Tie

    2011-01-01

    Full Text Available A field experiment was conducted in a heavy SO2 pollution area located in north China plain (NCP. During the experiment, SO2 and other air pollutants, liquid water content (LWC of fog droplets, and basic meteorological parameters were measured. During the experiment, an intensive fog event occurred between 5 and 8 November 2009. During the fog period, the concentrations of SO2 showed a strong variability, and the variability was closely correlated to the appearances of fogs and LWC. For example, the averaged concentration of SO2 during the non-fog period was about 25 ppbv. By contrast, during the fog period, the concentration of SO2 reduced to about 4–7 ppbv. The large reduction of SO2 suggests that a majority of SO2 (about 70–80% had been converted from gas-phase to aqueous-phase, showing a high solubility of SO2. However, according to the value of Henry Law constant, the solubility of SO2 is modest, which cannot explain the measured large reduction of SO2. This study highlights that the aqueous reactions of SO2 in the droplets of fogs play important roles to enhance the solubility of SO2. To account for the effect of aqueous reactions on the solubility of SO2, an "effective" Henry Law constant of SO2 is proposed in this study. The study shows that without considering aqueous reactions of SO2 in fog droplets, the estimate of the partitioning of SO2 in droplets is significantly lower than the measured values. By contrast, when the "effective" Henry Law constant is applied in the calculation, the calculated SO2 concentrations are significantly improved, showing that the aqueous reactions of SO2 play important roles in controlling the solubility of SO2, and should be considered in model calculations.

  13. SO2 photoexcitation mechanism links mass-independent sulfur isotopic fractionation in cryospheric sulfate to climate impacting volcanism

    DEFF Research Database (Denmark)

    Hattori, Shohei; Schmidt, Johan Albrecht; Johnson, Matthew Stanley

    2013-01-01

    Natural climate variation, such as that caused by volcanoes, is the basis for identifying anthropogenic climate change. However, knowledge of the history of volcanic activity is inadequate, particularly concerning the explosivity of specific events. Some material is deposited in ice cores...... plume chemistry, allowing the production and preservation of a mass-independent sulfur isotope anomaly in the sulfate product. The model accounts for the amplitude, phases, and time development of Δ(33)S/δ(34)S and Δ(36)S/Δ(33)S found in glacial samples. We are able to identify the process controlling...

  14. Inclusion of Ash and SO2 emissions from volcanic eruptions in WRF-CHEM: development and some applications

    Directory of Open Access Journals (Sweden)

    S. Peckham

    2012-09-01

    Full Text Available We describe a new functionality within the Weather Research and Forecasting model with coupled Chemistry (WRF-Chem that allows simulating emission, transport, dispersion, transformation and sedimentation of pollutants released during volcanic activities. Emissions from both an explosive eruption case and relatively calm degassing situation are considered using the most recent volcanic emission databases. A preprocessor tool provides emission fields and additional information needed to establish the initial three-dimensional cloud umbrella/vertical distribution within the transport model grid, as well as the timing and duration of an eruption. From this source condition, the transport, dispersion and sedimentation of the ash-cloud can be realistically simulated by WRF-Chem using its own dynamics, physical parameterization as well as data assimilation. Examples of model validation include a comparison of tephra fall deposits from the 1989 eruption of Mount Redoubt (Alaska, and the dispersion of ash from the 2010 Eyjafjallajökull eruption in Iceland. Both model applications show good coincidence between WRF-Chem and observations.

  15. Inclusion of ash and SO2 emissions from volcanic eruptions in WRF-Chem: development and some applications

    Directory of Open Access Journals (Sweden)

    M. Stuefer

    2013-04-01

    Full Text Available We describe a new functionality within the Weather Research and Forecasting (WRF model with coupled Chemistry (WRF-Chem that allows simulating emission, transport, dispersion, transformation and sedimentation of pollutants released during volcanic activities. Emissions from both an explosive eruption case and a relatively calm degassing situation are considered using the most recent volcanic emission databases. A preprocessor tool provides emission fields and additional information needed to establish the initial three-dimensional cloud umbrella/vertical distribution within the transport model grid, as well as the timing and duration of an eruption. From this source condition, the transport, dispersion and sedimentation of the ash cloud can be realistically simulated by WRF-Chem using its own dynamics and physical parameterization as well as data assimilation. Examples of model applications include a comparison of tephra fall deposits from the 1989 eruption of Mount Redoubt (Alaska and the dispersion of ash from the 2010 Eyjafjallajökull eruption in Iceland. Both model applications show good coincidence between WRF-Chem and observations.

  16. Identification of tropospheric emissions sources from satellite observations: Synergistic use of HCHO, NO2, and SO2 trace gas measurements

    Science.gov (United States)

    Marbach, T.; Beirle, S.; Khokhar, F.; Platt, U.

    2005-12-01

    We present case studies for combined HCHO, NO2, and SO2 satellite observations, derived from GOME measurements. Launched on the ERS-2 satellite in April 1995, GOME has already performed continuous operations over 8 years providing global observations of the different trace gases. In this way, satellite observations provide unique opportunities for the identifications of trace gas sources. The satellite HCHO observations provide information concerning the localization of biomass burning (intense source of HCHO). The principal biomass burning areas can be observed in the Amazon basin region and in central Africa Weaker HCHO sources (south east of the United States, northern part of the Amazon basin, and over the African tropical forest), not correlated with biomass burning, could be due to biogenic isoprene emissions. The HCHO data can be compared with NO2 and SO2 results to identify more precisely the tropospheric sources (biomass burning events, human activities, additional sources like volcanic emissions). Biomass burning are important tropospheric sources for both HCHO and NO2. Nevertheless HCHO reflects more precisely the biomass burning as it appears in all biomass burning events. NO2 correlate with HCHO over Africa (grassland fires) but not over Indonesia (forest fires). In south America, an augmentation of the NO2 concentrations can be observed with the fire shift from the forest to grassland vegetation. So there seems to be a dependence between the NO2 emissions during biomass burning and the vegetation type. Other high HCHO, SO2, and NO2 emissions can be correlated with climatic events like the El Nino in 1997, which induced dry conditions in Indonesia causing many forest fires.

  17. Mobile IR- and UV-Spectroscopic Measurements of CO, SO2 and VOC in Megacities

    Science.gov (United States)

    Samuelsson, J.; Mellqvist, J.; Galle, B.; de Foy, B.; Garcia, A.; Molina, L. T.; Molina, M. J.; Volkamer, R.; Flores, E.; Grutter, M.

    2004-12-01

    Three different types of optical instruments have been deployed at a field campaign in the Mexico City Metropolitan Area (MCMA) 2003 within three main applications: 1) Retrieval of total columns of CO at various positions within the MCMA. 2) Emission inventory of VOC (volatile organic compounds) and SO2 from a major industrial source in Tula 100km north of the MCMA. 3) SO2 emission inventory of the volcano Popocatepetl located nearby the MCMA. The instruments used were: a) A mobile solar FTIR (Fourier Transform InfraRed) system consisting of a fast sun tracker connected to a 0.5 cm-1 resolution FTIR spectrometer, measuring spectra between 2 and 14 μ m wavelength. b) A mobile blue sky UV (ultra violet) spectrometer measuring in the 245 to 380 nm region. c) Two open path FTIR spectrometers with 1 cm-1 respectively 0.1 cm-1 resolution, operating between 2-5.5 μ m and 2-14 μ m wavelength, respectively. The two instruments were located about 5km apart within the MCMA and measured path averaged concentrations of for instance CO, CO2, NO, H2CO, VOC, CH4, N2O over 860m and 500m path respectively. In the first application, the mobile solar FTIR measured atmospheric columns of CO at various locations within and outside the MCMA region, in order to investigate both their temporal and spatial variability. This was combined with the two fixed position long path FTIR spectrometers for studying issues like concentration heterogeneity, mixing height, horizontal advection and possibly total area CO emission. A mesoscale meteorological model (MM5) in combination with a chemical model was run by MIT (Massachusetts Institute of Technology) to generate total CO columns for comparisons. The feasibility of the method will be discussed. In the second application, emissions from a major industrial complex consisting of a powerplant, a refinery and a petrochemical industry were studied in Tula (100km north of MCMA). The solar FTIR system was used to retrieve total columns of VOC, and the

  18. The 2011 Nabro eruption, a SO2 plume height analysis using IASI measurements

    Directory of Open Access Journals (Sweden)

    L. Clarisse

    2014-03-01

    Full Text Available In the wake of the June 2011 Nabro eruption, large stratospheric plumes were observed by several instruments up to altitudes of 21 km, much higher than initial reported injection heights. It has been debated whether deep convection associated with the Asian Summer Monsoon anticyclone played a vital role in the vertical transport of the plume. Here we present a new and fast SO2 height retrieval algorithm for observations of the Infrared Atmospheric Sounding Interferometer (IASI. A comprehensive validation with forward trajectories and coincident CALIOP measurements is presented which indicates an accuracy better than 2 km for plumes below 20 km and SO2 columns up to the 1 DU level. We use this new product to analyse the Nabro eruption. Our findings indicate an initial plume located mainly between 15 and 17 km for which the lower parts underwent in succession rapid descent and uplift, within the Asian Monsoon anticyclone circulation, up to the stable thermal tropopause between 16 and 18 km, from where it slowly ascended further into the stratosphere. Evidence is presented that emissions in the first week of the eruption also contributed to the stratospheric sulfur input. This includes a second eruption between 15 and 17 km on the 16th and continuous emissions in the mid-troposphere of which some were also entrained and lifted within the anticyclonic circulation.

  19. Estimating the volcanic emission rate and atmospheric lifetime of SO2 from space: a case study for Kīlauea volcano, Hawai`i

    Directory of Open Access Journals (Sweden)

    S. Beirle

    2014-08-01

    Full Text Available We present an analysis of SO2 column densities derived from GOME-2 satellite measurements for the Kīlauea volcano (Hawai`i for 2007–2012. During a period of enhanced degassing activity in March–November 2008, monthly mean SO2 emission rates and effective SO2 lifetimes are determined simultaneously from the observed downwind plume evolution and meteorological wind fields, without further model input. Kīlauea is particularly suited for quantitative investigations from satellite observations owing to the absence of interfering sources, the clearly defined downwind plumes caused by steady trade winds, and generally low cloud fractions. For March–November 2008, the effective SO2 lifetime is 1–2 days, and Kīlauea SO2 emission rates are 9–21 kt day−1, which is about 3 times higher than initially reported from ground-based monitoring systems.

  20. Mobile MAX-DOAS and in situ measurements of NO2 and SO2

    Science.gov (United States)

    Wittrock, Folkard; Peters, Enno; Seyler, André; Mathieu-Üffing, Barbara; Kattner, Lisa; Richter, Andreas; Burrows, John P.

    2017-04-01

    The project MeSMarT (Measurements of shipping emissions in the marine troposphere) has been established as a cooperation between the University of Bremen and the German Bundesamt für Seeschifffahrt und Hydrographie (Federal Maritime and Hydrographic Agency) to estimate the influence of shipping emissions on the chemistry of the atmospheric boundary layer and to establish a monitoring system for main shipping routes. As part of the project in 2015 a mobile lab has been set up, which includes among other instrumentation for air pollution and meteorological parameters a scientific-grade MAX-DOAS system as well as in situ instruments for nitrogen oxides and sulfur dioxide (trace level). Focusing on NO2 and SO2 we present intercomparison results between the different instruments onboard the mobile lab as well as comparisons to standard instrumentation used at different sites in Northern Germany within the project.

  1. Residentś risk perception of and response to SO2 risk in east Iceland during the volcanic eruption in Bárðarbunga/Holuhraun 2014-2015

    Science.gov (United States)

    Gísladóttir, Guðrún; Jóhannesdóttir, Guðrún

    2016-04-01

    Many Icelandic communities are exposed to volcanic eruptions every two to three years. In order to reduce risk and enhance resilience in communities exposed to volcanic hazards, involvement of local communities is essential during all phases of disaster management, from prevention and preparedness, to response and recovery. Preparedness plans for volcanic eruptions are in place for many of the volcanic hazards in Iceland especially evacuation of residents due to immediate threat from glacial outburst floods from sub-glacial eruptions. Some of the recent risks associated with volcanic eruptions have had a slow onset (volcanic gas) while others have had a sudden onset (volcanic ash). The risks are both linked to air quality in inhabited areas and dispersal are highly dependent on prevailing winds so timely forecast and modelling is needed in order to inform the population about the risk. Without preparedness plans many communities in Iceland were exposed to an unanticipated volcanic gas risks from Sulphur Dioxide (SO2) in 2014-2015 during an eruption in Bárðarbunga/Holuhraun. With no system in place to measure the highly toxic gas from the eruption, the Environmental Agency, The Department of Civil Protection and Emergency Management and the Directorate of Health set up a system with over 40 handheld gas detectors and online links to 7 detectors around Iceland to monitor the gas. The defined health limit of SO2 is 350 μg/m3 for one hour, while 2600 μg/m3 for 15 minutes for working outdoors. Nevertheless, some communities in Iceland experienced much higher values and the highest measured concentration in communities during the eruption was 21.000 μg/m3. When the concentration of SO2 reached the level of >1000 μg/m3 a warning was issued and SMS text messages were sent to all mobile phones in the affected area. In order to engage with residents during the eruption the Civil Protection and local authorities, Directorate of Health, scientist and specialists

  2. Measurements of SO2 Degassing from Popocatépetl Volcano by an Ultraviolet Camera and a Set of Different Bandpass Filters.

    Science.gov (United States)

    Schiavo, B.; Stremme, W.; Grutter, M.; Campion, R.; Rivera, C. I.; Inguaggiato, S.

    2016-12-01

    The importance of monitoring and the time series of volcanic gas emissions is described and proven by many scientific studies. A time series of the Popocatépetl volcano will allow us to detect the volcanic gas as well as anomalies in volcanic processes and help to estimate the total emission flux of SO2 to improve our understanding of the atmospheric composition and balance. Monitoring of the activity of the Popocatépetl volcano is even more important because of the population in the closest proximity around the volcano and due its location of only 50 km south east of Mexico City and its airport. The images captured with the camera require a correction for different optical and environmental effects. In the contribution we present an SO2 camera system based on a Quantum Scientific Imaging (QSI) UV camara with automatic filterwheel, and describe how the main instrumental properties of the optical system can be characterized. Dark current, vignetting and filter characterization represent the instrumental part of a proper image correction, which is fairly constant and independent of the ambient conditions. However, other effects like "flattening" and the simplification of the radiative transfer dependence on environmental conditions need to be corrected as well to reduce the errors in the results. Images of volcanic SO2 plumes from the active Popocatépetl volcano in Mexico are presented, showing persistent passive degassing. The measurment are taken from the Altzomoni Atmospheric Observatory (19.12N, -98.65W, 3,985 m.a.s.l.), which forms part of the RUOA (www.ruoa.unam.mx) and NDACC (https://www2.acom.ucar.edu/irwg) networks. It is located north of the crater at 11 km distance. The data to calculate SO2 slant column densities (molec/cm2 or ppm*m) were recorded with the QSI UV camera and processed using Python scripts.

  3. Airborne Measurement of CO2, SO2, and H2S Emission Rates During the 2004-2005 Eruption of Mount St. Helens

    Science.gov (United States)

    Doukas, M. P.; McGee, K. A.; Gerlach, T. M.

    2005-12-01

    Volcanic gas measurements by helicopter and fixed-wing aircraft began on 27 September 2004 during the initial unrest. Target gases included CO2, SO2, and H2S measured by remote (COSPEC, FLYSPEC) and extraction (LI-COR, Interscan) techniques. These measurements defined periods of negligible, wet, and dry volcanic degassing. Measurements during the period of early seismic unrest on September 2-30 showed little or no CO2 above atmospheric levels; SO2 and H2S were absent. These results suggest involvement of degassed magma, confinement of gases because of reduction in permeability since the 1980-86 dome eruptions, or almost complete gas scrubbing at high water to gas mass ratios. Following the first steam and ash explosion on October 1, a large increase in the number of fumaroles on the 1980-86 dome and frequent detection of CO2 above atmospheric levels together with more frequent detection of H2S characterized the period of wet volcanic degassing. Wet degassing of CO2 and H2S included observed emission by ejection of large bubbles through pools of water, however the few CO2 emission rates available for this period were rose, steaming increased, and rock adjacent to the invading magma dried out. These conditions enabled a buoyant plume to rise above the crater and enter higher elevation winds, facilitating airborne measurements of gas emission rates. Gas emission rates have been notably low and declined gradually throughout the eruption. Emission rates of CO2 were mostly in the 500-1000 t/d range until early February 2005, when they fell to 150-500 t/d and remained there. Emission rates of SO2 rose to 240 t/d during 2004 then declined and remained below 100 t/d (often CO2) and 100 t/d (SO2).

  4. Measuring SO2 flow rate emission from ships by means of DOAS Spectrometer

    Science.gov (United States)

    Masieri, Samuele; Giovanelli, Giorgio; Bortoli, Daniele; Kostadinov, Ivan; Petritoli, Andrea; Premuda, Margherita; Ravegnani, Fabrizio

    2010-05-01

    The ships emissions are considered as a potential source of pollutants in harbour and nearby urban areas. For this reason the development of remote sensing methods for continuous monitoring of flow rate ship emissions is subject of increasing interest. This work presents a new approach for implementation of off-axis DOAS measurements devoted to this aim. The method, especially developed, was tested in a field campaign for measuring of ships gas emissions. The technique consists of some scanning in a vertical plane normal to ships direction at different line of sight, i.e. 1,2,3,4,5,6,8,10,15,20,30,40° over the horizon. The selected measurements performed before and after the passage of ships are used to retrieve the difference in SO2 optical depth. This difference is therefore used to retrieve flow rate emission of this gas. This technique was applied in Venice for a period of 5 month. Detailed description of adopted method and obtained results are presented.

  5. Unmanned aerial vehicle measurements of volcanic carbon dioxide fluxes

    Science.gov (United States)

    McGonigle, A. J. S.; Aiuppa, A.; Giudice, G.; Tamburello, G.; Hodson, A. J.; Gurrieri, S.

    2008-03-01

    We report the first measurements of volcanic gases with an unmanned aerial vehicle (UAV). The data were collected at La Fossa crater, Vulcano, Italy, during April 2007, with a helicopter UAV of 3 kg payload, carrying an ultraviolet spectrometer for remotely sensing the SO2 flux (8.5 Mg d-1), and an infrared spectrometer, and electrochemical sensor assembly for measuring the plume CO2/SO2 ratio; by multiplying these data we compute a CO2 flux of 170 Mg d-1. Given the deeper exsolution of carbon dioxide from magma, and its lower solubility in hydrothermal systems, relative to SO2, the ability to remotely measure CO2 fluxes is significant, with promise to provide more profound geochemical insights, and earlier eruption forecasts, than possible with SO2 fluxes alone: the most ubiquitous current source of remotely sensed volcanic gas data.

  6. Anthropogenic, biomass burning, and volcanic emissions of black carbon, organic carbon, and SO2 from 1980 to 2010 for hindcast model experiments

    Directory of Open Access Journals (Sweden)

    D. Streets

    2012-09-01

    Full Text Available Two historical emission inventories of black carbon (BC, primary organic carbon (OC, and SO2 emissions from land-based anthropogenic sources, ocean-going vessels, air traffic, biomass burning, and volcanoes are presented and discussed for the period 1980–2010. These gridded inventories are provided to the internationally coordinated AeroCom Phase II multi-model hindcast experiments. The horizontal resolution is 0.5°×0.5° and 1.0°×1.0°, while the temporal resolution varies from daily for volcanoes to monthly for biomass burning and aircraft emissions, and annual averages for land-based and ship emissions. One inventory is based on inter-annually varying activity rates of land-based anthropogenic emissions and shows strong variability within a decade, while the other one is derived from interpolation between decadal endpoints and thus exhibits linear trends within a decade. Both datasets capture the major trends of decreasing anthropogenic emissions over the USA and Western Europe since 1980, a sharp decrease around 1990 over Eastern Europe and the former USSR, and a steep increase after 2000 over East and South Asia. The inventory differences for the combined anthropogenic and biomass burning emissions in the year 2005 are 34% for BC, 46% for OC, and 13% for SO2. They vary strongly depending on species, year and region, from about 10% to 40% in most cases, but in some cases the inventories differ by 100% or more. Differences in emissions from wild-land fires are caused only by different choices of the emission factors for years after 1996 which vary by a factor of about 1 to 2 for OC depending on region, and by a combination of emission factors and the amount of dry mass burned for years up to 1996. Volcanic SO2 emissions, which are only provided in one inventory, include emissions from explosive, effusive, and quiescent degassing events for 1167 volcanoes.

  7. OMI-measured increasing SO2 emissions due to energy industry expansion and relocation in northwestern China

    Science.gov (United States)

    Ling, Zaili; Huang, Tao; Zhao, Yuan; Li, Jixiang; Zhang, Xiaodong; Wang, Jinxiang; Lian, Lulu; Mao, Xiaoxuan; Gao, Hong; Ma, Jianmin

    2017-07-01

    The rapid growth of economy makes China the largest energy consumer and sulfur dioxide (SO2) emitter in the world. In this study, we estimated the trends and step changes in the planetary boundary layer (PBL) vertical column density (VCD) of SO2 from 2005 to 2015 over China measured by the Ozone Monitoring Instrument (OMI). We show that these trends and step change years coincide with the effective date and period of the national strategy for energy development and relocation in northwestern China and the regulations in the reduction of SO2 emissions. Under the national regulations for the reduction of SO2 emissions in eastern and southern China, SO2 VCD in the Pearl River Delta (PRD) of southern China exhibited the largest decline during 2005-2015 at a rate of -7 % yr-1, followed by the North China Plain (NCP) (-6.7 % yr-1), Sichuan Basin (-6.3 % yr-1), and Yangtze River Delta (YRD) (-6 % yr-1). The Mann-Kendall (MK) test reveals the step change points of declining SO2 VCD in 2009 for the PRD and 2012-2013 for eastern China responding to the implementation of SO2 control regulation in these regions. In contrast, the MK test and regression analysis also revealed increasing trends of SO2 VCD in northwestern China, particularly for several hot spots featured by growing SO2 VCD in those large-scale energy industry bases in northwestern China. The enhanced SO2 VCD is potentially attributable to increasing SO2 emissions due to the development of large-scale energy industry bases in energy-abundant northwestern China under the national strategy for the energy safety of China in the 21st century. We show that these large-scale energy industry bases could overwhelm the trends and changes in provincial total SO2 emissions in northwestern China and contribute increasingly to the national total SO2 emissions in China. Given that northwestern China is more ecologically fragile and uniquely susceptible to atmospheric pollution than the rest of China, increasing SO2 emissions in

  8. Subminute measurements of SO2 at low parts per trillion by volume mixing ratios in the atmosphere

    Science.gov (United States)

    Nicks, Dennis K., Jr.; Benner, Richard L.

    2001-11-01

    The continuous sulfur dioxide detector (CSD) is a sensitive instrument for reliable measurements at high time resolution in the atmosphere. This new instrument is based on a SO2 measurement technique utilizing the sulfur chemiluminescence detector, previously validated in a rigorously blind experiment sponsored by the National Science Foundation. Simplified sample handling, dénuder separation technology, and the intrinsic sensitivity and fast response of the detector permit measurement at levels below 100 parts per trillion by volume in tens of seconds with the CSD. The CSD provides a differential measurement where response from ambient SO2 is determined by the difference between air containing SO2 and air scrubbed of SO2, where both air samples contain other detectable sulfur species. Digital signal post processing with phase-locked amplification of the detector signal enhances the precision and temporal resolution of the CSD. Oversampling of the detector signal at 10 Hz permits subsequent data retrieval to be adapted to changing ambient levels by either enhancing signal to noise when sulfur dioxide levels are low or by maximizing temporal resolution of derived data when levels are high. he instrument has advantages over existing instruments based on Chromatographie separation in that the CSD provides accurate and reliable measurements at low parts per trillion by volume sulfur dioxide with high time resolution. The CSD is compact and automated and does not require cryogenic materials, making this instrument suitable for remote field locations. The high temporal resolution, specificity for SO2, and sensitivity of the CSD make it a good candidate for installation on an aircraft. Airborne studies of SO2 with a sensitive, fast time response instrument may offer new insight into the understanding of phenomena such as gas-to-particle conversion, long-range transport of pollutants, and the oxidation of biogenically produced sulfur gases.

  9. REAL-TIME MEASUREMENT OF AIRWAY RESPONSES TO SULOFUR DIOXIDE (SO2) IN AN INTACT, AWAKE GUINEA PIG MODEL

    Science.gov (United States)

    Real-time measurment of airway responses to Sulfur Dioxide (SO2) in an intact, awake guinea pig model. J Stanek1,2, Q Krantz2, J Nolan2, D Winsett2, W Watkinson2, and D Costa2. 1College of Veterinary Medicine, NCSU, Raleigh, NC, USA; 2Pulmonary Toxicology Branch, ETD, NHEERL, US...

  10. Missing SO2 oxidant in the coastal atmosphere? – Evidence from high resolution measurements of OH and atmospheric sulfur compounds

    Directory of Open Access Journals (Sweden)

    H. Berresheim

    2014-01-01

    Full Text Available Diurnal and seasonal variations of gaseous sulfuric acid (H2SO4 and methane sulfonic acid (MSA were measured in N.E. Atlantic air at the Mace Head atmospheric research station during the years 2010 and 2011. The measurements utilized selected ion/chemical ionization mass spectrometry (SI/CIMS with a detection limit for both compounds of 4.3 × 10 4 cm−3 at 5 min signal integration. The H2SO4 and MSA gas-phase concentrations were analysed in conjunction with the condensational sink for both compounds derived from 3 nm–10 μm (diameter aerosol size distributions. Accommodation coefficients of 1.0 for H2SO4 and 0.12 for MSA were assumed leading to estimated atmospheric lifetimes of the order of 7 min and 25 min, respectively. With the SI/CIMS instrument in OH measurement mode alternating between OH signal and background (non-OH signal evidence was obtained for the presence of one or more unknown oxidants of SO2 in addition to OH. Depending on the nature of the oxidant(s their ambient concentration may be enhanced in the CIMS inlet system by additional production. The apparent unknown SO2 oxidant was additionally confirmed by direct measurements of SO2 in conjunction with calculated H2SO4 concentrations. The calculated concentrations were consistently lower than the measured concentrations by a factor 4.8 ± 3.4 when considering the oxidation of SO2 by OH as the only source of H2SO4. Both the OH and the background signal were also observed to increase significantly during daytime aerosol nucleation events, independent of the ozone photolysis frequency, J(O1D, and were followed by peaks in both H2SO4 and MSA concentrations. This suggests a strong relation between the unknown oxidant(s, OH chemistry, and the atmospheric photo-oxidation of biogenic iodine compounds. As to the identity of the oxidant(s, we have been able to exclude ClO, BrO, IO, and OIO as possible candidates based on ab initio calculations. Stabilized Criegee intermediates (s

  11. Two years of MAXDOAS measurements of NO2, HONO, SO2 and HCHO at SORPES station in Nanjing, China

    Science.gov (United States)

    Hao, Nan; Ding, Aijun; Van Roozendael, Michel; Hendrick, Francois; Shen, Yicheng; Valks, Pieter

    2015-04-01

    The Yangtze River Delta (YRD) region includes the mega-city Shanghai and the well-industrialized and urbanized areas of Zhejiang Province and Jiangsu Province, with over ten large cities, such as Hangzhou, Suzhou and Nanjing. Covering only 2% land area, this region produces over 20% of China's Gross Domestic Product (GDP) which makes it the most densely populated region and one of the most polluted regions in China. In the YRD region, knowledge gaps still exist in the understanding of the source and transport of air pollutants because only few measurement studies have been conducted. This work presents two years measurements of air pollutants including NO2, HONO, SO2, HCHO and CHOCHO at a regional back-ground site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. A retrieval algorithm, based on an on-line implementation of the radiative transfer code LIDORT and the optimal estimation technique, has been used to provide information on trace gases vertical profiles and vertical column densities (VCDs). The seasonal and diurnal cycles of trace gases have been studies and compared with in situ measurements. The retrieved tropospheric NO2, HCHO and SO2 VCDs were compared to satellite measurements, while the NO2 and SO2 near surface concentrations (0-200 m layer) were compared to measurements from in situ instruments at SORPES.

  12. Airborne multi-axis DOAS measurements of tropospheric SO2 plumes in the Po-valley, Italy

    Directory of Open Access Journals (Sweden)

    P. Wang

    2006-01-01

    Full Text Available During the second FORMAT (FORMaldehyde as A Tracer of oxidation in the troposphere campaign in 2003 the airborne multi-axis DOAS instrument (AMAXDOAS performed scattered-light spectroscopic measurements of SO2 over the city of Mantova and the power plant Porto Tolle, both situated in the Po-valley, Northern Italy. The SO2 vertical columns and emission flux were derived from two days of measurements, 26 and 27 September 2003. The SO2 emission flux from the power plant Porto Tolle was calculated to 1.93×1025 molec s-1 on 26 September and in good agreement with official emission data, which quote 2.25×1025 molec s-1. On 27 September the measured flux was much lower (3.77×1024 molec s-1 if ECMWF wind data are used, but of comparable magnitude (2.4×1025 molec s-1 if the aircraft on-board wind measurements are utilised. Official emission data was 2.07×1025 molec s-1 indicating only a small change from the previous day. Over the city of Mantova, the observed SO2 vertical columns were 1.1×1016 molec cm-2 and 1.9×1016 molec cm-2 on 26 and 27 September, respectively. This is in good agreement with ground-based measurements of 5.9 ppbv and 10.0 ppbv which correspond to 1.2×1016 molec cm-2 and 2.2×1016 molec cm-2 if a well mixed boundary layer of 500m altitude is assumed.

  13. Canopy stomatal uptake of NOX, SO2 and O3 by mature urban plantations based on sap flow measurement

    Science.gov (United States)

    Hu, Yanting; Zhao, Ping; Niu, Junfeng; Sun, Zhenwei; Zhu, Liwei; Ni, Guangyan

    2016-01-01

    Canopy stomatal uptake of NOX (NO, NO2), SO2 and O3 by three mature urban plantations (of Schima superba, Eucalyptus citriodora and Acacia auriculaeformis) were studied using the sap flow-based approach under free atmospheric conditions. The annual mean concentration for NO, NO2, SO2 and O3 were 18.2, 58.1, 12.8 and 42.4 μg m-3, respectively. The atmospheric concentration exhibited a spring or winter maximum for NO, NO2 and SO2, whereas the concentration maximum for O3 occurred in the autumn. Despite the daytime mean canopy stomatal conductance (GC) being positively related with the photosynthetically active radiation (PAR) and negatively with the vapour pressure deficit (VPD), the maximal daytime mean GC did not appear when the PAR was at its highest level or the VPD was at its lowest level because a positive correlation was noted between the daytime mean PAR and VPD (P < 0.001) under field conditions. The GC value was regulated by the cooperation of the PAR and VPD. When analysing the respective effect of the PAR or VPD on GC separately, a positive logarithmical correlation was noted between the daytime mean GC and PAR as the following equation:Gc = a × lnPAR - b (P < 0.01), and the daytime mean GC was negatively logarithmically correlated with the VPD: Gc =Gsref - m × lnVPD (P < 0.001). The daytime mean GC declined with decreases in the soil water content (SWC) under similar meteorological condition. Differences in the seasonal pattern of the canopy stomatal conductance and atmospheric concentrations led to a differentiated peak flux. The flux for NO, NO2 and SO2 exhibited a spring maximum, whereas the flux maximum for O3 appeared in the autumn or summer. The annual cumulative stomatal flux for NO, NO2, O3 and SO2 was 100.19 ± 3.76, 510.68 ± 24.78, 748.59 ± 52.81 and 151.98 ± 9.33 mg m-2 a-1, respectively. When we focus on the foliar uptake of trace gases, the effect of these gases on the vegetation in turn should be considered, particularly for regions

  14. Laboratory Measurements And Modeling Of Molecular Photoabsorption Cross Sections In The Ultraviolet: N2, So2, S2, Co2

    Science.gov (United States)

    Stark, Glenn; Smith, P. L.; Lewis, B. R.; Heays, A. N.; Blackie, D.; Pickering, J.

    2010-10-01

    Our research program comprises the measurement and modeling of ultraviolet molecular photoabsorption cross sections with the highest practical resolution. Measurement and modeling efforts on molecular nitrogen, sulfur dioxide, diatomic sulfur, and carbon dioxide are in progress. N2: We measure line f-values and widths within the complex spectrum between 80 and 100 nm. Our measurements are incorporated into a theoretical model of the absorption spectrum of N2 which has established the mechanisms responsible for predissociation and reproduces the observed features in all N2 isotopomers as a function of temperature. SO2: We provide astronomers with high-resolution cross section data for the complex ultraviolet SO2 absorption spectrum. Using the Imperial College VUV Fourier transform spectrometer, we have completed and published cross sections from 198 to 325 nm (295 K) and from 199 to 220 nm (160 K). We have completed work on further low-temperature measurements from 220 to 325 nm. S2: Interpretations of atmospheric (Io, Jupiter) S2 absorption features are hindered by a complete lack of laboratory cross sections in the ultraviolet. We have begun to quantify the photoabsorption spectrum of S2 from 200 to 300 nm. We have designed an experimental apparatus to produce a stable column of S2 vapor. Measurements of S2 absorption features at high resolution will be complemented by coupled-channel calculations of the relevant transitions. CO2: The photodissociation of CO2 is a fundamental photochemical process in the atmospheres of Mars and Venus. Our research centers on the measurement of high resolution cross sections from 87 to 120 nm. We have completed measurements at 295 K and 195 K over the 106 to 120 nm region. We have recently completed preliminary room temperature measurements in the 87 to 106 nm region. We acknowledge grant support from NASA (NNX08AE78G), STFC-PPARC, and ARC (DP0558962).

  15. Transport of Cerro Hudson SO2 clouds

    Science.gov (United States)

    Doiron, Scott D.; Bluth, Gregg J. S.; Schnetzler, Charles C.; Krueger, Arlin J.; Walter, Louis S.

    The Cerro Hudson volcano in southern Chile (45.92°S, 73.0°W) emitted large ash and sulfur dioxide clouds on August 12-15, following several days of minor activity [Global Volcanism Network Bulletin, 1991]. The SO2 clouds were observed using (preliminary) near real-time data from the Total Ozone Mapping Spectrometer (TOMS) as they encircled the south polar region. The injection of SO2 into the stratosphere has essentially created a gigantic chemical tracer that could provide new insights into the wind patterns and seasonal circulation around the Antarctic region.around the Antarctic region. The TOMS instrument, on board the National Aeronautic and Space Administration's Nimbus 7 satellite, measures the ratio of backscattered Earth radiance to incoming solar irradiance in the ultraviolet spectrum. Although originally designed to measure ozone, it was later discovered that the TOMS instrument could also detect and quantify SO2 [Krueger, 1985]. After this discovery, measurements from TOMS were examined for SO2 emissions for all recorded volcanic eruptions since Nimbus-7 was launched in October 1978, and current data are analyzed as new eruptions occur. The satellite is in a polar, Sun-synchronous orbit so that it crosses the equator at local noon and observes the whole sunlit Earth in approximately 14 orbits each day. Total column amounts of SO2 are determined that represent the amount of gas affecting the reflection of ultraviolet light through a column of the atmosphere from the satellite to the reflecting surface, Earth, given in terms of milli atmospheres centimeter (1000 milli atm cm = a gas layer 1-cm thick at STP). The mass of SO2 is calculated by integrating over the cloud area to obtain a volume, then converting to tons.

  16. [Outcome measures in perinatal medicine--pO2 and SO2. With remarks on pulse oximetry].

    Science.gov (United States)

    Roemer, V M

    2005-10-01

    Due to the outstanding pioneer work of Ronald E. Myers (Bethesda, Maryland) using term rhesus monkey fetuses we know for sure that hypoxia is the leading cause for brain damage and death when exposure occurs perinatally. He defined threshold values for oxygen content and time variables leading to death or cerebral injury. Years later pulsoximetry was developed for measuring fetal oxygen saturation (%) continuously. In this context the obstetrician wants to know: 1) what is the diagnostic potential of pO(2) (mmHg), SO(2) (%) and oxygen content (vol%) in umbilical blood? and 2) using these data could we ascertain fetal pulsoximetry which in addition uses the factor time. In a sample of 7814 term fetuses, delivered in cephalic presentation by the vaginal route, actual blood gases and the variables of the fetal acid-base balance were determined in umbilical blood using equipments (BMS up to ABL 3) from RADIOMETER, Copenhagen. Measurements were done immediately post-partum by trained medical personal. Fetal oxygen saturation (%) for HbF was computed using the algorithm of Ruiz et al. Oxygen content (vol%) was determined according to Severinghaus using Hb values (g%) in each case. The median pO(2) in blood of the umbilical artery (UA) was 17.9 (mean: 18.8 +/- 8.3) mm Hg and in the umbilical vein (UV) 28.5 (mean: 29.3 +/- 9.2) mmHg, respectively. The median oxygen saturation (%) amounted to 24.8 (UA) and 60.9 (UV) using pO(2), pH and pCO(2) for computation in each case. The oxygen variable pO(2) showed no clinically important correlation neither with actual pH (r = 0.032, P = 0.005) nor with base excess (r = 0.047, P values of 6.9 are associated with 10 % oxygen saturation only in UA. P (50) values change dramatically with lowering pH values, i. e., acidosis. Oxygen content (vol %) offers no diagnostic advantages over oxygen saturation. Separation of the whole sample (N = 7814) according to the boundary of 30 % saturation in UA/UV blood leads necessarily to a big

  17. On the absolute calibration of SO2 cameras

    Science.gov (United States)

    Lübcke, Peter; Bobrowski, Nicole; Illing, Sebastian; Kern, Christoph; Alvarez Nieves, Jose Manuel; Vogel, Leif; Zielcke, Johannes; Delgados Granados, Hugo; Platt, Ulrich

    2013-01-01

    Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 300 and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. One important step for correct SO2 emission rate measurements that can be compared with other measurement techniques is a correct calibration. This requires conversion from the measured optical density to the desired SO2 column density (CD). The conversion factor is most commonly determined by inserting quartz cells (cuvettes) with known amounts of SO2 into the light path. Another calibration method uses an additional narrow field-of-view Differential Optical Absorption Spectroscopy system (NFOVDOAS), which measures the column density simultaneously in a small area of the camera’s field-of-view. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements.

  18. Comparing different light-emitting diodes as light sources for long path differential optical absorption spectroscopy NO2 and SO2 measurements

    Institute of Scientific and Technical Information of China (English)

    Chan Ka-Lok; Mark Wenig; Ling Liu-Yi; Andreas Hartl; Zheng Ni-Na; Gerrit Kuhlmann; Qin Min; Sun You-Wen; Xie Pin-Hua; Liu Wen-Qing

    2012-01-01

    In this paper,we present a comparison of different light-emitting diodes (LEDs) as the light source for long path differential optical absorption spectroscopy (LP-DOAS) atmospheric trace gas measurements.In our study,we use a fiberoptic design,where high power LEDs used as the light source are coupled into the telescope using a Y shape fiber bundle.Two blue and one ultraviolet (UV) LEDs with different emission wavelength ranges are tested for NO2 and SO2 measurements.The detailed description of the instrumental setup,the NO2 and SO2 retrieval procedure,the error analysis,and the preliminary results from the measurements carried out in Science Island,Hefei,Anhui,China are presented.Our first measurement results show that atmospheric NO2 and SO2 have strong temporal variations in that area and that the measurement accuracy is strongly dependent on the visibility conditions.The measured NO2 and SO2 data are compared to the Ozone Monitoring Instrument (OMI) satellite observations.The results show that the OMI NO2 product underestimates the ground level NO2 by 45%,while the OMI SO2 data are highly influenced by clouds and aerosols,which can lead to large biases in the ground level concentrations.During the experiment,the mixing ratios of the atmospheric NO2 and SO2 vary from 8 ppbv to 36 ppbv and from 3 ppbv to 18 ppbv,respectively.

  19. Comparing different light-emitting diodes as light sources for long path differential optical absorption spectroscopy NO2 and SO2 measurements

    Science.gov (United States)

    Chan, Ka-Lok; Ling, Liu-Yi; Andreas, Hartl; Zheng, Ni-Na; Gerrit, Kuhlmann; Qin, Min; Sun, You-Wen; Xie, Pin-Hua; Liu, Wen-Qing; Mark, Wenig

    2012-11-01

    In this paper, we present a comparison of different light-emitting diodes (LEDs) as the light source for long path differential optical absorption spectroscopy (LP-DOAS) atmospheric trace gas measurements. In our study, we use a fiberoptic design, where high power LEDs used as the light source are coupled into the telescope using a Y shape fiber bundle. Two blue and one ultraviolet (UV) LEDs with different emission wavelength ranges are tested for NO2 and SO2 measurements. The detailed description of the instrumental setup, the NO2 and SO2 retrieval procedure, the error analysis, and the preliminary results from the measurements carried out in Science Island, Hefei, Anhui, China are presented. Our first measurement results show that atmospheric NO2 and SO2 have strong temporal variations in that area and that the measurement accuracy is strongly dependent on the visibility conditions. The measured NO2 and SO2 data are compared to the Ozone Monitoring Instrument (OMI) satellite observations. The results show that the OMI NO2 product underestimates the ground level NO2 by 45%, while the OMI SO2 data are highly influenced by clouds and aerosols, which can lead to large biases in the ground level concentrations. During the experiment, the mixing ratios of the atmospheric NO2 and SO2 vary from 8 ppbv to 36 ppbv and from 3 ppbv to 18 ppbv, respectively.

  20. Finding regions of influence on SO2 and SO=4 daily concentration measurements at four sites in Spain

    Directory of Open Access Journals (Sweden)

    R. Méndez

    Full Text Available Contamination by the pollutants SO2 and SO=4 was analyzed for the 1989–1992 period at four regional stations in Spain under the auspices of the EMEP-BAPMON program. The evolution of the time series of the daily pollution has also been assessed, and high mean concentrations at La Cartuja and Logroño observed, with values of 3.8 and 4.5 μg m–3 for SO2, respectively. Maximum annual concentrations were recorded in 1989, when SO2 reached values of 6.24, 5.39, 5.71, and 9.30 μg m–3 for the stations of La Cartuja, San Pablo de los Montes, Roquetas, and Logroño, respectively. This work attempts to establish a relationship between the concentrations of the pollutants – both SO2 gas and SO=4 aerosol – and the zones of emission or persistence of these long-range transported pollutants. In this way, those regions showing a greater impact on the air quality in each season have been determined. To achieve this, the trajectories of the air masses carrying away the pollution to each of the receiving stations were considered and followed by a sectorial analysis. Nonparametric statistical methods were implemented to contrast the chemical homogeneity among the different sectors. The criterion that several homogeneous sectors form a chemically homogeneous region was used. To improve this sectorial analysis, we have proposed a new technique based on the Potential-Source-Contribution Function (PSCF. Starting out from a set of specified regions, considered to be chemically homogeneous domains, it is possible to determine the likelihood that an air mass with particular characteristics (e.g., that a value of the daily concentration higher than the mean recorded at the station has been obtained will arrive at a given station after having crossed one of the previously defined regions. Using this technique, it is possible to determine the source regions through which the air masses circulate and bring high pollution concentrations to the studied stations

  1. Changes in Atmospheric Sulfur Dioxide (SO2) over the English Channel - 1.5 Years of Measurements from the Penlee Point Atmospheric Observatory

    Science.gov (United States)

    Yang, Mingxi; Bell, Thomas; Hopkins, Frances; Smyth, Timothy

    2016-04-01

    Atmospheric sulfur dioxide (SO2) was measured continuously from the Penlee Point Atmospheric Observatory near Plymouth, United Kingdom between May 2014 and November 2015. This coastal site is exposed to marine air across a wide wind sector. The predominant southwesterly winds carry relatively clean background Atlantic air. In contrast, air from the southeast is heavily influenced by exhaust plumes from ships in the English Channel as well as near near the Plymouth Sound. International Maritime Organization regulation came into force in January 2015 to reduce sulfur emissions tenfold in Sulfur Emission Control Areas such as the English Channel. We observed a three-fold reduction from 2014 to 2015 in the estimated ship-emitted SO2 during southeasterly winds. Dimethylsulfide (DMS) is an important source of atmospheric SO2 even in this semi-polluted region. The relative contribution of DMS oxidation to the SO2 burden over the English Channel increased from ~1/3 in 2014 to ~1/2 in 2015 due to the reduction in ship sulfur emissions. Our diel analysis suggests that SO2 is removed from the marine atmospheric boundary layer in about half a day, with dry deposition to the ocean accounting for a quarter of the total loss.

  2. Low level measurements of atmospheric DMS, H2S, and SO2 for GTE/CITE-3

    Science.gov (United States)

    Saltzman, Eric; Cooper, David

    1991-01-01

    This project involved the measurement of atmospheric dimethylsulfide (DMS) and hydrogen sulfide (H2S) as part of the GTE/CITE-3 instrument intercomparison program. The two instruments were adapted for use on the NASA Electra aircraft and participated in all phases of the mission. This included ground-based measurements of NIST-provided standard gases and a series of airborne missions over the Western Atlantic Ocean. Analytical techniques used are described and the results are summarized.

  3. A four-channel portable solar radiometer for measuring particulate and/or aerosol opacity and concentration of NO2 and SO2 in stack plumes

    Science.gov (United States)

    Exton, R. J.; Gregory, R. W.

    1976-01-01

    Solar absorption radiometry has been investigated as a method of measuring stackplume effluents. A simple and inexpensive instrument was constructed for observing the sun at four wavelengths: 800, 600, 400, and 310 nm. Higher wavelength channels measured the effect of the particulates and NO2, and an ultraviolet channel measured the contribution of SO2 to the attenuation. Stack-plume measurements of opacity and concentration of NO2 and SO2 were in basic agreement with in-stack measurements. The major limitation on the use of the radiometer is the requirement for an accessible viewing position which allows the sun-plume-observer relationship to be attained. It was concluded that the solar radiometer offers an inexpensive method for monitoring plume effluents when the viewing position is not restricted.

  4. OMI-measured SO2 in a large-scale national energy industrial base and its effect on the capital city of Xinjiang, Northwest China

    Science.gov (United States)

    Wang, Jinxiang; Mo, Jingyue; Li, Jixiang; Ling, Zaili; Huang, Tao; Zhao, Yuan; Zhang, Xiaodong; Mao, Xiaoxuan; Gao, Hong; Shen, Yanjie; Ma, Jianmin

    2017-10-01

    Although considerable efforts have been made to improve air quality in Urumqi city, the capital of Xinjiang-Uyghur Autonomous Region in northwestern China and one of the ten cities with worst air quality in China, this city is still experiencing heavy air pollution during the wintertime. The satellite remote sensing of air quality using Ozone Monitoring Instrument (OMI) measured data discerned an increasing trend of the planetary boundary layer (PBL) columns of sulfur dioxide (SO2) in Midong national petrochemical and coal chemical industry base from 2005 to 2016, located in the northeast of Urumqi. The increasing trend of OMI columnar SO2 in this area is in contrast to the widespread decreases in SO2 emissions in eastern and southern China. This is mainly induced by rapid development in the energy industry in this region over the past decade under the national strategy for energy industry expansion and relocation to northwestern China. We observed a significant correlation of OMI columnar SO2 between this energy industrial base and Urumqi city in winter (R = 0.504, p < 0.005), suggesting that SO2 emitted from heavily contaminated energy industrial base exacerbated the air quality in Urumqi city. The Weather Research and Forecasting Chemistry (WRF-Chem) modeling confirms that the occurrence of heavy smog in this capital city during the wintertime was attributed primarily to strong emissions of air contaminants from the energy industrial base under favorable winds. A numerical case study with and without taking the Midong Industry Base into consideration revealed that this industry base contributed 38% to the SO2 level in Urumqi city, offsetting the considerable efforts made by the local government to improve air quality in this city.

  5. On the absolute calibration of SO2 cameras

    Directory of Open Access Journals (Sweden)

    P. Lübcke

    2013-03-01

    Full Text Available Sulphur dioxide emission rate measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 300 and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. One important step for correct SO2 emission rate measurements that can be compared with other measurement techniques is a correct calibration. This requires conversion from the measured optical density to the desired SO2 column density (CD. The conversion factor is most commonly determined by inserting quartz cells (cuvettes with known amounts of SO2 into the light path. Another calibration method uses an additional narrow field-of-view Differential Optical Absorption Spectroscopy system (NFOV-DOAS, which measures the column density simultaneously in a small area of the camera's field-of-view. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different, calibration methods (DOAS and calibration cells. Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (I-DOAS, are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an I-DOAS to verify the calibration curve over the spatial extent of the image. The results show that calibration cells, while working fine in some cases, can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration

  6. MAX-DOAS measurements and satellite validation of tropospheric NO2 and SO2 vertical column densities at a rural site of North China

    Science.gov (United States)

    Jin, Junli; Ma, Jianzhong; Lin, Weili; Zhao, Huarong; Shaiganfar, Reza; Beirle, Steffen; Wagner, Thomas

    2016-05-01

    North China (NC), namely Huabei in Chinese, is one of the most severely polluted regions in China, and the air pollution issues in this region have received a worldwide attention. We performed ground-based Multi Axis Differential Absorption Spectroscopy (MAX-DOAS) measurements at Gucheng, (39°08‧N, 115°40‧E), a rural site of North China about 110 km southwest of Beijing, from September 2008 to September 2010. The tropospheric vertical column densities (VCDs) of NO2 and SO2 were retrieved using the so-called geometric approximation. The results show that the tropospheric NO2 and SO2 VCDs over NC have nearly the same seasonal variation pattern, with the maximum in winter and minimum in summer, while their diurnal variations are different. We also compared the tropospheric NO2 and SO2 VCDs from our MAX-DOAS measurements with several products of corresponding OMI (Ozone Monitoring Instrument) satellite observations. While in summer good agreement is found, the satellite observations systematically underestimate the tropospheric NO2 in winter over the polluted rural area of NC, probably mostly due to the so called aerosol shielding effect. In contrast, for SO2 no such clear conclusion can be drawn, probably owing to the larger uncertainties from MAX-DOAS and in particular satellite retrievals. This indicates that improvements of the retrieval algorithm for MAX-DOAS and off-line corrections of satellite measurements for the tropospheric SO2 VCDs should be given more emphasis in the future.

  7. A rapid, one step preparation for measuring selected free plus SO2-bound wine carbonyls by HPLC-DAD/MS.

    Science.gov (United States)

    Han, Guomin; Wang, Hua; Webb, Michael R; Waterhouse, Andrew L

    2015-03-01

    Carbonyl compounds are produced during fermentation and chemical oxidation during wine making and aging, and they are important to wine flavor and color stability. Since wine also contains these compounds as α-hydroxysulfonates as a result of their reaction with sulfur dioxide, an alkaline pre-treatment requiring oxygen exclusion has been used to release these bound carbonyls for analysis. By modifying the method to hydrolyze the hydroxysulfonates with heating and acid in the presence of 2,4-dinitrophenylhydrazine (DNPH), the carbonyl compounds are simultaneously and quickly released and derivatized, resulting in a simpler and more rapid method. In addition, the method avoids air exclusion complications during hydrolysis by the addition of sulfur dioxide. The method was optimized for temperature, reaction time, and the concentrations of DNPH, sulfur dioxide and acid. The hydrazones were shown to be stable for 10 h, adequate time for chromatographic analysis by HPLC-DAD/MS. This method is demonstrated for 2-ketoglutaric acid, pyruvic acid, acetoin and acetaldehyde, wine carbonyls of very different reactivities, and it offers good specificity, high recovery and low limits of detection. This new rapid, simple method is demonstrated for the measurement of carbonyl compounds in a range of wines of different ages and grape varieties. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. [Pertinence of simultaneous measurements of pO2 and sO2 on ABL 510].

    Science.gov (United States)

    Gouget, B; Manene, D; Andrimahatratra, R; Bogard, M; Gourmelin, Y

    1992-01-01

    Blood tonometry is the only method to assess the accuracy of the pO2 determination on blood gas analyzers. ABL instruments by Radiometer were tested by two types of tonometry (film and bubble tonometry) and the validity of the algorithm for pO2 correction was analysed with these results. The role of the presentation of the specimen is also discussed. For the precision study on the ABL 510 analyzer, coefficients of variation for pO2 were < 0.37% and < 1.7% for within-run and day-to-day series respectively. pO2 accuracy was excellent. Linearity was verified between 0-620 mmHg (82.5 kPa), and interinstrument comparisons demonstrated a strict correlation with the Ciba-Corning 178 instrument. ABL 510 measures simultaneously oxygen saturation by spectrophotometry. Analytical results showed an acceptable level of imprecision, but the definition and the clinical significance of this parameter are ambiguous.

  9. Fabry-Perot interferometer-based remote sensing of SO2

    Science.gov (United States)

    Kuhn, Jonas; Bobrowski, Nicole; Lübcke, Peter; Pöhler, Denis; Tirpitz, Jan-Lukas; Vogel, Leif; Platt, Ulrich

    2015-04-01

    We studied SO2 degassing from volcanoes and monitored the corresponding SO2 fluxes. Besides the effect on climate and the hazardous effects at a local scale, the absolute magnitude of SO2 fluxes or ratios of SO2 with other volcanic gases can be an indicator for volcanic activity and even help to understand and model processes in the interior of volcanoes. Due to its characteristic absorption structure, high abundance in the volcanic plume and low atmospheric background, SO2 can be easily identified and quantified by remote sensing techniques. DOAS and FTIR became standard techniques for volcanic SO2 measurements. Along with the development of portable devices they offer the advantage of simultaneous measurements of multiple gas species. However, both techniques often need complex data evaluation and observations are usually limited to a single viewing direction. Spatially resolved measurements, which are for instance required to determine gas fluxes, frequently have to be obtained sequentially leading to a relatively low time resolution. A further, today nearly established method to determine SO2 emission fluxes is the "SO2 camera". The SO2 camera has the advantage of a high spatial and temporal resolution, but is very limited in spectral information using only two wavelength channels and thus being less selective. Cross-interferences with volcanic plume aerosol, the ozone background, and other trace gases frequently cause problems in SO2 camera measurements. Here we introduce a novel passive remote sensing method for SO2 measurements in the atmosphere using a Fabry-Perot interferometer (FPI) setup. The transmission profile of this FPI consists of periodic transmission peaks that match the periodic SO2 absorption bands in the UV. In principle, this method allows imaging of two-dimensional SO2 distributions similarly to SO2 cameras. Interferences of standard SO2 cameras are greatly reduced with the FPI method. In addition, this technique can also be applied to other

  10. Scanning and mobile multi-axis DOAS measurements of SO2 and NO2 emissions from an electric power plant in Montevideo, Uruguay

    Science.gov (United States)

    Frins, E.; Bobrowski, N.; Osorio, M.; Casaballe, N.; Belsterli, G.; Wagner, T.; Platt, U.

    2014-12-01

    In March 2012 the emissions of NO2 and SO2 from a power station located on the east side of Montevideo Bay (34° 53‧ 10″ S, 56° 11‧ 49″ W) were quantified by simultaneously using mobile and scanning multi-axis differential optical absorption spectroscopy (in the following mobile DOAS and scanning DOAS, respectively). The facility produces electricity by means of two technologies: internal combustion motors and steam generators. The motors are powered with centrifuged heavy oil and produce a maximum power of 80 MW approximately. The steam generators produce approximately 305 MW and are powered with heavy fuel oil. We compare the emissions obtained from the measured slant column densities (mobile DOAS and scanning DOAS) with the emissions estimated from fuel mass balance. On one occasion it was possible to distinguish between the two types of sources, observing two plumes with different SO2 and NO2 emission rates. During the period of the campaign the mean SO2 emission flux was determined to be 0.36 (±0.12) kg s-1 and 0.26 (±0.09) kg s-1 retrieved from mobile and scanning DOAS respectively, while the calculated SO2 flux from the sulphur content of the fuel was 0.34 (±0.03) kg s-1. The average NO2 flux calculated from mobile DOAS was determined to be 11 (±3) × 10-3 kg s-1. Using the scanning DOAS approach a mean NO2 flux of 5.4 (±1.7) × 10-3 kg s-1 was obtained, which is significantly lower than by the mobile measurements. The differences between the results of mobile MAX-DOAS measurements and scanning DOAS measurements are most probably caused by the variability and the limited knowledge of the wind speed and direction.

  11. Absolute quantum yield measurements for the formation of oxygen atoms after UV laser excitation of SO2 at 222.4 nm

    Indian Academy of Sciences (India)

    Mohammed Abu-Bajeh; Melanie Cameron; Kyung-Hoon Jung; Christoph Kappel; Almuth Läuter; Kyoung-Seok Lee; Hari P Upadhyaya; Rajesh K Vatsa; Hans-Robert Volpp

    2002-12-01

    The dynamics of formation of oxygen atoms after UV photoexcitation of SO2 in the gas-phase was studied by pulsed laser photolysis-laser-induced fluorescence `pump-and-probe' technique in a flow reactor. SO2 at room-temperature was excited at the KrCl excimer laser wavelength (222.4 nm) and O(3P) photofragments were detected under collision-free conditions by vacuum ultraviolet laser-induced fluorescence. The use of narrow-band probe laser radiation, generated via resonant third-order sum-difference frequency conversion of dye laser radiation in Krypton, allowed the measurement of the nascent O(3P=2,1,0) fine-structure state distribution: =2/=1/=0 = (0.88 ± 0.02)/(0.10 ± 0.01)/(0.02 ± 0.01). Employing NO2 photolysis as a reference, a value of O(3P) = 0.13 ± 0.05 for the absolute O(3P) atom quantum yield was determined. The measured O(3P) quantum yield is compared with the results of earlier fluorescence quantum yield measurements. A suitable mechanism is suggested in which the dissociation proceeds via internal conversion from high rotational states of the initially excited SO2(∼ 1 B2) (1, 2, 2) vibronic level to nearby continuum states of the electronic ground state.

  12. Vertical Profiles of SO2 and NO2 in the Alberta Oil Sands: MAX-DOAS Measurements and Comparison to in-situ Instrumentation

    Science.gov (United States)

    Davis, Zoe; Lobo, Akshay; McLaren, Robert

    2015-04-01

    Understanding the levels of industrially emitted gas pollutants in the Alberta oil sands is essential to making quality environmental management decisions but is currently limited due to scarcity of top-down quantification studies. Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements of nitrogen dioxide (NO2) and sulfur dioxide (SO2) , important tropospheric trace gas pollutants, contributes to improved knowledge of these pollutants' levels, vertical distributions and chemical transformations. A mini-MAX-DOAS instrument measured spectra at multiple viewing elevation angles in order to retrieve NO2 and SO2 differential slant column densities (dSCDs) at an Environment Canada research site north of Fort McMurray, Alberta in the fall of 2013. For the first time in the oil sands, tropospheric vertical profiles of NO2 and SO2 were retrieved by applying the optimal estimation technique to the MAX-DOAS measurements. The DOAS fit retrievals of SO2 dSCDs were validated by comparison with retrievals obtained with a quartz calibration cell with known SO2 SCD placed in front of the MAX-DOAS telescope at multiple elevation angles on a clean day. Retrieved SO2 dSCDs varied significantly from the true value depending on the chosen wavelength fitting interval. At the lowest wavelength intervals, interference by stray light and O3 differential structures significantly reduced dSCDs and caused an elevation angle dependence. These results indicate that MAX-DOAS dSCD retrieval settings, particularly for weak absorbers with differential absorption structures in low-intensity spectral regions, must be chosen carefully in order to achieve the most accurate results. Tropospheric vertical column densities (VCDs) and vertical profile retrievals of NO2, SO2 and aerosol extinction during significant pollution events will be illustrated. Trace gas vertical profiles exhibited significant variability between days and at different times of day and were often spatially

  13. Flux Emissions of SO2 and NO2 Measured at the Tula Industrial Complex (Mexico) during MCMA 2006 Field Campaign using a Mini-DOAS System

    Science.gov (United States)

    Sosa, G.; Rivera, C.; Wöhrnschimmel, H.; de Foy, B.; Johansson, M.; Molina, L. T.

    2007-05-01

    The Tula industrial zone is located 60 km northeast from the Mexico City Metropolitan Area (MCMA), in the Hidalgo State in México. This region is known as the Tula-Vito-Apasco industrial corridor, where a number of industries are located. According to the latest information from the environmental authority, about 313,000 ton/year of SO2 and 40,000 ton/year of NOx are released in this region. The Miguel Hidalgo refinery (MHR) and the Francisco Pérez Ríos power plant (FPRPP) are the main emitters, contributing almost 90% of SO2 and 80% of NOx from the total emission inside the Hidalgo State. Other industries such as cement plants, open-sky mines and agricultural activities are also responsible for important emissions of particulat matter (PM) into the atmosphere and soil erosion. This highly industrialized region is thought to influence the air quality in the MCMA, where in some occasions SO2 concentrations in the north part of the city have exceeded the Mexican air quality standard (130 ppb as a 24 hour average), which could not be attributed to irregular operations of industries located in the surrounding area. To address the question of emissions from the refinery and the power plant, the total fluxes of SO2 and NO2 were determined by measurements of their respective integrated vertical column in the neighborhood of the Tula industrial zone, using a Mini-DOAS system. These measurements were carried out as part of the MCMA-2006/MILAGRO Field Campaign, from March 24th to April 18th 2006. Meteorological measurements at the height of the plume dispersion were also determined using pilot balloons and radiosondes techniques. The experimental data were complemented by model simulations. Forward Lagrangian stochastic trajectories were calculated to simulate the plume using FLEXPART in combination with meso-scale meteorological simulations with MM5. The experimental data set was used to evaluate model performance. The simulations were used as an additional estimate of

  14. Aircraft measurements of SO2, NOx, CO, and O3 over the coastal and offshore area of Yellow Sea of China.

    Science.gov (United States)

    Yang, Xiaoyang; Wang, Xinhua; Yang, Wen; Xu, Jun; Ren, Lihong; He, Youjiang; Liu, Bing; Bai, Zhipeng; Meng, Fan; Hu, Min

    2016-09-01

    In order to investigate long-range transport of the air pollution in the East Asia, air pollutants, including SO2, NOx, CO, and O3, were observed by aircraft measurement over the coastal and offshore area of Yellow Sea of China in April 2011. NOx and SO2 seemed to become moderate in recent years, and the concentrations during the whole observations ranged from 0.49 to 9.57 ppb and from 0.10 to 16.02 ppb, respectively. The high concentrations of CO were measured with an average value of 0.98 ppm. The measured O3 average concentration was 76.25 ppb, which showed a higher level comparing with the results from some previous studies. Most of the results for the concentration values generally followed the typical characteristic of vertical and spatial distribution, which were "low altitude > high altitude" and "land/coastal > sea," respectively. Transport of polluted air mass from the continent to the aircraft measurement area was confirmed in some days during the observation by the meteorological analysis, while the measurement results supposed to represent the background level of the pollutants in rest days. Additionally, some small-scale air pollution plumes were observed. Significant positive correlations between NOx and SO2 indicated that these two species originated from the same region. On the other hand, good positive correlations between NOx and O3 found during 2-day flight suggested that the O3 formation was probably under "NOx-limited" regime in these days.

  15. Atmospheric measurements of gas-phase HNO3 and SO2 using chemical ionization mass spectrometry during the MINATROC field campaign 2000 on Monte Cimone

    Directory of Open Access Journals (Sweden)

    M. Hanke

    2003-01-01

    Full Text Available The EU-project MINATROC (MINeral dust And TROpospheric Chemistry aims at enabling an estimation of the influence of mineral dust, a major, but to date largely ignored component of tropospheric aerosol, on tropospheric oxidant cycles. Within the scope of this project continuous atmospheric measurements of gas-phase HNO3 and SO2 were conducted in June and July 2000 at the CNR WMO station, situated on Monte Cimone (MTC (44°11' N --10°42' E, 2165 m asl, Italy. African air transporting dust is occasionally advected over the Mediterranean Sea to the site, thus mineral aerosol emitted from Africa will encounter polluted air masses and provide ideal conditions to study their interactions. HNO3 and SO2 were measured with an improved CIMS (chemical ionization mass spectrometry system for ground-based measurements that was developed and built at MPI-K Heidelberg. Since HNO3  is a very sticky compound special care was paid for the air-sampling and background-measurement system. Complete data sets could be obtained before, during and after major dust intrusions. For the first time these measurements might provide a strong observational indication of efficient uptake of gas-phase HNO3 by atmospheric mineral-dust aerosol particles.

  16. On the absolute calibration of SO2 cameras

    Directory of Open Access Journals (Sweden)

    J. Zielcke

    2012-09-01

    Full Text Available Sulphur dioxide emission flux measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 305 nm and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. While this approach is simple and delivers valuable insights into the two-dimensional SO2 distribution, absolute calibration has proven to be difficult. An accurate calibration of the SO2 camera (i.e., conversion from optical density to SO2 column density, CD is crucial to obtain correct SO2 CDs and flux measurements that are comparable to other measurement techniques and can be used for volcanological applications. The most common approach for calibrating SO2 camera measurements is based on inserting quartz cells (cuvettes containing known amounts of SO2 into the light path. It has been found, however, that reflections from the windows of the calibration cell can considerably affect the signal measured by the camera. Another possibility for calibration relies on performing simultaneous measurements in a small area of the camera's field-of-view (FOV by a narrow-field-of-view Differential Optical Absorption Spectroscopy (NFOV-DOAS system. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different calibration methods (DOAS and calibration cells. Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (IDOAS, are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The

  17. Intercomparison of Nox,SO2,O3,and Aromatic Hydrocarbons Measured by a Commercial DOAS System and Traditional Point Monitoring Techniques

    Institute of Scientific and Technical Information of China (English)

    谢品华; 刘文清; 付强; 王瑞斌; 刘建国; 魏庆农

    2004-01-01

    A field-based intercomparison study of a commercial Differential Optical Absorption Spectroscopy (DOAS) instrument (OPSIS AB, Sweden) and different point-sample monitoring techniques (PM, based on an air monitoring station, an air monitoring vehicle, and various chemical methods) was conducted in Beijing from October 1999 to January 2000. The mixing ratios of six trace gases including NO, NO2, SO2,O3, benzene, and toluene were monitored continuously during the four months. A good agreement between the DOAS and PM data was found for NO2 and SO2. However, the concentrations of benzene, toluene,and NO obtained by DOAS were significantly lower than those measured by the point monitors. The ozone levels monitored by the DOAS were generally higher than those measured by point monitors. These results may be attributed to a strong vertical gradient of the NO-O3-NO2 system and of the aromatics at the measurement site. Since the exact data evaluation algorithm is not revealed by the manufacturer of the DOAS system, the error in the DOAS analysis can also not be excluded.

  18. Emission factors of SO2, NOx and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling

    Directory of Open Access Journals (Sweden)

    J. Beecken

    2014-10-01

    Full Text Available Emission factors of SO2, NOx and size distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an MI-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the river Neva in the city area of Saint Petersburg. Most ships were running at reduced speed (10 knots, i.e. not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal with averages of 4.6 gSO2 kgfuel−1 and 18.2 gSO2 kgfuel−1 for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content SECA limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal with an average of 58 gNOx kgfuel−1. The corresponding emission related to the generated power yields an average of 12.1 gNOx kWh−1. The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 μm size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm the other above 2 μm. The average particle emission factors were found to be in the range from 0.7 to 2.7 × 1016 particles kgfuel−1 and 0.2 to 3.4 gPM kgfuel−1, respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in

  19. Volcanic plume measurements using a UAV for the 2014 Mt. Ontake eruption

    Science.gov (United States)

    Mori, Toshiya; Hashimoto, Takeshi; Terada, Akihiko; Yoshimoto, Mitsuhiro; Kazahaya, Ryunosuke; Shinohara, Hiroshi; Tanaka, Ryo

    2016-03-01

    A phreatic eruption of Mt. Ontake, Japan, started abruptly on September 27, 2014, and caused the worst volcanic calamity in recent 70 years in Japan. We conducted volcanic plume surveys using an electric multirotor unmanned aerial vehicle to elucidate the conditions of Mt. Ontake's plume, which is flowing over 3000 m altitude. A plume gas composition, sulfur dioxide flux and thermal image measurements and a particle sampling were carried out using the unmanned aerial vehicle for three field campaigns on November 20 and 21, 2014, and June 2, 2015. Together with the results of manned helicopter and aircraft observations, we revealed that the plume of Mt. Ontake was not directly emitted from the magma but was influenced by hydrothermal system, and observed SO2/H2S molar ratios were decreasing after the eruption. High SO2 flux of >2000 t/d observed at least until 20 h after the onset of the eruption implies significant input of magmatic gas and the flux quickly decreased to about 130 t/d in 2 months. In contrast, H2S fluxes retrieved using SO2/H2S ratio and SO2 flux showed significantly high level of 700-800 t/d, which continued at least between 2 weeks and 2 months after the eruption. This is a peculiar feature of the 2014 Mt. Ontake eruption. Considering the trends of the flux changes of SO2 and H2S, we presume that majority of SO2 and H2S are supplied, respectively, from high-temperature magmatic fluid of a deep origin and from hydrothermal system. From the point of view of SO2/H2S ratios and fumarolic temperatures, the plume degassing trend after the 2014 eruption is following the similar course as that after the 1979 eruptions, and we speculate the 2014 eruptive activity will cease slowly similar to the 1979 eruption.

  20. Variations of the BrO/SO2 ratios from Tungurahua volcano, Ecuador

    Science.gov (United States)

    Warnach, Simon; Lübcke, Peter; Dinger, Florian; Bobrowski, Nicole; Hidalgo, Silvana; Arellano, Santiago; Battaglia, Jean; Galle, Bo; Hörmann, Christoph; Ruiz, Mario; Vogel, Leif; Wagner, Thomas; Platt, Ulrich

    2016-04-01

    The amount and composition of volcanic gas emissions can yield information about magmatic processes. Apart from the SO2 emission rate, which is used as a widespread tool in monitoring volcanoes, the molar ratio of BrO/SO2 in a volcanic plume has shown the potential for interpreting volcanic activity. The evaluation of long-term spectral data collected with UV-scanning spectrometers through the Network for Observation of Volcanic and Atmospheric Change (NOVAC) using the DOAS technique can help to obtain a better understanding of the BrO/SO2 molar ratio and its correlation to magmatic processes. BrO and SO2 emissions as well as the BrO/SO2 ratio have been successfully retrieved from NOVAC data at Nevado del Ruiz (Colombia), where a decrease of the BrO/SO2 ratio was observed prior to a large eruption. We apply this evaluation algorithm to determine the plume composition of Tungurahua volcano, Ecuador, which is part of NOVAC since 2007. Different from Nevado del Ruiz the retrieved column densities of SO2 and BrO at Tungurahua are typically more than a factor of two lower during the respective period of observation. In addition, changes in the volcanic activity appear on a smaller timescale, as Tungurahua displays a succession of activity and quiescence phases. In order to still obtain robust BrO/SO2 ratios at Tungurahua, it is necessary to improve the data evaluation as well as applying a more sophisticated scheme to calculate the BrO/SO2 ratio. By combining both methods we create a time series of the BrO/SO2 ratio for several eruptive phases between 2007 and 2014. The ratio shows values between 2 and 8 × 10-5. The variation of the BrO/SO2 ratio during these eruptive phases is compared to seismic data and volcanological phenomenological observations as well as satellite and ground based SO2 measurements. During several eruptive phases we observe an increase in the BrO/SO2 ratio on the transition from high explosive activity to low explosive activity. During the

  1. Volcanic Gas Measurements During the 2004 Unrest at Mount St. Helens

    Science.gov (United States)

    McGee, K. A.; Gerlach, T. M.; Doukas, M. P.; Sutton, A. J.

    2004-12-01

    Volcanic gas observations during the 2004 unrest at Mount St. Helens began with helicopter measurements on September 27 and shifted to fixed-wing aircraft measurements on October 7. Helicopter measurements were done by downwind plume profiling at the crater rim and crater breach, orbiting the dome and cross traversing the top of the dome. Fixed-wing aircraft measurements consisted of profiling the downwind plume as it spilled over the crater rim. Target gases included CO2, SO2, and H2S measured by LI-COR, COSPEC and Interscan analyzers. These measurements defined three periods of volcanic degassing: (a) an initial period of negligible volcanic degassing characterized by scrubbing or sealing-in of all gases; (b) an intermediate period of wet volcanic degassing when gas scrubbing dominated volcanic degassing; and (c) a period of dry volcanic degassing when volcanic degassing exceeded gas scrubbing. Measurements during the September 27-30 period of negligible volcanic degassing showed little or no CO2 above atmospheric levels; SO2 and H2S were not detected. The absence of these gases implies fairly complete gas scrubbing at high water to gas mass ratios (greater than 100) or confinement of the gases by post-1986 sealing of gas transport channel ways. Scrubbing seems likely to have dominated sealing; the high rates of concurrent seismicity and deformation favored reestablishment of transport along fractures, and the unrest followed a period with an unusually large potential for groundwater recharge. No August-September interval since the cessation of dome-building eruptions in 1986 has had heavier rainfall than in 2004, and growth of the crater glacier since 1986 has increased the amount of water available for recharge in late summer. Measurements during the period of wet volcanic degassing that began on October 1 after the first steam and ash eruption showed an increase in the frequency and size of CO2 peaks together with the increasingly common detection of H2S

  2. GOSAT/TANSO-FTS Measurement of Volcanic and Geothermal CO2 Emissions

    Science.gov (United States)

    Schwandner, Florian M.; Carn, Simon A.; Newhall, Christopher G.

    2010-05-01

    volcanic CO2 anomalies using GOSAT and correlation with Aura/OMI, AIRS, and ASTER determined SO2 fluxes and ground based monitoring of CO2 and other geophysical and geochemical parameters. This will provide the ground work for future higher spatial resolution satellite missions. This is a joint effort from two GOSAT-IBUKI data application projects: "Satellite-Borne Quantification of Carbon Dioxide Emissions from Volcanoes and Geothermal Areas" (PI Schwandner), and "Application of GOSAT/TANSO-FTS to the Measurement of Volcanic CO2 Emissions" (PI Carn).

  3. Volcanic sulfur dioxide and carbon dioxide measurements using small unmanned aerial systems

    Science.gov (United States)

    Pieri, D. C.; Diaz, J. A.; Fladeland, M. M.; Bland, G.; Alan, A., Jr.; Alegria, O.; Buongiorno, M. F.; Christensen, L. E.; Corrales, E.; Linick, J.; Mouginis-Mark, P. J.; Ramsey, M. S.; Realmuto, V. J.; Schwandner, F. M.

    2015-12-01

    Volcanoes emit gases continuously with significant pre-post-eruption changes, mainly H2O and CO2, plus SO2, and others. The SO2/CO2 ratio changes within volcanic life cycles making it an indicator of oncoming eruption phases: it can dip weeks to months before eruptions, then increase, and decrease back to background after eruptions. Over the last five years, we have made an effort to develop small and inexpensive lighter-than-air and fixed wing unmanned aerial vehicle (UAV) platforms in Costa Rica at Turrialba Volcano. Turrialba is an appropriate natural laboratory to test and prove platforms and instrumentation in low-level steady state volcanogenic gas and aerosol emissions at moderate altitudes (UAVs during ASTER overpasses, and (3) reconciliation of the orbital results with in situ data to validate mass retrieval and transport models. As part of the NASA HyspIRI Preparatory Airborne Activities program, we will conduct similar observations at Kilauea volcano using small UAVs and for both SO2 and CO2 in situ. One of the salient characteristics of the long lived Kilauea eruptions since 1983 has been the emission of SO2 in significant amounts, generating environmental stresses on local inhabitants due to lowered air quality, and stress on vegetation. Kilauea volcanic plumes, as with Turrialba, are mainly gases and liquid--SO2 is hydrolyzed to H2SO4 and the resulting highly acidic liquid aerosol is termed "vog," an environmental health hazard. Measurement of the diffuse CO2 emissions at Kilauea will also be of interest. Such measurements at Turrialba, indicate summit CO2 concentrations of up to 4000ppmv, and flank CO2 values of up to1500ppmv. We will discuss our SO2 and CO2 results at Turrialba and in Italy, and plans for Hawaii. Work presented here was done, in part, under contract to the NASA Earth Surface and Interior Focus Area, at the Jet Propulsion Laboratory of the California Institute of Technology.

  4. Aerosol optical depth, backscattering profiles and column NO2 and SO2 measurements during March 2006 in Tenango del Aire, Mexico.

    Science.gov (United States)

    Hernandez, A.; Basaldud, R.; Grutter, M.; Baumgardner, D.; Slusser, J.; Steinbrecher, R.; Ruiz-Suarez, L. G.

    2007-05-01

    The Tenango del Aire site (19.16°N, 98.86°W, 2380 masl) is located some 40 km SE from Mexico City in the Chalco Valley, where some pollution otflow has been predicted by air quality models. Direct and diffuse ground-based irradiance measurements have been made at this site during the MILAGRO field campaign by a UV-MultiFilter Rotating ShadowBand Radiometer (UV-MFRSR) at seven channels (300-, 305-, 311-, 317-, 325-, 332- and 368-nm with 2-nm nominal bandpass) from which several parameters could be calculated, including the aerosol optical depths (AOD), total ozone column (TOC), asymmetry factor (g) and aerosol single scattering albedo (SSA) via an optimal estimation algorithm. NO2 and SO2 column concentrations were measured with the zenith-sky DOAS (differential absorption spectrometer) technique. LIDAR (light detection and ranging) remote sensing of aerosols was done with a Vaisala Ceilometer Model LD40 from which mixing layer heights were estimated. The results of these measurements and a preliminary analysis of the possible sources of the aerosols are presented.

  5. The US SO2 Auction

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Christensen, Jan Lien

    1998-01-01

    An annual discriminative and revenue-neutral auction is linked to the new Acid Rain Program which allows electric utilities all over the US to trade SO2 emission permits. This innovative SO2 auction distributes 2% of the permits in circulation and takes place at the Chicago Board of Trade. Early...

  6. The US SO2 Auction

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Christensen, Jan Lien

    1998-01-01

    An annual discriminative and revenue-neutral auction is linked to the new Acid Rain Program which allows electric utilities all over the US to trade SO2 emission permits. This innovative SO2 auction distributes 2% of the permits in circulation and takes place at the Chicago Board of Trade. Early...

  7. Hard target LIDAR calibration for SO2

    CSIR Research Space (South Africa)

    Du Plessis, A

    2006-01-01

    Full Text Available Presentation on hard target LIDAR calibration for SO2. This project aimed at measuring the concentration of the atmospheric pollutants such as gases and mobile laser system for remote detection...

  8. Surface area and volume measurements of volcanic ash particles by SEM stereoscopic imaging

    Science.gov (United States)

    Ersoy, Orkun

    2010-05-01

    Surface area of volcanic ash particles is of great importance to research including plume dynamics, particle chemical and water reactions in the plume, modelling (i.e. plume shape, particle interactions , dispersion etc.), remote sensing of transport and SO2, HCl, H2O, CO2 levels, forecasting plume location, and transportation and deposition of ash particles. The implemented method presented in this study offer new insights for surface characterization of volcanic ash particles on macro-pore regions. Surface area and volumes of volcanic ash particles were measured using digital elevation models (DEM) reconstructed from stereoscopic images acquired from different angles by scanning electron microscope (SEM). The method was tested using glycidyl methacrylate (GMA) micro-spheres which exhibit low spherical imperfections. The differences between measured and geometrically calculated surface areas were introduced for both micro-spheres and volcanic ash particles in order to highlight the probable errors in modelling on volcanic ash behaviour. The specific surface areas of volcanic ash particles using this method are reduced by half (from mean values of 0.045 m2/g to 0.021 m2/g) for the size increment 63 μm to 125 μm. Ash particles mostly have higher specific surface area values than the geometric forms irrespective of particle size. The specific surface area trends of spheres and ash particles resemble for finer particles (63 μm). Approximation to sphere and ellipsoid have similar margin of error for coarser particles (125 μm) but both seem to be inadequate for representation of real ash surfaces.

  9. Continuous measurements of volcanic gases from Popocatepetl volcano by thermal emission spectroscopy

    Science.gov (United States)

    Taquet, Noemie; Stremme, Wolfgang; Meza, Israel; Grutter, Michel

    2016-04-01

    Passive volcanic gas emissions have been poorly studied despite their impact on the atmospheric chemistry with important consequences on its geochemical cycles and climate change on regional and global scale. Therefore, long-term monitoring of volcanic gas plumes and their composition are of prime importance for climatic models and the estimation of the volcanic contribution to climate change. We present a new measurement and analysis strategy based on remote thermal emission spectroscopy which can provide continuous (day and night) information of the composition of the volcanic plume. In this study we show results from the Popocatepetl volcano in Mexico with measurements performed during the year 2015 from the Altzomoni Atmospheric Observatory (19.12N, -98.65W, 3,985 masl). This site, which forms part of the RUOA (www.ruoa.unam.mx) and NDACC (https://www2.acom.ucar.edu/irwg) networks, is located north of the crater of this active volcano at 12 km distance. Emission spectra were recorded with an FTIR spectrometer (OPAG22, Bruker) at 0.5 cm-1 spectral resolution and processed using the SFIT4 radiative transfer and profile retrieval code, based on the Optimal Estimation method (Rodgers, 1976; 1990; 2000). This newly improved methodology is intercompared to a former retrieval strategy using measurements from 2008 and recent results of the variability of the SiF4/SO2 composition ratio during 2015 is presented. A discussion of how the new measurements improve the understating of the impact of volcanic gas emissions on the atmosphere on global and regional scale is included.

  10. Ground-based and airborne measurements of volcanic gas emissions at White Island in New Zealand

    Science.gov (United States)

    Tirpitz, Jan-Lukas; Poehler, Denis; Bobrowski, Nicole; Christenson, Bruce; Platt, Ulrich

    2017-04-01

    Quantitative understanding of volcanic gas emissions has twofold relevance for nature and society: 1) Variation in gas emission and/or in emitted gas ratios are tracers of the dynamic processes in the volcano interior indicating its activity. 2) Volcanic degassing plays an important role for the Earth's climate, for local sometimes even regional air quality and atmospheric chemistry. In autumn 2015, a campaign to White Island Volcano in New Zealand was organized to perform ground-based as well as airborne in-situ and remote sensing gas measurements of sulfur dioxide (SO2), carbon dioxide (CO2) and bromine monoxide (BrO). For all three gases the ratios and total emission rates were determined in different plume types and ages. An overview over the data will be presented with focus on the two most notable outcomes: 1) The first determination of the BrO/SO2 ratio in the White Island plume and a minimum estimate of the volcano's bromine emission rate; two of many parameters, which are important to assess the impact of volcanic degassing on the atmospheric halogen chemistry. 2) In-situ SO2 data was very successfully recorded with the PITSA, a prototype of a portable and cost-effective optical instrument. It is based on the principle of non-dispersive UV absorption spectroscopy and features different advantages over the customary electrochemical sensors, including a sub second response time, negligible cross sensitivities to other gases, and inherent calibration. The campaign data demonstrates the capabilities and limitations of the PITSA and shows, that it can be well applied as substitute for conventional electrochemical systems.

  11. The 2010 Eyja eruption evolution by using IR satellite sensors measurements: retrieval comparison and insights into explosive volcanic processes

    Science.gov (United States)

    Piscini, A.; Corradini, S.; Merucci, L.; Scollo, S.

    2010-12-01

    The 2010 April-May Eyja eruption caused an unprecedented disruption to economic, political and cultural activities in Europe and across the world. Because of the harming effects of fine ash particles on aircrafts, many European airports were in fact closed causing millions of passengers to be stranded, and with a worldwide airline industry loss estimated of about 2.5 billion Euros. Both security and economical issues require robust and affordable volcanic cloud retrievals that may be really improved through the intercomparison among different remote sensing instruments. In this work the Thermal InfraRed (TIR) measurements of different polar and geostationary satellites instruments as the Moderate Resolution Imaging Spectroradiometer (MODIS), the Advanced Very High Resolution Radiometer (AVHRR) and the Spin Enhanced Visible and Infrared Imager (SEVIRI), have been used to retrieve the volcanic ash and SO2 in the entire eruption period over Iceland. The ash retrievals (mass, AOD and effective radius) have been carried out by means of the split window BTD technique using the channels centered around 11 and 12 micron. The least square fit procedure is used for the SO2 retrieval by using the 7.3 and 8.7 micron channels. The simulated TOA radiance Look-Up Table (LUT) needed for both the ash and SO2 column abundance retrievals have been computed using the MODTRAN 4 Radiative Transfer Model. Further, the volcanic plume column altitude and ash density have been computed and compared, when available, with ground observations. The results coming from the retrieval of different IR sensors show a good agreement over the entire eruption period. The column height, the volcanic ash and the SO2 emission trend confirm the indentified different phases occurred during the Eyja eruption. We remark that the retrieved volcanic plume evolution can give important insights into eruptive dynamics during long-lived explosive activity.

  12. Dispersion and Lifetime of the SO2 Cloud from the August 2008 Kasatochi Eruption

    Science.gov (United States)

    Krotkov, N. A.; Schoeberl, M. R.; Morris, G. A.; Carn, S.; Yang, K.

    2010-01-01

    Hemispherical dispersion of the SO2 cloud from the August 2008 Kasatochi eruption is analyzed using satellite data from the Ozone Monitoring Instrument (OMI) and the Goddard Trajectory Model (GTM). The operational OMI retrievals underestimate the total SO2 mass by 20-30% on 8-11 August, as compared with more accurate offline Extended Iterative Spectral Fit (EISF) retrievals, but the error decreases with time due to plume dispersion and a drop in peak SO2 column densities. The GTM runs were initialized with and compared to the operational OMI SO2 data during early plume dispersion to constrain SO2 plume heights and eruption times. The most probable SO2 heights during initial dispersion are estimated to be 10-12 km, in agreement with direct height retrievals using EISF algorithm and IR measurements. Using these height constraints a forward GTM run was initialized on 11 August to compare with the month-long Kasatochi SO2 cloud dispersion patterns. Predicted volcanic cloud locations generally agree with OMI observations, although some discrepancies were observed. Operational OMI SO2 burdens were refined using GTM-predicted mass-weighted probability density height distributions. The total refined SO2 mass was integrated over the Northern Hemisphere to place empirical constraints on the SO2 chemical decay rate. The resulting lower limit of the Kasatochi SO2 e-folding time is approx.8-9 days. Extrapolation of the exponential decay back in time yields an initial erupted SO2 mass of approx.2.2 Tg on 8 August, twice as much as the measured mass on that day.

  13. A Novel and Inexpensive Method for Measuring Volcanic Plume Water Fluxes at High Temporal Resolution

    Directory of Open Access Journals (Sweden)

    Tom D. Pering

    2017-02-01

    Full Text Available Water vapour (H2O is the dominant species in volcanic gas plumes. Therefore, measurements of H2O fluxes could provide valuable constraints on subsurface degassing and magmatic processes. However, due to the large and variable concentration of this species in the background atmosphere, little attention has been devoted to monitoring the emission rates of this species from volcanoes. Instead, the focus has been placed on remote measurements of SO2, which is present in far lower abundances in plumes, and therefore provides poorer single flux proxies for overall degassing conditions. Here, we present a new technique for the measurement of H2O emissions at degassing volcanoes at high temporal resolution (≈1 Hz, via remote sensing with low cost digital cameras. This approach is analogous to the use of dual band ultraviolet (UV cameras for measurements of volcanic SO2 release, but is focused on near infrared absorption by H2O. We report on the field deployment of these devices on La Fossa crater, Vulcano Island, and the North East Crater of Mt. Etna, during which in-plume calibration was performed using a humidity sensor, resulting in estimated mean H2O fluxes of ≈15 kg·s−1 and ≈34 kg·s−1, respectively, in accordance with previously reported literature values. By combining the Etna data with parallel UV camera and Multi-GAS observations, we also derived, for the first time, a combined record of 1 Hz gas fluxes for the three most abundant volcanic gas species: H2O, CO2, and SO2. Spectral analysis of the Etna data revealed oscillations in the passive emissions of all three species, with periods spanning ≈40–175 s, and a strong degree of correlation between the periodicity manifested in the SO2 and H2O data, potentially related to the similar exsolution depths of these two gases. In contrast, there was a poorer linkage between oscillations in these species and those of CO2, possibly due to the deeper exsolution of carbon dioxide, giving

  14. Retrieval of near-surface sulfur dioxide (SO2 concentrations at a global scale using IASI satellite observations

    Directory of Open Access Journals (Sweden)

    S. Bauduin

    2015-10-01

    Full Text Available SO2 from volcanic eruptions is now operationally monitored from space in both ultraviolet (UV and thermal infrared (TIR spectral range, but anthropogenic SO2 has almost solely been measured from UV sounders. Indeed, TIR instruments are well-known to have a poor sensitivity to the boundary layer (PBL, due to generally low thermal contrast (TC between the ground and the air above it. Recent studies have demonstrated the capability of the Infrared Atmospheric Sounding Interferometer (IASI to measure near-surface SO2 locally, for specific atmospheric conditions. In this work, we develop a retrieval method allowing the inference of SO2 near-surface concentrations from IASI measurements at a global scale. This method consists of two steps. Both are based on the computation of radiance indexes representing the strength of the SO2 ν3 band in IASI spectra. The first step allows retrieving the peak altitude of SO2 and selecting near-surface SO2. In the second step, 0–4 km columns of SO2 are inferred using a look-up table (LUT approach. Using this new retrieval method, we obtain the first global distribution of near-surface SO2 from IASI-A, and identify the dominant anthropogenic hotspot sources and volcanic degassing. The 7-year daily time evolution of SO2 columns above two industrial source areas (Beijing in China and Sar Cheshmeh in Iran is investigated and correlated to the seasonal variations of the parameters that drive the IASI sensitivity to the PBL composition. Apart from TC, we show that humidity is the most important parameter which determines IR sensitivity to near-surface SO2. As IASI provides twice daily global measurements, the differences between the retrieved columns for the morning and evening orbits are investigated. This paper finally presents a first intercomparison of the measured 0–4 km columns with an independent iterative retrieval method and with observations of the Ozone Monitoring Instrument (OMI.

  15. What have we learned about global SO2 pollution with Aura/OMI data?

    Science.gov (United States)

    Krotkov, N.; Yang, K.; Bhartia, P. K.; Carn, S.; Krueger, A.; Dickerson, R.; Li, C.

    2008-05-01

    Sulfur Dioxide (SO2) is a short-lived gas produced by volcanoes, power plants, refineries, metal smelting and general burning of fossil fuels. It is one of five EPA criteria pollutants. Emitted SO2 is soon converted to sulfate aerosol, with climate effects that include direct radiative forcing and aerosol-induced changes in cloud microphysics and the hydrological cycle. The Ozone Monitoring Instrument (OMI) launched on NASA Aura satellite in July 2004 offers unprecedented spatial resolution, coupled with contiguous daily global coverage, for space- based UV measurements of volcanic and anthropogenic SO2 emissions. Anthropogenic SO2 emissions in the PBL present challenges, because these typically weak signals need to be separated from the noise in the radiances. Plumes from strong surface sources of SO2 (such as smelters and coal burning power plants) and from strong regional pollution can currently be detected in the operational pixel data. Operational data were evaluated with in-situ aircraft SO2 profiles measured in the lower troposphere over China during the East-AIRE campaign in April 2005. This comparison demonstrates that OMI can distinguish between background SO2 conditions and heavy pollutions on a daily basis, suggesting potential of using OMI SO2 data for the regional pollution monitoring. Chinese SO2 pollution lofting above the PBL and long-range transport over Pacific Ocean was first confirmed using OMI data. Quantification of anthropogenic SO2 emissions requires off-line corrections of the average photon path, characterized by the operational air-mass factor (AMF). The AMF corrections in turn require a-priori information about the altitude of the SO2 plume center of mass, the total ozone, and surface albedo. In addition, aerosols and subpixel clouds affect the AMF in different ways depending on their amounts and vertical distribution. Therefore, ancillary cloud, snow and aerosol information available from near simultaneous A-train sensors is valuable

  16. Sulfur dioxide emissions from Alaskan volcanoes quantified using an ultraviolet SO_{2} camera

    Science.gov (United States)

    Kern, Christoph; Werner, Cynthia; Kelly, Peter; Brewer, Ian; Ketner, Dane; Paskievitch, John; Power, John

    2016-04-01

    several hundred t/d as well as short-term (active volcanic center. Our presentation will include a brief description of our SO2 camera, a system we designed and built for rapid deployment at active volcanoes, and the results of the measurements will be discussed. These results will be compared to other available monitoring data and interpreted with regard to their importance for assessing the current level of activity of these remote Alaskan volcanoes.

  17. SO2 Emissions in China - Their Network and Hierarchical Structures

    Science.gov (United States)

    Yan, Shaomin; Wu, Guang

    2017-04-01

    SO2 emissions lead to various harmful effects on environment and human health. The SO2 emission in China has significant contribution to the global SO2 emission, so it is necessary to employ various methods to study SO2 emissions in China with great details in order to lay the foundation for policymaking to improve environmental conditions in China. Network analysis is used to analyze the SO2 emissions from power generation, industrial, residential and transportation sectors in China for 2008 and 2010, which are recently available from 1744 ground surface monitoring stations. The results show that the SO2 emissions from power generation sector were highly individualized as small-sized clusters, the SO2 emissions from industrial sector underwent an integration process with a large cluster contained 1674 places covering all industrial areas in China, the SO2 emissions from residential sector was not impacted by time, and the SO2 emissions from transportation sector underwent significant integration. Hierarchical structure is obtained by further combining SO2 emissions from all four sectors and is potentially useful to find out similar patterns of SO2 emissions, which can provide information on understanding the mechanisms of SO2 pollution and on designing different environmental measure to combat SO2 emissions.

  18. Variations of the BrO/SO2 molar ratios during the 2015 Cotopaxi eruption

    Science.gov (United States)

    Dinger, Florian; Arellano, Santiago; Battaglia, Jean; Bobrowski, Nicole; Galle, Bo; Hernandez, Stephen; Hidalgo, Silvana; Hörmann, Christoph; Lübcke, Peter; Platt, Ulrich; Ruiz, Mario; Warnach, Simon; Wagner, Thomas

    2016-04-01

    Cotopaxi volcano is located 50 km south of Quito, the capital of Ecuador. In case of a large eruption producing lahars, these may cause damage to the inhabited areas located to the south and north of the volcano and to the local water supply and other infrastructure. After almost 140 years of relative quiescence, increasing activity is observed in seismicity and gas emissions since May 2015. During August 2015 ash and gas emissions are recorded. Cotopaxi volcano is part of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) since 2009, thus the observations include the overall eruptive activity onset and its evolution. NOVAC regularly monitors the SO2 emissions of more than 30 volcanoes using scanning UV-spectrometers. Today, monitoring of volcanic SO2 emissions by UV-spectrometers is a widespread tool but its interpretation can be improved by additionally recording halogen/sulphur emission ratios. Recently, it has been shown that spectra from NOVAC instruments can also be used to retrieve the BrO/SO2 molar ratio by applying Differential Optical Absorption Spectroscopy (DOAS). We apply this new technique to analyse the plume composition of Cotopaxi volcano and will present time series of the BrO/SO2 ratios as monitored by the ground-based NOVAC instruments since March 2015. The SO2 column densities were below 6\\cdot1016 molec/cm^2 prior to May 2015 and up to 1.5\\cdot1018 molec/cm^2 between May and August 2015. For these periods, the BrO column densities were below the detection limit of 3\\cdot1013 molec/cm^2. After the phreatic explosions on 14.08.2015, SO2 column densities of up to 3\\cdot1018 molec/cm^2 and BrO column densities of up to 5\\cdot1014 molec/cm^2 were observed. Until December 2015 these SO2 column densities kept at about the same level but the BrO column densities increased up to 3\\cdot1014 molec/cm^2. After the phreatic explosions we find a detectable signal of BrO. Soon after the eruption the BrO/SO2 molar ratio was low as 1

  19. A global catalogue of large SO2 sources and emissions derived from the Ozone Monitoring Instrument

    Science.gov (United States)

    Fioletov, Vitali E.; McLinden, Chris A.; Krotkov, Nickolay; Li, Can; Joiner, Joanna; Theys, Nicolas; Carn, Simon; Moran, Mike D.

    2016-09-01

    Sulfur dioxide (SO2) measurements from the Ozone Monitoring Instrument (OMI) satellite sensor processed with the new principal component analysis (PCA) algorithm were used to detect large point emission sources or clusters of sources. The total of 491 continuously emitting point sources releasing from about 30 kt yr-1 to more than 4000 kt yr-1 of SO2 per year have been identified and grouped by country and by primary source origin: volcanoes (76 sources); power plants (297); smelters (53); and sources related to the oil and gas industry (65). The sources were identified using different methods, including through OMI measurements themselves applied to a new emission detection algorithm, and their evolution during the 2005-2014 period was traced by estimating annual emissions from each source. For volcanic sources, the study focused on continuous degassing, and emissions from explosive eruptions were excluded. Emissions from degassing volcanic sources were measured, many for the first time, and collectively they account for about 30 % of total SO2 emissions estimated from OMI measurements, but that fraction has increased in recent years given that cumulative global emissions from power plants and smelters are declining while emissions from oil and gas industry remained nearly constant. Anthropogenic emissions from the USA declined by 80 % over the 2005-2014 period as did emissions from western and central Europe, whereas emissions from India nearly doubled, and emissions from other large SO2-emitting regions (South Africa, Russia, Mexico, and the Middle East) remained fairly constant. In total, OMI-based estimates account for about a half of total reported anthropogenic SO2 emissions; the remaining half is likely related to sources emitting less than 30 kt yr-1 and not detected by OMI.

  20. Volcanic gas measurements at Mount Cleveland, 14-15 August 2015

    Science.gov (United States)

    Werner, Cynthia A.; Kern, Christoph; Kelly, Peter

    2017-01-01

    On 14-15 August 2015, helicopter-based measurements were made of the volcanic gases emitted from Mount Cleveland, AK. An upward-looking differential optical absorption spectroscopy (DOAS) system was used to measure incident scattered solar ultraviolet radiation while traversing beneath the plume on multiple occasions 14-15 August. This data was used to derive SO2 emission rates. Additionally, a Multi-Component Gas Analyzer System (Multi-GAS) was used to make measurements of trace gas concentrations while on a dedicated measurement flight passing through the gas plume on 15 August (19:15 - 19:56 UTC). Radiance spectra and gas compositions were both recorded at 1 second time resolution. Each spectrum and gas measurement was stamped with the GPS time and location. Each spectrum was saved in a separate ASCII file which includes 2048 radiances measured in the 285 - 430 nm spectral region and metadata associated with each acquisition. The Multi-GAS measurements are saved in a spreadsheet in the *.csv format.

  1. Detection of an SO2 plume over Sapporo, Japan from the eruption of Mt. Kasatochi using a balloon sounding technique

    Science.gov (United States)

    Morris, G. A.; Hirokawa, J.; Fujiwara, M.; Hasebe, F.; Ishida, K.; Krotkov, N.; Schoeberl, M. R.; Komhyr, W.; Lefer, B.

    2008-12-01

    During the month of August 2008, ten ozonesondes were launched from Hokkaido University in Sapporo, Japan as part of a study to examine regional pollution during the Olympic period. Seven of these soundings included a second instrument with a filter designed to remove SO2 from the intake air stream. SO2 interferes with the normal chemistry of the electrochemical cell (ECC) method for ozone detection, with the net result being that each molecule of SO2 registers as minus one molecule of O3. Thus the unfiltered sonde reports [O3] - [SO2] while the filtered sonde reports [O3]. Laboratory tests of the SO2 filter at Hokkaido University prior to launch indicate that the filter is >85% effective at SO2 removal while destroying little to no O3. The differences between the readings of a filtered and an unfiltered instrument launched as a pair on the same payload can provide profiles of SO2. In this presentation, we demonstrate the effectiveness of this technique in the lower and middle troposphere by examining days both with and without SO2 present. Using SO2 data from the Ozone Monitoring Instrument (OMI) and trajectories from the NASA Goddard Trajectory model, we demonstrate the arrival of a plume of SO2 over Hokkaido, Japan on the 21st and 22nd of August that had its origins 10 - 14 days earlier in the volcanic eruption of Mt. Kasatochi 8 - 11 August. The arrival of this plume coincides with the detection of SO2 by our balloon borne instruments at 3 km and 1 km on the 21st and 22nd of August, respectively. Comparisons between integrated SO2 columns derived from our sonde measurements with OMI are also provided.

  2. Sulfur dioxide (SO2 from MIPAS in the upper troposphere and lower stratosphere 2002–2012

    Directory of Open Access Journals (Sweden)

    M. Höpfner

    2015-06-01

    Full Text Available Vertically resolved distributions of sulfur dioxide (SO2 with global coverage in the height region from the upper troposphere to ~20 km altitude have been derived from observations by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS on Envisat for the period July 2002 to April 2012. Retrieved volume mixing ratio profiles representing single measurements are characterized by typical errors in the range of 70–100 pptv and by a vertical resolution ranging from 3 to 5 km. Comparison with observations by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS revealed a slightly varying bias with altitude of −20 to 50 pptv for the MIPAS data set in case of volcanically enhanced concentrations. For background concentrations the comparison showed a systematic difference between the two major MIPAS observation periods. After debiasing, the difference could be reduced to biases within −10 to 20 pptv in the altitude range of 10–20 km with respect to ACE-FTS. Further comparisons of the debiased MIPAS data set with in situ measurements from various aircraft campaigns showed no obvious inconsistencies within a range of around ±50 pptv. The SO2 emissions of more than 30 volcanic eruptions could be identified in the upper troposphere and lower stratosphere (UTLS. Emitted SO2 masses and lifetimes within different altitude ranges in the UTLS have been derived for a large part of these eruptions. Masses are in most cases within estimations derived from other instruments. From three of the major eruptions within the MIPAS measurement period – Kasatochi in August 2008, Sarychev in June 2009 and Nabro in June 2011 – derived lifetimes of SO2 for the altitude ranges 10–14, 14–18 and 18–22 km are 13.3 ± 2.1, 23.6 ± 1.2 and 32.3 ± 5.5 days respectively. By omitting periods with obvious volcanic influence we have derived background mixing ratio distributions of SO2. At 10 km altitude these indicate an annual

  3. Sulfur dioxide (SO2 from MIPAS in the upper troposphere and lower stratosphere 2002–2012

    Directory of Open Access Journals (Sweden)

    M. Höpfner

    2015-02-01

    Full Text Available Vertically resolved distributions of sulfur dioxide (SO2 with global coverage in the height region from the upper troposphere to ~ 20 km altitude have been derived from observations by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS on Envisat for the period July 2002 to April 2012. Retrieved volume mixing ratio profiles representing single measurements are characterized by typical errors in the range of 70–100 pptv and by a vertical resolution ranging from 3–5 km. Comparison with ACE-FTS observations revealed a slightly varying bias with altitude of −20 to 50 pptv for the MIPAS dataset in case of volcanically enhanced concentrations. For background concentrations the comparison showed a systematic difference between the two major MIPAS observation periods. After debiasing, the difference could be reduced to biases within −10 to 20 pptv in the altitude range of 10–20 km with respect to ACE-FTS. Further comparisons of the debiased MIPAS dataset with in-situ measurements from various aircraft campaigns showed no obvious inconsistencies within a range of around ±50 pptv. The SO2 emissions of more than thirty volcanic eruptions could be identified in the upper troposphere and lower stratosphere (UTLS. Emitted SO2 masses and lifetimes within different altitude ranges in the UTLS have been derived for a large part of these eruptions. Masses are in most cases within estimations derived from other instruments. From three of the major eruptions within the MIPAS measurement period – Kasatochi in August 2008, Sarychev in June 2009 and Nabro in June 2011 – derived lifetimes of SO2 for the altitude ranges 10–14, 14–18, and 18–22 km are 13.3±2.1, 23.6±1.2, and 32.3±5.5 d, respectively. By omitting periods with obvious volcanic influence we have derived background mixing ratio distributions of SO2. At 10 km altitude these indicate an annual cycle at northern mid- and high latitudes with maximum values in summer and

  4. Next-Generation Aura/OMI NO2 and SO2 Products

    Science.gov (United States)

    Krotkov, Nickolay; Yang, Kai; Bucsela, Eric; Lamsal, Lok; Celarier, Edward; Swartz, William; Carn, Simon; Bhartia, Pawan; Gleason, James; Pickering, Ken; Dickerson, Russ

    2011-01-01

    The measurement of both SO2 and NO2 gases are recognized as an essential component of atmospheric composition missions. We describe current capabilities and limitations of the operational Aura/OMI NO2 and SO2 data that have been used by a large number of researchers. Analyses of the data and validation studies have brought to light a number of areas in which these products can be expanded and improved. Major improvements for new NASA standard (SP) NO2 product include more accurate tropospheric and stratospheric column amounts, along with much improved error estimates and diagnostics. Our approach uses a monthly NO2 climatology based on the NASA Global Modeling Initiative (GMI) chemistry-transport model and takes advantage of OMI data from cloudy scenes to find clean areas where the contribution from the trap NO2 column is relatively small. We then use a new filtering, interpolation and smoothing techniques for separating the stratospheric and tropospheric components of NO2, minimizing the influence of a priori information. The new algorithm greatly improves the structure of stratospheric features relative to the original SP. For the next-generation OMI SO2 product we plan to implement operationally the offline iterative spectral fitting (ISF) algorithm and re-process the OMI Level-2 SO2 dataset using a priori SO2 and aerosol profiles, clouds, and surface reflectivity appropriate for observation conditions. This will improve the ability to detect and quantify weak tropospheric SO2 loadings. The new algorithm is validated using aircraft in-situ data during field campaigns in China (2005 and 2008) and in Maryland (Frostburg, 2010 and DISCOVER-AQ in July 2011). The height of the SO2 plumes will also be estimated for high SO2 loading cases (e.g., volcanic eruptions). The same SO2 algorithm will be applied to the data from OMPS sensor to be launched on NPP satellite later this year. The next-generation NO2 and SO2 products will provide critical information (e

  5. SO2 and BrO observation in the plume of the Eyjafjallajökull volcano 2010: CARIBIC and GOME-2 retrievals

    Directory of Open Access Journals (Sweden)

    P. F. J. van Velthoven

    2011-03-01

    Full Text Available The ash cloud of the Eyjafjallajökull (also referred to as: Eyjafjalla (e.g. Schumann et al., 2011, Eyjafjöll or Eyjafjoll (e.g. Ansmann et al., 2010 volcano on Iceland caused closure of large parts of European airspace in April and May 2010. For the validation and improvement of the European volcanic ash forecast models several research flights were performed. Also the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container flying laboratory, which routinely measures at cruise altitude (≈11 km performed three dedicated measurements flights through sections of the ash plume. Although the focus of these flights was on the detection and quantification of the volcanic ash, we report here on sulphur dioxide (SO2 and bromine monoxide (BrO measurements with the CARIBIC DOAS (Differential Optical Absorption Spectroscopy instrument during the second of these special flights on 16 May 2010. As the BrO and the SO2 observations coincide, we assume the BrO to have been formed inside the volcanic plume. Average SO2 and BrO mixing ratios of ≈40 ppb and ≈5 ppt respectively are retrieved inside the plume. The BrO to SO2 ratio retrieved from the CARIBIC observation is ≈1.3×10−4. Both SO2 and BrO observations agree well with simultaneous satellite (GOME-2 observations. SO2 column densities retrieved from satellite observations are often used as an indicator for volcanic ash. As the CARIBIC O4 column densities changed rapidly during the plume observation, we conclude that the aerosol and the SO2 plume are collocated. For SO2 some additional information on the local distribution can be derived from a comparison of forward and back scan GOME-2 data. More details on the local plume size and position are retrieved by combining CARIBIC and GOME-2 data.

  6. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2–C10 volatile organic compounds (VOCs, CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    Directory of Open Access Journals (Sweden)

    A. J. Weinheimer

    2010-08-01

    Full Text Available Oil sands comprise 30% of the world's oil reserves and the crude oil reserves in Canada's oil sands deposits are second only to Saudi Arabia. The extraction and processing of oil sands is much more challenging than for light sweet crude oils because of the high viscosity of the bitumen contained within the oil sands and because the bitumen is mixed with sand and contains chemical impurities such as sulphur. Despite these challenges, the importance of oil sands is increasing in the energy market. To our best knowledge this is the first peer-reviewed study to characterize volatile organic compounds (VOCs emitted from Alberta's oil sands mining sites. We present high-precision gas chromatography measurements of 76 speciated C2–C10 VOCs (alkanes, alkenes, alkynes, cycloalkanes, aromatics, monoterpenes, oxygenates, halocarbons, and sulphur compounds in 17 boundary layer air samples collected over surface mining operations in northeast Alberta on 10 July 2008, using the NASA DC-8 airborne laboratory as a research platform. In addition to the VOCs, we present simultaneous measurements of CO2, CH4, CO, NO, NO2, NOy, O3 and SO2, which were measured in situ aboard the DC-8. Methane, CO, CO2, NO, NO2, NOy, SO2 and 53 VOCs (e.g., halocarbons, sulphur species, NMHCs showed clear statistical enhancements (up to 1.1–397× over the oil sands compared to local background values and, with the exception of CO, were higher over the oil sands than at any other time during the flight. Twenty halocarbons (e.g., CFCs, HFCs, halons, brominated species either were not enhanced or were minimally enhanced (4–C9 alkanes, C5–C6 cycloalkanes, C6–C8 aromatics, together with CO; and (2 emissions associated with the mining effort (i.e., CO2, CO, CH4, NO, NO2, NOy, SO2, C2–C4 alkanes, C2–C4 alkenes, C9 aromatics, short-lived solvents such as C2Cl4 and C2HCl3, and longer-lived species such as HCFC-22 and HCFC-142b. Prominent in the second group, SO2 and NO were

  7. Monitoring the Eyjafjöll volcanic plume using OPGC platforms : remote sensing and in-situ measurements

    Science.gov (United States)

    Labazuy, Philippe; Gouhier, Mathieu; Hervo, Maxime; Freville, Patrick; Quehennen, Boris; Donnadieu, Frank; Guehenneux, Yannick; Cacault, Philippe; Colomb, Aurélie; Gayet, Jean-François; Pichon, Jean-Marc; Rivet, Sandrine; Schwarzenböck, Alfons; Sellegri, Karine

    2010-05-01

    OPGC (Observatoire de Physique du Globe de Clermont-Ferrand) presents a unique combination of knowledge in volcanology and atmosphere physics, for the tracking and the monitoring of volcanic plumes. These competences interact through the combination of the mastering of Lidar and radar techniques; gas and aerosol measurement (in-situ and airborne) by the Laboratoire de Météorologie Physique (LaMP,OPGC) and the expertise of the Laboratoire Magmas et Volcans (LMV,OPGC) in eruption dynamics and spatial remote sensing. Platforms for observations benefit from the technical support and expertise of the OPGC staff. HOTVOLC group is dedicated to the near-real-time monitoring of thermal anomalies related to the eruptive activity of volcanoes. The main goal of HOTVOLC deals with estimation of quantitative parameters that give stringent constraints on ash plumes dynamics, from the vent to the atmosphere. Datas from HOTVOLC give near -real time monitoring of ash plume, and its height, crucial parameter for predictive models and risk assessment. The height of the plume of Eyjafjöll on April 15 2010 at 12:00 UTC was estimated at 5000-6500 m, in accordance with ground observations and Lidar data. TERRA MODIS and AURA OMI sensors were used for the daily quantitative estimation of ash and SO2 burden , respectively. Two peaks of ash and SO2 emissions occurring on April 15 (100 kt and 8 kt) and 19 (170 kt and 12 kt) were determined. HOTVOLC is involved in the monitoring of the eruption at Eyjafjöll(Iceland) and belongs to a volcano alert group, at the request of the MEEDDM (French Ministry for ecology, energy, sustainable development and sea). LIDAR at the OPGC, is a Rayleigh-Mie LIDAR emitting at 355nm, with parallel and crossed polarization channels. On April 19, a layer of depolarizing particles i.e.non-spherical particles was observed at 3000 m a.s.l, with maximum thickness of 500m. The instrumented station at the top of the Puy de Dôme allows measurements of gas-phase and of

  8. Emission of SO2 from Cement Production

    DEFF Research Database (Denmark)

    Hu, Guilin

    2007-01-01

    Ph. D. afhandlingen omhandler problemstillinger af speciel relevans for cementproduktion med lave emissioner af svolvdioxid. Afhandlingen omfatter dels pyritoxidation – dvs. dannelse af SO2, dels direkte sulfatering af kalksten – dvs. absorptionen af SO2 på CaCO3 under oxiderende betingelser i te...

  9. Volcanic monitoring from space using neural networks approach. Simultaneous ash and sulfur dioxide retrievals using multispectral measurements

    Science.gov (United States)

    Piscini, A.; Corradini, S.; Chini, M.; Merucci, L.; Stramondo, S.; Picchiani, M.; Del Frate, F.

    2012-04-01

    In this work a Multi Layer Perceptron Neural Networks (MLPNN) approach has been used for a simultaneous volcanic ash and sulfur dioxide retrievals considering the MODIS measurements. As test case the 2010 Eyjafjallajokull eruption have been considered. A network was built for each parameter to be retrieved. Additionally, for volcanic ash, a network for the classification of "ash image pixels" was implemented, which was then used to mask the estimates. Several network topologies were compared in terms of their performance. Concerning the training phase and networks testing, a set of MODIS images was selected covering the Eyjafjallajokull May events. The classification NNs were trained with the volcanic ash classification map obtained with the Brightness Temperature Difference algorithm, assumed as benchmark. The neural networks for the quantitative estimation of the parameters associated with volcanic ash, mass, effective radius, aerosol optical depth and SO2, were instead trained with maps obtained using consolidated estimation algorithms based on simulated radiances at the top of the atmosphere, generated in turn applying a radiative transfer model to remote sensing data. The networks proved to be very effective in solving the inversion problem related to the estimation of the parameters of the volcanic cloud, settling the crucial issue related to false alarms in the detection of volcanic ash. Furthermore, once the training phase is complete, NNs provide a faster inversion technique, useful for the applications. From this point of view the technique satisfies the need to respond quickly as a result of disastrous natural hazards, such as volcanic eruptions. Future activities include testing the effectiveness of the technique under different lighting conditions (night images) and on other types of multispectral data, such as that provided by high temporal resolution sensors like SEVIRI-MSG, on board the METEOSAT second Generation satellites. The latter would be

  10. Mechanism of SO2 removal by carbon

    Science.gov (United States)

    Lizzio, Anthony A.; DeBarr, Joseph A.

    1997-01-01

    The reaction of SO2 with carbon (C) in the presence of O2 and H2O involves a series of reactions that leads to the formation of sulfuric acid as the final product. The rate-determining step in the overall process is the oxidation of SO2 to SO3. Three SO2 oxidation reactions are possible. Adsorbed SO2 (C−SO2) can react either with gas phase O2 or with adsorbed oxygen (C−O complex) to form sulfur trioxide (SO3), or gas phase SO2 can react directly with the C−O complex. In optimizing the SO2 removal capabilities of carbon, most studies only assume a given mechanism for SO2 adsorption and conversion to H2SO4 to be operable. The appropriate SO2 oxidation step and role of the C−O complex in this mechanism remain to be determined. The ultimate goal of this study was to prepare activated char from Illinois coal with optimal properties for low-temperature (80−150°C) removal of sulfur dioxide from coal combustion flue gas. The SO2 adsorption capacity of activated char was found to be inversely proportional to the amount of oxygen adsorbed on its surface. A temperature-programmed desorption technique was developed to titrate those sites responsible for adsorption of SO2 and conversion to H2SO4. On the basis of these results, a mechanism for SO2 removal by carbon was proposed. The derived rate expression showed SO2 adsorption to be dependent only on the fundamental rate constant and concentration of carbon atoms designated as free sites. Recent studies indicate a similar relationship exists between the rate of carbon gasification (in CO2 or H2O) and the number of reactive sites as determined by transient kinetics experiments. Utilizing the concept of active or free sites, it was possible to produce a char from Illinois coal having an SO2 adsorption capacity surpassing that of a commercial catalytic activated carbon.

  11. Variability of SO2 in an intensive fog in North China Plain: Evidence of high solubility of SO2

    Institute of Scientific and Technical Information of China (English)

    Qiang Zhang; Xuexi Tie; Weili Lin; Junji Cao; Jiannong Quan; Liang Ran; Wanyun Xu

    2013-01-01

    A field experiment was conducted in an intensive fog event between November 5 and November 8,2009,in a heavily SO2-polluted area in North China Plain (NCP),to measure SO2 and other air pollutants,liquid water content (LWC) of fog droplets,and other basic meteorological parameters.During the fog period,the concentrations of SO2 showed large variability,which was closely related to the LWC in the fogdroplets.The averaged concentration of SO2 during non-fog periods was about 25 ppbv,while during the fog period,it rapidly reduced to about 4-7 ppbv.Such large reduction of SO2 suggested that a majority of SO2 (about 70%-80%) had reverted from gas to aqueous phase on account of the high solubility of SO2 in water in the fog droplets.However,the calculated gas to aqueous phase conversion was largely underestimated by merely using the Henry's Law constant of SO2,thus suggesting that aqueous reaction of SO2 in fog droplets might play some important role in enhancing the solubility of SO2.To simplify the phenomenon,an "effective solubility coefficient" is proposed in this study.This variability of SO2 measurement during the extensive fog event provides direct evidence of oxidation of SO2 in fog droplets,thus providing important implications for better understanding of the acidity in clouds,precipitation,and fogs in NCP,now a central environmental focus in China due to its rapid economic development.

  12. A Decade of Volcanic Observations from Aura and the A-Train

    Science.gov (United States)

    Carn, Simon A.; Krotkov, Nickolay Anatoly; Yang, Kai; Krueger, Arlin J.; Hughes, Eric J.; Wang, Jun; Flower, Verity; Telling, Jennifer

    2014-01-01

    Aura observations have made many seminal contributions to volcanology. Prior to the Aura launch, satellite observations of volcanic degassing (e.g., from TOMS) were mostly restricted to large eruptions. However, the vast majority of volcanic gases are released during quiescent 'passive' degassing between eruptions. The improved sensitivity of Aura OMI permitted the first daily, space-borne measurements of passive volcanic SO2 degassing, providing improved constraints on the source locations and magnitude of global SO2 emissions for input to atmospheric chemistry and climate models. As a result of this unique sensitivity to volcanic activity, OMI data were also the first satellite SO2 measurements to be routinely used for volcano monitoring at several volcano observatories worldwide. Furthermore, the Aura OMI SO2 data also offer unprecedented sensitivity to volcanic clouds in the UTLS, elucidating the transport, fate and lifetime of volcanic SO2 and providing critical input to aviation hazard mitigation efforts. Another major advance has been the improved vertical resolution of volcanic clouds made possible by synergy between Aura and other A-Train instruments (e.g., AIRS, CALIPSO, CloudSat), advanced UV SO2 altitude retrievals, and inverse trajectory modeling of detailed SO2 cloud maps. This altitude information is crucial for climate models and aviation hazards. We will review some of the highlights of a decade of Aura observations of volcanic activity and look ahead to the future of volcanic observations from space.

  13. Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in situ measurements

    Science.gov (United States)

    Fu, Guangliang; Heemink, Arnold; Lu, Sha; Segers, Arjo; Weber, Konradin; Lin, Hai-Xiang

    2016-07-01

    The forecast accuracy of distal volcanic ash clouds is important for providing valid aviation advice during volcanic ash eruption. However, because the distal part of volcanic ash plume is far from the volcano, the influence of eruption information on this part becomes rather indirect and uncertain, resulting in inaccurate volcanic ash forecasts in these distal areas. In our approach, we use real-life aircraft in situ observations, measured in the northwestern part of Germany during the 2010 Eyjafjallajökull eruption, in an ensemble-based data assimilation system combined with a volcanic ash transport model to investigate the potential improvement on the forecast accuracy with regard to the distal volcanic ash plume. We show that the error of the analyzed volcanic ash state can be significantly reduced through assimilating real-life in situ measurements. After a continuous assimilation, it is shown that the aviation advice for Germany, the Netherlands and Luxembourg can be significantly improved. We suggest that with suitable aircrafts measuring once per day across the distal volcanic ash plume, the description and prediction of volcanic ash clouds in these areas can be greatly improved.

  14. Real-time in situ measurements of volcanic plume physico-chemical properties using Controlled METeorological balloons

    Science.gov (United States)

    Durant, Adam; Voss, Paul; Watson, Matthew; Roberts, Tjarda; Thomas, Helen; Prata, Fred; Sutton, Jeff; Mather, Tamsin; Witt, Melanie; Patrick, Matthew

    2010-05-01

    While the climatic effects of volcanogenic sulphate aerosol in the stratosphere are well characterised, the nature and global impact of sustained tropospheric volcanic degassing is less well understood. In situ measurement of volcanic emissions can be used to understand plume processes (e.g., microphysics and chemistry), and used to validate and improve remote sensing techniques. New developments in sensor and communication technologies have led to the production of miniaturized lightweight unmanned atmospheric measurement platforms. Controlled METeorological (CMET) balloons collect real-time observations of atmospheric physico-chemical properties at altitudes of up to 5 km for hours or even days at a time. Standard measurements include pressure (± 10 mb), aspirated temperature (± 0.3 C), relative humidity (± 5 %) and location (GPS position ± 5 m horizontal, ± 50 m vertical). Balloon platform-based measurements of volcanic plume properties were made for the first time using CMET balloons equipped with miniature electrochemical sensors during the eruption of Halema'uma'u crater (Kilauea) in Hawai'i in 2008. In addition, multiple measurement platforms were simultaneously deployed that included (1) ground-based remote measurements (mini-DOAS and UV camera); (2) satellite-based sensors (MODIS and OMI); and (3) in situ sampling at the emission source using ground-based electrochemical sensor instrumentation. During the 25 July 2008 flight, a single CMET balloon remained in the plume and collected data for several hours. Ratios of [H2O] and [SO2] correlate in proximal regions of the plume, though were found to anti-correlate further downwind. Correlation is explained through co-emission of SO2 and H2O at source, as has been frequently previously observed e.g. by FTIR. Anti-correlation of [H2O] and [SO2] ratios has not previously been reported and may reflect dehydration of the aged plume through condensation of water vapour on volcanogenic sulphate aerosol. The

  15. SO2 - An indirect source of energy

    DEFF Research Database (Denmark)

    Kriek, R.J.; Van Ravenswaay, J.P.; Potgieter, M.

    2013-01-01

    Global sulphur dioxide (SO2) emissions peaked around the mid- 1970s, after which they declined. However, with the growth of specifically China, emissions are on the rise again. In 2008, global anthropogenic SO2 emissions totalled 127 Mt, with energy production accounting for 63.2 Mt and metal......-related processes 12.8 Mt. As a well-known gaseous pollutant, SO2 is not per se known as a source of energy. However, in the presence of water SO2 can be electro-oxidized at the anode of an electrolyser to produce hydrogen ions, which in turn can be reduced at the cathode of the electrolyser to produce hydrogen gas...

  16. Mechanisms of radical removal by SO2

    DEFF Research Database (Denmark)

    Rasmussen, Christian Lund; Glarborg, Peter; Marshall, Paul

    2007-01-01

    It is well established from experiments in premixed, laminar flames, jet-stirred reactors, flow reactors, and batch reactors that SO2 acts to catalyze hydrogen atom removal at stoichiometric and reducing conditions. However, the commonly accepted mechanism for radical removal, SO2 + H...... that the interaction of SO, with the radical pool is more complex than previously assumed, involving HOSO and SO, as well as, at high temperatures also HSO, SH, and S. The revised mechanism with a high rate constant for H + SO2 recombination and with SO + H2O, rather than SO2 + H-2, as major products of the HOSO + H...... reaction is in agreement with a range of experimental results from batch and flow reactors, as well as laminar flames....

  17. Measurements of HNO3, SO2 High Resolution Aerosol SO4 (sup 2-), and Selected Aerosol Species Aboard the NASA DC-8 Aircraft: During the Transport and Chemical Evolution Over the Pacific Airborne Mission (TRACE-P)

    Science.gov (United States)

    Talbot, Robert W.; Dibb, Jack E.

    2004-01-01

    The UNH investigation during TRACE-P provided measurements of selected acidic gases and aerosol species aboard the NASA DC-8 research aircraft. Our investigation focused on measuring HNO3, SO2, and fine (less than 2 microns) aerosol SO4(sup 2-) with two minute time resolution in near-real-time. We also quantified mixing ratios of aerosol ionic species, and aerosol (210)Pb and (7)Be collected onto bulk filters at better than 10 minute resolution. This suite of measurements contributed extensively to achieving the principal objectives of TRACE-P. In the context of the full data set collected by experimental teams on the DC-8, our observations provide a solid basis for assessing decadal changes in the chemical composition and source strength of Asian continental outflow. This region of the Pacific should be impacted profoundly by Asian emissions at this time with significant degradation of air quality over the next few decades. Atmospheric measurements in the western Pacific region will provide a valuable time series to help quantify the impact of Asian anthropogenic activities. Our data also provide important insight into the chemical and physical processes transforming Asian outflow during transport over the Pacific, particularly uptake and reactions of soluble gases on aerosol particles. In addition, the TRACE-P data set provide strong constraints for assessing and improving the chemical fields simulated by chemical transport models.

  18. SO2 emissions from Popocatépetl volcano: emission rates and plume imaging using optical remote sensing techniques

    Science.gov (United States)

    Grutter, M.; Basaldud, R.; Rivera, C.; Harig, R.; Junkerman, W.; Caetano, E.; Delgado-Granados, H.

    2008-11-01

    Sulfur dioxide emissions from the Popocatépetl volcano in central Mexico were measured during the MILAGRO field campaign in March 2006. A stationary scanning DOAS (Differential Optical Absorption Spectrometer) was used to monitor the SO2 emissions from the volcano and the results were compared with traverses done with a COSPEC from the ground and a DOAS instrument on board an ultra-light aircraft. Daytime evolutions as well as day-to-day variation of the SO2 emissions are reported. A value of 2.45±1.39 Gg/day of SO2 is reported from all the daily averages obtained during the month of March 2006, with large variation in maximum and minimum daily averages of 5.97 and 0.56 Gg/day, respectively. The large short-term fluctuations in the SO2 emissions obtained could be confirmed through 2-D visualizations of the SO2 plume measured with a scanning imaging infrared spectrometer. This instrument, based on the passive detection of thermal radiation from the volcanic gas and analysis with FTIR spectrometry, is used for the first time for plume visualization of a specific volcanic gas. A 48-h forward trajectory analysis indicates that the volcanic plume was predominantly directed towards the Puebla/Tlaxcala region (63%), followed by the Mexico City and Cuernavaca/Cuautla regions with 19 and 18% occurrences, respectively. 25% of the modeled trajectories going towards the Puebla region reached altitudes lower than 4000 m a.s.l. but all trajectories remained over this altitude for the other two regions.

  19. SO2 emissions from Popocatépetl volcano: emission rates and plume imaging using optical remote sensing techniques

    Directory of Open Access Journals (Sweden)

    H. Delgado-Granados

    2008-11-01

    Full Text Available Sulfur dioxide emissions from the Popocatépetl volcano in central Mexico were measured during the MILAGRO field campaign in March 2006. A stationary scanning DOAS (Differential Optical Absorption Spectrometer was used to monitor the SO2 emissions from the volcano and the results were compared with traverses done with a COSPEC from the ground and a DOAS instrument on board an ultra-light aircraft. Daytime evolutions as well as day-to-day variation of the SO2 emissions are reported. A value of 2.45±1.39 Gg/day of SO2 is reported from all the daily averages obtained during the month of March 2006, with large variation in maximum and minimum daily averages of 5.97 and 0.56 Gg/day, respectively. The large short-term fluctuations in the SO2 emissions obtained could be confirmed through 2-D visualizations of the SO2 plume measured with a scanning imaging infrared spectrometer. This instrument, based on the passive detection of thermal radiation from the volcanic gas and analysis with FTIR spectrometry, is used for the first time for plume visualization of a specific volcanic gas. A 48-h forward trajectory analysis indicates that the volcanic plume was predominantly directed towards the Puebla/Tlaxcala region (63%, followed by the Mexico City and Cuernavaca/Cuautla regions with 19 and 18% occurrences, respectively. 25% of the modeled trajectories going towards the Puebla region reached altitudes lower than 4000 m a.s.l. but all trajectories remained over this altitude for the other two regions.

  20. SO2 emissions from Popocatépetl volcano: emission rates and plume imaging using optical remote sensing techniques

    Directory of Open Access Journals (Sweden)

    E. Caetano

    2008-04-01

    Full Text Available Sulfur dioxide emissions from Popocatépetl volcano in central Mexico were measured during the MILAGRO field campaign in March 2006. A stationary scanning DOAS (Differential Optical Absorption Spectrometer was used to monitor the SO2 emissions from the volcano and the results were compared with traverses done with a COSPEC from the ground and a DOAS instrument on board an ultra-light aircraft. Daytime evolutions as well as day-to-day variation of the SO2 emissions are reported. A value of 2.45±1.39 Gg/day of SO2 is reported from all the daily averages obtained during the month of March 2006, with large variation in maximum and minimum daily averages of 5.97 and 0.56 Gg/day, respectively. The large short-term fluctuations in the SO2 emissions obtained could be confirmed through 2-D visualizations of the SO2 plume measured with a scanning imaging infrared spectrometer. This instrument, based on the passive detection of thermal radiation from the volcanic gas and analysis with FTIR spectrometry, is used for the first time for plume visualization of a specific volcanic gas. A 48-h forward trajectory analysis indicates that the volcanic plume was predominately directed towards the Puebla/Tlaxcala region (63%, followed by the Mexico City and Cuernavaca/Cuautla regions with 19 and 18% occurrences, respectively. 25% of the modeled trajectories going towards the Puebla region reached altitudes lower than 4000 m a.s.l. and all trajectories remained over this altitude for the other two regions.

  1. Emission of gas and atmospheric dispersion of SO2 during the December 2013 eruption at San Miguel volcano (El Salvador, Central America)

    Science.gov (United States)

    Granieri, Domenico; Salerno, Giuseppe; Liuzzo, Marco; La Spina, Alessandro; Giuffrida, Giovanni; Caltabiano, Tommaso; Giudice, Gaetano; Gutierrez, Eduardo; Montalvo, Francisco; Burton, Michael R.; Papale, Paolo

    2015-07-01

    San Miguel volcano, El Salvador, erupted on 29 December 2013, after a 46 year period characterized by weak activity. Prior to the eruption a trend of increasing SO2 emission rate was observed, with all values measured after mid-November greater than the average value of the previous year (~310 t d-1). During the eruption, SO2 emissions increased from the level of ~330 t d-1 to 2200 t d-1, dropping after the eruption to an average level of 680 t d-1. Wind measurements and SO2 emission rates during the preeruptive, syneruptive, and posteruptive stages were used to model SO2 dispersion around the volcano. Atmospheric SO2 concentration exceeded the dangerous threshold of 5 ppm in the crater region and in some sectors with medium elevation of the highly visited volcanic cone. Combining the SO2 emission rate with measured CO2/SO2, HCl/SO2, and HF/SO2 plume gas ratios, we estimate the CO2, HCl, and HF outputs for the first time on this volcano.

  2. Characterization of trace gases measured over Alberta oil sands mining operations: 76 speciated C2-C10 volatile organic compounds (VOCs), CO2, CH4, CO, NO, NO2, NOy, O3 and SO2

    Science.gov (United States)

    Simpson, I. J.; Blake, N. J.; Barletta, B.; Diskin, G. S.; Fuelberg, H. E.; Gorham, K.; Huey, L. G.; Meinardi, S.; Rowland, F. S.; Vay, S. A.; Weinheimer, A. J.; Yang, M.; Blake, D. R.

    2010-12-01

    Oil sands comprise 30% of the world's oil reserves and the crude oil reserves in Canada's oil sands deposits are second only to Saudi Arabia. The extraction and processing of oil sands is much more challenging than for light sweet crude oils because of the high viscosity of the bitumen contained within the oil sands and because the bitumen is mixed with sand and contains chemical impurities such as sulphur. Despite these challenges, the importance of oil sands is increasing in the energy market. To our best knowledge this is the first peer-reviewed study to characterize volatile organic compounds (VOCs) emitted from Alberta's oil sands mining sites. We present high-precision gas chromatography measurements of 76 speciated C2-C10 VOCs (alkanes, alkenes, alkynes, cycloalkanes, aromatics, monoterpenes, oxygenated hydrocarbons, halocarbons and sulphur compounds) in 17 boundary layer air samples collected over surface mining operations in northeast Alberta on 10 July 2008, using the NASA DC-8 airborne laboratory as a research platform. In addition to the VOCs, we present simultaneous measurements of CO2, CH4, CO, NO, NO2, NOy, O3 and SO2, which were measured in situ aboard the DC-8. Carbon dioxide, CH4, CO, NO, NO2, NOy, SO2 and 53 VOCs (e.g., non-methane hydrocarbons, halocarbons, sulphur species) showed clear statistical enhancements (1.1-397×) over the oil sands compared to local background values and, with the exception of CO, were greater over the oil sands than at any other time during the flight. Twenty halocarbons (e.g., CFCs, HFCs, halons, brominated species) either were not enhanced or were minimally enhanced (polluted megacities such as Mexico City and are attributed to coke combustion. By contrast, relatively poor correlations between CH4, ethane and propane suggest low levels of natural gas leakage despite its heavy use at the surface mining sites. Instead the elevated CH4 levels are attributed to methanogenic tailings pond emissions. In addition to the

  3. Distillation and detection of SO2 using a microfluidic chip.

    Science.gov (United States)

    Ju, Wei-Jhong; Fu, Lung-Ming; Yang, Ruey-Jen; Lee, Chia-Lun

    2012-02-07

    A miniaturized distillation system is presented for separating sulfurous acid (H(2)SO(3)) into sulfur dioxide (SO(2)) and water (H(2)O). The major components of the proposed system include a microfluidic distillation chip, a power control module, and a carrier gas pressure control module. The microfluidic chip is patterned using a commercial CO(2) laser and comprises a serpentine channel, a heating zone, a buffer zone, a cooling zone, and a collection tank. In the proposed device, the H(2)SO(3) solution is injected into the microfluidic chip and is separated into SO(2) and H(2)O via an appropriate control of the distillation time and temperature. The gaseous SO(2) is then transported into the collection chamber by the carrier gas and is mixed with DI water. Finally, the SO(2) concentration is deduced from the absorbance measurements obtained using a spectrophotometer. The experimental results show that a correlation coefficient of R(2) = 0.9981 and a distillation efficiency as high as 94.6% are obtained for H(2)SO(3) solutions with SO(2) concentrations in the range of 100-500 ppm. The SO(2) concentrations of two commercial red wines are successfully detected using the developed device. Overall, the results presented in this study show that the proposed system provides a compact and reliable tool for SO(2) concentration measurement purposes.

  4. Surface Hydrophobicity Causes SO2 Tolerance in Lichens

    Science.gov (United States)

    Hauck, Markus; Jürgens, Sascha-René; Brinkmann, Martin; Herminghaus, Stephan

    2008-01-01

    Background and Aims The superhydrophobicity of the thallus surface in one of the most SO2-tolerant lichen species, Lecanora conizaeoides, suggests that surface hydrophobicity could be a general feature of lichen symbioses controlling their tolerance to SO2. The study described here tests this hypothesis. Methods Water droplets of the size of a raindrop were placed on the surface of air-dry thalli in 50 lichen species of known SO2 tolerance and contact angles were measured to quantify hydrophobicity. Key Results The wettability of lichen thalli ranges from strongly hydrophobic to strongly hydrophilic. SO2 tolerance of the studied lichen species increased with increasing hydrophobicity of the thallus surface. Extraction of extracellular lichen secondary metabolites with acetone reduced, but did not abolish the hydrophobicity of lichen thalli. Conclusions Surface hydrophobicity is the main factor controlling SO2 tolerance in lichens. It presumably originally evolved as an adaptation to wet habitats preventing the depression of net photosynthesis due to supersaturation of the thallus with water. Hydrophilicity of lichen thalli is an adaptation to dry or humid, but not directly rain-exposed habitats. The crucial role of surface hydrophobicity in SO2 also explains why many markedly SO2-tolerant species are additionally tolerant to other (chemically unrelated) toxic substances including heavy metals. PMID:18077467

  5. Improving the accuracy of S02 column densities and emission rates obtained from upward-looking UV-spectroscopic measurements of volcanic plumes by taking realistic radiative transfer into account

    Science.gov (United States)

    Kern, Christoph; Deutschmann, Tim; Werner, Cynthia; Sutton, A. Jeff; Elias, Tamar; Kelly, Peter J.

    2012-01-01

    Sulfur dioxide (SO2) is monitored using ultraviolet (UV) absorption spectroscopy at numerous volcanoes around the world due to its importance as a measure of volcanic activity and a tracer for other gaseous species. Recent studies have shown that failure to take realistic radiative transfer into account during the spectral retrieval of the collected data often leads to large errors in the calculated emission rates. Here, the framework for a new evaluation method which couples a radiative transfer model to the spectral retrieval is described. In it, absorption spectra are simulated, and atmospheric parameters are iteratively updated in the model until a best match to the measurement data is achieved. The evaluation algorithm is applied to two example Differential Optical Absorption Spectroscopy (DOAS) measurements conducted at Kilauea volcano (Hawaii). The resulting emission rates were 20 and 90% higher than those obtained with a conventional DOAS retrieval performed between 305 and 315 nm, respectively, depending on the different SO2 and aerosol loads present in the volcanic plume. The internal consistency of the method was validated by measuring and modeling SO2 absorption features in a separate wavelength region around 375 nm and comparing the results. Although additional information about the measurement geometry and atmospheric conditions is needed in addition to the acquired spectral data, this method for the first time provides a means of taking realistic three-dimensional radiative transfer into account when analyzing UV-spectral absorption measurements of volcanic SO2 plumes.

  6. Laboratory simulation of SO2 heterogeneous reactions on hematite surface under different SO2 concentrations

    Institute of Scientific and Technical Information of China (English)

    CUI Huxiong; CHENG Tiantao; YU Xingna; CHEN Jianmin; XU Yongfu; FANG Wen

    2009-01-01

    The variations of sulfate formation and optical coefficients during SO2 heterogeneous reactions on hematite surface under different SO2 concentrations were examined using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatograph (IC). Laboratory experiments revealed that within ambient SO2 of 0.51--18.6 ppmv, sulfate product, producing velocity, absorption and backward scattering coefficients showed an increasing trend with SO2 concentration. Under given SO2 concentration, the velocity of sulfate producing performed an evolution of initial increasing, midterm decreasing and final stabilizing. The reactive uptake and Brunauer-Emmett-Teller (BET) uptake coefficients of heterogeneous reactions rose with SO2 and exhibited high reactivities. Considering global warming, this result is important for the knowledge of heterogeneous reactions of SO2 on mineral particle surface in the atmosphere and the assessment of their impacts on radiative forcing.

  7. New ground-based lidar enables volcanic CO2 flux measurements.

    Science.gov (United States)

    Aiuppa, Alessandro; Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Nuvoli, Marcello; Chiodini, Giovanni; Minopoli, Carmine; Tamburello, Giancarlo

    2015-09-01

    There have been substantial advances in the ability to monitor the activity of hazardous volcanoes in recent decades. However, obtaining early warning of eruptions remains challenging, because the patterns and consequences of volcanic unrests are both complex and nonlinear. Measuring volcanic gases has long been a key aspect of volcano monitoring since these mobile fluids should reach the surface long before the magma. There has been considerable progress in methods for remote and in-situ gas sensing, but measuring the flux of volcanic CO2-the most reliable gas precursor to an eruption-has remained a challenge. Here we report on the first direct quantitative measurements of the volcanic CO2 flux using a newly designed differential absorption lidar (DIAL), which were performed at the restless Campi Flegrei volcano. We show that DIAL makes it possible to remotely obtain volcanic CO2 flux time series with a high temporal resolution (tens of minutes) and accuracy (volcanic CO2 represents a major step forward in volcano monitoring, and will contribute improved volcanic CO2 flux inventories. Our results also demonstrate the unusually strong degassing behavior of Campi Flegrei fumaroles in the current ongoing state of unrest.

  8. Validation Studies of the Accuracy of Various SO2 Gas Retrievals in the Thermal InfraRed (8-14 μm)

    Science.gov (United States)

    Gabrieli, A.; Wright, R.; Lucey, P. G.; Porter, J. N.; Honniball, C.; Garbeil, H.; Wood, M.

    2016-12-01

    Quantifying hazardous SO2 in the atmosphere and in volcanic plumes is important for public health and volcanic eruption prediction. Remote sensing measurements of spectral radiance of plumes contain information on the abundance of SO2. However, in order to convert such measurements into SO2 path-concentrations, reliable inversion algorithms are needed. Various techniques can be employed to derive SO2 path-concentrations. The first approach employs a Partial Least Square Regression model trained using MODTRAN5 simulations for a variety of plume and atmospheric conditions. Radiances at many spectral wavelengths (8-14 μm) were used in the algorithm. The second algorithm uses measurements inside and outside the SO2 plume. Measurements in the plume-free region (background sky) make it possible to remove background atmospheric conditions and any instrumental effects. After atmospheric and instrumental effects are removed, MODTRAN5 is used to fit the SO2 spectral feature and obtain SO2 path-concentrations. The two inversion algorithms described above can be compared with the inversion algorithm for SO2 retrievals developed by Prata and Bernardo (2014). Their approach employs three wavelengths to characterize the plume temperature, the atmospheric background, and the SO2 path-concentration. The accuracy of these various techniques requires further investigation in terms of the effects of different atmospheric background conditions. Validating these inversion algorithms is challenging because ground truth measurements are very difficult. However, if the three separate inversion algorithms provide similar SO2 path-concentrations for actual measurements with various background conditions, then this increases confidence in the results. Measurements of sky radiance when looking through SO2 filled gas cells were collected with a Thermal Hyperspectral Imager (THI) under various atmospheric background conditions. These data were processed using the three inversion approaches

  9. Measurements of the gas emission from Holuhraun volcanic fissure eruption on Iceland, using Scanning DOAS instruments

    Science.gov (United States)

    Galle, Bo; Pfeffer, Melissa; Arellano, Santiago; Bergsson, Baldur; Conde, Vladimir; Barsotti, Sara; Stefansdottir, Gerdur; Ingvarsson, Thorgils; Bergsson, Bergur; Weber, Konradin

    2016-04-01

    On 31 August 2014 a volcanic fissure eruption started at Holuhraun on Iceland. The eruption lasted for 6 months and was by far the strongest source of sulfur dioxide in Europe over the last 230 years, with sustained emission rates exceeding 100 000 ton/day. This gas emission severely affected people within Iceland. Under the scope of the EU-project FUTUREVOLC, a project with 3.5 years duration, aiming at making Iceland a supersite for volcanological research as a European contribution to GEO, a version of the Scanning DOAS instrument that is adapted to high latitudes with low UV radiation and severe meteorological conditions was developed. Since the first day of the eruption several of these novel instruments were monitoring the SO2 emission from the eruption. A lot of work was needed to sustain this operation during the winter at a very remote site and under severe field conditions. At the same time the very high concentrations in the gas plume, in combination with bad meteorological conditions has required the development of novel methods to derive reliable flux estimates. A simple approach to make a first order correction for atmospheric scattering has been applied, as well as filtering of the dataset to remove the data most affected by scattering. Substantial work has also been made to obtain realistic information on plume height and wind speed. The data from these instruments are the only sustained ground-based measurements of this important gas emission event. In this presentation we will discuss the instrumental issues and evaluation procedures and present the latest version of the emission estimates made from our measurements.

  10. Io's SO2 Atmosphere Viewed in Silhouette by Jupiter Lyman-α

    Science.gov (United States)

    Retherford, Kurt D.; Roth, Lorenz; Feaga, Lori M.; Becker, Tracy M.; Tsang, Constantine; Jessup, Kandis-Lea; Grava, Cesare

    2016-10-01

    We report a new technique for mapping Io's SO2 vapor distribution. Hubble's Space Telescope Imaging Spectrograph (STIS) instrument observed Io during four Jupiter transit events to obtain medium resolution far-UV spectral images near the Lyman-α wavelength of 121.6 nm. Jupiter's bright Lyman-α dayglow provides a background light source for opacity measurements, much like during a stellar occultation or transiting exoplanet event. Peaks in the photoabsorption cross-sections for sulfur dioxide occur near 122 nm, with resulting absorptions raising the altitude where a tangential line of sight opacity of tau=1 is detected up to resolvable distances above the disk. This method of measuring column densities along lines of sight above the limb complements Lyman-α reflectance imaging and other methods for measuring Io's SO2 gas. For example, interpretation of Io's surface reflected components at far-UV wavelengths is complicated by SO2 frost features being correlated with regions of known volcanic outgassing activity, while Jupiter's Lyman-α dayglow provides a more spatially uniform background light source. Initial examination of these near-terminator limb observations with STIS confirms the findings from previous Lyman-α disk reflectance imaging using STIS's G140L mode (e.g., Feldman et al., GRL, 2000; Feaga et al. 2009) that Io's polar SO2 density is roughly an order of magnitude lower than found at the equator. As Strobel & Wolven (2001) described it, Io appears to wear its dayside atmosphere as "a belt" around the equator. We describe detailed simulations, now underway, that incorporate the STIS point spread function and consideration of additional attenuation by atmospheric hydrogen atoms, which are produced by charge exchange reactions between magnetospheric protons and Io's atmosphere.

  11. Measuring Water Vapor and Ash in Volcanic Eruptions with a Millimeter-Wave Radar/Imager

    CERN Document Server

    Bryan, Sean; Vanderkluysen, Loÿc; Groppi, Christopher; Paine, Scott; Bliss, Daniel W; Aberle, James; Mauskopf, Philip

    2016-01-01

    Millimeter-wave remote sensing technology can significantly improve measurements of volcanic eruptions, yielding new insights into eruption processes and improving forecasts of drifting volcanic ash for aviation safety. Radiometers can measure water vapor density and temperature inside eruption clouds, improving on existing measurements with infrared cameras that are limited to measuring the outer cloud surface. Millimeter-wave radar can measure the 3D mass flow of volcanic ash inside eruption plumes and drifting fine ash clouds, offering better sensitivity than existing weather radar measurements and the unique ability to measure ash particle size in-situ. Here we present sensitivity calculations in the context of developing the WAMS (Water and Ash Millimeter-wave Spectrometer) instrument. WAMS, a radar/radiometer system constructed with off-the-shelf components, would be able to measure water vapor and ash throughout an entire eruption cloud, a unique capability.

  12. Reference dataset of volcanic ash physicochemical and optical properties for atmospheric measurement retrievals and transport modelling

    Science.gov (United States)

    Vogel, Andreas; Durant, Adam; Sytchkova, Anna; Diplas, Spyros; Bonadonna, Costanza; Scarnato, Barbara; Krüger, Kirstin; Kylling, Arve; Kristiansen, Nina; Stohl, Andreas

    2016-04-01

    Explosive volcanic eruptions emit up to 50 wt.% (total erupted mass) of fine ash particles (threat for aviation operations. Recent volcanic eruptions, such as the 2010 Icelandic Eyjafjallajökull event, illustrated how volcanic ash can severely impact commercial air traffic. In order to manage the threat, it is important to have accurate forecast information on the spatial extent and absolute quantity of airborne volcanic ash. Such forecasts are constrained by empirically-derived estimates of the volcanic source term and the nature of the constituent volcanic ash properties. Consequently, it is important to include a quantitative assessment of measurement uncertainties of ash properties to provide realistic ash forecast uncertainty. Currently, information on volcanic ash physicochemical and optical properties is derived from a small number of somewhat dated publications. In this study, we provide a reference dataset for physical (size distribution and shape), chemical (bulk vs. surface chemistry) and optical properties (complex refractive index in the UV-vis-NIR range) of a representative selection of volcanic ash samples from 10 different volcanic eruptions covering the full variability in silica content (40-75 wt.% SiO2). Through the combination of empirical analytical methods (e.g., image analysis, Energy Dispersive Spectroscopy, X-ray Photoelectron Spectroscopy, Transmission Electron Microscopy and UV/Vis/NIR/FTIR Spectroscopy) and theoretical models (e.g., Bruggeman effective medium approach), it was possible to fully capture the natural variability of ash physicochemical and optical characteristics. The dataset will be applied in atmospheric measurement retrievals and atmospheric transport modelling to determine the sensitivity to uncertainty in ash particle characteristics.

  13. SO(2,3 noncommutative gravity model

    Directory of Open Access Journals (Sweden)

    Dimitrijević Marija

    2014-01-01

    Full Text Available In this paper the noncommutative gravity is treated as a gauge theory of the noncommutative SO(2,3* group, while the noncommutativity is canonical. The Seiberg-Witten (SW map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action plus the cosmological term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are zeroth, first, . . . and fourth power of the curvature tensor. Finally, we discuss physical consequences of those correction terms in the limit of big cosmological constant.

  14. SO(2, 3) noncommutative gravity model

    Science.gov (United States)

    Dimitrijević, M.; Radovanović, V.

    2014-12-01

    In this paper the noncommutative gravity is treated as a gauge theory of the non-commutative SO(2, 3)★ group, while the noncommutativity is canonical. The Seiberg-Witten (SW) map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action plus the cosmological term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are zeroth, first, ... and fourth power of the curvature tensor. Finally, we discuss physical consequences of those correction terms in the limit of big cosmological constant.

  15. Enhanced SO2 Concentrations Observed over Northern India: Role of Long-range Transport

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, C.; Lal, S.; Naja, M.; Chand, Duli; Venkataramani, S.; Joshi, H.; Pant, P.

    2013-01-17

    Volcanic emissions and coal burning are among the major sources of SO2 over the continental environment. In this study, we show episodes of long-range transport of volcanic SO2 from Africa to Northern India using satellite observations. Monthly averaged SO2 from OMI were of the order of 0.6-0.9 DU during November, 2008 over the Indo-Gangetic Plain (IGP), which far exceeded background values (<0.3 DU) retrieved from observations across different locations over North India during 2005-2010. The columnar SO2 loadings were much higher on November 6 over most of the IGP and even exceeded 6 DU, a factor of 10 higher than background levels at some places. These enhanced SO2 levels were, however, not reciprocated in satellite derived NO2 or CO columns, indicating transport from a non-anthropogenic source of SO2. Backward trajectory analysis revealed strong winds in the free troposphere, which originated from the Dalaffilla volcanic eruption over the Afar region of Ethiopia during November 4-6, 2008. Wind streams and stable atmospheric conditions were conducive to the long-range transport of volcanic plume into the IGP. As most of the local aerosols over IGP region are below 3 km, a well separated layer at 4-5 km is observed from CALIPSO, most likely as a result of this transport. Apart from known anthropogenic sources, the additional transport of volcanic SO2 over the IGP region would have implications to air quality and radiation balance over this region.

  16. CO2, SO2, and H2S Degassing Related to the 2009 Redoubt Eruption, Alaska

    Science.gov (United States)

    Werner, C. A.; Kelly, P. J.; Evans, W.; Doukas, M. P.; McGimsey, R. G.; Neal, C. A.

    2012-12-01

    The 2009 eruption of Redoubt Volcano, Alaska was particularly well monitored for volcanic gas emissions with 35 airborne measurements of CO2, SO2, and H2S that span from October 2008 to August 2010. Increases in CO2 degassing were detected up to 5 months prior to the eruption and varied between 3630 and 9020 tonnes per day (t/d) in the 6 weeks prior to the eruption. Increased pre-eruptive CO2 degassing was accompanied by comparatively low S emission, resulting in molar C/S ratios that ranged between 30-60. However, the C/S ratio dropped to 2.4 coincident with the first phreatic explosion on March 15, 2009, and remained steady during the explosive (March 22 - April 4, 2009), effusive dome-building (April 5 - July 1, 2009), and waning phases (August 2009 onward) of the eruption. Observations of ice-melt rates, melt water discharge, and water chemistry in the months leading up to the eruption suggested that surface waters represented drainage from surficial, perched reservoirs of condensed magmatic steam and glacial meltwater. While the surface waters were capable of scrubbing many thousands of t/d of SO2, sampling of these fluids revealed that only a few hundred tonnes of SO2 was reacting to a dissolved component each day. This is also much less than the ~ 2100 t/d SO2 expected from degassing of magma in the upper crust (3-6.5 km), where petrologic analysis shows the final magma equilibration occurred. Thus, the high pre-eruptive C/S ratios observed could reflect bulk degassing of upper-crustal magma followed by nearly complete loss of SO2 in a magmatic-hydrothermal system. Alternatively, high C/S ratios could be attributed to degassing of low silica andesitic magma that intruded into the mid-crust in the 5 months prior to eruption; modeling suggests that mixing of this magma with pre-existing high silica andesite magma or mush would have caused a reduction of the C/S ratio to a value consistent with that measured during the eruption. Monitoring emissions regularly

  17. Crater size-frequency distribution measurements and age of the Compton-Belkovich Volcanic Complex

    Science.gov (United States)

    Shirley, K. A.; Zanetti, M.; Jolliff, B.; van der Bogert, C. H.; Hiesinger, H.

    2016-07-01

    The Compton-Belkovich Volcanic Complex (CBVC) is a 25 × 35 km feature on the lunar farside marked by elevated topography, high albedo, high thorium concentration, and high silica content. Morphologies indicate that the complex is volcanic in origin and compositions indicate that it represents rare silicic volcanism on the Moon. Constraining the timing of silicic volcanism at the complex is necessary to better understand the development of evolved magmas and when they were active on the lunar surface. We employ image analysis and crater size-frequency distribution (CSFD) measurements on several locations within the complex and at surrounding impact craters, Hayn (87 km diameter), and Compton (160 km diameter), to determine relative and absolute model ages of regional events. Using CSFD measurements, we establish a chronology dating regional resurfacing events and the earliest possible onset of CBVC volcanism at ∼3.8 Ga, the formation of Compton Crater at 3.6 Ga, likely resurfacing by volcanism at the CBVC at ∼3.5 Ga, and the formation of Hayn Crater at ∼1 Ga. For the CBVC, we find the most consistent results are obtained using craters larger than 300 m in diameter; the small crater population is affected by their approach to an equilibrium condition and by the physical properties of regolith at the CBVC.

  18. Spatially Resolved Spectroscopy of Io's Pele Plume and SO 2 Atmosphere

    Science.gov (United States)

    McGrath, Melissa A.; Belton, Michael J. S.; Spencer, John R.; Sartoretti, Paola

    2000-08-01

    We report on the first successful, spatially resolved spectroscopic observations of Io's SO 2 atmosphere. Observations made with the Hubble Space Telescope Faint Object Spectrograph on 1 August 1996 using the 0.26 '' aperture have provided detections of SO 2 gas in absorption in three locations on the Io disk: the Pele volcano, the Ra volcano, and T3 (a control region at latitude 45°S, longitude 300°W). The column densities of SO 2 at these three locations have been determined by best-fit models of the geometric albedo and vary by a factor of five, with NSO 2=3.25× 10 16, 1.5× 10 16, and 7×10 15 cm -2 for Pele, Ra, and T3, respectively. Thus, SO 2 gas is found to be present, and collisionally "thick" ( N≳6×10 14 cm -2), in all three locations. The factor of five difference in column densities among the three targets provides the first direct evidence that the Io atmosphere is spatially inhomogeneous. Models of the SO 2 gas band absorption at different temperatures give best-fit models with temperatures of T=280 (Pele), 150 (Ra), and 200 K (T3). Addition of SO to the models in the amounts NSO ˜2.5×10 15 (Pele), 5×10 14 (Ra), and 1.5×10 15 cm -2 (T3) provides improved (χ 2) fits to the data for all three locations and gives reasonably good agreement with the previous detection of SO in the Io atmosphere at an abundance ˜0.1 times that of SO 2. We set an upper limit of 2×10 14 cm -2 on the abundance of CS 2. Observations with the HST WFPC2 obtained on 24 July 1996, 7 days earlier than our FOS spectra, showed an active plume over the Pele volcano. If Pele was still active on 1 August, our results imply that the regions of highest SO 2 gas density on Io may be associated with active volcanic plumes and not sublimation from the visibly bright SO 2 frost patches common on the surface of the satellite. As a result of the positive detection of atomic sulfur emission from the S I] 1900 Å multiplet from two of our three targets (˜3.6 kR, Pele; ˜1.6 kR, T3

  19. SO2 oxidation products other than H2SO4 as a trigger of new particle formation – Part 2: Comparison of ambient and laboratory measurements, and atmospheric implications

    Directory of Open Access Journals (Sweden)

    B. Umann

    2008-05-01

    Full Text Available Atmospheric new particle formation is generally thought to occur due to homogeneous or ion-induced nucleation of sulphuric acid. We compare ambient nucleation rates with laboratory data from nucleation experiments involving either sulphuric acid or oxidized SO2. Atmospheric nucleation occurs at H2SO4 concentrations 2–4 orders of magnitude lower than binary or ternary H2SO4 nucleation. In contrast, the atmospheric nucleation rates and H2SO4 concentrations are very well replicated in the SO2 oxidation experiments. We explain these features by the formation of free HSO5 radicals in pace with H2SO4 during the SO2 oxidation. We suggest that at temperatures above ~250 K these radicals produce nuclei of new aerosols much more efficiently than H2SO4. These nuclei are activated to further growth by H2SO4 and possibly other trace species. However, at lower temperatures the atmospheric relative acidity is high enough for the H2SO4–H2O nucleation to dominate.

  20. Estimation of volcanic ash emission profiles using ceilometer measurements and transport models

    Science.gov (United States)

    Chan, Ka Lok; Geiß, Alexander; Gasteiger, Josef; Wagner, Frank; Wiegner, Matthias

    2016-04-01

    In recent years, the number of active remote sensing systems grows rapidly, since several national weather services initiated ceilometer networks. These networks are excellent tools to monitor the dispersion of volcanic ash clouds and to validate chemical transport models. Moreover, it is expected that the can be used to refine model calculations to better predict situations that might be dangerous for aviation. As a ceilometer can be considered as a simple single-wavelength backscatter lidar, quantitative aerosol profile information, i.e., the aerosol backscatter coefficient (βp) profile, can be derived provided that the ceilometer is calibrated. Volcanic ash concentration profile can then be estimated by using prior optical properties of volcanic ash. These profiles are then used for the inverse calculation of the emission profile of the volcanic eruption, thus, improving one of the most critical parameters of the numerical simulation. In this study, the Lagrangian particle dispersion model FLEXPART (FLEXible PARTicle dispersion model) is used to simulate the dispersion of volcanic ash. We simulate the distribution of ash for a given time/height grid, in order to compute the sensitivity functions for each measurements. As an example we use ceilometer measurements of the German weather service to reconstruct the temporal and spatial emission profile of Eyjafjallajökull eruption in April 2010. We have also examined the sensitivity of the retrieved emission profiles to different measurement parameters, e.g., geolocation of the measurement sites, total number of measurement sites, temporal and vertical resolution of the measurements, etc. The first results show that ceilometer measurements in principle are feasible for the inversion of volcanic ash emission profiles.

  1. NOx and SO2 emission factors for Serbian lignite Kolubara

    Directory of Open Access Journals (Sweden)

    Jovanović Vladimir V.

    2012-01-01

    Full Text Available Emission factors are widely accepted tool for estimation of various pollutants emissions in USA and EU. Validity of emission factors is strongly related to experimental data on which they are based. This paper is a result of an effort to establish reliable NOx and SO2 emission factors for Serbian coals. The results of NOx and SO2 emissions estimations based on USA and EU emission factors from thermal power plants Nikola Tesla Obrenovac A and B utilizing the Serbian lignite Kolubara are compared with experimental data obtained during almost one decade (2000-2008 of emissions measurements. Experimental data are provided from regular annual emissions measurement along with operational parameters of the boiler and coal (lignite Kolubara ultimate and proximate analysis. Significant deviations of estimated from experimental data were observed for NOx, while the results for SO2 were satisfactory. Afterwards, the estimated and experimental data were plotted and linear regression between them established. Single parameter optimization was performed targeting the ideal slope of the regression line. Results of this optimization provided original NOx and SO2 emission factors for Kolubara lignite.

  2. [Analysis About Spatial and Temporal Distribution of SO2 and An Ambient SO2 Pollution Process in Beijing During 2000-2014].

    Science.gov (United States)

    Cheng, Nian-liang; Zhang, Da-wei; Li, Yun-ting; Chen, Tian; Li, Jin-xiang; Dong, Xin; Sun, Rui-wen; Meng, Fan

    2015-11-01

    Spatial and temporal distribution of SO2 during 2000-2014 was all analyzed based on the SO2 monitoring data that Beijing Municipal Environmental Monitoring Center released and the formation mechanism of a typical air pollution episode in January 2014 was also investigated by combining numerical model CAM(x). Analysis results showed that mass concentration of ρ(SO2) in Beijing in 2014 decreased 69% compared to that in 2000 with an annual gradient from 2000 to 2014 of - 3.5 μg x (m3 x a)(-1). Monthly average concentration of SO2 changed in a U shape curve and from the lowest to the highest, and seasonal variations of SO2 concentrations were as follows: winter > spring > autumn > summer; concentration of SO2 in heating season was significantly higher than that in non heating season. Annual average concentration of SO2 was lower in northern and western regions while higher in six city area and southern area. Concentrations of SO2 at Shijingshan, Dongsi, Tongzhou monitoring sites were significantly decreased related to SO2 emission reduction measures. During a heavy air pollution process in January 14 - 18th 2014 there was obviously SO2 regional transportation and model simulation analysis based on PAST showed that the contribution of SO2 regional transport to Beijing was 83% with elevated power plants surrounding Beijing accounting for 21% and the four major Beijing power plants contributing about 3.5% to the SO2 concentration during this heavy air pollution process.

  3. Retrieval of absolute SO2 column amounts from scattered-light spectra: implications for the evaluation of data from automated DOAS networks

    Science.gov (United States)

    Lübcke, Peter; Lampel, Johannes; Arellano, Santiago; Bobrowski, Nicole; Dinger, Florian; Galle, Bo; Garzón, Gustavo; Hidalgo, Silvana; Chacón Ortiz, Zoraida; Vogel, Leif; Warnach, Simon; Platt, Ulrich

    2016-11-01

    Scanning spectrometer networks using scattered solar radiation in the ultraviolet spectral region have become an increasingly important tool for monitoring volcanic sulfur dioxide (SO2) emissions. Often measured spectra are evaluated using the differential optical absorption spectroscopy (DOAS) technique. In order to obtain absolute column densities (CDs), the DOAS evaluation requires a Fraunhofer reference spectrum (FRS) that is free of absorption structures of the trace gas of interest. For measurements at volcanoes such a FRS can be readily obtained if the scan (i.e. series of measurements at different elevation angles) includes viewing directions where the plume is not seen. In this case, it is possible to use these viewing directions (e.g. zenith) as FRS. Possible contaminations of the FRS by the plume can then be corrected by calculating and subtracting an SO2 offset (e.g. the lowest SO2 CD) from all viewing directions of the respective scan. This procedure is followed in the standard evaluations of data from the Network for Observation of Volcanic and Atmospheric Change (NOVAC). While this procedure is very efficient in removing Fraunhofer structures and instrumental effects it has the disadvantage that one can never be sure that there is no SO2 from the plume in the FRS. Therefore, using a modelled FRS (based on a high-resolution solar atlas) has a great advantage. We followed this approach and investigated an SO2 retrieval algorithm using a modelled FRS. In this paper, we present results from two volcanoes that are monitored by NOVAC stations and which frequently emit large volcanic plumes: Nevado del Ruiz (Colombia) recorded between January 2010 and June 2012 and from Tungurahua (Ecuador) recorded between January 2009 and December 2011. Instrumental effects were identified with help of a principal component analysis (PCA) of the residual structures of the DOAS evaluation. The SO2 retrieval performed extraordinarily well with an SO2 DOAS retrieval error of

  4. A Fabry–Perot interferometer based camera for two-dimensional mapping of SO2 distributions

    Directory of Open Access Journals (Sweden)

    J. Kuhn

    2014-05-01

    Full Text Available We examine a new imaging method for the remote sensing of volcanic gases, which relies on the regularly spaced narrow-band absorption structures in the UV-VIS of many molecules. A Fabry–Perot interferometer (FPI is used to compare the scattered sunlight radiance at wavelengths corresponding to absorption bands with the radiance at wavelengths in between the bands, thereby identifying and quantifying the gas. In this first theoretical study, we present sample calculations for the detection of sulfur dioxide (SO2. Optimum values for the FPI set-up parameters are proposed. Further, the performance of the FPI method is compared to SO2 cameras. We show that camera systems using a FPI are far less influenced by changes in atmospheric radiative transfer (e.g. due to aerosol and have a great potential as a future technique to examine emissions of SO2 (or other gases from volcanic sources and other point sources.

  5. Calibration of microbolometer infrared cameras for measuring volcanic ash mass loading

    Science.gov (United States)

    Carroll, Russell C.

    Small spacecraft with thermal infrared (TIR) imaging capabilities are needed to detect dangerous levels of volcanic ash that can severely damage jet aircraft engines and must be avoided. Grounding aircraft after a volcanic eruption may cost the airlines millions of dollars per day, while accurate knowledge of volcanic ash density might allow for safely routing aircraft around dangerous levels of volcanic ash. There are currently limited numbers of satellites with TIR imaging capabilities so the elapsed time between revisits can be large, and these instruments can only resolve total mass loading along the line-of-sight. Multiple small satellites could allow for decreased revisit times as well as multiple viewing angles to reveal the three-dimensional structure of the ash cloud through stereoscopic techniques. This paper presents the design and laboratory evaluation of a TIR imaging system that is designed to fit within the resource constraints of a multi-unit CubeSat to detect volcanic ash mass loading. The laboratory prototype of this TIR imaging system uses a commercial off-the shelf (COTS) camera with an uncooled microbolometer sensor, two narrowband filters, a black body source and a custom filter wheel. The infrared imaging system detects the difference in attenuation of volcanic ash at 11 mum and 12 mum by measuring the brightness temperature at each band. The brightness temperature difference method is used to measure the column mass loading. Multi-aspect images and stereoscopic techniques are needed to estimate the mass density from the mass loading, which is the measured mass per unit area. Laboratory measurements are used to characterize the noise level and thermal stability of the sensor. A calibration technique is developed to compensate for sensor temperature drift. The detection threshold of volcanic ash density of this TIR imaging system is found to be from 0.35 mg/m3 to 26 mg/m3 for ash clouds that have thickness of 1 km, while ash cloud densities

  6. A new method for GPS-based wind speed determinations during airborne volcanic plume measurements

    Science.gov (United States)

    Doukas, Michael P.

    2002-01-01

    Begun nearly thirty years ago, the measurement of gases in volcanic plumes is today an accepted technique in volcano research. Volcanic plume measurements, whether baseline gas emissions from quiescent volcanoes or more substantial emissions from volcanoes undergoing unrest, provide important information on the amount of gaseous output of a volcano to the atmosphere. Measuring changes in gas emission rates also allows insight into eruptive behavior. Some of the earliest volcanic plume measurements of sulfur dioxide were made using a correlation spectrometer (COSPEC). The COSPEC, developed originally for industrial pollution studies, is an upward-looking optical spectrometer tuned to the ultraviolet absorption wavelength of sulfur dioxide (Millán and Hoff, 1978). In airborne mode, the COSPEC is mounted in a fixed-wing aircraft and flown back and forth just underneath a volcanic plume, perpendicular to the direction of plume travel (Casadevall and others, 1981; Stoiber and others, 1983). Similarly, for plumes close to the ground, the COSPEC can be mounted in an automobile and driven underneath a plume if a suitable road system is available (Elias and others, 1998). The COSPEC can also be mounted on a tripod and used to scan a volcanic plume from a fixed location on the ground, although the effectiveness of this configuration declines with distance from the plume (Kyle and others, 1990). In the 1990’s, newer airborne techniques involving direct sampling of volcanic plumes with infrared spectrometers and electrochemical sensors were developed in order to measure additional gases such as CO2 and H2S (Gerlach and others, 1997; Gerlach and others, 1999; McGee and others, 2001). These methods involve constructing a plume cross-section from several measurement traverses through the plume in a vertical plane. Newer instruments such as open-path Fourier transform infrared (FTIR) spectrometers are now being used to measure the gases in volcanic plumes mostly from fixed

  7. Developing and testing a low cost method for high resolution measurements of volcanic water vapour emissions at Vulcano and Mt. Etna

    Science.gov (United States)

    Pering, Tom D.; McGonigle, Andrew J. S.; Tamburello, Giancarlo; Aiuppa, Alessandro; Bitetto, Marcello; Rubino, Cosimo

    2015-04-01

    The most voluminous of emissions from volcanoes are from water vapour (H2O) (Carroll and Holloway, 1994), however, measurements of this species receive little focus due to the difficulty of independent measurement, largely a result of high atmospheric background concentrations which often undergo rapid fluctuations. A feasible method of measuring H2O emissions at high temporal and spatial resolutions would therefore be highly valuable. We describe a new and low-cost method combining modified web cameras (i.e. with infrared filters removed) with measurements of temperature and relative humidity to produce high resolution measurements (≈ 0.25 Hz) of H2O emissions. The cameras are affixed with near-infrared filters at points where water vapour absorbs (940 nm) and doesn't absorb (850 nm) incident light. Absorption of H2O is then determined by using Lambert-Beer's law on a pixel by pixel basis, producing a high spatial resolution image. The system is then calibrated by placing a Multi-GAS unit within the gas source and camera field-of-view, which measures; SO2, CO2, H2S and relative humidity. By combining the point measurements of the Multi-GAS unit with pixel values for absorption, first correcting for the width of the gas source (generally a Gaussian distribution), a calibration curve is produced which allows the conversion of absorption values to mass of water within a pixel. In combination with relative humidity measurements made outside of the plume it is then possible to subtract the non-volcanic background H2O concentration to produce a high resolution calibrated volcanic H2O flux. This technique is demonstrated in detail at the active fumarolic system on Vulcano (Aeolian Islands, Italy). Data processing and image acquisition was completed in Matlab® using a purpose built code. The technique is also demonstrated for the plume of the North-East Crater of Mt. Etna (Sicily, Italy). Here, contemporaneously acquired measurements of SO2 using a UV camera, combined

  8. VolcLab: A balloon-borne instrument package to measure ash, gas, electrical, and turbulence properties of volcanic plumes

    Science.gov (United States)

    Airey, Martin; Harrison, Giles; Nicoll, Keri; Williams, Paul; Marlton, Graeme

    2017-04-01

    Release of volcanic ash into the atmosphere poses a significant hazard to air traffic. Exposure to appreciable concentrations (≥4 mg m-3) of ash can result in engine shutdown, air data system loss, and airframe damage, with sustained lower concentrations potentially causing other long-term detrimental effects [1]. Disruption to flights also has a societal impact. For example, the closure of European airspace following the 2010 eruption of Eyjafjallajökull resulted in global airline industry losses of order £1100 million daily and disruption to 10 million passengers. Accurate and effective measurement of the mass of ash in a volcanic plume along with in situ characterisation of other plume properties such as charge, turbulence, and SO2 concentration can be used in combination with plume dispersion modelling, remote sensing, and more sophisticated flight ban thresholds to mitigate the impact of future events. VolcLab is a disposable instrument package that may be attached to a standard commercial radiosonde, for rapid emergency deployment on a weather balloon platform. The payload includes a newly developed gravimetric sensor using the oscillating microbalance principle to measure mass directly without assumptions about particles' optical properties. The package also includes an SO2 gas detector, an optical sensor to detect ash and cloud backscatter from an LED source [2], a charge sensor to characterise electrical properties of the plume [3], and an accelerometer to measure in-plume turbulence [4]. VolcLab uses the established PANDORA interface [5], to provide data exchange and power from the radiosonde. In addition to the VolcLab measurements, the radiosonde provides standard meteorological data of temperature, pressure, and relative humidity, and GPS location. There are several benefits of using this instrument suite in this design and of using this method of deployment. Firstly, this is an all-in-one device requiring minimal expertise on the part of the end

  9. Application of DBD and DBCD in SO2 Removal

    Institute of Scientific and Technical Information of China (English)

    孙岩洲; 邱毓昌; 余发山; 袁兴成

    2004-01-01

    The dielectric barrier corona discharge(DBCD) in a wire-cylinder configuration and the dielectric barrier discharge(DBD) in a coaxial cylinder configuration are studied. The discharge current in DBD has a higher pulse amplitude than in DBCD. The dissipated power and the gas-gap voltage are calculated by analyzing the measured Lissajous figure. With the increasing applied voltage, the energy utilization factor for SO2 removal increases in DBCD but decreases in DBD because of the difference in their electric field distribution. Experiments of SO2 removal show that in the absence of NH3 the energy utilization factor can reach 31 g/kWh in DBCD and 39 g/kWh in DBD.

  10. Sulfur dioxide (SO2 as observed by MIPAS/Envisat: temporal development and spatial distribution at 15–45 km altitude

    Directory of Open Access Journals (Sweden)

    M. Höpfner

    2013-10-01

    Full Text Available We present a climatology of monthly and 10° zonal mean profiles of sulfur dioxide (SO2 volume mixing ratios (vmr derived from MIPAS/Envisat measurements in the altitude range 15–45 km from July 2002 until April 2012. The vertical resolution varies from 3.5–4 km in the lower stratosphere up to 6–10 km at the upper end of the profiles, with estimated total errors of 5–20 pptv for single profiles of SO2. Comparisons with the few available observations of SO2 up to high altitudes from ATMOS for a volcanically perturbed situation from ACE-FTS and, at the lowest altitudes, with stratospheric in situ observations reveal general consistency of the datasets. The observations are the first empirical confirmation of features of the stratospheric SO2 distribution, which have only been shown by models up to now: (1 the local maximum of SO2 at around 25–30 km altitude, which is explained by the conversion of carbonyl sulfide (COS as the precursor of the Junge layer; and (2 the downwelling of SO2-rich air to altitudes of 25–30 km at high latitudes during winter and its subsequent depletion on availability of sunlight. This has been proposed as the reason for the sudden appearance of enhanced concentrations of condensation nuclei during Arctic and Antarctic spring. Further, the strong increase of SO2 to values of 80–100 unit{pptv} in the upper stratosphere through photolysis of H2SO4 has been confirmed. Lower stratospheric variability of SO2 could mainly be explained by volcanic activity, and no hints of a strong anthropogenic influence have been found. Regression analysis revealed a QBO (quasi-biennial oscillation signal of the SO2 time series in the tropics at about 30–35 km, an SAO (semi-annual oscillation signal at tropical and subtropical latitudes above 32 km and annual periodics predominantly at high latitudes. Further, the analysis indicates a correlation with the solar cycle in the tropics and southern subtropics above 30 km

  11. Historical Analysis of SO2 Pollution Control Policies in China

    Science.gov (United States)

    Gao, Cailing; Yin, Huaqiang; Ai, Nanshan; Huang, Zhengwen

    2009-03-01

    Coal is not only an important energy source in China but also a major source of air pollution. Because of this, China’s national sulfur dioxide (SO2) emissions have been the highest in the world for many years, and since the 1990s, the territory of China’s south and southwest has become the third largest acid-rain-prone region in the world. In order to control SO2 emissions, the Chinese government has formulated and promulgated a series of policies and regulations, but it faces great difficulties in putting them into practice. In this retrospective look at the history of SO2 control in China, we found that Chinese SO2 control policies have become increasingly strict and rigid. We also found that the environmental policies and regulations are more effective when central officials consistently give environmental protection top priority. Achieving China’s environmental goals, however, has been made difficult by China’s economic growth. Part of this is due to the practice of environmental protection appearing in the form of an ideological “campaign” or “storm” that lacks effective economic measures. More recently, better enforcement of environmental laws and regulations has been achieved by adding environmental quality to the performance assessment metrics for leaders at all levels. To continue making advances, China needs to reinforce the economic and environmental assessments for pollution control projects and work harder to integrate economic measures into environmental protection. Nonetheless, China has a long way to go before economic growth and environmental protection are balanced.

  12. First results from the permanent SO2 Camera system at Stromboli

    Science.gov (United States)

    Salerno, Giuseppe G.; Burton, Mike; Caltabiano, Tommaso; D'Auria, Luca; Maugeri, Roberto; Mure, Filippo

    2015-04-01

    Since the 1980's volcano monitoring has undergone stunning changes, evolving from descriptive and sparse observations to a systematic-quantitative approach of science and technology. Surveillance of chemical gas composition and their emission rate is a vital part of efforts in interpreting volcanic activity of observatories since their changes are closely linked with seismicity and deformation swings. In this unruly technology progression, volcanic gas sensing observations have also undergone a profound revolution, for example by increasing observation frequency of SO2 flux from a few samples per day to Hz. In May 2013, a permanent-robotic SO2 dual-camera system was installed by the Istituto Nazionale di Geofisica e Vulcanologia at Stromboli as a part of the ultraviolet scanning spectrometers network FLAME, with the intent to underpin the geochemical surveillance and shed light on degassing and volcanic processes. Here, we present the first results of SO2 flux observed by the permanent SO2 camera system in the period between May 2013 and April 2015. Results are corroborated with the well established FLAME ultraviolet scanning network and also compared with VLP signals from the seismic network.

  13. SO2 Emissions in China – Their Network and Hierarchical Structures

    Science.gov (United States)

    Yan, Shaomin; Wu, Guang

    2017-01-01

    SO2 emissions lead to various harmful effects on environment and human health. The SO2 emission in China has significant contribution to the global SO2 emission, so it is necessary to employ various methods to study SO2 emissions in China with great details in order to lay the foundation for policymaking to improve environmental conditions in China. Network analysis is used to analyze the SO2 emissions from power generation, industrial, residential and transportation sectors in China for 2008 and 2010, which are recently available from 1744 ground surface monitoring stations. The results show that the SO2 emissions from power generation sector were highly individualized as small-sized clusters, the SO2 emissions from industrial sector underwent an integration process with a large cluster contained 1674 places covering all industrial areas in China, the SO2 emissions from residential sector was not impacted by time, and the SO2 emissions from transportation sector underwent significant integration. Hierarchical structure is obtained by further combining SO2 emissions from all four sectors and is potentially useful to find out similar patterns of SO2 emissions, which can provide information on understanding the mechanisms of SO2 pollution and on designing different environmental measure to combat SO2 emissions. PMID:28387301

  14. SO2 Spectroscopy with A Tunable UV Laser

    Science.gov (United States)

    Morey, W. W.; Penney, C. M.; Lapp, M.

    1973-01-01

    A portion of the fluorescence spectrum of SO2 has been studied using a narrow wavelength doubled dye laser as the exciting source. One purpose of this study is to evaluate the use of SO2 resonance re-emission as a probe of SO2 in the atmosphere. When the SO2 is excited by light at 300.2 nm, for example, a strong reemission peak is observed which is Stokes-shifted from the incident light wavelength by the usual Raman shift (the VI symmetric vibration frequency 1150.5/cm ). The intensity of this peak is sensitive to small changes (.01 nm) in the incident wavelength. Measurements of the N2 quenching and self quenching of this re-emission have been obtained. Preliminary analysis of this data indicates that the quenching is weak but not negligible. The dye laser in our system is pumped by a pulsed N2 laser. Tuning 'and spectral narrowing are accomplished using a telescope-echelle grating combination. In a high power configuration the resulting pulses have a spectral width of about 5 x 10(exp -3) nm and a time duration of about 6 nsec. The echelle grating is rotated by a digital stepping motor, such that each step shifts the wavelength by 6 x 10(exp -4) nm. In addition to the tunable, narrow wavelength uv source and spectral analysis of the consequent re-emission, the system also provides time resolution of the re-emitted light to 6 nsec resolution. This capability is being used to study the lifetime of low pressure S02 fluorescence at different wavelengths and pressures.

  15. Soil radon measurements as a potential tracer of tectonic and volcanic activity

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-01

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009–2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  16. Soil radon measurements as a potential tracer of tectonic and volcanic activity.

    Science.gov (United States)

    Neri, Marco; Ferrera, Elisabetta; Giammanco, Salvatore; Currenti, Gilda; Cirrincione, Rosolino; Patanè, Giuseppe; Zanon, Vittorio

    2016-04-15

    In Earth Sciences there is a growing interest in studies concerning soil-radon activity, due to its potential as a tracer of numerous natural phenomena. Our work marks an advance in the comprehension of the interplay between tectonic activity, volcanic eruptions and gas release through faults. Soil-radon measurements, acquired on Mt. Etna volcano in 2009-2011, were analyzed. Our radon probe is sensitive to changes in both volcanic and seismic activity. Radon data were reviewed in light of the meteorological parameters. Soil samples were analyzed to characterize their uranium content. All data have been summarized in a physical model which identifies the radon sources, highlights the mechanism of radon transport and envisages how such a mechanism may change as a consequence of seismicity and volcanic events. In the NE of Etna, radon is released mainly from a depth of 50 m/day. Three periods of anomalous gas release were found (February 2010, January and February 2011). The trigger of the first anomaly was tectonic, while the second and third had a volcanic origin. These results mark a significant step towards a better understanding of the endogenous mechanisms that cause changes in soil-radon emission at active volcanoes.

  17. Measurements and Slope Analyses of Quaternary Cinder Cones, Camargo Volcanic Field, Chihuahua, Mexico

    Science.gov (United States)

    Gallegos, M. I.; Espejel-Garcia, V. V.

    2012-12-01

    The Camargo volcanic field (CVF) covers ~3000 km2 and is located in the southeast part of the state of Chihuahua, within the Basin and Range province. The CVF represents the largest mafic alkali volcanic field in northern Mexico. Over a 300 cinder cones have been recognized in the Camargo volcanic field. Volcanic activity ranges from 4.7 to 0.09 Ma revealed by 40Ar/39Ar dating methods. Previous studies say that there is a close relationship between the cinder cone slope angle, due to mechanical weathering, and age. This technique is considered a reliable age indicator, especially in arid climates, such as occur in the CVF. Data were acquired with digital topographic maps (DRG) and digital elevation models (DEM) overlapped in the Global Mapper software. For each cone, the average radius (r) was calculated from six measurements, the height (h) is the difference between peak elevation and the altitude of the contour used to close the radius, and the slope angle was calculated using the equation Θ = tan-1(h/r). The slope angles of 30 cinder cones were calculated showing angles ranging from 4 to 15 degrees. A diffusion model, displayed by an exponential relationship between slope angle and age, places the ages of these 30 cones from 215 to 82 ka, within the range marked by radiometric methods. Future work include the analysis of more cinder cones to cover the whole CVF, and contribute to the validation of this technique.

  18. The role of SO2 on Mars and on the primordial oxygen isotope composition of water on Earth and Mars

    Science.gov (United States)

    Waenke, H.; Dreibus, G.; Jagoutz, E.; Mukhin, L. M.

    1992-01-01

    We stress the importance of SO2 on Mars. In the case that water should have been supplied in sufficient quantities to the Martian surface by a late veneer and stored in the near surface layers in form of ice, temporary greenhouse warming by SO2 after large SO2 discharges may have been responsible for melting of ice and break-out of water in areas not directly connected to volcanic activity. Aside from water, liquid SO2 could explain at least some of the erosion features on the Martian surface.

  19. SO2 degassing at Tungurahua volcano (Ecuador) between 2007 and 2013: Transition from continuous to episodic activity

    Science.gov (United States)

    Hidalgo, Silvana; Battaglia, Jean; Arellano, Santiago; Steele, Alexander; Bernard, Benjamin; Bourquin, Julie; Galle, Bo; Arrais, Santiago; Vásconez, Freddy

    2015-06-01

    We present continuous SO2 measurements performed at Tungurahua volcano with a permanent network of 4 scanning DOAS instruments between 2007 and 2013. The volcano has been erupting since September 1999, but on the contrary to the first years of eruption when the activity was quasi-continuous, the activity transitioned in late 2008 towards the occurrence of distinct eruptive phases separated by periods of quiescence. During our study period we distinguish 11 phases lasting from 17 to 527 days separated by quiescence periods of 26 to 184 days. We propose a new routine to quantify the SO2 emissions when data from a dense DOAS monitoring network are available. This routine consists in summing all the highest validated SO2 measurements among all stations during the 10 h of daily working-time to obtain a daily observed SO2 mass. Since measurement time is constant at Tungurahua the "observed" amounts can be expressed in tons per 10 h and can easily be converted to a daily average flux or mass per day. Our results provide time series having an improved correlation on a long time scale with the eruptive phases and with quiescence periods. A total of 1.25 Mt (1.25 × 109 kg) of SO2 has been released by Tungurahua during the study period, with 95% of these emissions occurring during phases of activity and only 5% during quiescence. This shows a contrast with previous volcanic behaviour when passive degassing dominated the total SO2 emissions. SO2 average daily mass emission rates are of 73 ± 56 t/d during quiescent periods, 735 ± 969 t/d during long-lasting phases and 1424 ± 1224 t/d during short-lasting phases. Degassing during the different eruptive phases displays variable patterns. However, two contrasting behaviours can be distinguished for the onset of eruptive phases with both sudden and progressive onsets being observed. The first is characterised by violent opening of the conduit by high energy Vulcanian explosions; and the second by a progressive, in crescendo

  20. The ISA-MIP Historical Eruption SO2 Emissions Assessment (HErSEA): an intercomparison for interactive stratospheric aerosol models

    Science.gov (United States)

    Mann, Graham; Dhomse, Sandip; Sheng, Jianxiong; Mills, Mike

    2016-04-01

    Major historical volcanic eruptions have injected huge amounts of sulphur dioxide into the stratosphere with observations showing an enhancement of the stratospheric aerosol layer for several years (ASAP, 2006). Such long-lasting increases in stratospheric aerosol loading cool the Earth's surface by scattering incoming solar radiation and warm the stratosphere via absorption of near infra-red solar and long-wave terrestrial radiation with complex effects on climate (e.g. Robock, 2000). Two recent modelling studies of Mount Pinatubo (Dhomse et al., 2014; Sheng et al. 2015) have highlighted that observations suggest the sulphur loading of the volcanically enhanced stratospheric aerosol may have been considerably lower than suggested by measurements of the injected SO2. This poster describes a new model intercomparison activity "ISA-MIP" for interactive stratospheric aerosol models within the framework of the SPARC initiative on Stratospheric Sulphur and its Role in Climate (SSiRC). The new "Historical Eruption SO2 emissions Assessment" (HErSEA) will intercompare model simulations of the three largest volcanic perturbations to the stratosphere in the last 50 years, 1963 Mt Agung, 1982 El Chichon and 1991 Mt Pinatubo. The aim is to assess how effectively the emitted SO2 translates into perturbations to stratospheric aerosol properties and simulated radiative forcings in different composition-climate models with interactive stratospheric aerosol (ISA). Each modelling group will run a mini-ensemble of transient AMIP-type runs for the 3 eruptions with a control no-eruption run followed by upper and lower bound injection amount estimates and 3 different injection height settings for two shallow (e.g. 19-21km amd 23-25km) and one deep (e.g. 19-25km) injection. First order analysis will intercompare stratospheric aerosol metrics such as 2D-monthly AOD(550nm, 1020nm) and timeseries of tropical and NH/SH mid-visible extinction at three different models levels (15, 20 and 25km

  1. Simultaneous removal of NOx and SO2 from NO-SO2-CO2-N2- O2 gas mixtures by corona radical shower systems

    Science.gov (United States)

    Park, J. Y.; Tomicic, I.; Round, G. F.; Chang, J. S.

    1999-05-01

    In this study, an experimental investigation has been conducted to remove NOx and SO2 simultaneously from NO-SO2-CO2-N2-O2 gas mixtures using a d.c. corona discharge activated radical shower system. The gas mixtures consisted of NO-SO2-CO2-N2- O2([NO]o:200 ppm and [SO2]o:800 ppm) and the injection gas used as the radical source gas was NH3-Ar-air. The effect of NH3 radical injection rate on the NOx and SO2 removal efficiency and other by-product gases was measured by Fourier transform infrared (FTIR), as well as SO2, NOx and NO2 gas detectors. By-product aerosol particles were also observed using a condensation nucleation particle counter (CNPC) and SEM imaging after sampling. The results showed that significant aerosol particle formation was observed during simultaneous NOx and SO2 removal by corona radical shower systems. Electrode surface conditions had a significant influence on the NOx and SO2 removal characteristics. The NOx removal efficiency significantly increased with increasing applied voltage and NH3 injection rate. The SO2 removal efficiency was not significantly affected by applied voltage and slightly increased with increasing acid gas to NH3 molecular ratio.

  2. The flight of Arcadia: spatial CO2/SO2 variations in a cross section above the Nord East crater of Etna volcano

    Science.gov (United States)

    Giuffrida, Giovanni; Calabrese, Sergio; Bobrowski, Nicole; Finkenzeller, Henning; Pecoraino, Giovannella; Scaglione, Sarah

    2015-04-01

    The CO2/SO2 ratio in volcanic plumes of open conduit volcanoes can provide useful information about the magma depth inside a conduit and the possible occurrence of an eruptive event. Moreover, the same CO2 measurement when combined with a SO2 flux measurement, commonly carried out at many volcanoes nowadays, is used to contribute to an improved estimate of global volcanic CO2 budget. Today worldwide at 13 volcanoes automated in-situ instruments (known as Multi-GAS stations) are applied to continuously determine CO2/SO2 ratios and to use this signal as additional parameter for volcanic monitoring. Usually these instruments carry out measurements of half an hour 4 - 6 times/day and thus provide continuous CO2/SO2 values and their variability. The stations are located at crater rims in a position that according to the prevailing winds is invested by the plume. Obviously, although the stations are carefully positioned, it is inevitable that other sources than the plume itself, e.g. soil degassing and surrounding fumaroles, contribute and will be measured as well, covering the 'real' values. Between July and September 2014 experiments were carried out on the North East crater (NEC) of Mount Etna, installing a self-made cable car that crossed the crater from one side to the other. The basket, called "Arcadia", was equipped with an automated standard Multi-GAS station and a GPS, which acquired at high frequency (0.5 Hz) the following parameters : CO2, SO2, H2S, Rh, T, P and geo-coordinates. The choice of NEC of the volcano Etna was based on its accessibility, the relative small diameter (about 230 m) and the presence of a relatively constant and rather concentrated plume. Actually, NEC belongs also to the monitoring network EtnaPlume (managed by the INGV of Palermo). The aim of these experiments was to observe variations of each parameter, in particular the fluctuation of the CO2/SO2 ratio within the plume, moving from the edge to the center of the crater. The gained

  3. Lyman Alpha Camera for Io's SO2 atmosphere and Europa's water plumes

    Science.gov (United States)

    McEwen, Alfred S.; Sandel, Bill; Schneider, Nick

    2014-05-01

    The Student Lyman-Alpha Mapper (SLAM) was conceived for the Io Volcano Observer (IVO) mission proposal (McEwen et al., 2014) to determine the spatial and temporal variations in Io's SO2 atmosphere by recording the H Ly-α reflection over the disk (Feldman et al., 2000; Feaga et al., 2009). SO2 absorbs at H Ly-α, thereby modulating the brightness of sunlight reflected by the surface, and measures the density of the SO2 atmosphere and its variability with volcanic activity and time of day. Recently, enhancements at the Ly-α wavelength (121.57 nm) were seen near the limb of Europa and interpreted as active water plumes ~200 km high (Roth et al., 2014). We have a preliminary design for a very simple camera to image in a single bandpass at Ly-α, analogous to a simplified version of IMAGE EUV (Sandel et al. 2000). Our goal is at least 50 resolution elements across Io and/or Europa (~75 km/pixel), ~3x better than HST STIS, to be acquired at a range where the radiation noise is below 1E-4 hits/pixel/s. This goal is achieved with a Cassegrain-like telescope with a 10-cm aperture. The wavelength selection is achieved using a simple self-filtering mirror in combination with a solar-blind photocathode. A photon-counting detector based on a sealed image intensifier preserves the poisson statistics of the incoming photon flux. The intensifier window is coated with a solar-blind photocathode material (CsI). The location of each photon event is recorded by a position-sensitive anode based on crossed delay-line or wedge-and-strip technology. The sensitivity is 0.01 counts/pixel/sec/R, sufficient to estimate SO2 column abundances ranging from 1E15 to 1E17 per cm2 in a 5 min (300 sec) exposure. Sensitivity requirements to search for and image Europa plumes may be similar. Io's Ly-α brightness of ~3 kR exceeds the 0.8 kR brightness of Europa's plume reported by Roth et al. (2014), but the plume brightness is a direct measurement rather than inferring column abundance from

  4. Comparing SO2 Emissions to Seismic and Acoustic Records: the Value and Limitations of the new UV Camera Technique

    Science.gov (United States)

    Dalton, M. P.; Waite, G. P.; Nadeau, P. A.; Watson, I. M.

    2008-12-01

    SO2 emission measurements are an important component of monitoring volcanic eruption processes. Owing mainly to limitations in the temporal resolution of measurements, the goal of merging a gas flux record with other geophysical datasets (seismic, acoustic) with the aim of investigating subsurface processes has been elusive. In recent years, ground-based, ultraviolet (UV) digital cameras have improved upon previous methods of SO2 observation by capturing a large portion of the plume in one measurement- a single image. The UV digital camera can record at up to 1Hz, producing a data set that is more comparable with other monitoring techniques, allowing for a more precise record of SO2 flux, and directly providing the plume speed. Many monitoring advantages are gained by using this technique, but the accuracy and limitations require thorough investigation. The effect of some user-controlled parameters, include image exposure length, the diameter of the lens aperture, the regularity of calibration cell imaging, and the use of the single or paired bandpass filters, are addressed in this study. Laboratory and field experiments were conducted to clarify methodological consequences and quantify accuracy. Digital images of calibration cells were collected under varying observational conditions, and SO2 retrieval results from a coal power plant plume were compared to direct sampling measurements. The results indicate that the UV camera retrieval compares favorably with direct sampling methods; that careful attention must be paid to exposure times; and that there is some latitude in the calibration cell conversion technique. A multi-instrument field campaign was undertaken at Pacaya volcano, Guatemala to relate complementary high-temporal-resolution datasets. Between January 5 and January 9, 2008 SO2 flux was recorded at Pacaya using the UV camera. These measurements were coincident with recordings from a temporary network of five broadband seismometers and five low

  5. Global volcanic emissions: budgets, plume chemistry and impacts

    Science.gov (United States)

    Mather, T. A.

    2012-12-01

    Over the past few decades our understanding of global volcanic degassing budgets, plume chemistry and the impacts of volcanic emissions on our atmosphere and environment has been revolutionized. Global volcanic emissions budgets are needed if we are to make effective use of regional and global atmospheric models in order to understand the consequences of volcanic degassing on global environmental evolution. Traditionally volcanic SO2 budgets have been the best constrained but recent efforts have seen improvements in the quantification of the budgets of other environmentally important chemical species such as CO2, the halogens (including Br and I) and trace metals (including measurements relevant to trace metal atmospheric lifetimes and bioavailability). Recent measurements of reactive trace gas species in volcanic plumes have offered intriguing hints at the chemistry occurring in the hot environment at volcanic vents and during electrical discharges in ash-rich volcanic plumes. These reactive trace species have important consequences for gas plume chemistry and impacts, for example, in terms of the global fixed nitrogen budget, volcanically induced ozone destruction and particle fluxes to the atmosphere. Volcanically initiated atmospheric chemistry was likely to have been particularly important before biological (and latterly anthropogenic) processes started to dominate many geochemical cycles, with important consequences in terms of the evolution of the nitrogen cycle and the role of particles in modulating the Earth's climate. There are still many challenges and open questions to be addressed in this fascinating area of science.

  6. Emission of gas and atmospheric dispersion of SO2 during the December 2013 eruption at San Miguel volcano (El Salvador)

    Science.gov (United States)

    Salerno, Giuseppe G.; Granieri, Domenico; Liuzzo, Marco; La Spina, Alessandro; Giuffrida, Giovanni B.; Caltabiano, Tommaso; Giudice, Gaetano; Gutierrez, Eduardo; Montalvo, Francisco; Burton, Michael; Papale, Paolo

    2016-04-01

    y Recursos Naturales (MARN) of El Salvador and by a network of geophysical and geochemical stations established on the volcano by the Italian Istituto Nazionale di Geofisica e Vulcanologia (INGV), immediately after the December 2013 eruption, on the request of MARN. During the eruption, SO2 emissions increased from a background level of ~330 t d-1 to 2200 t d-1, dropping after the eruption to an average level of 680 t d-1. Wind measurements and SO2 fluxes during the pre-, syn- and post-eruptive stages were used to model SO2 dispersion around the volcano. Air SO2 concentration exceeds the dangerous threshold of 5 ppm in the crater region, and in some middle sectors of the highly visited volcanic cone.

  7. 大气SO2柱总量遥感反演算法比较分析及验证∗%Comparison and validation of band residual difference algorithm and principal comp onent analysis algorithm for retrievals of atmospheric SO2 columns from satellite observations

    Institute of Scientific and Technical Information of China (English)

    闫欢欢; 李晓静; 张兴赢; 王维和; 陈良富; 张美根; 徐晋

    2016-01-01

    Meter for Atmospheric CHartographY (SCIAMACHY), and Ozone Monitoring Instrument (OMI) have high SO2 monitoring capability. The OMI, which was launched on the EOS/Aura platform in July 2004, has the same hyperspectral measurements as the GOME and SCIAMACHY, but offers the improved spatial resolution at nadir (13 × 24 km2) and daily global coverage for short-lifetime SO2. For OMI operational SO2 planetary boundary layer (PBL) retrieval, the previous band residual difference (BRD) algorithm has been replaced by principal component analysis (PCA) algorithm, which effectively reduces the systematic biases in SO2 column retrievals. However, there are few studies on the evaluations and validations of PCA SO2 retrievals over China, and the long-term comparisons with BRD SO2 retrievals also need to be conducted. In this study, the accuracies of PCA and BRD SO2 retrievals are validated by using ground-based multi axis differential optical absorption spectroscopy (MAX-DOAS) located in Beijing, and regional atmospheric modeling system, community multi-scale air quality (RAMS-CMAQ) modeling system model which can simulate the vertical distribution of atmospheric SO2. Moreover, BRD and PCA SO2 retrievals from oceanic area, eastern China and Reunion volcanic eruption are compared to find the long-term trend and spatiotemporal dif-ferences between SO2 columns. Finally, the uncertainty of SO2 retrieval, caused by measurement errors, band selection and input parameter errors in radiative transfer model, are analysed to understand the limitations of BRD and PCA algorithms. Results show that both PCA and BRD SO2 retrievals over Beijing are lower than ground-based MAX-DOAS mea-surements of SO2. PCA and BRD SO2 retrievals over eastern China are lower than the simulated SO2 columns fromRAMS-CMAQ in winter 2008, but in July and August BRD SO2 columns are higher than RAMS-CMAQ simulations. The values of SO2 columns from BRD over China are more consistent with those from ground-based MAX-DOAS and

  8. Particle size and compositional retrievals of the Chaiten volcanic ash from spaceborne, high spectral resolution infrared AIRS and IASI measurements

    Science.gov (United States)

    Prata, F.; Gangale, G.; Clarisse, L.

    2008-12-01

    The eruption of Chaiten volcano in early May 2008 produced copious amounts of ash and little SO2 gas. The ash clouds could be detected very well by several satellite instruments, but was unusual in that true- colour daytime MODIS satellite imagery showed the ash to be quite light in colour and difficult to distinguish from ordinary meteorological clouds. High spectral resolution infrared spectrometer and interferometer measurements from AIRS and IASI were analysed to investigate the spectral signature of the Chaiten ash clouds and compare these with ash clouds from other volcanoes, which generally appear much darker in visible imagery. It was found that the Chaiten ash had a distinctive spectral signature between 800 to 1200 wavenumbers and that this correlated very well with the signature expected from rhyolitic ash. A radiative transfer code and an ash microphysical model were used to retrieve the mean particle size of fine ash in the Chaiten clouds and best fits were found for rhyolitic particles with small (less than 2 micron) radii. These results suggest that infrared spectra may be used to retrieve both compositional and particle size information in ash clouds. Based on the spectral signatures found for these ash clouds, a new ash detection algorithm was designed and found to have improved sensitivity to thin (low opacity) ash clouds and low sensitivity to surface effects. The new algorithm offers the possibility of tracking ash clouds for longer periods of time and over greater distances. Results from both the AIRS and IASI measurements are presented for the May ash clouds from Chaitén volcano and compared with the signatures of ash clouds from andesitic volcanic clouds and quartz dominated windblown dust.

  9. SO2 anodic reaction kinetics in zinc electrowinning%电解锌的SO2阳极反应动力学

    Institute of Scientific and Technical Information of China (English)

    苏毅; 金作美; 代祖元

    2001-01-01

    研究了湿法炼锌电解过程中,用SO2在阳极放电代替传统的水分解放电而降低槽电压,以达到节能的目的。使用铂作阳极,在电解液中通入SO2进行电解,节能可达40%。通过SO2阳极极化曲线的测定,考察了SO2浓度、 H2SO4浓度、温度和搅拌速度对阳极反应速率的影响。研究表明:在铂阳极上SO2阳极反应符合电化学控制,遵从塔菲尔公式; SO2的反应级数为3.3,表观活化能为31.8 kJ/mol,硫酸的反应级数为零。%The anodic oxidation of sulfur dioxide instead of water in zinc hyrometallurgy was studied for energy saving. The experimental results show that under experimental conditions energy consumption can be reduced by 40%. The effects of SO2 concentration, H2SO4 concentration, temperature and stirring speed on anodic reaction rate were investigated using potentiostatic polarization measurement. The results indicate that the SO2 anodic reaction process is electrochemically controlled and obeys Tafel equation. The apparent activation energy for SO2 anodic reaction is 31.8?kJ/mol, and the orders of anodic reaction are 3.30 and zero with respect to SO2 and H2SO4 respectively.

  10. The heterogeneous oxidation of SO2 on aerosol surface

    Institute of Scientific and Technical Information of China (English)

    高会旺; 黄美元; 徐华英

    1997-01-01

    A heterogeneous chemical model is developed by coupling aerosol, gas-phase and liquid-phase chemical model. SO2 oxidation rates on the aerosol surface are calculated and the influence of some factors is discussed. Model simulations indicate that SO2 heterogeneous oxidation rates are sensitive to the mass concentration and chemical composition of aerosols, relative humidity, initial values of SO2 and H2O2. The heterogeneous chemical model is coupled with a Eulerian deposition model. Model results show that oxidation of SO2 on the aerosol surface is found to reduce SO2 levels by 5%-33%, to increase SO2-4 concentrations by 8%-50% in the surface layer.

  11. First observations of volcanic eruption clouds from L1 by DSCOVR/EPIC

    Science.gov (United States)

    Carn, S. A.; Krotkov, N. A.; Taylor, S.; Fisher, B. L.; Li, C.; Hughes, E. J.; Bhartia, P. K.; Prata, F.

    2016-12-01

    Volcanic emissions of sulfur dioxide (SO2) and ash have been measured by ultraviolet (UV) sensors on US and European polar-orbiting satellites since the late 1970s. Although successful, the main limitation of these UV observations from low-Earth orbit has been poor temporal resolution. Timeliness can be crucial when detecting hazardous volcanic eruption clouds that threaten aviation, and most operational geostationary satellites cannot detect SO2, a key tracer of volcanic plumes. In 2015, the launch of the Earth Polychromatic Imaging Camera (EPIC) aboard the Deep Space Climate Observatory (DSCOVR) provided the first opportunity to observe volcanic clouds from the L1 Lagrange point. EPIC is a 10-band spectroradiometer spanning UV to near-IR wavelengths with two UV channels sensitive to SO2, and a ground resolution of 25 km. The unique L1 vantage point provides continuous observations of the sunlit Earth disk, potentially offering multiple daily observations of volcanic SO2 and ash clouds in the EPIC field of view. When coupled with complementary retrievals from polar-orbiting UV and infrared (IR) sensors such as the Ozone Monitoring Instrument (OMI), the Ozone Mapping and Profiler Suite (OMPS), and the Atmospheric Infrared Sounder (AIRS), the increased observation frequency afforded by DSCOVR/EPIC will permit more timely volcanic eruption detection, improved trajectory modeling, and novel analyses of the temporal evolution of volcanic clouds. We demonstrate the sensitivity of EPIC UV radiances to volcanic clouds using examples from the first year of EPIC observations including the December 2015 paroxysmal eruption of Etna volcano (Italy). When combined with OMI and OMPS measurements, the EPIC SO2 data permit hourly tracking of the Etna eruption cloud as it drifts away from the volcano. We also describe ongoing efforts to adapt existing UV backscatter (BUV) algorithms to produce operational EPIC SO2 and Ash Index (AI) products.

  12. Ground based measurements of the gas emission from the Holuhraun volcanic fissure eruption on Iceland 2014/2015

    Science.gov (United States)

    Galle, Bo; Arellano, Santiago; Conde, Vladimir; Pfeffer, Melissa; Barsotti, Sara; Stefansdottir, Gerður; Bergsson, Baldur; Bergsson, Bergur; Ingvarsson, Thorgils; Weber, Konradin

    2015-04-01

    The since 31 August 2014 ongoing volcanic eruption at Holuhraun on Iceland is by far the strongest source of sulfur dioxide in Europe over the last 230 years with sustained emission rates exceeding 100 000 ton/day. This gas emission severely affects local population and has become a concern also for air traffic. The eruption has in December continued at constant pace for 3.5 months. Three scenarios are envisaged for the future; (1) the eruption stops, (2) the fissure extends under the Vattnajökul glacier and (3) Bardarbunga volcano erupts. The two later scenarios will cause increased gas emission, severe ash emissions and extended flooding. Under the scope of the EU-project FUTUREVOLC, a project with 3.5 years duration, aiming at making Iceland a supersite for volcanological research as a European contribution to GEO, we are developing a version of the Scanning DOAS instrument that is adapted to high latitudes with low UV radiation and severe meteorological conditions. Since the first day of the eruption several of these novel instruments has been monitoring the SO2 emission from the eruption. Data from our instruments are still after 3.5 months the only sustained ground-based monitoring of this gas emission. A lot of work is however needed to sustain this operation at a very remote site and under severe field conditions. At the same time the very high concentrations in the gas plume, in combination with bad meteorological conditions require the development of novel methods to derive reliable flux estimates. In this presentation we will discuss the instrumental issues and present the latest version of the emission estimates made from our measurements.

  13. Measurement of the Dielectric Properties of Volcanic Scoria and Basalt at 9370 MHz

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yongchun; WANG Shijie; OUYANG Ziyuan; LI Xiongyao

    2005-01-01

    Dielectric data for volcanic scoria and basalt on the earth at microwave frequency are extremely sparse, and also crucial for volcanic terrains imaging, and development. In consideration of their similarity to lunar regolith (soils and rocks) in chemical and mineral composition, the dielectric data is significative for passive and active microwave remote sensing on the Moon. This study provides the data about the dielectric properties of three kinds of scoria and two kinds of basalt in China. The method put forward in this paper is also applicable for measuring the dielectric properties of dry rocks and other granular ground materials with low complex dielectric constants. Firstly, the authors measured the ε' and tanδvalues of strip specimens prepared from the mixture of scoria or basalt powder and polythene with the resonant cavity perturbation method at 9370 MHz. Secondly, from the ε' and tanδ values of the mixture, the ε's and ranδs values of solid scoria and basalt were calculated using Lichtenecker's mixture formulae. Finally, the effective complex dielectric constants, ε'e and tanδe, of scoria at different bulk densities were calculated. The results have shown that the ε's and tancδs values of all solid basaltic materials measured (both solid basaltic scoria or basalt) are approximately 7 and 0.05, respectively. With increasing bulk density of scoria, the ε'e and tanδe values of scoria increase significantly.

  14. Tracking the Kasatochi SO2 plume using the Ensemble Kalman Filter and OMI observations

    Science.gov (United States)

    Vira, Julius; Theys, Nicolas; Sofiev, Mikhail

    2016-04-01

    This paper discusses an application of the Ensemble Kalman Filter (EnKF) data assimilation method in improving prediction of volcanic plumes. Column retrievals of SO2 from the OMI instrument are assimilated into the SILAM chemistry transport model during 8 days following the 2008 eruption of Kasatochi. The analysis ensemble is shown to accurately capture the observed horizontal distribution of the plume, and moreover, comparison with backscatter profiles from the CALIOP instrument indicates that the analysis recovers the vertical distribution of SO2 realistically. The total SO2 burden following the eruption converges to about 2 Tg, which is within the range of previous estimates. The assimilation scheme uses an 80-member ensemble generated by perturbing the source term and the meteorological input data. The SO2 emission flux is sampled from a log-normal probability distribution resulting in large initial spread in the ensemble. A prescribed umbrella profile and a power law relation between the injection height and mass flux are assumed. However, despite the assumptions in the source term perturbations, the analysis ensemble is shown to be capable of reproducing complex, multi-layer SO2 profiles consistent with previous modeling studies on the Kasatochi eruption. The meteorological perturbations are introduced in the form of random time shifts in the input data, which ensures that the input data for each ensemble member remain physically consistent. Including the meteorological perturbations prevents the ensemble spread from decreasing unrealistically as the simulation proceeds, and consequently, the assimilation remains effective in correcting the predictions throughout the simulated period. In conclusion, EnKF is a promising approach for assimilating satellite observations in volcanic plume forecasts. An advantage of the ensemble approach is that model uncertainty, which is often difficult to handle in other schemes, can be included by perturbing the ensemble. A

  15. Assimilating aircraft-based measurements to improve forecast accuracy of volcanic ash transport

    NARCIS (Netherlands)

    Fu, G.; Lin, H.X.; Heemink, A.W.; Segers, A.J.; Lu, S.; Palsson, T.

    2015-01-01

    The 2010 Eyjafjallajökull volcano eruption had serious consequences to civil aviation. This has initiated a lot of research on volcanic ash transport forecast in recent years. For forecasting the volcanic ash transport after eruption onset, a volcanic ash transport and diffusion model (VATDM) needs

  16. Assimilating aircraft-based measurements to improve forecast accuracy of volcanic ash transport

    NARCIS (Netherlands)

    Fu, G.; Lin, H.X.; Heemink, A.W.; Segers, A.J.; Lu, S.; Palsson, T.

    2015-01-01

    The 2010 Eyjafjallajokull volcano eruption had serious consequences to civil aviation. This has initiated a lot of research on volcanic ash transport forecast in recent years. For forecasting the volcanic ash transport after eruption onset, a volcanic ash transport and diffusion model (VATDM) needs

  17. Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in situ measurements

    NARCIS (Netherlands)

    Fu, G.; Heemink, A.; Lu, S.; Segers, A.; Weber, K.; Lin, H.X.

    2016-01-01

    The forecast accuracy of distal volcanic ash clouds is important for providing valid aviation advice during volcanic ash eruption. However, because the distal part of volcanic ash plume is far from the volcano, the influence of eruption information on this part becomes rather indirect and uncertain,

  18. Halogen Chemistry in Volcanic Plumes (Invited)

    Science.gov (United States)

    Roberts, Tjarda

    2017-04-01

    Volcanoes release vast amounts of gases and particles in the atmosphere. Volcanic halogens (HF, HCl, HBr, HI) are co-emitted alongside SO2, and observations show rapid formation of BrO and OClO in the plume as it disperses into the troposphere. The development of 1D and Box models (e.g. PlumeChem) that simulate volcanic plume halogen chemistry aims to characterise how volcanic reactive halogens form and quantify their atmospheric impacts. Following recent advances, these models can broadly reproduce the observed downwind BrO/SO2 ratios using "bromine-explosion" chemistry schemes, provided they use a "high-temperature initialisation" to inject radicals (OH, Cl, Br and possibly NOx) which "kick-start" the low-temperature chemistry cycles that convert HBr into reactive bromine (initially as Br2). The modelled rise in BrO/SO2 and subsequent plateau/decline as the plume disperses downwind reflects cycling between reactive bromine, particularly Br-BrO, and BrO-HOBr-BrONO2. BrCl is produced when aerosol becomes HBr-depleted. Recent model simulations suggest this mechanism for reactive chlorine formation can broadly account for OClO/SO2 reported at Mt Etna. Predicted impacts of volcanic reactive halogen chemistry include the formation of HNO3 from NOx and depletion of ozone. This concurs with HNO3 widely reported in volcanic plumes (although the source of NOx remains under question), as well as observations of ozone depletion reported in plumes from several volcanoes (Mt Redoubt, Mt Etna, Eyjafjallajokull). The plume chemistry can transform mercury into more easily deposited and potentially toxic forms, for which observations are limited. Recent incorporation of volcanic halogen chemistry in a 3D regional model of degassing from Ambrym (Vanuatu) also predicts how halogen chemistry causes depletion of OH to lengthen the SO2 lifetime, and highlights the potential for halogen transport from the troposphere to the stratosphere. However, the model parameter-space is vast and

  19. 76 FR 19661 - Response to Petition From New Jersey Regarding SO2

    Science.gov (United States)

    2011-04-07

    ... technical analysis conducted by EPA. \\1\\ AERMOD stands for the American Meteorological Society... particularly in at-risk populations including children, the elderly and asthmatics. EPA's NAAQS for 1-hour SO 2... . Control measures that reduce SO 2 can generally be expected to reduce people's exposure to all gaseous...

  20. SO2/Hg removal from flue gas by dry FGD

    Institute of Scientific and Technical Information of China (English)

    Wang Fan; Wang Hongmei; Zhang Fan; Zhu Jinwei; Tian Gang; Liu Yu; Mao Jixian

    2012-01-01

    To study the mechanism of SO2 and Hg removal from flue gas,an experimental packed bed reactor was designed to simulate the dry FGD,where a mixture of lime and fly ash in ratio 1∶3 w/w was used as the SO2 and Hg sorbent,and steam at temperature of 100 ℃ was applied for activation of the sorbent,while the activation time set to 20 min.The experimental factors including the SO2/Hg sorbent characteristics,50% breakthrough time for SO2/Hg removal,sorbent packed bed depth and reaction temperature were investigated.The experimental results show that after steam activation,the BET specific surface area and specific pore volume increased from 37.8 to 45.5 m2/g and from 0.42 to 0.51 cm3/g,respectively.With activation of the sorbent by steam,the 50% breakthrough times of SO2 and Hg removal increased from 34 to 42 min and from 23 to 45 min,respectively.When the packed bed depth was increased from 5 to 25 mm,the 50% breakthrough times for Hg and SO2 removal increased from 12 to 52 min and from 6 to 47 min,respectively.With the increase of the reaction temperature,the 50% breakthrough of SO2/Hg removal decreased accordingly.Steam activation can efficiently improve SO2/Hg removal simultaneously.

  1. Efficient SO2 capture by amine functionalized PEG.

    Science.gov (United States)

    Yang, Dezhong; Hou, Minqiang; Ning, Hui; Zhang, Jianling; Ma, Jun; Han, Buxing

    2013-11-07

    Polyethylene glycols (PEGs) are a class of non-toxic, non-volatile, biocompatible, and widely available polymers. In this work, we synthesized N-ethyl-N-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)-2-aminoethanol (EE3AE) that combines the properties of PEG and amines, and N-decyl-N-ethyl-2-aminoethanol (DEAE). Their performances to capture SO2 were studied at different temperatures, pressures, and absorption times. The interaction between the absorbents and SO2 were characterized by NMR and FTIR techniques. It was demonstrated that both EE3AE and DEAE could absorb SO2 efficiently, and there existed chemical and physical interactions between the absorbents and SO2. In particular, the absorption capacity of EE3AE could be as high as 1.09 g SO2 per g EE3AE at 1 atm. The absorption capacity of EE3AE was much larger than that of DEAE because the ether group in the EE3AE interacted with SO2 more strongly than the alkyl group in the DEAE. The SO2 absorbed by EE3AE could be stripped out by bubbling N2 or by applying a vacuum and the EE3AE could be reused. Moreover, both absorbents exhibited a high SO2-CO2 selectivity.

  2. The US SO2 Auction: Analysis and Generalization

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Christensen, J.L.

    1999-01-01

    An annual discriminative and revenue-neutral auction is linked to the new Acid Rain Program which allows electric utilities all over the US to trade SO2 emission permits. This innovative SO2 auction distributes 2% of the permits in circulation and takes place at the Chicago Board of Trade. Early...

  3. The US SO2 Auction: Analysis and Generalization

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Christensen, J.L.

    1999-01-01

    An annual discriminative and revenue-neutral auction is linked to the new Acid Rain Program which allows electric utilities all over the US to trade SO2 emission permits. This innovative SO2 auction distributes 2% of the permits in circulation and takes place at the Chicago Board of Trade. Early...

  4. Revisiting noncovalent So2- amine chemistry: an indicator-displacement assay for colorimetric detection of So2.

    Science.gov (United States)

    Leontiev, Alexander V; Rudkevich, Dmitry M

    2005-10-19

    A supramolecular approach for potential detection of SO2 is presented, which is based on the "old" donor-acceptor chemistry between SO2 and amines and includes an indicator-displacement assay. When amines were added to Zn-tetraphenylporphyrin 1 in CHCl3, the solution changed from red to dark green. A bathochromic shift of Deltalambda approximately 10 nm was observed for the Soret band, indicating the formation of 1*amine complexes. After this, SO2 gas was introduced, and the original red color of the solution was restored. The Soret band returned to its position for free porphyrin 1. The 1*amine complexes dissociated, and new SO2*amine adducts formed. Porphyrin 1 thus served as an indirect colorimetric indicator for SO2. The system discriminates between SO2 and such typical exhaust gases as COX, NOX, and H2O. From the indicator-displacement assay, the Kassoc values between 1000 and 30 000 M-1 for SO2*amine complexes were determined, which are comparable to those obtained by direct titration experiments between SO2 and the amines. Spectroscopic features of SO2*amine complexes are also presented.

  5. Volcanic CO2 flux measurement at Campi Flegrei by tunable diode laser absorption spectroscopy

    Science.gov (United States)

    Pedone, M.; Aiuppa, A.; Giudice, G.; Grassa, F.; Cardellini, C.; Chiodini, G.; Valenza, M.

    2014-04-01

    Near-infrared room temperature tunable diode lasers (TDL) have recently found increased usage in atmospheric chemistry and air monitoring research, but applications in volcanology are still limited to a few examples. Here, we explored the potential of a commercial infrared laser unit (GasFinder 2.0 from Boreal Laser Ltd) for measurement of volcanic CO2 mixing ratios, and ultimately for estimating the volcanic CO2 flux. Our field tests were conducted at Campi Flegrei near Pozzuoli, Southern Italy, where the GasFinder was used during three campaigns in October 2012, January 2013 and May 2013 to repeatedly measure the path-integrated mixing ratios of CO2 along cross sections of the atmospheric plumes of two major fumarolic fields (Solfatara and Pisciarelli). By using a tomographic post-processing routine, we resolved, for each of the two fields, the contour maps of CO2 mixing ratios in the atmosphere, from the integration of which (and after multiplication by the plumes' transport speeds) the CO2 fluxes were finally obtained. We evaluate a total CO2 output from the Campi Flegrei fumaroles of ˜490 Mg/day, in line with independent estimates based on in situ (Multi-GAS) observations. We conclude that TDL technique may enable CO2 flux quantification at other volcanoes worldwide.

  6. Next Generation Aura-OMI SO2 Retrieval Algorithm: Introduction and Implementation Status

    Science.gov (United States)

    Li, Can; Joiner, Joanna; Krotkov, Nickolay A.; Bhartia, Pawan K.

    2014-01-01

    We introduce our next generation algorithm to retrieve SO2 using radiance measurements from the Aura Ozone Monitoring Instrument (OMI). We employ a principal component analysis technique to analyze OMI radiance spectral in 310.5-340 nm acquired over regions with no significant SO2. The resulting principal components (PCs) capture radiance variability caused by both physical processes (e.g., Rayleigh and Raman scattering, and ozone absorption) and measurement artifacts, enabling us to account for these various interferences in SO2 retrievals. By fitting these PCs along with SO2 Jacobians calculated with a radiative transfer model to OMI-measured radiance spectra, we directly estimate SO2 vertical column density in one step. As compared with the previous generation operational OMSO2 PBL (Planetary Boundary Layer) SO2 product, our new algorithm greatly reduces unphysical biases and decreases the noise by a factor of two, providing greater sensitivity to anthropogenic emissions. The new algorithm is fast, eliminates the need for instrument-specific radiance correction schemes, and can be easily adapted to other sensors. These attributes make it a promising technique for producing long-term, consistent SO2 records for air quality and climate research. We have operationally implemented this new algorithm on OMI SIPS for producing the new generation standard OMI SO2 products.

  7. [The effects of SO2 on electric activity learning and memory of rat hippocampal neurons].

    Science.gov (United States)

    Liu, Xiaoli; Yang, Dongsheng; Meng, Ziqiang

    2008-11-01

    To study the toxicological mechanism of SO2 on central neural system by electrophysiological method. Male SD rats were housed in exposure chambers and treated at the concentration of 28 mg/m3 SO2 for 7 days (6h/d), while control rats were treated with filtered air in the same condition. Using glass micro-electrodes recording in vivo, the frequencies and numbers of spontaneous discharge in hippocampal CAI neurons were measured. Influences of the learning and memory functions were measured by setting up passive avoidance behavior reflex. SO2 decreased significantly the neurons spontaneous discharge frequency and prolonged the neurons spontaneous period in hippocampal CAl. SO2 significantly decreased the learning and memory function of rats. The results indicated that SO2 could be a neurotoxin. It could inhibit the hippocampal neurons excitability and affect the learning and memory function of rats.

  8. Thermophilic biofilter for SO2 removal: performance and microbial characteristics.

    Science.gov (United States)

    Zhang, Jingying; Li, Lin; Liu, Junxin

    2015-03-01

    A bench-scale thermophilic biofilter was applied to remove SO2 at 60°C in the present study. The SO2 concentration in the inlet stream ranged from 100mg/m(3) to 200mg/m(3). An average SO2 removal efficiency of 93.10% was achieved after developing acclimated organisms that can degrade SO2. The thermophilic biofilter effectively reduced SO2, with a maximum elimination capacity of 50.67g/m(3)/h at a loading rate of 51.44g/m(3)/h. Removal efficiency of the thermophilic biofilter was largely influenced by the water containing rate of the packing materials. The SO2 transfer in the biofilter included adsorption by the packing materials, dissolution in liquid, and microbial degradation. The main product of SO2 degradation was SO4(2-). The temporal shifts in the bacterial community that formed in the biofilter were determined through polymerase chain reaction-denaturing gradient gel electrophoresis and DNA sequence analysis. These shifts revealed a correlation between biofilter performance and bacterial community structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Guided Dropsonde: Unmanned aerial technology for measuring/sampling volcanic ash plumes in the atmosphere

    Science.gov (United States)

    Wardell, L. J.; Douglas, J.

    2011-12-01

    Given the constraints associated with current airborne host platforms, a technological solution is needed for efficiently obtaining in situ atmospheric data/samples at targeted locations and altitudes for hazardous situations such as volcanic ash clouds. Guided dropsondes have significant implications to advance research requiring in situ atmospheric measurements. Compared to conventional free-fall dropsondes that rely on parachutes, guided dropsondes could offer speed controlled descents combined with loiter abilities therefore yielding time averaged data for a particular region-a feature not currently available with existing dropsonde technology. The guided dropsonde's ability to move to targeted areas of interest gains sensors/samplers an unprecedented level of access to extreme areas and events. With flight controls, the guided system can be retrievable as well as deployed from high altitudes. The system to be presented offers additional advantages over conventional UAVs in regards to aviation and technology transfer restrictions and regulations making rapid deployment possible. For large volcanic eruptions this can become a powerful new tool where few options, if any, currently exist to collect in situ data and/or samples. The most recent results from flight tests and evaluations of the guided dropsonde will be presented.

  10. Assimilating Aircraft-based measurements to improve the State of Distal Volcanic Ash Cloud

    Science.gov (United States)

    Fu, Guangliang; Lin, Hai Xiang; Heemink, Arnold; Segers, Arjo; Lu, Sha; Palsson, Thorgeir

    2015-04-01

    The sudden eruption at the 1666 m high, ice-capped Eyjafjallajökull volcano, in south Iceland during 14 April to 23 May 2010, had caused an unprecedented closure of the European and North Atlantic airspace resulting in global economic losses of US5 billion. This has initiated a lot of research on how to improve aviation advice after eruption onset. Good estimation of both the state of volcanic ash cloud and the emission of volcano are crucial for providing a successful aviation advice. Currently most of the approaches, employing satellite-based and ground-based measurements, are in the focus of improving the definition of Eruption Source Parameters (ESPs) such as plume height and mass eruption rate, which are certainly very important for estimating volcano emission and state of volcanic ash cloud near to the volcano. However, for ash cloud state in a far field, these approaches can hardly make improvements. This is mainly because the influence of ESPs on the ash plume becomes weaker as the distance to the volcano is getting farther, thus for a distal plume the information of ESPs will have little influence. This study aims to find an efficient way to improve the state of distal volcanic ash cloud. We use real-life aircraft-based observations, measured along Dutch border between Borken and Twist during the 2010 Eyjafjallajökull eruption, in an data assimilation system combining with a transport model to identify the potential benefit of this kind of observations and the influence on the ash state around Dutch border. We show that assimilating aircraft-based measurements can significantly improve the state of distal ash clouds, and further provide an improved aviation advice on distal ash plume. We compare the performances of different sequential data assimilation methods. The results show standard Ensemble Kalman Filter (EnKF) works better than others, which is because of the strong nonlinearity of the dynamics and the EnKF's resampling Gaussianity nature

  11. Soil radon measurements as potential tracer of seismic and volcanic activity at Etna

    Science.gov (United States)

    Neri, Marco; Giammanco, Salvatore; Galli, Gianfranco; Ferrera, Elisabetta

    2014-05-01

    Radon is a radioactive noble gas present in all rocks of the Earth. It's used by the scientific community as a tracer of natural phenomena related to outgassing from the soil along faults, fractures and crustal discontinuity. Recently, radon has also been used on active volcanoes such as Etna, both as a precursor of volcanic phenomena as well as in the study of the dynamics of faults. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) performs discrete and continuous measurements of radon from soil at Etna since 2002. First studies concerned measurements of radon and thoron emissions from soil carried out on the E and SW flanks of Etna, in zones characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds, producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. These studies confirmed that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover. INGV permanent radon monitoring network was installed in July 2005. First results were obtained during the July 2006 eruption. The radon signal recorded at Torre del Filosofo (TdF, ~2950 m asl) was compared with volcanic tremor and thermal radiance data. The onset of explosive activity and a lava fountaining episode were preceded by some hours with increases in radon activity and more gradual increases in volcanic tremor. After 2006, Etna produced dozens of paroxysmal episodes from a new vent opened on the eastern flank of the Southeast Crater (summit area), that have built up a new, huge pyroclastic cone. In many cases we observed increase in radon activity some hours before the eruptive events. These observations suggest that radon emissions from the TdF zone are sensitive to the local geodynamic pressure induced by magma dynamics in the conduit systems. Other promising results were

  12. SO2 flux monitoring at Stromboli with the new permanent INGV SO2 camera system: A comparison with the FLAME network and seismological data

    Science.gov (United States)

    Burton, M. R.; Salerno, G. G.; D'Auria, L.; Caltabiano, T.; Murè, F.; Maugeri, R.

    2015-07-01

    We installed a permanent SO2 camera system on Stromboli, Italy, in May 2013, in order to improve our capacity to monitor the SO2 emissions from this volcano. The camera collects images of SO2 concentrations with a period of 10 s, allowing quantification of short-term processes, such as the gas released during the frequent explosions which are synonymous with Stromboli. It also allows quantification of the quiescent gas flux, and therefore comparison with the FLAME network of scanning ultraviolet spectrometers previously installed on the island. Analysis of results from the SO2 camera demonstrated a good agreement with the FLAME network when the plume was blown fully into the field of view of the camera. Permanent volcano monitoring with SO2 cameras is still very much in its infancy, and therefore this finding is a significant step in the use of such cameras for monitoring, whilst also highlighting the requirement of a favourable wind direction and strength. We found that the explosion gas emissions are correlated with seismic events which have a very long period component. There is a variable time lag between event onset time and the increase in gas flux observed by the camera as the explosion gas advects into the field of view of the camera. This variable lag is related to the plume direction, as shown by comparison with the plume location detected with the FLAME network. The correlation between explosion gas emissions and seismic signal amplitude show is consistent with a gas slug-driven mechanism for seismic event production. Comparison of the SO2 camera measurements of the quiescent gas flux shows a fair quantitative agreement with the SO2 flux measured with the FLAME network. Overall, the SO2 camera complements the FLAME network well, as it allows frequent quantification of the explosion gas flux produced by Stromboli, whose signal is in general too brief to be measured with the FLAME network. Further work is required, however, to fully automate the

  13. 非相干光宽带腔增强吸收光谱技术应用于SO2弱吸收的测量%An Incoherent Broadband Optical Cavity Spectroscopy for Measuring Weak Absorption Cross Section of Sulfur Dioxide

    Institute of Scientific and Technical Information of China (English)

    段俊; 秦敏; 方武; 胡仁志; 卢雪; 沈兰兰; 王丹; 谢品华; 刘建国

    2016-01-01

    As a highly sensitive detection technology ,incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) have successfully measured a variety of trace gases .According to the principle of cavity enhanced absorption spectroscopy ,if the accurate concentration of the target gas ,the curve of the mirror reflectance ,effective absorption path length ,the light intensity of the absorbing gas and non-absorbing gas are known ,the absorption cross section of the absorption gas can be measured .The accurate measurements of absorption cross section are necessary for satellite retrievals of atmospheric trace gases and the atmos-pheric research .This paper describes an incoherent broadband cavity enhanced absorption spectroscopy (IBBCEAS) instrument with 365 nm LED as the light source for measuring absorption cross section of SO2 from 357 to 385 nm which is arising from the spin-forbidden a3 B1 — X1 A1 transition .In comparison to the literature absorption cross section of SO 2 ,and correlation coeffi-cient r is 0.997 3 .The result shows the potential of the IBBCEAS system for measuring weak absorption cross section .%非相干光宽带腔增强吸收光谱作为高灵敏检测技术 ,已成功应用于多种大气痕量气体浓度的测量.根据腔增强吸收光谱技术测量原理可知 ,若已知测量气体准确浓度 ,镜片反射率随波长的变化曲线、有效吸收长度、光学腔内有无测量气体吸收前后的光辐射变化 ,可测量出待测气体的吸收截面.SO2 由于 a 3 B1 —X1 A1 自旋禁阻跃迁 ,在345~420 nm波段吸收截面较低(~10-22 cm2/molecule) ,其测量有一定难度 ,而准确的弱吸收截面对于卫星反演大气痕量气体浓度以及大气研究等方面均有重要意义.采用365 nm L ED光源的宽带腔增强吸收光谱实验装置测量357~385 nm波段范围SO2 的弱吸收 ,获得该波段SO2 弱吸收截面 ,并与已公开发表的SO2 吸收截面进行对比 ,相关系数 r为0. 997 3 ,验证

  14. Lessons Learned from OMI Observations of Point Source SO2 Pollution

    Science.gov (United States)

    Krotkov, N.; Fioletov, V.; McLinden, Chris

    2011-01-01

    The Ozone Monitoring Instrument (OMI) on NASA Aura satellite makes global daily measurements of the total column of sulfur dioxide (SO2), a short-lived trace gas produced by fossil fuel combustion, smelting, and volcanoes. Although anthropogenic SO2 signals may not be detectable in a single OMI pixel, it is possible to see the source and determine its exact location by averaging a large number of individual measurements. We describe new techniques for spatial and temporal averaging that have been applied to the OMI SO2 data to determine the spatial distributions or "fingerprints" of SO2 burdens from top 100 pollution sources in North America. The technique requires averaging of several years of OMI daily measurements to observe SO2 pollution from typical anthropogenic sources. We found that the largest point sources of SO2 in the U.S. produce elevated SO2 values over a relatively small area - within 20-30 km radius. Therefore, one needs higher than OMI spatial resolution to monitor typical SO2 sources. TROPOMI instrument on the ESA Sentinel 5 precursor mission will have improved ground resolution (approximately 7 km at nadir), but is limited to once a day measurement. A pointable geostationary UVB spectrometer with variable spatial resolution and flexible sampling frequency could potentially achieve the goal of daily monitoring of SO2 point sources and resolve downwind plumes. This concept of taking the measurements at high frequency to enhance weak signals needs to be demonstrated with a GEOCAPE precursor mission before 2020, which will help formulating GEOCAPE measurement requirements.

  15. Volcanic ash from Iceland over Munich: mass concentration retrieved from ground-based remote sensing measurements

    Science.gov (United States)

    Gasteiger, J.; Gro{ß}, S.; Freudenthaler, V.; Wiegner, M.

    2011-03-01

    Volcanic ash plumes, emitted by the Eyjafjallajökull volcano (Iceland) in spring 2010, were observed by the lidar systems MULIS and POLIS in Maisach (near Munich, Germany), and by a CIMEL Sun photometer and a JenOptik ceilometer in Munich. We retrieve mass concentrations of volcanic ash from the lidar measurements; spectral optical properties, i.e.~extinction coefficients, backscatter coefficients, and linear depolarization ratios, are used as input for an inversion. The inversion algorithm searches for model aerosol ensembles with optical properties that agree with the measured values within their uncertainty ranges. The non-sphericity of ash particles is considered by assuming spheroids. Optical particle properties are calculated using the T-matrix method supplemented by the geometric optics approach. The lidar inversion is applied to observations of the pure volcanic ash plume in the morning of 17 April 2010. We find 1.45 g m-2 for the ratio between the mass concentration and the extinction coefficient at λ = 532 nm, assuming an ash density of 2.6 g cm-3. The uncertainty range for this ratio is from 0.87 g m-2 to 2.32 g m-2. At the peak of the ash concentration over Maisach the extinction coefficient at λ = 532 nm was 0.75 km-1 (1-h-average), which corresponds to a maximum mass concentration of 1.1 mg m-3 (0.65 to 1.8 mg m-3). Model calculations show that particle backscatter at our lidar wavelengths (λ ≤ 1064 nm), and thus the lidar retrieval, is hardly sensitive to large particles (r ≳ 3 μm); large particles, however, may contain significant amounts of mass. Therefore, as an independent cross check of the lidar retrieval and to investigate the presence of large particles in more detail, we model ratios of sky radiances in the aureole of the Sun and compare them to measurements of the CIMEL. These ratios are sensitive to particles up to r ≈ 10 μm. This approach confirms the mass concentrations from the lidar retrieval. We conclude that synergistic

  16. SO2 frost - UV-visible reflectivity and Io surface coverage

    Science.gov (United States)

    Nash, D. B.; Fanale, F. P.; Nelson, R. M.

    1980-01-01

    The reflectance spectrum in the range 0.24-0.85 microns of SO2 frost is measured in light of the discovery of SO2 gas in the atmosphere of Io and the possible discovery of the frost on its surface. Frost deposits up to 1.5 mm thick were grown in vacuum at 130 K and bi-directional reflectance spectra were obtained. Typical SO2 frost is found to exhibit very low reflectivity (2-5%) at 0.30 microns, rising steeply at 0.32 microns to attain a maximum reflectivity (75-80%) at 4.0 microns and uniformly high reflectivity throughout the visible and near infrared. Comparison with the full disk spectrum of Io reveals that no more than 20% of the surface can be covered with optically thick SO2 frost. Combinations of surface materials including SO2 frost which can produce the observed spectrum are indicated.

  17. SO2 frost - UV-visible reflectivity and Io surface coverage

    Science.gov (United States)

    Nash, D. B.; Fanale, F. P.; Nelson, R. M.

    1980-01-01

    The reflectance spectrum in the range 0.24-0.85 microns of SO2 frost is measured in light of the discovery of SO2 gas in the atmosphere of Io and the possible discovery of the frost on its surface. Frost deposits up to 1.5 mm thick were grown in vacuum at 130 K and bi-directional reflectance spectra were obtained. Typical SO2 frost is found to exhibit very low reflectivity (2-5%) at 0.30 microns, rising steeply at 0.32 microns to attain a maximum reflectivity (75-80%) at 4.0 microns and uniformly high reflectivity throughout the visible and near infrared. Comparison with the full disk spectrum of Io reveals that no more than 20% of the surface can be covered with optically thick SO2 frost. Combinations of surface materials including SO2 frost which can produce the observed spectrum are indicated.

  18. Volcanic CO2 mapping and flux measurements at Campi Flegrei by Tunable Diode Laser absorption Spectroscopy

    Science.gov (United States)

    Pedone, Maria; Aiuppa, Alessandro; Giudice, Gaetano; Grassa, Fausto; Chiodini, Giovanni; Valenza, Mariano

    2014-05-01

    Near-infrared room-temperature Tunable Diode Lasers (TDL) have recently found increased usage in atmospheric chemistry and air monitoring research, but applications in Volcanology are still limited to a few examples. Here, we explored the potentiality of a commercial infrared laser unit (GasFinder 2.0 from Boreal Laser Ltd) to measurement of volcanic CO2 flux emissions. Our field tests were conducted at Campi Flegrei (near Pozzuoli, Southern Italy), where the GasFinder was used (during three campaigns in October 2012, January 2013 and May 2013) to repeatedly measure the path-integrated concentrations of CO2 along cross-sections of the atmospheric plumes of the two main fumarolic fields in the area (Solfatara and Pisciarelli). By using ad-hoc designed field-set-up and a tomographic post-processing routine, we resolved, for each of the 2 manifestations, the contour maps of CO2 concentrations in their atmospheric plumes, from the integration of which (and after multiplication by the plumes' transport speeds) the CO2 fluxes were finally obtained [1]. The so-calculated fluxes average of 490 tons/day, which agrees well with independent evaluations of Aiuppa et al. (2013) [2] (460 tons/day on average), and support a significant contribution of fumaroles to the total CO2 budget. The cumulative (fumarole [this study] +soil [2]) CO2 output from Campi Flegrei is finally evaluated at 1600 tons/day. The application of lasers to volcanic gas studies is still an emerging (though intriguing) research field, and requires more testing and validation experiments. We conclude that TDL technique may valuably assist CO2 flux quantification at a number of volcanic targets worldwide. [1] Pedone M. et al. (2013) Gold2013:abs:5563, Goldschmidt Conference, session 11a. [2] Aiuppa A. et al. (2013) Geochemistry Geophysics Geosystems. doi: 10.1002/ggge.20261. [3] Chiodini G. et al. (2010) Journal of Geophysical Research, Volume 115, B03205. doi:10.1029/2008JB006258.

  19. Imaging trace gases in volcanic plumes with Fabry Perot Interferometers

    Science.gov (United States)

    Kuhn, Jonas; Platt, Ulrich; Bobrowski, Nicole; Lübcke, Peter; Wagner, Thomas

    2017-04-01

    Within the last decades, progress in remote sensing of atmospheric trace gases revealed many important insights into physical and chemical processes in volcanic plumes. In particular, their evolution could be studied in more detail than by traditional in-situ techniques. A major limitation of standard techniques for volcanic trace gas remote sensing (e.g. Differential Optical Absorption Spectroscopy, DOAS) is the constraint of the measurement to a single viewing direction since they use dispersive spectroscopy with a high spectral resolution. Imaging DOAS-type approaches can overcome this limitation, but become very time consuming (of the order of minutes to record a single image) and often cannot match the timescales of the processes of interest for volcanic gas measurements (occurring at the order of seconds). Spatially resolved imaging observations with high time resolution for volcanic sulfur dioxide (SO2) emissions became possible with the introduction of the SO2-Camera. Reducing the spectral resolution to two spectral channels (using interference filters) that are matched to the SO2 absorption spectrum, the SO2-Camera is able to record full frame SO2 slant column density distributions at a temporal resolution on the order of BrO) and chlorine dioxide (OClO) both yield absorption features that allow their detection with the FPI correlation technique. From BrO and OClO data, ClO levels in the plume could be calculated. We present an outline of applications of the FPI technique to imaging a series of trace gases in volcanic plumes. Sample calculations on the sensitivity and selectivity of the technique, first proof of concept studies and proposals for technical implementations are presented.

  20. Short-time electrical effects during volcanic eruption: Experiments and field measurements

    Science.gov (United States)

    Büttner, Ralf; Zimanowski, Bernd; Röder, Helmut

    2000-02-01

    Laboratory experiments on the fragmentation and expansion of magmatic melt have been performed using remelted volcanic rock at magmatic temperatures as magma simulant. A specially designed dc amplifier in combination with high speed data recording was used to detect short-time electrostatic field effects related to the fragmentation and expansion history of the experimental system, as documented by simultaneous force and pressure recording, as well as by high-speed cinematography. It was found that (1) the voltage-time ratio of electrostatic field gradients (100 to 104 V/s) reflects different physical mechanisms of fragmentation and expansion and (2) the maximum voltage measured in 1 m distance (-0.1 to -180 V) can be correlated with the intensity of the respective processes. Based on these experimental results, a field method was developed and tested at Stromboli volcano in Italy. A 0.8 m rod antenna was used to detect the dc voltage against local ground (i.e., the electrostatic field gradient), at a distance of 60 to 260 m from the respective vent. Upwind position of the detection site was chosen to prevent interference caused by contact of charged ash particles with the antenna. A standard 8 Hz geophone was used to detect the accompanying seismicity. Three types of volcanic activity occurred during the surveillance operation; two of these could be clearly related to specific electrical and seismical signals. A typical delay time was found between the electrical and the seismical signal, corresponding to the seismic velocity within the crater deposits. Using a simple first-order electrostatic model, the field measurements were recalibrated to the laboratory scale. Comparison of field and laboratory data at first approximation revealed striking similarities, thus encouraging the further development of this technique for real-time surveillance operation at active volcanoes.

  1. Summit CO2 emission rates by the CO2/SO2 ratio method at Kīlauea Volcano, Hawaiʻi, during a period of sustained inflation

    Science.gov (United States)

    Hager, S.A.; Gerlach, T.M.; Wallace, P.J.

    2008-01-01

    The emission rate of carbon dioxide escaping from the summit of Kīlauea Volcano, Hawaiʻi, proved highly variable, averaging 4900 ± 2000 metric tons per day (t/d) in June–July 2003 during a period of summit inflation. These results were obtained by combining over 90 measurements of COSPEC-derived SO2emission rates with synchronous CO2/SO2 ratios of the volcanic gas plume along the summit COSPEC traverse. The results are lower than the CO2 emission rate of 8500 ± 300 t/d measured by the same method in 1995–1999 during a period of long-term summit deflation [Gerlach, T.M., McGee, K.A., Elias, T., Sutton, A.J. and Doukas, M.P., 2002. Carbon dioxide emission rate of Kīlauea Volcano: Implications for primary magma and the summit reservoir. Journal of Geophysical Research-Solid Earth, 107(B9): art. no.-2189.]. Analysis of the data indicates that the emission rates of the present study likely reflect changes in the magma supply rate and residence time in the summit reservoir. It is also likely that emission rates during the inflation period were heavily influenced by SO2 pulses emitted adjacent to the COSPEC traverse, which biased CO2/SO2 ratios towards low values that may be unrepresentative of the global summit gas plume. We conclude that the SO2 pulses are consequences of summit re-inflation under way since 2003 and that CO2 emission rates remain comparable to, but more variable than, those measured prior to re-inflation.

  2. What do we need to know to model the microphysical evolution of volcanic clouds and how can we make these measurements?

    Science.gov (United States)

    English, J. M.; Toon, O. B.; Mills, M. J.

    2015-12-01

    Large volcanic eruptions can inject millions of tons of ash, sulfate and gaseous precursors into the stratosphere. The magnitude and duration of the volcanic cloud on Earth's temperatures, circulation, clouds, and stratospheric ozone is strongly affected by the microphysical properties of the aerosol size distribution, which can evolve in complex ways. This presentation will cover the impacts and uncertainties associated with microphysical aerosol measurements and modeling of the 1991 Mount Pinatubo eruption, and valuable future measurements after the next large volcanic eruption. These additional measurements can help improve our understanding of stratospheric processes as well as possible consequences of large volcanic eruptions and hypothetical geoengineering scenarios on radiative forcing and chemistry.

  3. Inhibition of photosynthesis and leaf conductance interactions induced by SO 2, NO 2 and SO 2 + NO 2

    Science.gov (United States)

    Bennett, Jesse H.; Lee, Edward H.; Heggestad, Howard E.

    Effects of 2-h exposures to 0-1 μmol mol -1 SO 2, NO 2 and (1:1) SO 2 + NO 2 on CO 2 uptake by standardized snap bean leaves were studied. Interactions resulting from pollutant-induced changes in leaf conductance were evaluated. Minimum exposure concentrations required to depress CO 2 exchange rates (CER) under the test conditions were:0.17 μmol mol -1 SO 2, 0.38 μmol mol -1 NO 2, and 0.08 μmol mol -1 of each pollutant in the 1:1 mixture. Treatments with 1 μmol mol -1 NO 2 reduced CER 10% without affecting leaf conductance. One μmol mol -1 SO 2 depressed CER by 50%. Leaf conductances increased in SO 2-treated leaves showing 30% inhibition of CER. Greater inhibition led to subsequent stomatal closure. Inhibition caused by the individual pollutants (applied singly) was linear over the range of concentrations investigated. The dual-pollutant mixture produced a synergistic response that was most pronounced at the lower pollutant concentrations. The potentiated effect was correlated with marked stomatal closure. Experimental plants for this study were grown under low moisture stress conditions to enhance stomatal opening in the plant stock material and reduce (damp) the potential for further SO 2-induced stimulation of stomatal opening. The experiments were designed to obtain limiting data for the test conditions.

  4. Characterizing Volcanic Eruptions on Venus: Some Realistic (?) Scenarios

    Science.gov (United States)

    Stofan, E. R.; Glaze, L. S.; Grinspoon, D. H.

    2011-01-01

    When Pioneer Venus arrived at Venus in 1978, it detected anomalously high concentrations of SO2 at the top of the troposphere, which subsequently declined over the next five years. This decline in SO2 was linked to some sort of dynamic process, possibly a volcanic eruption. Observations of SO2 variability have persisted since Pioneer Venus. More recently, scientists from the Venus Express mission announced that the SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument had measured varying amounts of SO2 in the upper atmosphere; VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) measured no similar variations in the lower atmosphere (ESA, 4 April, 2008). In addition, Fegley and Prinn stated that venusian volcanoes must replenish SO2 to the atmosphere, or it would react with calcite and disappear within 1.9 my. Fegley and Tremain suggested an eruption rate on the order of approx 1 cubic km/year to maintain atmospheric SO2; Bullock and Grinspoon posit that volcanism must have occurred within the last 20-50 my to maintain the sulfuric acid/water clouds on Venus. The abundance of volcanic deposits on Venus and the likely thermal history of the planet suggest that it is still geologically active, although at rates lower than Earth. Current estimates of resurfacing rates range from approx 0.01 cubic km/yr to approx 2 cubic km/yr. Demonstrating definitively that Venus is still volcanically active, and at what rate, would help to constrain models of evolution of the surface and interior, and help to focus future exploration of Venus.

  5. Photochemistry in Terrestrial Exoplanet Atmospheres II: H2S and SO2 Photochemistry in Anoxic Atmospheres

    CERN Document Server

    Hu, Renyu; Bains, William

    2013-01-01

    Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H2S and SO2) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative transfer model to investigate the sulfur chemistry in atmospheres ranging from reducing to oxidizing. The most important finding is that both H2S and SO2 are chemically short-lived in virtually all types of atmospheres on terrestrial exoplanets, based on models of H2, N2, and CO2 atmospheres. This implies that direct detection of surface sulfur emission is unlikely, as their surface emission rates need to be extremely high (>1000 times Earth's volcanic sulfur emission) for these gases to build up to a detectable level. We also find that sulfur compounds emitted from the surface lead to photochemical formation of element...

  6. Volcanic Event Layers-A Marker Bed of Correlation of Coal Measures

    Institute of Scientific and Technical Information of China (English)

    贾炳文; 周安朝; 马美玲; 贾晓云

    2001-01-01

    Upper Carboniferous-Lower Permian volcanic event deposits from two cross sections in Nanpiao, Liaoning Province, and the Daqing Mountains, Inner Mongolia, were examined by systematic rock and mineral identification, differential thermal analysis, X-ray diffraction, scanning electron microscopy and trace element and rare earth element quantitative analysis. According to the results, twelve sequences of volcanic event deposits have been distinguished from bottom to top, including 34?9 volcanic event layers. As these layers each have their own distinctive petrological, mineralogical and geochemical characteristics and were derived from the same source, they provide new evidence for further ascertaining the distribution characteristics of volcanic event deposits on the northern margin of the North China plate and carrying out the stratigraphic correlation using volcanic event layers as marker beds.

  7. SO2 oxidation catalyst model systems characterized by thermal methods

    DEFF Research Database (Denmark)

    Hatem, G; Eriksen, Kim Michael; Gaune-Escard, M;

    2002-01-01

    The molten salts M2S2O7 and MHSO4, the binary molten salt Systems M2S2O7-MHSO4 and the molten salt-gas systems M2S2O7 V2O5 and M2S2O7-M2SO4 V2O5 (M = Na, K, Rb, Cs) in O-2, SO2 and At atmospheres have been investigated by thermal methods like calorimetry, Differential Enthalpic Analysis (DEA) and...... to the mechanism Of SO2 oxidation by V2O5 based industrial catalysts....

  8. A new quantum so(2,2) algebra

    OpenAIRE

    Herranz, Francisco J.

    1999-01-01

    By starting from the non-standard quantum deformation of the sl(2,R) algebra, a new quantum deformation for the real Lie algebra so(2,2) is constructed by imposing the former to be a Hopf subalgebra of the latter. The quantum so(2,2) algebra so obtained is realized as a quantum conformal algebra of the (1+1) Minkowskian spacetime. This Hopf algebra is shown to be the symmetry algebra of a time discretization of the (1+1) wave equation and its contraction gives rise to a new $(2+1)$ quantum Po...

  9. Regional climate responses to geoengineering with tropical and Arctic SO2 injections

    Science.gov (United States)

    Robock, Alan; Oman, Luke; Stenchikov, Georgiy L.

    2008-08-01

    Anthropogenic stratospheric aerosol production, so as to reduce solar insolation and cool Earth, has been suggested as an emergency response to geoengineer the planet in response to global warming. While volcanic eruptions have been suggested as innocuous examples of stratospheric aerosols cooling the planet, the volcano analog actually argues against geoengineering because of ozone depletion and regional hydrologic and temperature responses. To further investigate the climate response, here we simulate the climate response to both tropical and Arctic stratospheric injection of sulfate aerosol precursors using a comprehensive atmosphere-ocean general circulation model, the National Aeronautics and Space Administration Goddard Institute for Space Studies ModelE. We inject SO2 and the model converts it to sulfate aerosols, transports the aerosols and removes them through dry and wet deposition, and calculates the climate response to the radiative forcing from the aerosols. We conduct simulations of future climate with the Intergovernmental Panel on Climate Change A1B business-as-usual scenario both with and without geoengineering and compare the results. We find that if there were a way to continuously inject SO2 into the lower stratosphere, it would produce global cooling. Tropical SO2 injection would produce sustained cooling over most of the world, with more cooling over continents. Arctic SO2 injection would not just cool the Arctic. Both tropical and Arctic SO2 injection would disrupt the Asian and African summer monsoons, reducing precipitation to the food supply for billions of people. These regional climate anomalies are but one of many reasons that argue against the implementation of this kind of geoengineering.

  10. Alkali-Alumina Sorbents for Regenerable SO_2 Removal in Fluidized-Coal Combustion

    OpenAIRE

    Gavalas, George R.; Weston, Theresa A.; Stephanopoulos, Maria F.

    1985-01-01

    Sodium and sodium-lithium oxides supported on porous alumina have been investigated as regenerable SO_2 sorbents for fluidized coal combustion. In adsorption the oxides are converted to sulfates. In regeneration, carried out by reduction with CO, the sulfates are converted back to oxides while sulfur is removed in elemental form (S_2), SO_2 and COS. The transient composition of sorbent and gaseous products was measured in a thermogravimetric analyzer and a packed-bed microreactor in order to ...

  11. A global catalogue of large SO2 sources and emissions derived from the Ozone Monitoring Instrument

    OpenAIRE

    Fioletov, Vitali E.; McLinden, Chris A; Krotkov, Nickolay; Li, Can; Joiner, Joanna; Theys, Nicolas; Carn, Simon; Moran, Mike D.

    2016-01-01

    Sulfur dioxide (SO2) measurements from the Ozone Monitoring Instrument (OMI) satellite sensor processed with the new principal component analysis (PCA) algorithm were used to detect large point emission sources or clusters of sources. The total of 491 continuously emitting point sources releasing from about 30 kt yr−1 to more than 4000 kt yr−1 of SO2 per year have been identified and grouped by country and by primary source origin: volcanoes (76 sources); power plants (297);...

  12. A global catalogue of large SO2 sources and emissions derived from the Ozone Monitoring Instrument

    OpenAIRE

    Fioletov, Vitali E.; McLinden, Chris A; Krotkov, Nickolay; Li, Can; Joiner, Joanna; Theys, Nicolas; Carn, Simon; Moran, Mike D.

    2016-01-01

    Sulphur dioxide (SO2) measurements from the Ozone Monitoring Instrument (OMI) satellite sensor processed with the new Principal Component Analysis (PCA) algorithm were used to detect large point emission sources or clusters of sources. The total of 491 continuously emitting point sources releasing from about 30 kt yr−1 to more than 4000 kt yr−1 of SO2 per year have been identified and grouped by country and by primary source origin: volcanoes (76 sources); power plants (297); smel...

  13. Sulfation of Condensed Potassium Chloride by SO2

    DEFF Research Database (Denmark)

    Sengeløv, Louise With; Hansen, Troels Bruun; Bartolomé, Carmen;

    2013-01-01

    The interaction between alkali chloride and sulfur oxides has important implications for deposition and corrosion in combustion of biomass. In the present study, the sulfation of particulate KCl (90–125 μm) by SO2 was studied in a fixed bed reactor in the temperature range 673–1023 K and with rea...

  14. Gas-phase SO2 in absorption towards massive protostars

    NARCIS (Netherlands)

    Keane, JV; Boonman, AMS; Tielens, AGGM; van Dishoeck, EF; Dishoeck, E. F.; Lahuis, F. van; Wright, C. M.; Doty, S. D.

    2001-01-01

    We present the first detection of the v(3) ro-vibrational band of gas-phase SO2 in absorption in the mid-infrared spectral region around 7.3 mum of a sample of deeply embedded massive protostars. Comparison with model spectra shows that the derived excitation temperatures correlate with previous C2H

  15. SO2 : Nutrient or toxin for Chinese cabbage

    NARCIS (Netherlands)

    Yang, Liping

    2005-01-01

    Chinese cabbage (Brassica pekinensis) is one of the most important high-yield vegetable crops in China, and is often cultivated around big cities. Atmospheric SO2 pollution may affect Chinese cabbage, which is usually produced under intensive farming practice with low-sulfur or even sulfur-free fert

  16. Spatially resolved SO2 flux emissions from Mt Etna

    Science.gov (United States)

    Bitetto, M.; Delle Donne, D.; Tamburello, G.; Battaglia, A.; Coltelli, M.; Patanè, D.; Prestifilippo, M.; Sciotto, M.; Aiuppa, A.

    2016-01-01

    Abstract We report on a systematic record of SO2 flux emissions from individual vents of Etna volcano (Sicily), which we obtained using a permanent UV camera network. Observations were carried out in summer 2014, a period encompassing two eruptive episodes of the New South East Crater (NSEC) and a fissure‐fed eruption in the upper Valle del Bove. We demonstrate that our vent‐resolved SO2 flux time series allow capturing shifts in activity from one vent to another and contribute to our understanding of Etna's shallow plumbing system structure. We find that the fissure eruption contributed ~50,000 t of SO2 or ~30% of the SO2 emitted by the volcano during the 5 July to 10 August eruptive interval. Activity from this eruptive vent gradually vanished on 10 August, marking a switch of degassing toward the NSEC. Onset of degassing at the NSEC was a precursory to explosive paroxysmal activity on 11–15 August.

  17. Cost-effective control of SO2 emissions in Asia

    NARCIS (Netherlands)

    Cofala, J.; Amann, M.; Gyarfas, F.; Schoepp, F.; Boudri, J.C.; Hordijk, L.; Kroeze, C.; Li Junfeng,; Dai Lin, D.; Panwar, T.S.; Gupta, S.

    2004-01-01

    Despite recent efforts to limit the growth of SO2 emissions in Asia, the negative environmental effects of sulphur emissions are likely to further increase in the future. This paper presents an extension of the RAINS-Asia integrated assessment model for acidification in Asia with an optimisation rou

  18. SO2 : Nutrient or toxin for Chinese cabbage

    NARCIS (Netherlands)

    Yang, Liping

    2005-01-01

    Chinese cabbage (Brassica pekinensis) is one of the most important high-yield vegetable crops in China, and is often cultivated around big cities. Atmospheric SO2 pollution may affect Chinese cabbage, which is usually produced under intensive farming practice with low-sulfur or even sulfur-free

  19. Analyse van hemellichtspectra op aanwezigheid van SO2

    NARCIS (Netherlands)

    Tromp; F.*

    1984-01-01

    Vergeleken worden de Barringer hardware en OMA software correlatiespectrometers ter bepaling van atmosferische SO2-gaslasten. De softwaremethode is te prefereren boven de hardware, omdat: a) de software methode een betrouwbaarheidsgrens voor de geschatte gaslast heeft. b) de software methode in

  20. The US SO2 Auction and Environmental Regulation

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Christensen, J.L.

    1999-01-01

    The US Acid Rain Program (ARP) is now well-established. The ARP relies on tradable permits and includes an annual revenue-neutral SO2 auction. Has this auction been an important factor in establishing low transaction costs and a successful market? In answering this question, we first compare...

  1. The US SO2 Auction and Environmental Regulation

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard; Christensen, J.L.

    1999-01-01

    The US Acid Rain Program (ARP) is now well-established. The ARP relies on tradable permits and includes an annual revenue-neutral SO2 auction. Has this auction been an important factor in establishing low transaction costs and a successful market? In answering this question, we first compare...

  2. Reaction of SO2 with OH in the atmosphere.

    Science.gov (United States)

    Long, Bo; Bao, Junwei Lucas; Truhlar, Donald G

    2017-03-15

    The OH + SO2 reaction plays a critical role in understanding the oxidation of SO2 in the atmosphere, and its rate constant is critical for clarifying the fate of SO2 in the atmosphere. The rate constant of the OH + SO2 reaction is calculated here by using beyond-CCSDT correlation energy calculations for a benchmark, validated density functional methods for direct dynamics, canonical variational transition state theory with anharmonicity and multidimensional tunneling for the high-pressure rate constant, and system-specific quantum RRK theory for pressure effects; the combination of these methods can compete in accuracy with experiments. There has been a long-term debate in the literature about whether the OH + SO2 reaction is barrierless, but our calculations indicate a positive barrier with an transition structure that has an enthalpy of activation of 0.27 kcal mol(-1) at 0 K. Our results show that the high-pressure limiting rate constant of the OH + SO2 reaction has a positive temperature dependence, but the rate constant at low pressures has a negative temperature dependence. The computed high-pressure limiting rate constant at 298 K is 1.25 × 10(-12) cm(3) molecule(-1) s(-1), which agrees excellently with the value (1.3 × 10(-12) cm(3) molecule(-1) s(-1)) recommended in the most recent comprehensive evaluation for atmospheric chemistry. We show that the atmospheric lifetime of SO2 with respect to oxidation by OH depends strongly on altitude (in the range 0-50 km) due to the falloff effect. We introduce a new interpolation procedure for fitting the combined temperature and pressure dependence of the rate constant, and it fits the calculated rate constants over the whole range with a mean unsigned error of only 7%. The present results provide reliable kinetics data for this specific reaction, and also they demonstrate convenient theoretical methods that can be reliable for predicting rate constants of other gas-phase reactions.

  3. The fast oxidation of SO2 in oil sands regions of Alberta,Canada

    Science.gov (United States)

    Amiri, N.; Norman, A. L.

    2016-12-01

    Secondary aerosols in the atmosphere play a significant role in the Earth's radiation budget and in human health. It is important to understand how secondary aerosols are formed. Atmospheric SO2 oxidation leads to secondary sulfate aerosols. The SO2 oxidation rate needs to be well defined to better understand aerosols and their effects and oxidation varies depending on the oxidants present. This research presents the results of a field campaign from 13 Aug to 5 Sep 2013 at the Wood Buffalo Air Monitoring Station 13 (AMS13) site just south of Fort MacKay, in which two lines of evidence show fast oxidation of SO2 in the region. Size-segregated sulfate aerosols and SO2 gas were collected on microfiber glass filters and filters treated by K2CO3 and glycerin respectively. The sulfur isotopic composition of sulfate aerosols and SO2 were measured. Periods when a nearby instrument was in operation (20m away), displayed markedly distinct d34S values from periods when it was not operational. The nearby instrument used enriched 34SO2, and this affected the resulting d34S values for all sulfate size fractions but not SO2 from our high volume sampler. The most pronounced contamination was observed for sulfate aerosols Dambient tracer experiment in the Oil Sands region, and that this SO2 was oxidized before reaching the high volume sampler. The results from our study show that SO2 oxidation in the Oil Sands regions in the presence of pollutants such as hydrocarbons is rapid.

  4. Volcanic hazard management in dispersed volcanism areas

    Science.gov (United States)

    Marrero, Jose Manuel; Garcia, Alicia; Ortiz, Ramon

    2014-05-01

    Traditional volcanic hazard methodologies were developed mainly to deal with the big stratovolcanoes. In such type of volcanoes, the hazard map is an important tool for decision-makers not only during a volcanic crisis but also for territorial planning. According to the past and recent eruptions of a volcano, all possible volcanic hazards are modelled and included in the hazard map. Combining the hazard map with the Event Tree the impact area can be zoned and defining the likely eruptive scenarios that will be used during a real volcanic crisis. But in areas of disperse volcanism is very complex to apply the same volcanic hazard methodologies. The event tree do not take into account unknown vents, because the spatial concepts included in it are only related with the distance reached by volcanic hazards. The volcanic hazard simulation is also difficult because the vent scatter modifies the results. The volcanic susceptibility try to solve this problem, calculating the most likely areas to have an eruption, but the differences between low and large values obtained are often very small. In these conditions the traditional hazard map effectiveness could be questioned, making necessary a change in the concept of hazard map. Instead to delimit the potential impact areas, the hazard map should show the expected behaviour of the volcanic activity and how the differences in the landscape and internal geo-structures could condition such behaviour. This approach has been carried out in La Palma (Canary Islands), combining the concept of long-term hazard map with the short-term volcanic scenario to show the expected volcanic activity behaviour. The objective is the decision-makers understand how a volcanic crisis could be and what kind of mitigation measurement and strategy could be used.

  5. Study on SO2 Emission Mitigation of Thermal Power Plants in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    With the rapid development of electricity production, SO2 from coal-fired power stations causes severe air pollution problem. In 1997, the SO2 emitted from thermal power plants reached 7.0 Mt, accounting for about 33% of the national emissions. At present and in the future, thermal power stations will still be the primary pollution sources. The Chinese government and power departments accord considerable importance to the SO2 emissions from thermal power plants. New sets of environmentally friendly policies have been formulated. But, enforcement of laws and regulations needs to be further improved and broadened, especially those responding to market conditions. This paper focuses particular attention on the analysis of strategy, policies, and measures that have been or should be taken against SO2 emissions from thermal power plants so as to achieve the environmental protection targets, on the basis of which the technical options for the future are given.

  6. Formation of Nanodroplets in N2/H2O/SO2 under Irradiation of Fast Proton Beams

    DEFF Research Database (Denmark)

    Nakai, Youchi; Shigeoka, Tomita; Funada, Shuhei

    of the droplet growth in thebinary nucleation process of water and H2SO4.We have performed irradiation of proton beam on the gas mixture of N2/H2O/SO2 andAir/H2O/SO2. The reduction of SO2 concentration by beam irradiation was monitored usingan SO2 meter and the size distributions of generated droplets were...... measured with adifferential mobility analyzer. We found that the mass yield of generated droplets showedlinear dependence on the amount of SO2 oxidation. This behavior is different from binarynucleation theory of water and H2SO4. The difference might indicates importance ofconsidering the droplet formation...

  7. Low SO2 Emission Preheaters for Cement Production

    DEFF Research Database (Denmark)

    Rasmussen, Martin Hagsted

    in this thesis has been to produce CaO with a large surface area in order to increase the absorption of SO2. For this purpose flash calcination of CaCO3, calcination under vacuum, calcination in a fixed bed and a fluid bed has been tested between 650 °C and 850 °C. The results showed that flash calcination...... reaction between SO2 and CaO is so fast that the observed rates exclusively are determined by solid state diffusion in the product layer of the non-porous CaO grains. An activation energy of 115 kJ/mole was found to fit all CaO sources very well, even though data fitting by the least sum of squares method...

  8. Effect of airborne particle on SO 2-calcite reaction

    Science.gov (United States)

    Böke, Hasan; Göktürk, E. Hale; Caner-Saltık, Emine N.; Demirci, Şahinde

    1999-02-01

    In modern urban atmosphere, sulphur dioxide (SO 2) attacks calcite (CaCO 3) in calcareous stone-producing gypsum (CaSO 4·2H 2O) which forms crust at rain sheltered surfaces and accelerates erosion at areas exposed to rain. The airborne particles collected on stone surfaces have always been considered to enhance the gypsum crust formation and thus it is believed that they should be removed from the surface to decrease the effects of SO 2. In this study, our aim was to investigate this event by carrying out a series of experiments in laboratory using pure calcium carbonate powder to represent calcareous stone. Sodium montmorillonite, activated carbon, ferric oxide, vanadium pentoxide and cupric chloride were mixed in the pure calcium carbonate powder as substitutes of the airborne particles in the polluted atmosphere. The samples have been exposed at nearly 10 ppmv SO 2 concentrations at 90% relative humidity conditions in a reaction chamber for several days. The mineralogical composition of the exposed samples were determined by X-ray diffraction (XRD) analysis and infrared spectrometer (IR). Sulphation reaction products, calcium sulphite hemihydrate, gypsum and unreacted calcite, were determined quantitatively using IR. Exposed samples have also been investigated morphologically using a scanning electron microscope (SEM). Experimental results reveal that calcium sulphite hemihydrate is the main reaction product of the SO 2-calcite reaction. It turns out that airborne particles play an important catalytic role in the oxidation of calcium sulphite hemihydrate into gypsum, although their presence does not very significantly affect the extent of sulphation reaction. This behaviour of airborne particles is explained by the presence of liquid film on the calcium carbonate surface where a series of reactions in the gas-liquid-solid interfaces takes place.

  9. Retrieval columns of SO2 in industrial chimneys using DOAS passive in traverse

    Science.gov (United States)

    Galicia Mejía, Rubén; de la Rosa Vázquez, José Manuel; Sosa Iglesias, Gustavo

    2011-10-01

    The optical Differential Optical Absorption Spectroscopy (DOAS) is a technique to measure pollutant emissions like SO2, from point sources and total fluxes in the atmosphere. Passive DOAS systems use sunlight like source. Measurements with such systems can be made in situ and in real time. The goal of this work is to report the implementation of hardware and software of a portable system to evaluate the pollutants emitted in the atmosphere by industrial chimneys. We show SO2 measurements obtained around PEMEX refinerys in Tula Hidalgo that enables the identification of their pollution degree with the knowledge of speed wind.

  10. Effect of SO2 Dry Deposition on Porous Dolomitic Limestones

    Science.gov (United States)

    Olaru, Mihaela; Aflori, Magdalena; Simionescu, Bogdana; Doroftei, Florica; Stratulat, Lacramioara

    2010-01-01

    The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain) used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100) and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA) were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.

  11. Effect of SO2 Dry Deposition on Porous Dolomitic Limestones

    Directory of Open Access Journals (Sweden)

    Florica Doroftei

    2010-01-01

    Full Text Available The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100 and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.

  12. Catalytic Activity and Deactivation of SO2 Oxidation Catalysts in Simulated Power Plant Flue Gases

    DEFF Research Database (Denmark)

    Masters, Stephen G.; Chrissanthopoulos, Asthanassios; Eriksen, Kim Michael

    1997-01-01

    The catalyst deactivation and the simultaneious formation of compounds in commercial SO2 oxidation catalysts have been studied by combined activity measurements and in situ EPR spectroscopy in the temperature range 350-480 C in wet and dry simulated power plant flue gas.......The catalyst deactivation and the simultaneious formation of compounds in commercial SO2 oxidation catalysts have been studied by combined activity measurements and in situ EPR spectroscopy in the temperature range 350-480 C in wet and dry simulated power plant flue gas....

  13. Composition of volcanic gases emitted during repeating Vulcanian eruption stage of Shinmoedake, Kirishima volcano, Japan

    Science.gov (United States)

    Shinohara, H.

    2013-06-01

    Volcanic gas compositions of Shinmoedake, Kirishima volcano, Japan were measured by Multi-GAS during the persistent degassing period with repeating Vulcanian eruptions from March 2011 to March 2012. In order to avoid risks due to eruptions, the measurements were performed with the Unmanned Aerial Vehicles (UAV) that fly through the plume with the Multi-GAS and by an automatic Multi-GAS monitoring station installed 5 km away from the summit. Based on the UAV measurements on May 18, 2011, most of the major volcanic gas components were quantified as CO2/SO2 = 8, SO2/H2S = 0.8, H2O/CO2 = 70 and H2/SO2 = 0.03 (mol ratio), and the SO2/H2S ratio of the plume was quantified as 8 on March 15, 2011. The Multi-GAS monitoring station occasionally detected a dilute plume with an SO2/H2S ratio ranging from 0.8 to 3.3 from April 2011 to March 2012. The decrease of the SO2/H2S ratio from March 15, 2011, to May 18, 2011, is interpreted as the result of a ten times increase of the degassing pressure. Based on the SO2 fluxes and the gas compositions, the conduit magma convection is considered to be the gas supply mechanism at the Shinmoedake, and the degassing pressure changes are attributed to the change of depth of the convecting magma column top.

  14. Calculated rate constants of the chemical reactions involving the main byproducts SO2F, SOF2, SO2F2 of SF6 decomposition in power equipment

    Science.gov (United States)

    Fu, Yuwei; Rong, Mingzhe; Yang, Kang; Yang, Aijun; Wang, Xiaohua; Gao, Qingqing; Liu, Dingxin; Murphy, Anthony B.

    2016-04-01

    SF6 is widely used in electrical equipment as an insulating gas. In the presence of an electric arc, partial discharge (PD) or spark, SF6 dissociation products (such as SF2, SF3 and SF4) react with the unavoidable gas impurities (such as water vapor and oxygen), electrodes and surrounding solid insulation materials, forming several toxic and corrosive byproducts. The main stable decomposition products are SO2F, SO2F2 and SOF2, which have been confirmed experimentally to have a direct relationship with discharge faults, and are thus expected to be useful in the fault diagnosis of power equipment. Various studies have been performed of the main SF6 decomposition species and their concentrations under different types of faults. However, most of the experiments focused on the qualitative analysis of the relationship between the stable products and discharge faults. Although some theoretical research on the formation of main SF6 derivatives have been carried out using chemical kinetics models, the basic data (chemical reactions and their rate constants) adopted in the model are inaccurate and incomplete. The complex chemical reactions of SF6 with the impurities are ignored in most cases. The rate constants of some reactions obtained at ambient temperature or in a narrow temperature range are adopted in the models over a far greater range, for example up to 12 000 K, due to the difficulty in the experimental measurement and theoretical estimation of rate coefficients, particularly at high temperatures. Therefore, improved theoretical models require not only the consideration of additional SF6 decomposition reactions in the presence of impurities but also on improved values of rate constants. This paper is devoted to determining the rate constants of the chemical reactions relating to the main byproducts of SF6 decomposition in SF6 gas-insulated power equipment: SO2F, SOF2 and SO2F2. Quantum chemistry calculations with density functional theory, conventional

  15. High harmonic generation from impulsively aligned SO2

    Science.gov (United States)

    Devin, Julien; Wang, Song; Kaldun, Andreas; Bucksbaum, Phil

    2016-05-01

    Previous work in high harmonics generation (HHG) in aligned molecular gases has mainly focused on rotational dynamics in order to determine the contributions of different orbitals to the ionization step. In our experiment, we focus on the shorter timescale of vibrational dynamics. We generate high harmonics from impulsively aligned SO2 molecules in a gas jet and record the emitted attosecond pulse trains in a home-built high resolution vacuum ultra violet (VUV) spectrometer. Using the high temporal resolution of our setup, we are able to map out the effects of vibrational wavepackets with a sub-femtosecond resolution. The target molecule, SO2 gas, is impulsively aligned by a near-infrared laser pulse and has accessible vibrations on the timescale of the short laser pulse used. We present first experimental results for the response to this excitation in high-harmonics. We observe both fast oscillations in the time domain as well as shifts of the VUV photon energy outside of the pulse overlaps. Research supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Chemical Sciences, Geosciences, and Biosciences Division and by the National Science Foundation Graduate Research Fellowship.

  16. Investigation of BrO in volcanic plumes: Comparing satellite data from OMI and GOME-2

    Science.gov (United States)

    Warnach, Simon; Hörmann, Christoph; Sihler, Holger; Bobrowski, Nicole; Beirle, Steffen; Penning de Vries, Marloes; Dinger, Florian; Platt, Ulrich; Wagner, Thomas

    2017-04-01

    It has been repeatedly shown in the past by measurements from the ground and from space that volcanic plumes contain widely varying amounts of bromine monoxide (BrO). The relative amount of BrO in a volcanic plume, i. e. with respect to sulphur dioxide (SO2), is mainly affected by degassing composition as well as chemical processes, but the reasons for the variation is still not fully understood. Our study aims at obtaining a better understanding of bromine emissions from volcanoes. The high spatial resolution of current satellite instruments such as OMI (13x24 km2) and GOME-2 (40x80 km2), and particularly that of future instruments like TROPOMI (3.5x7 km2) allows to resolve the volcanic plume of eruptive events and makes. The combination of the high spatial resolution and the global coverage of satellite instruments make it possible to study the spatial variability of trace gases in a large number of volcanic plumes from a large number of volcanoes. In this study, we investigate the BrO and SO2 distribution as well as the BrO/SO2 ratio within volcanic plumes observed by OMI since 2007. We apply a plume detection algorithm which uses the retrieved SO2 column for plume identification. These data obtained from OMI measurements are compared to plumes identified from GOME-2 data. Differences in the number of identified plumes and the degree of agreement regarding the retrieved spatial distribution of BrO and SO2, as well as the calculated BrO/SO2 ratio between plumes observed by both instruments, are discussed. Differences are mainly attributed to the differences between the two instruments with respect to spatial resolution and overpass time (GOME-2 at 9:30, OMI at 13:30 local time).

  17. Physical and optical properties of 2010 Eyjafjallajökull volcanic eruption aerosol: ground-based, Lidar and airborne measurements in France

    Science.gov (United States)

    Hervo, M.; Quennehen, B.; Kristiansen, N. I.; Boulon, J.; Stohl, A.; Fréville, P.; Pichon, J.-M.; Picard, D.; Labazuy, P.; Gouhier, M.; Roger, J.-C.; Colomb, A.; Schwarzenboeck, A.; Sellegri, K.

    2012-02-01

    During the Eyjafjallajökull eruption (14 April to 24 May 2010), the volcanic aerosol cloud was observed across Europe by several airborne in situ and ground-based remote-sensing instruments. On 18 and 19 May, layers of depolarizing particles (i.e. non-spherical particles) were detected in the free troposphere above the Puy de Dôme station, (PdD, France) with a Rayleigh-Mie LIDAR emitting at a wavelength of 355 nm, with parallel and crossed polarization channels. These layers in the free troposphere (FT) were also well captured by simulations with the Lagrangian particle dispersion model FLEXPART, which furthermore showed that the ash was eventually entrained into the planetary boundary layer (PBL). Indeed, the ash cloud was then detected and characterized with a comprehensive set of in situ instruments at the Puy de Dôme station (PdD). In agreement with the FLEXPART simulation, up to 65 μg m-3 of particle mass and 2.2 ppb of SO2 were measured at PdD, corresponding to concentrations higher than the 95 percentile of 2 yr of measurements at PdD. Moreover, the number concentration of particles increased to 24 000 cm-3, mainly in the submicronic mode, but a supermicronic mode was also detected with a modal diameter of 2 μm. The resulting optical properties of the ash aerosol were characterized by a low scattering Ångström exponent (0.98), showing the presence of supermicronic particles. For the first time to our knowledge, the combination of in situ optical and physical characterization of the volcanic ash allowed the calculation of the mass-to-extinction ratio (η) with no assumptions on the aerosol density. The mass-to-extinction ratio was found to be significantly different from the background boundary layer aerosol (max: 1.57 g m-2 as opposed to 0.33 ± 0.03 g m-2). Using this ratio, ash mass concentration in the volcanic plume derived from LIDAR measurements was found to be 655 ± 23 μg m-3 when the plume was located in the FT (3000 m above the sea level

  18. Sulfur Isotope Fractionation Due to SO2 Photolysis in the Atmosphere

    Science.gov (United States)

    Lyons, J. R.; Blackie, D.; Stark, G.; Pickering, J.

    2012-12-01

    The discovery of unusual (i.e. mass-independent) sulfur isotope fractionation (or MIF) in Archean and Paleoproterozoic sedimentary rocks has promised to yield insights into the rise of O2 and the nature of the sulfur cycle on ancient Earth [1], but interpretation has been hampered by the lack of a clear mechanism for the sulfur isotope signature. Proposed MIF mechanisms include SO2 photolysis [1-4], atmospheric S3 (thiozone) formation, and thermal sulfate reduction in sediments [5]. Studies focusing only on SO2 photolysis, including measurements of isotopic cross sections [6], have yielded results differing greatly from theory [4], and have resulted in improbable interpretations [7]. In addition to ancient rocks, there are sulfur isotope MIF signatures in polar ice core sulfates associated with massive Plinian eruptions over the past ~1000 years (e.g., [8]). The ice core MIF signatures differ significantly from the ancient Earth MIF signatures, suggesting a different source mechanism. SO2 photolysis can generate sulfur isotope MIF signatures in two ways: 1) self-shielding by an optically-thick column of SO2, and 2) isotope-dependent differences in absorption line intensities and widths, which are espcially important for optically-thin conditions. The MIF signatures in ice core sulfates appear to be consistent with self-shielding in an optically-thick plume, but the Archean MIF clearly is not. To address the optically-thin case, we've made high-resolution ultraviolet cross section measurements of the sulfur isotopologues of SO2 made with the UV FTS at Imperial College. We measured cross sections at 1 cm-1 spectral resolution for 32SO2, 33SO2, 34SO2 and for a 36SO2/34SO2 mixture. Incorporating these cross sections into a simple atmospheric photochemical model with a solar UV flux, we find sulfur MIF signatures for SO and S that.are consistent with the Archean pyrites. We also find that additional mass-dependent fractionation during self-shielding by 32SO2 places an

  19. Noncommutative SO(2,3) gauge theory and noncommutative gravity

    CERN Document Server

    Dimitrijevic, Marija

    2014-01-01

    In this paper noncommutative gravity is constructed as a gauge theory of the noncommutative SO(2,3) group, while the noncommutativity is canonical (constant). The Seiberg-Witten map is used to express noncommutative fields in terms of the corresponding commutative fields. The commutative limit of the model is the Einstein-Hilbert action with the cosmological constant term and the topological Gauss-Bonnet term. We calculate the second order correction to this model and obtain terms that are of zeroth to fourth power in the curvature tensor and torsion. Trying to relate our results with $f(R)$ and $f(T)$ models, we analyze different limits of our model. In the limit of big cosmological constant and vanishing torsion we obtain a $x$-dependent correction to the cosmological constant, i.e. noncommutativity leads to a $x$-dependent cosmological constant. We also discuss the limit of small cosmological constant and vanishing torsion and the teleparallel limit.

  20. Controlling SO2 by Using Low Cost Adsorbents

    Directory of Open Access Journals (Sweden)

    Nenavath Gandhi

    2013-01-01

    Full Text Available Sulphur oxides are formed during high temperature combustion processes from the oxidation of sulphur in the air. The principal source of sulphur oxides is sulphur oxide (SO and sulphur dioxide (SO2, collectively known as SOx. SO and SO2 concentrations are therefore the highest in industrial area. Other important sources are power stations, heating plants, and industrial processes. Long-term exposure to sulphur dioxide may affect lung function, and that exposure to sulphur dioxide enhances the response to allergens in sensitized individuals. The feasibility of using waste materials as adsorbent for air pollutant SOx was evaluated in the present study. The experiments were carried out in laboratory on certain waste materials like Neem leaf powder, orange peel powder, custard apple leaf powder, Horse gram seed powder, Ragi seed powder, mango bark dust, mixed algae, and Neem bark dust. The experimental investigations were carried out by traditional adsorption studies, and they showed that all substances had certain capacity to adsorb SOx from aqueous solution of SOx. The order of adsorption by different low cost materials is Mango bark dust > Orange peel powder >Custard apple leaf powder> Neem leaf powder> Horse gram seed powder> Ragi seed powder> Neem bark powder, mixed algae by 98%>95%>88%>82%>80%>78%>77%>74%, respectively. At lower concentration the adsorption is more compared to higher concentration. It is found that the adsorption increases with an increase in surface area.DOI: http://dx.doi.org/10.5755/j01.erem.62.4.1947

  1. Remote sensing of sulfur dioxide (SO2) using the Lineate Imaging Near-Ultraviolet Spectrometer (LINUS)

    OpenAIRE

    Khoo, Sing Soong

    2005-01-01

    Approved for public release, distribution is unlimited The Lineate Image Near Ultraviolet Spectrometer (LINUS) is a spectral imager developed to operate in the 0.3-0.4 micron spectral region. The 2-D imager operates with a scan mirror, forming image scenes over time intervals of 10-20 minutes. Sensor calibration was conducted in the laboratory, and the system response to Sulfur Dioxide (SO2) gas was determined. The absorption profile for SO2 was measured, and curves of growth were construc...

  2. Effect of SO2 on Performance of Solid Oxide Fuel Cell Cathodes

    Institute of Scientific and Technical Information of China (English)

    WANG De-jun; LENG Jing

    2012-01-01

    Effects of SO2 in ambient air on the performance and durability of solid oxide fuel cell(SOFC) cathode were evaluated by galvanostatic measurement.Comparison between two cathode materials was made to consider the cathode degradation mechanisms.The degradation performance is associated with a slow decomposition of the La0.6Sr0.4Co0.2Fe0.8O3(LSCF) due to the segregation of strontium oxide.Negligible deterioration for (La0.7Sr0.3)MnO3 (LSM) cathode was caused by SO2 poisoning under a current density of 200 mA/cm2.Metal sulphate formation may explain a slight deterioration under increasing high the concentration of SO2.It was verified that the poisoning mechanism for the two cathode materials resulted from the gradual decomposition of the cathode materials.

  3. Parametrization of electron impact ionization cross sections for CO, CO2, NH3 and SO2

    Science.gov (United States)

    Srivastava, Santosh K.; Nguyen, Hung P.

    1987-01-01

    The electron impact ionization and dissociative ionization cross section data of CO, CO2, CH4, NH3, and SO2, measured in the laboratory, were parameterized utilizing an empirical formula based on the Born approximation. For this purpose an chi squared minimization technique was employed which provided an excellent fit to the experimental data.

  4. 40 CFR 75.16 - Special provisions for monitoring emissions from common, bypass, and multiple stacks for SO2...

    Science.gov (United States)

    2010-07-01

    ... emissions for the unit as the sum of the SO2 mass emissions measured at the two stacks; or (2) Monitor SO2... would be substituted for the flow monitor installed on the main stack or flue under the missing data procedures in subpart D of this part if data from the flow monitor installed on the main stack or flue...

  5. New inferences from spectral seismic energy measurement of a link between regional seismicity and volcanic activity at Mt. Etna, Italy

    Science.gov (United States)

    Ortiz, R.; Falsaperla, S.; Marrero, J. M.; Messina, A.

    2009-04-01

    The existence of a relationship between regional seismicity and changes in volcanic activity has been the subject of several studies in the last years. Generally, activity in basaltic volcanoes such as Villarica (Chile) and Tungurahua (Ecuador) shows very little changes after the occurrence of regional earthquakes. In a few cases volcanic activity has changed before the occurrence of regional earthquakes, such as observed at Teide, Tenerife, in 2004 and 2005 (Tárraga et al., 2006). In this paper we explore the possible link between regional seismicity and changes in volcanic activity at Mt. Etna in 2006 and 2007. On 24 November, 2006 at 4:37:40 GMT an earthquake of magnitude 4.7 stroke the eastern coast of Sicily. The epicenter was localized 50 km SE of the south coast of the island, and at about 160 km from the summit craters of Mt. Etna. The SSEM (Spectral Seismic Energy Measurement) of the seismic signal at stations at 1 km and 6 km from the craters highlights that four hours before this earthquake the energy associated with volcanic tremor increased, reached a maximum, and finally became steady when the earthquake occurred. Conversely, neither before nor after the earthquake, the SSEM of stations located between 80 km and 120 km from the epicentre and outside the volcano edifice showed changes. On 5 September, 2007 at 21:24:13 GMT an earthquake of magnitude 3.2 and 7.9 km depth stroke the Lipari Island, at the north of Sicily. About 38 hours before the earthquake occurrence, there was an episode of lava fountain lasting 20 hours at Etna volcano. The SSEM of the seismic signal recorded during the lava fountain at a station located at 6 km from the craters highlights changes heralding this earthquake ten hours before its occurrence using the FFM method (e.g., Voight, 1988; Ortiz et al., 2003). A change in volcanic activity - with the onset of ash emission and Strombolian explosions - was observed a couple of hours before the occurrence of the regional

  6. Adsorption and desorption of SO2, NO and chlorobenzene on activated carbon.

    Science.gov (United States)

    Li, Yuran; Guo, Yangyang; Zhu, Tingyu; Ding, Song

    2016-05-01

    Activated carbon (AC) is very effective for multi-pollutant removal; however, the complicated components in flue gas can influence each other's adsorption. A series of adsorption experiments for multicomponents, including SO2, NO, chlorobenzene and H2O, on AC were performed in a fixed-bed reactor. For single-component adsorption, the adsorption amount for chlorobenzene was larger than for SO2 and NO on the AC. In the multi-component atmosphere, the adsorption amount decreased by 27.6% for chlorobenzene and decreased by 95.6% for NO, whereas it increased by a factor of two for SO2, demonstrating that a complex atmosphere is unfavorable for chlorobenzene adsorption and inhibits NO adsorption. In contrast, it is very beneficial for SO2 adsorption. The temperature-programmed desorption (TPD) results indicated that the binding strength between the gas adsorbates and the AC follows the order of SO2>chlorobenzene > NO. The adsorption amount is independent of the binding strength. The presence of H2O enhanced the component effects, while it weakened the binding force between the gas adsorbates and the AC. AC oxygen functional groups were analyzed using TPD and X-ray photoelectron spectroscopy (XPS) measurements. The results reveal the reason why the chlorobenzene adsorption is less affected by the presence of other components. Lactone groups partly transform into carbonyl and quinone groups after chlorobenzene desorption. The chlorobenzene adsorption increases the number of C=O groups, which explains the positive effect of chlorobenzene on SO2 adsorption and the strong NO adsorption.

  7. Abundant SO2 release from the 2014 Holuhraun eruption (Bárðarbunga, Iceland) and its impact on human health

    Science.gov (United States)

    Barsotti, Sara; Jóhannsson, Thorsteinn; Hellsing, Vanda Ú.; Pfeffer, Melissa A.; Guðnason, Thórólfur; Stefánsdottir, Gerdur

    2015-04-01

    The ongoing eruption in Holuhraun is significantly rich in gases and its prolonged duration probably makes it one of the largest natural source of SO2 in Iceland since the Laki eruption in 1783-84. Since its beginning, on the 31st of August 2014, the eruption has been releasing into the atmosphere an amount of SO2 at a rate of 400 kg/s with peaks larger than 1,000 kg/s. This quantity already exceeds the SO2 fluxes coming from some well-known degassing volcanoes, such as Masaya (Nicaragua) and Etna (Italy); and it is comparable with the prolonged degassing event at Miyjakejima volcano (Japan) in 2000-2004. Low injection velocities and a predominant buoyant style at the source imply quite low plume heights which have been in average between 2-3 km and never exceeded 5 km above sea level. This fact, together with the high SO2 fluxes, is the reason for the high SO2 concentrations measured at ground level all over Iceland in the last months. The air quality monitoring network, operated by the Environment Agency of Iceland (EAI), has been improved and extended since the beginning of the eruption to allow for a near-real time coverage of SO2 measurements across most of the country. Since then, high values have been recorded in many inhabited locations more than 100 km far from the eruption site. For example on October 26th values up to 21,000 µg/m3 were measured in Höfn in the South-East of Iceland, while in the North the town of Akureyri experienced concentrations higher than 2,000 µg/m3 for about 10 hours on October 31st. Due to the large variability in wind direction and wind speed, typical for the Icelandic meterology, almost every town has been affected by the gas cloud and many locations have exceeded the health safety limit of 350 µg/m3 per hour more than 20 times. Such prolonged exposure and acute short-lived concentrations of SO2 can have adverse effects on human health especially in individuals with underlying pulmonary diseases. In Iceland the Chief

  8. Novel SO2 spectral evaluation scheme using the 360–390 nm wavelength range

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2010-03-01

    Full Text Available Differential Optical Absorption Spectroscopy (DOAS is a well established spectroscopic method to determine trace gases in the atmosphere. During the last decade, passive DOAS, which uses solar radiation scattered in the atmosphere as a light source, has become a standard tool to determine SO2 column densities and emission fluxes from volcanoes and other large sources by ground based as well as satellite measurements. For the determination of SO2 column densities, the structured absorption of the molecule in the 300–330 nm region (due to the A1B1←X1A1 transition is used. However, there are several problems limiting the accuracy of the technique in this particular application. Here we propose to use an alternative wavelength region (360–390 nm due to the spin-forbidden a3B2←X1A1 transition for the DOAS evaluation of SO2 in conditions where high SO2 column densities prevail. We show this range to have considerable advantages in such cases, in particular when the particle content of the plume is high and when measurements are performed at large distances from the area of interest.

  9. Novel SO2 spectral evaluation scheme using the 360–390 nm wavelength range

    Directory of Open Access Journals (Sweden)

    T. Wagner

    2010-07-01

    Full Text Available Differential Optical Absorption Spectroscopy (DOAS is a well established spectroscopic method to determine trace gases in the atmosphere. During the last decade, passive DOAS, which uses solar radiation scattered in the atmosphere as a light source, has become a standard tool to determine SO2 column densities and emission fluxes from volcanoes and other large sources by ground based as well as satellite measurements. For the determination of SO2 column densities, the structured absorption of the molecule in the 300–330 nm region (due to the A1B1 ← X1A1 transition is used. However, there are several problems limiting the accuracy of the technique in this particular application. Here we propose to use an alternative wavelength region (360–390 nm due to the spin-forbidden a3B2 ← X1A1 transition for the DOAS evaluation of SO2 in conditions where high SO2 column densities prevail. We show this range to have considerable advantages in such cases, in particular when the particle content of the plume is high and when measurements are performed at large distances from the area of interest.

  10. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2014

    Directory of Open Access Journals (Sweden)

    N. A. Krotkov

    2015-10-01

    Full Text Available The Ozone Monitoring Instrument (OMI onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2 and sulfur dioxide (SO2, since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for the different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2014, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012–2014, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2014. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved to be very valuable in documenting rapid changes in

  11. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    Science.gov (United States)

    Krotkov, Nickolay A.; McLinden, Chris A.; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Folkert Boersma, K.; Pepijn Veefkind, J.; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-04-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50 % reduction in 2012-2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  12. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    Science.gov (United States)

    Krotkov, Nickolay A.; McLinden, Chris A; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; hide

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2/ and sulfur dioxide (SO2/, since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50% reduction in 2012- 2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  13. Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015

    Science.gov (United States)

    Krotkov, Nickolay A.; McLinden, Chris A; Li, Can; Lamsal, Lok N.; Celarier, Edward A.; Marchenko, Sergey V.; Swartz, William H.; Bucsela, Eric J.; Joiner, Joanna; Duncan, Bryan N.; Boersma, K. Folkert; Veefkind, J. Pepijn; Levelt, Pieternel F.; Fioletov, Vitali E.; Dickerson, Russell R.; He, Hao; Lu, Zifeng; Streets, David G.

    2016-01-01

    The Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite has been providing global observations of the ozone layer and key atmospheric pollutant gases, such as nitrogen dioxide (NO2/ and sulfur dioxide (SO2/, since October 2004. The data products from the same instrument provide consistent spatial and temporal coverage and permit the study of anthropogenic and natural emissions on local-to-global scales. In this paper, we examine changes in SO2 and NO2 over some of the world's most polluted industrialized regions during the first decade of OMI observations. In terms of regional pollution changes, we see both upward and downward trends, sometimes in opposite directions for NO2 and SO2, for different study areas. The trends are, for the most part, associated with economic and/or technological changes in energy use, as well as regional regulatory policies. Over the eastern US, both NO2 and SO2 levels decreased dramatically from 2005 to 2015, by more than 40 and 80 %, respectively, as a result of both technological improvements and stricter regulations of emissions. OMI confirmed large reductions in SO2 over eastern Europe's largest coal-fired power plants after installation of flue gas desulfurization devices. The North China Plain has the world's most severe SO2 pollution, but a decreasing trend has been observed since 2011, with about a 50% reduction in 2012- 2015, due to an economic slowdown and government efforts to restrain emissions from the power and industrial sectors. In contrast, India's SO2 and NO2 levels from coal power plants and smelters are growing at a fast pace, increasing by more than 100 and 50 %, respectively, from 2005 to 2015. Several SO2 hot spots observed over the Persian Gulf are probably related to oil and gas operations and indicate a possible underestimation of emissions from these sources in bottom-up emission inventories. Overall, OMI observations have proved valuable in documenting rapid changes in air quality over different

  14. Aura OMI Observations of Global SO2 and NO2 Pollution from 2005 to 2013

    Science.gov (United States)

    Krotkov, Nickolay; Li, Can; Lamsal, Lok; Celarier, Edward; Marchenko, Sergey; Swartz, William H.; Bucsela, Eric; Fioletov, Vitali; McLinden, Chris; Joiner, Joanna; Bhartia, Pawan K.; Duncan, Bryan; Dickerson, Russ

    2014-01-01

    The Ozone Monitoring Instrument (OMI), a NASA partnership with the Netherlands and Finland, flies on the NASA Aura satellite and uses reflected sunlight to measure the two critical atmospheric trace gases: nitrogen dioxide (NO2) and sulfur dioxide (SO2) characterizing daily air quality. Both gases and the secondary pollutants they produce (particulate matter, PM2.5, and tropospheric ozone) are USEPA designated criteria pollutants, posing serious threats to human health and the environment (e.g., acid rain, plant damage and reduced visibility). Our group at NASA GSFC has developed and maintained OMI standard SO2 and NO2 data products. We have recently released an updated version of the standard NO2 L2 and L3 products (SP v2.1) and continue improving the algorithm. We are currently in the process of releasing next generation pollution SO2 product, based on an innovative Principal Component Analysis (PCA) algorithm, which greatly reduces the noise and biases. These new standard products provide valuable datasets for studying anthropogenic pollution on local to global scales. Here we highlight some of the OMI observed changes in air quality over several regions. Over the US average NO2 and SO2 pollution levels had decreased dramatically as a result of both technological improvements (e.g., catalytic converters on cars) and stricter regulations of emissions. We see continued decline in pollution over Europe. Over China OMI observed an increase of about 60 percent in NO2 pollution between 2005 and 2013, despite a temporal reversal of the growing trend due to both 2008 Olympic Games and the economic recession in 2009. Chinese SO2 pollution seems to have stabilized since peaking in 2007, probably due to government efforts to curb SO2 emissions from the power sector. We have also observed large increases in both SO2 and NO2 pollution particularly in Eastern India where a number of large new coal power plants had been built in recent years. We expect that further

  15. Electron impact excitation of SO2 - Differential, integral, and momentum transfer cross sections

    Science.gov (United States)

    Vuskovic, L.; Trajmar, S.

    1982-01-01

    Electron impact excitation of the electronic states of SO2 was investigated. Differential, integral, and inelastic momentum transfer cross sections were obtained by normalizing the relative measurements to the elastic cross sections. The cross sections are given for seven spectral ranges of the energy-loss spectra extending from the lowest electronic state to near the first ionization limit. Most of the regions represent the overlap of several electronic transitions. No measurements for these cross sections have been reported previously.

  16. A Model Simulation of Pinatubo Volcanic Aerosols in the Stratosphere

    Science.gov (United States)

    Zhao , Jing-xia; Turco, Richard P.; Toon, Owen B.

    1995-01-01

    A one-dimensional, time-dependent model is used to study the chemical, microphysical, and radiative properties of volcanic aerosols produced by the Mount Pinatubo eruption on June 15, 1991. Our model treats gas-phase sulfur photochemistry, gas-to-particle conversion of sulfur, and the microphysics of sulfate aerosols and ash particles under stratospheric conditions. The dilution and diffusion of the volcanic eruption clouds are also accounted for in these conditions. Heteromolecular homogeneous and heterogeneous binary H2SO4/H2O nucleation, acid and water condensational growth, coagulation, and gravitational sedimentation are treated in detail in the model. Simulations suggested that after several weeks, the volcanic cloud was composed mainly of sulfuric acid/water droplets produced in situ from the SO2 emissions. The large amounts of SO2 (around 20 Mt) injected into the stratosphere by the Pinatubo eruption initiated homogeneous nucleation which generated a high concentration of small H2SO4/H2O droplets. These newly formed particles grew rapidly by condensation and coagulation in the first few months and then reach their stabilized sizes with effective radii in a range between 0.3 and 0.5 micron approximately one-half year after the eruption. The predicted volcanic cloud parameters reasonably agree with measurements in term of the vertical distribution and lifetime of the volcanic aerosols, their basic microphysical structures (e.g., size distribution, concentration, mass ratio, and surface area) and radiative properties. The persistent volcanic aerosols can produce significant anomalies in the radiation field, which have important climatic consequences. The large enhancement in aerosol surface area can result in measurable global stratospheric ozone depletion.

  17. Integration and Testing of Miniaturized Volcanic Gas-Sensing Instruments on UAS Platforms

    Science.gov (United States)

    Lopez, T. M.; Kern, C.; Diaz, J. A.; Vanderwaal, S. J.; Levy, A.

    2015-12-01

    Volcanologists measure the concentrations and emission rates of gases emitted from active volcanoes to understand magmatic processes, which aids in eruption forecasting, and to evaluate air quality for human and environmental health. Both of these applications become particularly important during periods of unusually high volcanic unrest when it is typically hazardous to approach a given volcano. Unmanned aerial systems (UASs) represent a promising platform for continued gas measurements during unrest, while reducing the risk to volcanologists. Two miniature gas-sensing instruments have been developed specifically for integration onto small UAS platforms. Both instruments weigh 1 kg or less, including integrated power. The microDOAS instrument is an upward-looking UV/vis spectrometer that measures the spectral absorption signature of SO2 and certain halogen oxides in scattered solar radiation. By flying beneath a volcanic plume, the instrument can measure the SO2 content in the plume cross-section which can be used to determine the SO2 emission rate. The miniGas instrument is flown within the volcanic plume and records in situ concentrations of CO2, SO2 and H2S, as well as atmospheric temperature, pressure, relative humidity and GPS location. All data are telemetered back to the base station to immediately alert the operator of potentially hazardous conditions. Both instruments have been successfully tested at active volcanoes in Alaska and Costa Rica and were integrated onto small ACUASI Ptarmigan hexacopters. A test mission was conducted at the Poker Flat Research Range in Alaska. During this experiment both instruments were successfully flown in flight patterns typical of manned volcanic gas measurements and new UAV-specific measurement strategies were developed. Here we describe the instruments and platforms employed, our experimental results and observations, and make recommendations for application to volcanic settings.

  18. Catastrophic volcanism

    Science.gov (United States)

    Lipman, Peter W.

    1988-01-01

    Since primitive times, catastrophes due to volcanic activity have been vivid in the mind of man, who knew that his activities in many parts of the world were threatened by lava flows, mudflows, and ash falls. Within the present century, increasingly complex interactions between volcanism and the environment, on scales not previously experienced historically, have been detected or suspected from geologic observations. These include enormous hot pyroclastic flows associated with collapse at source calderas and fed by eruption columns that reached the stratosphere, relations between huge flood basalt eruptions at hotspots and the rifting of continents, devastating laterally-directed volcanic blasts and pyroclastic surges, great volcanic-generated tsunamis, climate modification from volcanic release of ash and sulfur aerosols into the upper atmosphere, modification of ocean circulation by volcanic constructs and attendent climatic implications, global pulsations in intensity of volcanic activity, and perhaps triggering of some intense terrestrial volcanism by planetary impacts. Complex feedback between volcanic activity and additional seemingly unrelated terrestrial processes likely remains unrecognized. Only recently has it become possible to begin to evaluate the degree to which such large-scale volcanic processes may have been important in triggering or modulating the tempo of faunal extinctions and other evolutionary events. In this overview, such processes are examined from the viewpoint of a field volcanologist, rather than as a previous participant in controversies concerning the interrelations between extinctions, impacts, and volcanism.

  19. Remote sensing measurements of the volcanic ash plume over Poland in April 2010

    Science.gov (United States)

    Markowicz, K. M.; Zielinski, T.; Pietruczuk, A.; Posyniak, M.; Zawadzka, O.; Makuch, P.; Stachlewska, I. S.; Jagodnicka, A. K.; Petelski, T.; Kumala, W.; Sobolewski, P.; Stacewicz, T.

    2012-03-01

    This work provides information on selected optical parameters related to volcanic ash produced during the eruption of the Eyjafjöll volcano in Iceland in 2010. The observations were made between 16 and 18 April 2010 at four stations representative for northern (Sopot), central (Warsaw, Belsk) and south-eastern (Strzyzow) regions of Poland. The largest ash plume (in terms of aerosol optical thickness) over Poland was observed at night of 16/17 April 2010 in the layer between 4 and 5.5 km a.s.l. The highest values of the aerosol extinction coefficient reached 0.06-0.08 km -1 at 532 nm (based on lidar observations in Warsaw) and 0.02-0.04 km -1 at 1064 nm (based on ceilometer observations in Warsaw). The corresponding optical thickness due to volcanic ash reached values of about 0.05 at 532 nm and about 0.03 at 1064 nm. These values are similar to those reported for the Belsk station based on lidar observations. The ash mass concentration estimated based on the maximum aerosol extinction coefficient reached 0.22 ± 0.11 mg m -3. This value is significantly lower than the limit (2 mg m -3) for the aircraft operation.

  20. Thermal and Dynamic Properties of Volcanic Lava Inferred from Measurements on its Surface

    Science.gov (United States)

    Ismail-Zadeh, A.; Korotkii, A.; Kovtunov, D.; Tsepelev, I.; Melnik, O. E.

    2015-12-01

    Modern remote sensing technologies allow for detecting the absolute temperature at the surface of volcanic lava, and the heat flow could be then inferred from the Stefan-Boltzmann law. Is it possible to use these surface thermal data to constrain the thermal and dynamic conditions inside the lava? We propose a quantitative approach to reconstruct temperature and velocity in the steady-state volcanic lava flow from thermal observations at its surface. This problem is reduced to a combination of the direct and inverse problems of mass- and heat transport. Namely, using known conditions at the lava surface we determine the missing condition at the bottom of lava (the inverse problem) and then search for the physical properties of lava - temperature and flow velocity - inside the lava (the direct problem). Assuming that the lava rheology and the thermal conductivity are temperature-dependent, we determine the flow characteristics in the model domain using an adjoint method. We show that in the case of smooth input data (observations) the lava temperature and the flow velocity can be reconstructed with a high accuracy. The noise imposed on the smooth input data results in a less accurate solution, but still acceptable below some noise level.

  1. Atmospheric inversion of SO2 and primary aerosol emissions for the year 2010

    Directory of Open Access Journals (Sweden)

    N. Huneeus

    2013-07-01

    Full Text Available Natural and anthropogenic emissions of primary aerosols and sulphur dioxide (SO2 are estimated for the year 2010 by assimilating daily total and fine mode aerosol optical depth (AOD at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS satellite instrument into a global aerosol model of intermediate complexity. The system adjusts monthly emission fluxes over a set of predefined regions tiling the globe. The resulting aerosol emissions improve the model performance, as measured from usual skill scores, both against the assimilated observations and a set of independent ground-based measurements. The estimated emission fluxes are 67 Tg S yr−1 for SO2, 12 Tg yr−1 for black carbon (BC, 87 Tg yr−1 for particulate organic matter (POM, 17 000 Tg yr−1 for sea salt (SS, estimated at 80 % relative humidity and 1206 Tg yr−1 for desert dust (DD. They represent a difference of +53, +73, +72, +1 and −8%, respectively, with respect to the first guess (FG values. Constant errors throughout the regions and the year were assigned to the a priori emissions. The analysis errors are reduced with respect to the a priori ones for all species and throughout the year, they vary between 3 and 18% for SO2, 1 and 130% for biomass burning, 21 and 90 % for fossil fuel, 1 and 200% for DD and 1 and 5% for SS. The maximum errors on the global-yearly scale for the estimated fluxes (considering temporal error dependence are 3% for SO2, 14% for BC, 11% for POM, 14% for DD and 2% for SS. These values represent a decrease as compared to the global-yearly errors from the FG of 7% for SO2, 40% for BC, 55% for POM, 81% for DD and 300% for SS. The largest error reduction, both monthly and yearly, is observed for SS and the smallest one for SO2. The sensitivity and robustness of the inversion system to the choice of the first guess emission inventory is investigated by using different combinations of inventories for industrial, fossil fuel and biomass burning

  2. Bridge-based sensing of NOx and SO2 emissions from ocean-going ships

    Science.gov (United States)

    Burgard, Daniel A.; Bria, Carmen R. M.

    2016-07-01

    As emissions from nonroad mobile sources face increased regulatory scrutiny, a surprisingly few number of real-world, in-use measurements exist for these sources. This paper reports the first use of an open-path Remote Sensing Device (RSD) to measure emissions from ocean-going ships, including cruise ships. This noninvasive technique measured NOx and SO2 emission factors from 16 individually identified ocean-going ships as they passed under the Lions Gate Bridge in Vancouver, B.C. and their exhaust plumes passed through the sensing beam of the RSD on a bridge directly above. Ship NOx emissions generally agreed with previous studies showing no emissions trends across vessel type. Ship SO2 emissions were reasonable based on expected Environmental Control Area fuel sulfur requirements and corresponded to 0.4-2.4% sulfur in the fuels. This method's specificity of individual vessel SO2 measurements suggests that this technique could be used as a tool to detect high sulfur fuel use in vessels.

  3. Satellite detection, long-range transport, and air quality impacts of volcanic sulfur dioxide from the 2014-2015 flood lava eruption at Bárðarbunga (Iceland)

    Science.gov (United States)

    Schmidt, Anja; Leadbetter, Susan; Theys, Nicolas; Carboni, Elisa; Claire, Witham; John, Stevenson; Cathryn, Birch; Thordarson, Thorvaldur

    2016-04-01

    The 2014-2015 Bárðarbunga-Veiðivötn fissure eruption at Holuhraun produced about 1.5 km3 of lava, making it the largest eruption in Iceland in more than 200 years. Over the course of the eruption, daily volcanic sulfur dioxide (SO2) emissions exceeded daily SO2 emissions from all anthropogenic sources in Europe in 2010 by at least a factor of 3. We present surface air quality observations from across Northern Europe together with satellite remote sensing data and model simulations of volcanic SO2 for September 2014. We show that volcanic SO2 was transported in the lowermost troposphere over long distances and detected by air quality monitoring stations up to 2750 km away from the source. Using retrievals from the Ozone Monitoring Instrument (OMI) and the Infrared Atmospheric Sounding Interferometer (IASI), we calculate an average daily SO2 mass burden of 99 ± 49 kilotons (kt) of SO2 from OMI and 61 ± 18 kt of SO2 from IASI for September 2014. This volcanic burden is at least a factor of 2 greater than the average SO2 mass burden between 2007 and 2009 due to anthropogenic emissions from the whole of Europe. Combining the observational data with model simulations using the United Kingdom Met Office's Numerical Atmospheric-dispersion Modelling Environment model, we are able to constrain SO2 emission rates to up to 120 kilotons per day (kt/d) during early September 2014, followed by a decrease to 20-60 kt/d between 6 and 22 September 2014, followed by a renewed increase to 60-120 kt/d until the end of September 2014. Based on these fluxes, we estimate that the eruption emitted a total of 2.0 ± 0.6 Tg of SO2 during September 2014, in good agreement with ground-based remote sensing and petrological estimates. Although the volcanic air pollution episodes were transient and lava-dominated volcanic eruptions are sporadic events, the observations suggest that (i) during an eruption, volcanic SO2 measurements should be assimilated for near real-time air quality

  4. SO2 and NO2 over major urban regions of India: a tempo-spatial perspective

    Science.gov (United States)

    Mallik, C.; Lal, S.

    2012-12-01

    Demographic projections show that by the year 2025, 16 of the world's 29 megacities will be located in Asia, many of which have very basic problems in terms of air quality. Apart from being home to a burgeoning population, these regions of the globe are also major players in atmospheric chemistry as a result of myriad emission patterns combined with intense photochemistry. Like most of these Asian megacities, fast-paced development in some of the Indian cities has ramifications in increased emissions from industrial and transport sectors. These emissions release sulfur dioxide (SO2) and nitrogen dioxide (NO2), in addition to several pollutants, into the ambient air and have the potential to impact the chemistry and radiative balance on a regional scale. Surface measurements of these two criteria pollutants by the Central Pollution Control Board (CPCB), India during 2005-2010 from 13 urban locations in India have been analyzed to get an insight into their temporal and spatial variability. Stations are chosen to represent the entire Indian region: Indo-Gangetic plain or 'IGP' (Jalandhar, Delhi, Kanpur, Durgapur, Kolkata, Guwahati), western India (Jodhpur, Ahmedabad, Surat), central India (Nagpur, Hyderabad) and southern India (Chennai, Trivandrum). The monthly averaged surface level SO2 and NO2 have also been compared with monthly columnar averages of these gases as detected by the Ozone monitoring Instrument (OMI) over these station grids. Mean SO2 concentrations are found to be the highest for Surat (7.5 ppbv), located in a highly industrialized region. Elevated levels of NO2, observed for Durgapur and Kolkata (31 ppbv each), are close to the 24-hour 'National Ambient Air Quality' standard (30 ppbv). The surface concentrations for both SO2 and NO2 concentrations are found to be the highest during winter. Columnar SO2 over many stations show a maximum during summer monsoon. For most IGP stations, columnar NO2 values are elevated during winter. Wavelet analyses

  5. The measurement and evaluation of sulphur dioxide in dried longan, dried litchi, dried longan pulp and fresh longan in Guangxi market%广西市售龙眼(荔枝)干、桂圆肉、保鲜龙眼中SO2残留量测定及评价

    Institute of Scientific and Technical Information of China (English)

    刘守廷; 蒋天成; 叶开富; 罗平; 李健梅; 陶弋; 谭芳维; 唐琼

    2013-01-01

    Objective:To understand the situation of sulphur dioxide in dried longan, dried litchi, dried longan pulp and fresh longan available in Guangxi, and provide reference basis for the market regulators to strengthen food safety supervision. Methods: Sixty - four samples of dried longan, dried litchi, dried longan pulp and fresh fruits collected in the trading market from 2011 to 2012 were determined according to the second method of distillation method in Determination of Sulphite in Foods by GB/G5009. 34 -2003. Results: There were 43 samples consistent with the state standards and the qualified rate was 67%. The highest was fresh fruits (100% ) , followed by dried longan (75% ), dried litchi (69%) and dried longan pulp (50% ). Conclusion: In Guangxi, there are 33% of the dried longan, dried litchi and dried longan pulp exceeding the state health standard, performing different levels of SO2 residues, especially in the dried longan pulp, which is 8. 6 times of the state health standard.%目的:了解广西市售龙眼(荔枝)干、桂圆肉、保鲜龙眼中SO2的残留情况,为市场监管部门加强食品安全监督提供参考.方法:2010年-2012年随机抽取广西市场上的保鲜龙眼、龙眼(荔枝)干、桂圆肉64个样品,按GB/T5009.34-2003《食品中亚硫酸盐的测定》第二法测定SO2残留量.结果:符合国家卫生标准的43份,合格率67%,其合格率从高到低依次为保鲜龙眼(100%)>龙眼干(75%)>荔枝干(69%)>桂圆肉(50%).结论:广西市售龙眼(荔枝)干、桂圆肉中,超国家卫生标准的达33%,不同程度地存在SO2残留量超标的情况,桂圆肉中最高SO2残留量超国家卫生标准8.6倍.

  6. Behaviour of volcanogenic S-bearing compounds (H2S and SO2) in air at Vulcano Island (Aeolian Archipelago, southern Italy)

    Science.gov (United States)

    Caponi, Chiara; Tassi, Franco; Ricci, Andrea; Capecchiacci, Francesco; Venturi, Stefania; Cabassi, Jacopo; Vaselli, Orlando

    2017-04-01

    The main sources of SO2 and H2S in air consist of both natural fluid emissions related to active/quiescent volcanoes and hydrothermal systems, and anthropogenic activities (e.g. gas and oil refineries, steel industries, urban traffic). These gas compounds have a strong impact on air quality, since they are strong toxic and climate forcing agents. Notwithstanding, the behaviour of these S-compounds in air once they are released from the contaminant source(s) is poorly known, due to the scarce available data from thermodynamics and direct measurements. Hydrogen sulfide is considered to be relatively reactive in the atmosphere, being easily oxidized to SO2 by photochemical reactions, even though the efficiency of the H2S to SO2 conversion is significantly lowered under dark, dry and relatively cold conditions, leading to a residence time of H2S in air up to 42 days in winter. In this work, H2S and SO2 measurements in air carried out at the Levante beach (Vulcano Island, Aeolian Archipelago), where a number of hydrothermal fluid discharges consisting of fumaroles and submarine emissions occur, are presented and discussed. These volcanic fluids, characterized by an H2S-rich chemical composition, are released in a close proximity to the touristic village of Vulcano Porto. The measurements were carried out using a Thermo Scientific™ Model 450i Analyzer coupled with a Davis® Vantage Vue weather station (air humidity and temperature, wind direction and speed) in 34 fixed spots and along 8 pathways, selected according to: (i) distance from the contaminant source, (ii) wind direction and (iii) accessibility by car (where the instrument was installed). The main aim was to provide empirical insights on the behavior of these air pollutants in relation to the physical and chemical processes controlling their spatial distribution. The measured data were elaborated using a statistical approach to construct spatial distribution maps and conceptual models able to forecast the

  7. Crustal deformation and magmatic processes at Laguna del Maule volcanic field (Chile): Geodetic measurements and numerical models

    Science.gov (United States)

    Le Mével, Hélène

    The Laguna del Maule (LdM) volcanic field in Chile is an exceptional example of postglacial rhyolitic volcanism in the Southern Volcanic Zone of the Andes. Since 2007, LdM has experienced an unrest episode characterized by high rates of deformation measured by interferometric analysis of synthetic aperture radar (SAR) images acquired between 2007 and 2016, and data from the Global Positioning System (GPS) recorded since 2012 at five stations. The inflating region includes most of the 16--km-by--14--km ring of rhyolitic domes and coulees. The fastest-moving GPS station (MAU2) has a velocity vector of [[special character omited]72 +/- 4, 19 +/- 1, 194 +/- 3] mm/yr between 2012 and 2016 for the eastward, northward, and upward components, respectively. First, we model the InSAR observations assuming a rectangular dislocation in a half space with uniform elastic properties. The best time function for modeling the InSAR data set is a double exponential model with rates increasing from 2007 through 2010 and decreasing slowly since 2011. Modeling of historical uplift at Yellowstone, Long Valley, and Three Sisters volcanic fields suggests a common temporal evolution of vertical displacement rates. We hypothesize that magma intruding into an existing silicic magma reservoir is driving the surface deformation and present a new dynamic model to describe this process. A Newtonian fluid characterized by its viscosity, density, and pressure flows through a vertical conduit, intruding into a reservoir embedded in an elastic domain and leading to time-dependent surface deformation. Using a grid-search optimization, we minimize the misfit to the InSAR displacement data by varying the three parameters governing the analytical solution: the characteristic timescale tauP for magma propagation, the injection pressure, and the inflection time when the acceleration switches from positive to negative. For a spheroid with semi-major axis a = 6200 m, semi-minor axis c = 100 m, located at a

  8. Space-based observation of volcanic iodine monoxide

    Science.gov (United States)

    Schönhardt, Anja; Richter, Andreas; Theys, Nicolas; Burrows, John P.

    2017-04-01

    Volcanic eruptions inject substantial amounts of halogens into the atmosphere. Chlorine and bromine oxides have frequently been observed in volcanic plumes from different instrumental platforms such as from ground, aircraft and satellites. The present study is the first observational evidence that iodine oxides are also emitted into the atmosphere during volcanic eruptions. Large column amounts of iodine monoxide, IO, are observed in satellite measurements following the major eruption of the Kasatochi volcano, Alaska, in 2008. The IO signal is detected in measurements made both by SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY) on ENVISAT (Environmental Satellite) and GOME-2 (Global Ozone Monitoring Experiment-2) on MetOp-A (Meteorological Operational Satellite A). Following the eruption on 7 August 2008, strongly elevated levels of IO slant columns of more than 4 × 1013 molec cm-2 are retrieved along the volcanic plume trajectories for several days. The retrieved IO columns from the different instruments are consistent, and the spatial distribution of the IO plume is similar to that of bromine monoxide, BrO. Details in the spatial distribution, however, differ between IO, BrO and sulfur dioxide, SO2. The column amounts of IO are approximately 1 order of magnitude smaller than those of BrO. Using the GOME-2A observations, the total mass of IO in the volcanic plume injected into the atmosphere from the eruption of Kasatochi on 7 August 2008, is determined to be on the order of 10 Mg.

  9. East Asian SO2 pollution plume over Europe – Part 2: Evolution and potential impact

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-07-01

    Full Text Available We report on the first observation-based case study of an aged East Asian anthropogenic SO2 pollution plume over Europe. Our airborne measurements in that plume detected highly elevated SO2 mole fractions (up to 900 pmol/mol between about 5000 and 7000 m altitude. Here, we focus on investigations of the origin, dispersion, evolution, conversion, and potential impact of the observed excess SO2. In particular, we investigate SO2 conversion to gas-phase sulfuric acid and sulfuric acid aerosols. Our FLEXPART and LAGRANTO model simulations, along with additional trace gas measurements, suggest that the plume originated from East Asian fossil fuel combustion sources and, 8–7 days prior to its arrival over Europe, ascended over the coast region of central East Asia to 9000 m altitude, probably in a cyclonic system with an associated warm conveyor belt. During this initial plume ascent a substantial fraction of the initially available SO2 must have escaped from removal by cloud processes. Hereafter, while mostly descending slowly, the plume experienced advection across the North Pacific, North America and the North Atlantic. During its upper troposphere travel, clouds were absent in and above the plume and OH-induced gas-phase conversion of SO2 to gas-phase sulfuric acid (GSA was operative, followed by GSA nucleation and condensation leading to sulfuric acid aerosol formation and growth. Our AEROFOR model simulations indicate that numerous large sulfuric acid aerosol particles were formed, which at least tempora-rily, caused substantial horizontal visibility degradation, and which have the potential to act as water vapor condensation nuclei in liquid water cloud formation, already at water vapor supersaturations as low as about 0.1%. Our AEROFOR model simulations also indicate that those fossil fuel combustion generated soot particles, which have survived cloud induced removal during the initial plume ascent, have experienced extensive H2SO4/H2O

  10. Spectrally Enhanced Cloud Objects—A generalized framework for automated detection of volcanic ash and dust clouds using passive satellite measurements: 1. Multispectral analysis

    Science.gov (United States)

    Pavolonis, Michael J.; Sieglaff, Justin; Cintineo, John

    2015-08-01

    While satellites are a proven resource for detecting and tracking volcanic ash and dust clouds, existing algorithms for automatically detecting volcanic ash and dust either exhibit poor overall skill or can only be applied to a limited number of sensors and/or geographic regions. As such, existing techniques are not optimized for use in real-time applications like volcanic eruption alerting and data assimilation. In an effort to significantly improve upon existing capabilities, the Spectrally Enhanced Cloud Objects (SECO) algorithm was developed. The SECO algorithm utilizes a combination of radiative transfer theory, a statistical model, and image processing techniques to identify volcanic ash and dust clouds in satellite imagery with a very low false alarm rate. This fully automated technique is globally applicable (day and night) and can be adapted to a wide range of low earth orbit and geostationary satellite sensors or even combinations of satellite sensors. The SECO algorithm consists of four primary components: conversion of satellite measurements into robust spectral metrics, application of a Bayesian method to estimate the probability that a given satellite pixel contains volcanic ash and/or dust, construction of cloud objects, and the selection of cloud objects deemed to have the physical attributes consistent with volcanic ash and/or dust clouds. The first two components of the SECO algorithm are described in this paper, while the final two components are described in a companion paper.

  11. Tunable diode laser measurements of hydrothermal/volcanic CO2 and implications for the global CO2 budget

    Science.gov (United States)

    Pedone, M.; Aiuppa, A.; Giudice, G.; Grassa, F.; Francofonte, V.; Bergsson, B.; Ilyinskaya, E.

    2014-12-01

    Quantifying the CO2 flux sustained by low-temperature fumarolic fields in hydrothermal/volcanic environments has remained a challenge, to date. Here, we explored the potential of a commercial infrared tunable laser unit for quantifying such fumarolic volcanic/hydrothermal CO2 fluxes. Our field tests were conducted between April 2013 and March 2014 at Nea Kameni (Santorini, Greece), Hekla and Krýsuvík (Iceland) and Vulcano (Aeolian Islands, Italy). At these sites, the tunable laser was used to measure the path-integrated CO2 mixing ratios along cross sections of the fumaroles' atmospheric plumes. By using a tomographic post-processing routine, we then obtained, for each manifestation, the contour maps of CO2 mixing ratios in the plumes and, from their integration, the CO2 fluxes. The calculated CO2 fluxes range from low (5.7 ± 0.9 t d-1; Krýsuvík) to moderate (524 ± 108 t d-1; La Fossa crater, Vulcano). Overall, we suggest that the cumulative CO2 contribution from weakly degassing volcanoes in the hydrothermal stage of activity may be significant at the global scale.

  12. Tunable diode laser measurements of hydrothermal/volcanic CO2, and implications for the global CO2 budget

    Science.gov (United States)

    Pedone, M.; Aiuppa, A.; Giudice, G.; Grassa, F.; Francofonte, V.; Bergsson, B.; Ilyinskaya, E.

    2014-08-01

    Quantifying the CO2 flux sustained by low-temperature fumarolic fields in volcanic-hydrothermal environment has remained a challenge, to date. Here, we explored the potentiality of a commercial infrared tunable laser unit for quantifying such fumarolic volcanic/hydrothermal CO2 fluxes. Our field tests were conducted (between April 2013 and March 2014) at Nea Kameni (Santorini, Greece), Hekla and Krýsuvík (Iceland) and Vulcano (Aeolian Islands, Italy). At these sites, the tunable laser was used to measure the path-integrated CO2 mixing ratios along cross-sections of the fumaroles' atmospheric plumes. By using a tomographic post-processing routine, we then obtained, for each manifestation, the contour maps of CO2 mixing ratios in the plumes and, from their integration, the CO2 fluxes. The so-calculated CO2 fluxes range from low (5.7 ± 0.9 t day-1; Krýsuvík) to moderate (524 ± 108 t day-1; "La Fossa" crater, Vulcano). Overall, we suggest that the cumulative CO2 contribution from weakly degassing volcanoes in hydrothermal stage of activity may be significant at global scale.

  13. Tunable diode laser measurements of hydrothermal/volcanic CO2, and implications for the global CO2 budget

    Directory of Open Access Journals (Sweden)

    M. Pedone

    2014-08-01

    Full Text Available Quantifying the CO2 flux sustained by low-temperature fumarolic fields in volcanic-hydrothermal environment has remained a challenge, to date. Here, we explored the potentiality of a commercial infrared tunable laser unit for quantifying such fumarolic volcanic/hydrothermal CO2 fluxes. Our field tests were conducted (between April 2013 and March 2014 at Nea Kameni (Santorini, Greece, Hekla and Krýsuvík (Iceland and Vulcano (Aeolian Islands, Italy. At these sites, the tunable laser was used to measure the path-integrated CO2 mixing ratios along cross-sections of the fumaroles' atmospheric plumes. By using a tomographic post-processing routine, we then obtained, for each manifestation, the contour maps of CO2 mixing ratios in the plumes and, from their integration, the CO2 fluxes. The so-calculated CO2 fluxes range from low (5.7 ± 0.9 t day−1; Krýsuvík to moderate (524 ± 108 t day−1; "La Fossa" crater, Vulcano. Overall, we suggest that the cumulative CO2 contribution from weakly degassing volcanoes in hydrothermal stage of activity may be significant at global scale.

  14. Broadband spectroscopic sensor for real-time monitoring of industrial SO(2) emissions.

    Science.gov (United States)

    Xu, Feng; Zhang, Yungang; Somesfalean, Gabriel; Wang, Huashan; Wu, Shaohua; Zhang, Zhiguo

    2007-05-01

    A spectroscopic system for continuous real-time monitoring of SO(2) concentrations in industrial emissions was developed. The sensor is well suited for field applications due to simple and compact instrumental design, and robust data evaluation based on ultraviolet broadband absorption without the use of any calibration cell. The sensor has a detection limit of 1 ppm, and was employed both for gas-flow simulations with and without suspended particles, and for in situ measurement of SO(2) concentrations in the flue gas emitted from an industrial coal-fired boiler. The price/performance ratio of the instrument is expected to be superior to other comparable real-time monitoring systems.

  15. Rate constant for the reaction SO + BrO yields SO2 + Br

    Science.gov (United States)

    Brunning, J.; Stief, L.

    1986-01-01

    The rate of the radical-radical reaction SO + BrO yields SO2 + Br has been determined at 298 K in a discharge flow system near 1 torr pressure with detection of SO and BrO via collision-free sampling mass spectrometry. The rate constant was determined using two different methods: measuring the decay of SO radicals in the presence of an excess of BrO and measuring the decay of BrO radicals in excess SO. The results from the two methods are in reasonable agreement and the simple mean of the two values gives the recommended rate constant at 298 K, k = (5.7 + or - 2.0) x 10 to the -11th cu cm/s. This represents the first determination of this rate constant and it is consistent with a previously derived lower limit based on SO2 formation. Comparison is made with other radical-radical reactions involving SO or BrO. The reaction SO + BrO yields SO2 + Br is of interest for models of the upper atmosphere of the earth and provides a potential coupling between atmospheric sulfur and bromine chemistry.

  16. [Study of the Detecting System of CH4 and SO2 Based on Spectral Absorption Method and UV Fluorescence Method].

    Science.gov (United States)

    Wang, Shu-tao; Wang, Zhi-fang; Liu, Ming-hua; Wei, Meng; Chen, Dong-ying; Wang, Xing-long

    2016-01-01

    According to the spectral absorption characteristics of polluting gases and fluorescence characteristics, a time-division multiplexing detection system is designed. Through this system we can detect Methane (CH4) and sulfur dioxide (SO2) by using spectral absorption method and the SO2 can be detected by using UV fluorescence method. The system consists of four parts: a combination of a light source which could be switched, the common optical path, the air chamber and the signal processing section. The spectral absorption characteristics and fluorescence characteristics are measured first. Then the experiment of detecting CH4 and SO2 through spectral absorption method and the experiment of detecting SO2 through UV fluorescence method are conducted, respectively. Through measuring characteristics of spectral absorption and fluorescence, we get excitation wavelengths of SO2 and CH4 measured by spectral absorption method at the absorption peak are 280 nm and 1.64 μm, respectively, and the optimal excitation wavelength of SO2 measured by UV fluorescence method is 220 nm. we acquire the linear relation between the concentration of CH4 and relative intensity and the linear relation between the concentration of SO2 and output voltage after conducting the experiment of spectral absorption method, and the linearity are 98.7%, 99.2% respectively. Through the experiment of UV fluorescence method we acquire that the relation between the concentration of SO2 and the voltage is linear, and the linearity is 99.5%. Research shows that the system is able to be applied to detect the polluted gas by absorption spectrum method and UV fluorescence method. Combing these two measurement methods decreases the costing and the volume, and this system can also be used to measure the other gases. Such system has a certain value of application.

  17. 40 CFR 96.286 - Withdrawal from CAIR SO2 Trading Program.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR SO2 Opt-in Units § 96.286 Withdrawal from CAIR SO2 Trading Program. Except as...

  18. 40 CFR 97.286 - Withdrawal from CAIR SO2 Trading Program.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Withdrawal from CAIR SO2 Trading... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR SO2 Opt-in Units § 97.286 Withdrawal from CAIR SO2 Trading Program. Except as provided under paragraph (g)...

  19. INTERACTION BETWEEN SO2 FROM FLUE GAS AND SORBENT PARTICLES IN DRY FGD PROCESSES

    Institute of Scientific and Technical Information of China (English)

    Haiying; Qi; Changfu; You; Xuchang; Xu

    2005-01-01

    Among the technologies to control SO2 emission from coal-fired boilers, the dry flue gas desulphurization (FGD) method,with appropriate modifications, has been identified as a candidate for realizing high SO2 removal efficiency to meet both technical and economic requirements, and for making the best quality byproduct gypsum as a useful additive for improving alkali soil.Among the possible modifications two major factors have been selected for study:(1) favorable chemical reaction kinetics at elevated temperatures and the sorbent characteristics;(2) enhanced diffusion of SO2 to the surface and within the pores of sorbent particles that are closely related to gas-solid two-phase flow patterns caused by flue gas and sorbent particles in the reactor.To achieve an ideal pore structure, a sorbent was prepared through hydration reaction by mixing lime and fly ash collected from bag house of power plants to form a slurry, which was first dewatered and then dried. The dry sorbent was found capable of rapid conversion of 70% of its calcium content at 700 ℃, reaching a desulphurization efficiency of over 90% at a Ca/S ratio of 1.3.Experiments confirmed that the diffusion effect of SO2 is an important factor and that gas-solid two-phase flow plays a key role to mixing and contact between SO2 and sorbent particles. For designing the FDG reactor, a new theoretical drag model was developed by combination of CFD with the Energy Minimization Multi-Scale (EMMS) theory for dense fluidization systems. This new drag model was first verified by comparing calculated and measured drag values, and was then implemented in simulation of gas-solid two-phase flow in two circulating fluidized beds with different sizes and flow parameters. One riser has diameter and height of 0.15 m×3 m and another one 0.2 m×14.2 m. Their superficial gas velocities The results show that not only the static pressure drop along the riser height, but also radial distributions of particle volume fraction have

  20. 基于相关滤波技术的SO2气体浓度监测系统设计%Detection System of SO2 Concentration Based on Gas Filter Correlation Technology

    Institute of Scientific and Technical Information of China (English)

    姚娜; 张记龙; 王志斌; 王相如; 张跃国

    2011-01-01

    A method of non-dispersion infrared absorption technology based on gas filter correlation technology for measuring SO2 is described in this paper. Based on the correlation operation principle and the gas characteristics absorption in infrared region, the method combining correlation technology and gas filter correlation (GFC) technology effectively solves the problems that SO2 air pollution in china is serious in recent years and atmosphere SO2 detection with non-dispersion Infrared system faces the problem of high noise interference. It brings about modulation and detection for feeble spectrum signal. And it realizes the new monitor design of SO2 concentration in the eventual. The experiment results show that the detection sensitivity of system can reach lppm.%介绍一种基于相关滤波技术的非分散红外SO2气体浓度测量方法.该方法是在相关运算原理和SO2红外吸收特性基础上,结合相关检测和气体滤波技术,有效解决了近年来空气中SO2污染严重且在非分散红外SO2检测系统中噪声干扰大的问题,实现了对微弱光信号的调制和检测,并实现了新型SO2浓度监测仪的设计.试验表明,系统有10(-6)的检测灵敏度.

  1. The change in O3, SO2 and NO2 concentrations in Lithuania.

    Science.gov (United States)

    Girgzdiene, Rasa; Sopauskiene, Dalia; Girgzdys, Aloyzas

    2002-01-01

    Due to the dynamic nature of the atmosphere, substantial amounts of gaseous and particulate pollutants are transported to the areas distant from their sources. In order to determine the regional concentration levels of atmospheric pollutants in Lithuania, concentrations of gaseous O3, SO2, NO2 and other pollutants have been measured at the Preila background station (55 degrees 20' N and 21 degrees 00' E, 5 m a.s.l.) since 1981. The long-term concentration data set enabled us to get temporal trends, both on a seasonal and longer time scale, to identify source areas of pollutants and to relate them to the emission data. Based on the data obtained, the different tendencies in the pollutant concentration changes were revealed. Positive trends for ozone (of 2.9% per year during 1983-2000) and a distinct negative trend for both sulphur dioxide (of 3.8% per year during 1981-2000) and nitrogen dioxide (of 3.8% per year during 1983-2000) were found. The air mass back-trajectory analysis was used to assess the source region of air pollutants transported to Lithuania. The pollutant concentration levels were compared with their emission changes in Europe and Lithuania. The general trends in SO2 as well as in NO2 concentrations observed are consistent with changes in SO2 and NO2 emissions in Europe and Lithuania.

  2. Effects of NOx and SO2 in cathode stream on the performance of PEMFC

    Institute of Scientific and Technical Information of China (English)

    杨代军; 马建新; 周伟; 马晓伟; 邬敏忠; 徐麟; 万钢

    2006-01-01

    The effects of NOx(in a ratio of NO:NO2 = 9:1) and SO2 in cathode stream on the performance of a single proton exchange membrane fuel cell (PEMFC) were investigated. NOx with concentrations of 1×10-3% (in volume, the same as follows), 1.4×10-2% and 1×10-3% could cause significant detrimental effects on the cell performance. However, nearly complete recovery of the cell performance could be observed after NOx was shut off and purged with clean air. The electrochemical measurements suggested that the impacts of NOx resulted mainly from the superposition of the oxygen reduction reaction (ORR),NO and HNO2 oxidation reactions, and the increased cathodic impedance. Trace SO2 with concentrations of 5 × 10-6%, 5 ×10-3%, 2 × 10-4% and 3.2 × 10-4% influenced the cell much severer, which could be attributed to its strong adsorption on the surface of Pt atoms. The cell performance could not be completely recovered after purged with clean air and cyclic voltammetry (CV) tests, due to the changes of electrochemical impedance spectroscopy (ELS) and electrochemical active surface (EAS) caused by surface state change after SO2 exposure.

  3. Global volcanic aerosol properties derived from emissions, 1990-2014, using CESM1(WACCM): VOLCANIC AEROSOLS DERIVED FROM EMISSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Michael J. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Schmidt, Anja [School of Earth and Environment, University of Leeds, Leeds UK; Easter, Richard [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Solomon, Susan [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge Massachusetts USA; Kinnison, Douglas E. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Ghan, Steven J. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Neely, Ryan R. [School of Earth and Environment, University of Leeds, Leeds UK; National Centre for Atmospheric Science, University of Leeds, Leeds UK; Marsh, Daniel R. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Conley, Andrew [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Bardeen, Charles G. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Gettelman, Andrew [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA

    2016-03-06

    Accurate representation of global stratospheric aerosol properties from volcanic and non-volcanic sulfur emissions is key to understanding the cooling effects and ozone-loss enhancements of recent volcanic activity. Attribution of climate and ozone variability to volcanic activity is of particular interest in relation to the post-2000 slowing in the apparent rate of global average temperature increases, and variable recovery of the Antarctic ozone hole. We have developed a climatology of global aerosol properties from 1990 to 2014 calculated based on volcanic and non-volcanic emissions of sulfur sources. We have complied a database of volcanic SO2 emissions and plume altitudes for eruptions between 1990 and 2014, and a new prognostic capability for simulating stratospheric sulfate aerosols in version 5 of the Whole Atmosphere Community Climate Model, a component of the Community Earth System Model. Our climatology shows remarkable agreement with ground-based lidar observations of stratospheric aerosol optical depth (SAOD), and with in situ measurements of aerosol surface area density (SAD). These properties are key parameters in calculating the radiative and chemical effects of stratospheric aerosols. Our SAOD climatology represents a significant improvement over satellite-based analyses, which ignore aerosol extinction below 15 km, a region that can contain the vast majority of stratospheric aerosol extinction at mid- and high-latitudes. Our SAD climatology significantly improves on that provided for the Chemistry-Climate Model Initiative, which misses 60% of the SAD measured in situ. Our climatology of aerosol properties is publicly available on the Earth System Grid.

  4. An oscillating microbalance for meteorological measurements of ice and volcanic ash accumulation from a weather balloon platform

    Science.gov (United States)

    Airey, Martin; Harrison, Giles; Nicoll, Keri; Williams, Paul; Marlton, Graeme

    2017-04-01

    A new, low cost, instrument has been developed for meteorological measurements of the accumulation of ice and volcanic ash that can be readily deployed using commercial radiosondes and weather balloons. It is based on principles used by [1], an instrument originally developed to measure supercooled liquid water profiles in clouds. This new instrument introduces numerous improvements in terms of reduced complexity and cost. It uses the oscillating microbalance principle, whereby a wire vibrating at its natural frequency is subjected to increased loading of the property to be measured. The increase in mass modifies the wire properties such that its natural frequency of oscillation changes. By measuring this frequency, the increase in mass can be inferred and transmitted to a ground base station through the radiosonde's UHF antenna via the PANDORA interface [2], which has been previously developed to provide power and connection to the radiosonde telemetry. The device consists of a simple circuit board controlled by an ATMEGA microcontroller. For calibration, the controller is capable of driving the wire at specified frequencies via excitation by a piezo sounder upon which the wire is mounted. The same piezo sounder is also used during active operation to measure the frequency of the wire in its non-driven state in order to infer the mass change on the wire. A phase-locked loop implemented on the board identifies when resonance occurs and the measured frequency is stable, prompting the microcontroller to send the measurement through the data interface. The device may be used for any application that requires the measurement of incremental mass variation e.g. ice accumulation, frosting, or particle accumulation such as dust and volcanic ash. For the solid particle accumulation, a low temperature, high-tack, adhesive may be applied to the wire prior to deployment to collect the material. In addition, the same instrument may be used for ground-based applications, such as

  5. Sulfur Isotopic Fractionation During Vacuum Ultraviolet Photolysis of SO2: Implication for Meteorites and Early Earth

    Science.gov (United States)

    Chakraborty, S.; Jackson, T. L.; Rude, B.; Ahmed, M.; Thiemens, M. H.

    2016-12-01

    Several sulfur bearing gas phase species existed in the solar nebula, including H2S, SO2, SiS, OCS, CS2, CS, NS and SO as a consequence of multiple available chemical valence states (S2- to S6+). Sulfur directly condensed into refractory phases in the solar nebula under reducing conditions. Mass independent (MI) sulfur isotopic compositions have been measured in chondrules and organics from chondritic meteorites. Large 33S excesses in sulfides from achondrite meteoritic groups have also been found suggesting that refractory sulfide minerals condensed from a nebular gas with an enhanced carbon to oxygen ratio. Photochemical reactions in the early solar nebula have been inferred to be a leading process in generating MI sulfur compositions. Previously, we have reported wavelength dependent mass-independent sulfur isotopic compositions (with a varying degree in D33S and D36S) in the product elemental sulfur during vacuum ultraviolet (VUV) photodissociation of H2S. Recently we performed photodissociation of SO2 experiments in the wavelength region 98 to 200 nm at low pressures (0.5 torr) using the VUV photons from the Advanced Light Source Synchrotron in a differentially pumped reaction chamber. To our knowledge, this is the first ever experiment to determine the isotopic fractionation in VUV photodissociation of SO2. At VUV energy region, SO2 is mostly predissociative. The measured sulfur isotopic compositions in the product elemental sulfur are MI and dependent on the wavelength. These new results support the previous finding from photodissociation of other di- and tri-atomic molecules (CO, N2, H2S) that predissociative photodissociation produces MI isotopic products and is a quantum mechanically driven selective phenomenon. These new results are useful because (i) they are important in interpreting meteoritic data and decipher sulfur chemistry in the early nebula which is indicative of the redox condition of the nebula (ii) SO2 photolysis in the atmosphere of early

  6. 铁矿烧结烟气中SO2的排放规律%Emission rule of SO2 in flue gas during sintering

    Institute of Scientific and Technical Information of China (English)

    潘建; 朱德庆; 崔瑜; 陈栋; 周仙霖

    2011-01-01

    从烧结过程燃料用量、混合料水分、烧结矿碱度及混合料含硫量研究烧结工艺参数对烧结烟气中SO2排放的影响,发现烧结过程SO2的排放不受烧结工艺参数及原料含硫变化的影响,在烧结终点前始终存在一个排放浓度峰值区间,揭示烧结烟气SO2排放的自持性规律是由于烧结料层有选择性吸附SO2作用所导致,SO2的排放遵循硫化物、硫酸盐热分解生成-料层吸附-再分解-解吸的迁移及循环富集排放机理。%The effect of sinter technology parameters, including coke ratio, moisture, basicity and sulphur content in sinter mix, on the emission of SO2 in sintering flue gas was studied. The results show that the emission of SO2 rises to a peak value rapidly just before the sintering end point and declines dramatically no matter how parameters of sinter technology and the properties of raw material change. The self-sustaining characteristics of SO2 emission results from the selectively adsorbing SO2 by sinter bed, and the emission of SO2 is controlled by the mechanism of transfer and cycling enrichment which consists of sulphide and sulphate pyrogenation formation-sinter bed adsorption-further decomposition-desorption of SO2.

  7. Monitoring volcanic systems through cross-correlation of coincident A-Train satellite data.

    Science.gov (United States)

    Flower, V. J. B.; Carn, S. A.; Wright, R.

    2014-12-01

    The remote location and inaccessibility of many active volcanic systems around the world hinders detailed investigation of their eruptive dynamics. One methodology for monitoring such locations is through the utilisation of multiple satellite datasets to elucidate underlying eruption dynamics and aid volcanic hazard mitigation. Whilst satellite datasets are often analysed individually, here we exploit the multi-platform NASA A-Train satellite constellation, including the Ozone Monitoring Instrument (OMI) on Aura and Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua. OMI measures volcanic emissions (e.g. sulphur dioxide, ash) whilst MODIS enables monitoring of thermal anomalies (e.g. lava flows, lava lakes, pyroclastic deposits), allowing analysis of a more diverse range of volcanic unrest than is possible using a single measurement technique alone, and permitting cross-correlation between datasets for specific locations to assess cyclic activity. A Multi-taper (MTM) Fast Fourier Transform (FFT) analysis was implemented at an initial sample site (Soufriere Hills volcano [SHV], Montserrat) facilitating cycle identification and subsequent comparison with existing ground-based data. Corresponding cycles at intervals of 8, 12 and ~50 days were identified in both the satellite-based SO2 and thermal infrared signals and ground-based SO2 measurements (Nicholson et al. 2013), validating the methodology. Our analysis confirms the potential for identification of cyclical volcanic activity through synergistic analysis of satellite data, which would be of particular value at poorly monitored volcanic systems. Following our initial test at SHV, further sample sites have been selected in locations with varied eruption dynamics and monitoring capabilities including Ambrym (Vanuatu), Kilauea (Hawaii), Nyiragongo (DR Congo) and Etna (Italy) with the intention of identifying not only cyclic signals that can be attributed to volcanic systems but also those which are

  8. Computer-assisted design of imidazolate-based ionic liquids for improving SO2 capture, CO2 capture, and SO2/CO2 selectivity.

    Science.gov (United States)

    Cui, Guokai; Zhao, Ning; Wang, Jianji; Wang, Congmin

    2017-08-24

    A new strategy using computer-assisted design of substituted imidazolate-based ionic liquids (ILs) through tuning the absorption enthalpy as well as the basicity of ILs for improving SO2 capture, CO2 capture, and SO2/CO2 selectivity was reported. The best substituted imidazolate-based ILs as absorbents for different applications were predicted at first. During the absorption, a high SO2 capacity up to 5.28 and 2.38 mole SO2 per mole IL could be achieved by ILs with CH3-imidazolate anion under 1.0 and 0.1 bar, respectively, through tuning multiple N∙∙∙S interactions between SO2 and N atoms in the imidazolate anion with different substituent. In addition, CO2 capture by imidazolate-based ILs could also be easily tuned through changing the substitute of ILs, and Br-imidazolate IL showed the high CO2 capacity but low absorption enthalpy. Furthermore, the high selectivity for SO2/CO2 could be reached by imidazolate-based ILs with CN-imidazolate anion due to their high SO2 capacity but low CO2 capacity. The results put forward in this work are in good agreement with the prediction. Quantum chemical calculations, FT-IR and NMR analysis methods were used to discuss SO2 and CO2 absorption mechanism. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A 780-year record of explosive volcanism from DT263 ice core in east Antarctica

    Institute of Scientific and Technical Information of China (English)

    ZHOU Liya; LI Yuansheng; Jihong Cole-da; TAN Dejun; SUN BO; REN Jiawen; WEI Lijia; WANG Henian

    2006-01-01

    Ice cores recovered from polar ice sheet Received and preserved sulfuric acid fallout from explosive volcanic eruptions. DT263 ice core was retrieved from an east Antarctic location. The ice core is dated using a combination of annual layer counting and volcanic time stratigraphic horizon as 780 years (1215-1996 A.D.). The ice core record demonstrates that during the period of approximately 1460-1800 A.D., the accumulation is sharply lower than the levels prior to and after this period. This period coincides with the most recent neoglacial climatic episode, the "Little Ice Age (LIA)", that has been found in numerous Northern Hemisphere proxy and historic records.The non-sea-salt SO2-4 concentrations indicate seventeen volcanic events in DT263 ice core. Compared with those from previous Antarctic ice cores, significant discrepancies are found between these records in relative volcanic flux of several well-known events. The discrepancies among these records may be explained by the differences in surface topography, accumulation rate, snow drift and distribution which highlight the potential impact of local glaciology on ice core volcanic records, analytical techniques used for sulfate measurement, etc. Volcanic eruptions in middle and high southern latitudes affect volcanic records in Antarctic snow more intensively than those in the Iow latitudes.

  10. SO2毒化后质子交换膜燃料电池性能的恢复%Recovery of the proton exchange membrane fuel cell performance after being poisoned by SO2

    Institute of Scientific and Technical Information of China (English)

    翟俊香; 侯明; 邵志刚; 衣宝廉

    2012-01-01

    研究了二氧化硫(SO2)毒化后质子交换膜燃料电池性能恢复的方法.洁净空气吹扫、维持电池开路及I-U操作均可使毒化后的电池性能得到部分恢复,1.5×10-3% SO2毒化后电池性能分别恢复到初始性能的71%、94%及90%;循环伏安扫描和电压脉冲均可彻底清除电极上吸附的SO2,3.0× 10-3% SO2毒化后电池性能几乎得到完全恢复.%Recovery methods of the proton exchange membrane fuel cell performance after being poisoned by sulfur dioxide (SO2) were studied. Pure air purging,kept open circuit voltage and I-U operations all recovered partially the performance of the cell after poisoned.After poisoned by 1.5x 10-3% SO2,the performance of the cell recovered to 71%,94% and 90% of the initial one, respectively.Both cycle voltammery measurement and potential pulse could remove SO2 adsorbed on the electrode,almost complete recovery of the performance was obtained after the cell poisoned by3.0×l0-3% SO2.

  11. Adsorption of SO2 and NO from incineration flue gas onto activated carbon fibers.

    Science.gov (United States)

    Liu, Zhen-Shu

    2008-11-01

    Activated carbon fibers (ACFs) were used to remove SO2 and NO from incineration flue gas. Three types of ACFs in their origin state and after pretreatment with HNO3, NaOH, and KOH were investigated. The removal efficiencies of SO2 and NO were determined experimentally at defined SO2 and NO concentrations and at temperatures of 150, 200 and 260 degrees C. Experimental results indicated that the removal efficiencies of SO2 and NO using the original ACFs were < 56% and < 27%, respectively. All ACFs modified with HNO3, NaOH, and KOH solution could increase the removal efficiencies of SO(2) and NO. The mesopore volumes and functional groups of ACFs are important in determining the removal of SO2 and NO. When the mesopore volumes of the ACFs are insufficient for removing SO2 and NO, the functional groups on the ACFs are not important in determining the removal of SO2 and NO. On the contrary, the effects of the functional groups on the removal of SO2 and NO are more important than the mesopore volumes as the amount of mesopores on the ACFs is sufficient to remove SO2 and NO. Moreover, the removal efficiencies of SO2 and NO were greatest at 200 degrees C. When the inlet concentration of SO2 increased to 600 ppm, the removal efficiency of SO2 increased slightly and the removal efficiency of NO decreased.

  12. Sulfur isotope fractionation during heterogeneous oxidation of SO2 on mineral dust

    Directory of Open Access Journals (Sweden)

    P. Hoppe

    2012-06-01

    Full Text Available Mineral dust is a major fraction of global atmospheric aerosol, and the oxidation of SO2 on mineral dust has implications for cloud formation, climate and the sulfur cycle. Stable sulfur isotopes can be used to understand the different oxidation processes occurring on mineral dust. This study presents measurements of the 34S/32S fractionation factor α34 for oxidation of SO2 on mineral dust surfaces and in the aqueous phase in mineral dust leachate. Sahara dust, which accounts for ~60% of global dust emissions and loading, was used for the experiments. The fractionation factor for aqueous oxidation in dust leachate is αleachate = 0.9917±0.0046, which is in agreement with previous measurements of aqueous SO2 oxidation by iron solutions. This fractionation factor is representative of a radical chain reaction oxidation pathway initiated by transition metal ions. Oxidation on the dust surface at subsaturated relative humidity (RH had an overall fractionation factor of αhet = 1.0096±0.0036 and was found to be almost an order of magnitude faster when the dust was simultaneously exposed to ozone, light and RH of ~40%. However, the presence of ozone, light and humidity did not influence isotope fractionation during oxidation on dust surfaces at subsaturated relative humidity. All the investigated reactions showed mass-dependent fractionation of 33S relative to 34S. A positive matrix factorization model was used to investigate surface oxidation on the different components of dust. Ilmenite, rutile and iron oxide were found to be the most reactive components, accounting for 85% of sulfate production with a fractionation factor of α34 = 1.012±0.010. This overlaps within the analytical uncertainty with the fractionation of other major atmospheric oxidation pathways such as the oxidation of SO2 by H2O2 and O3 in the aqueous phase and OH in the gas phase. Clay minerals accounted for roughly 12% of the sulfate production, and oxidation on clay minerals

  13. Sulfur isotope fractionation during heterogeneous oxidation of SO2 on mineral dust

    Directory of Open Access Journals (Sweden)

    P. Hoppe

    2012-01-01

    Full Text Available Mineral dust is a major fraction of global atmospheric aerosol, and the oxidation of SO2 on mineral dust has implications for cloud formation, climate and the sulfur cycle. Stable sulfur isotopes can be used to understand the different oxidation processes occurring on mineral dust. This study presents measurements of the 34S/32S fractionation factor α34 for oxidation of SO2 on mineral dust surfaces and in the aqueous phase in mineral dust leachate. Sahara dust, which accounts for ~ 60% of global dust emissions and loading, was used for the experiments. The fractionation factor for aqueous oxidation in dust leachate is αleachate = 0.9917 ± 0.0046, which is in agreement with previous measurements of aqueous SO2 oxidation by iron solutions. This fractionation factor is representative of a radical chain reaction oxidation pathway initiated by transition metal ions. Oxidation on the dust surface at subsaturated relative humidity (RH had an overall fractionation factor of αhet = 1.0096 ± 0.0036 and was found to be almost an order of magnitude faster when the dust was simultaneously exposed to ozone, light and RH of ~ 40%. However, the presence of ozone, light and humidity did not influence isotope fractionation during oxidation on dust surfaces at subsaturated relative humidity. A positive matrix factorization model was used to investigate surface oxidation on the different components of dust. Ilmenite, rutile and iron oxide were found to be the most reactive components, accounting for 85% of sulfate production with a fractionation factor of α34 = 1.012 ± 0.010. This overlaps within the analytical uncertainty with the fractionation of other major atmospheric oxidation pathways such as the oxidation of SO2 by H2O2 and O3 in the aqueous phase and OH in the gas phase. Clay minerals accounted for roughly 12% of the sulfate production, and oxidation on clay minerals resulted in a very distinct fractionation factor of α34 = 1.085 ± 0.013. The

  14. 40 CFR 97.254 - Compliance with CAIR SO2 emissions limitation.

    Science.gov (United States)

    2010-07-01

    ... sulfur dioxide emissions, determined in accordance with subpart HHH of this part, from all CAIR SO2 units... subpart HHH of this part, from all CAIR SO2 units at the source for the control period; or (ii) If...

  15. 40 CFR 96.254 - Compliance with CAIR SO2 emissions limitation.

    Science.gov (United States)

    2010-07-01

    ... sulfur dioxide emissions, determined in accordance with subpart HHH of this part, from all CAIR SO2 units... subpart HHH of this part, from all CAIR SO2 units at the source for the control period; or (ii) If...

  16. Observations of SO2 and NO2 by mobile DOAS in the Guangzhou Eastern Area during the Asian Games 2010

    Directory of Open Access Journals (Sweden)

    J. G. Liu

    2013-01-01

    Full Text Available Mobile Differential Optical Absorption Spectroscopy measurements of SO2 and NO2 were performed in the Guangzhou Eastern Area (GEA during the Guangzhou Asian Games 2010 from November 2010 to December 2010. Spatial and temporal distributions of SO2 and NO2 in this area were obtained and emission sources were determined by using wind field data. The NO2 vertical column densities were found to agree with OMI values. The correlation coefficient (R2 was 0.88 after cloud filtering. During the Guangzhou Asian Games and Asian Paralympics (Para Games, the SO2 and NO2 emissions in the area were quantified using averaged wind speed and wind direction. For times outside the Games the average SO2 emission was estimated to be 9.50 ± 0.90 tons per hour and the average NO2 emission was estimated to be 3.50 ± 1.89 tons per hour. During the phases of the Asian and Asian Para Games, the SO2 and NO2 emissions were reduced by 53.5 and 46%, respectively, compared to the usual condition. We also investigated the influence of GEA on Guangzhou University Town, the main venue located northwest of the GEA, and found that SO2 concentrations here were about tripled by emissions from the GEA.

  17. Observations of SO2 and NO2 by mobile DOAS in the Guangzhou eastern area during the Asian Games 2010

    Science.gov (United States)

    Wu, F. C.; Xie, P. H.; Li, A.; Chan, K. L.; Hartl, A.; Wang, Y.; Si, F. Q.; Zeng, Y.; Qin, M.; Xu, J.; Liu, J. G.; Liu, W. Q.; Wenig, M.

    2013-09-01

    Mobile passive differential optical absorption spectroscopy measurements of SO2 and NO2 were performed in the Guangzhou eastern area (GEA) during the Guangzhou Asian Games 2010 from November 2010 to December 2010. The observations were carried out between 10:00 to 13:00 (local time, i.e., during daylight). Spatial and temporal distributions of SO2 and NO2 in this area were obtained and emission sources were determined using wind field data. The NO2 vertical column densities were found to agree with Ozone Monitoring Instrument values. The correlation coefficient (referred to as R2) was 0.88 after cloud filtering within a specific ground pixel. During the Guangzhou Asian Games and Asian Paralympics (Para) Games, the SO2 and NOx emissions in the area were quantified using averaged wind speed and wind direction. For times outside the games the average SO2 emission was estimated to be 9.50 ± 0.90 tons per hour and the average NOx emission was estimated to be 5.87 ± 3.46 tons per hour. During the phases of the Asian and Asian Para Games, the SO2 and NOx emissions were reduced by 53.50% and 43.50%, respectively, compared to the usual condition. We also investigated the influence of GEA on Guangzhou University Town, the main venue located northwest of the GEA, and found that SO2 concentrations here were about tripled by emissions from the GEA.

  18. Preliminary Discussion on Sinopec's Countermeasures to Control SO2 Pollution%中国石化控制SO2污染对策初探

    Institute of Scientific and Technical Information of China (English)

    李援

    2004-01-01

    根据我国SO2排放现状及国家对其控制的要求,分析了中国石化面临的紧迫形势,着重介绍和分析了美国利用排污权交易控制SO2的经验和我国排污权交易试点的进展、成果等,提出了中国石化控制SO2的方向、整体思路和需要解决的问题.

  19. Support to Aviation Control Service (SACS: an online service for near real-time satellite monitoring of volcanic plumes

    Directory of Open Access Journals (Sweden)

    H. Brenot

    2013-10-01

    Full Text Available Volcanic eruptions emit plumes of ash and gases in the atmosphere, potentially at very high altitudes. Ash rich plumes are hazardous for airplanes as ash is very abrasive and easily melts inside their engines. With more than 50 active volcanoes per year and the ever increasing number of commercial flights, the safety of airplanes is a real concern. Satellite measurements are ideal for monitoring global volcanic activity and, in combination with atmospheric dispersion models, to track and forecast volcanic plumes. Here we present the Support to Aviation Control Service (SACS, http://sacs.aeronomie.be, which is a free online service initiated by ESA for the near real-time (NRT satellite monitoring of volcanic plumes of SO2 and ash. It combines data from two UV-visible (OMI, GOME-2 and two infrared (AIRS, IASI spectrometers. This new multi-sensor warning system of volcanic plumes, running since April 2012, is based on the detection of SO2 and is optimised to avoid false alerts while at the same time limiting the number of notifications in case of large plumes. The system shows successful results with 95% of our notifications corresponding to true volcanic activity.

  20. Fourier Transform Infrared (FT-IR) Spectroscopy of Atmospheric Trace Gases HCl, NO and SO2

    Science.gov (United States)

    Haridass, C.; Aw-Musse, A.; Dowdye, E.; Bandyopadhyay, C.; Misra, P.; Okabe, H.

    1998-01-01

    Fourier Transform Infrared (FT-IR) spectral data have been recorded in the spectral region 400-4000/cm of hydrogen chloride and sulfur dioxide with I/cm resolution and of nitric oxide with 0.25 cm-i resolution, under quasi-static conditions, when the sample gas was passed through tubings of aluminum, copper, stainless steel and teflon. The absorbance was measured for the rotational lines of the fundamental bands of (1)H(35)Cl and (1)H(37)Cl for pressures in the range 100-1000 Torr and for the (14)N(16)O molecule in the range 100-300 Torr. The absorbance was also measured for individual rotational lines corresponding to the three modes of vibrations (upsilon(sub 1) - symmetric stretch, upsilon(sub 2) - symmetric bend, upsilon(sub 3) - anti-symmetric stretch) of the SO2 molecule in the pressure range 25-150 Torr. A graph of absorbance versus pressure was plotted for the observed rotational transitions of the three atmospherically significant molecules, and it was found that the absorbance was linearly proportional to the pressure range chosen, thereby validating Beer's law. The absorption cross-sections were determined from the graphical slopes for each rotational transition recorded for the HCl, NO and SO2 species. Qualitative and quantitative spectral changes in the FT-IR data will be discussed to identify and characterize various tubing materials with respect to their absorption features.

  1. Exploring a long-lasting volcanic eruption by means of in-soil radon measurements and seismic activity

    Science.gov (United States)

    Falsaperla, Susanna; Neri, Marco; Di Grazia, Giuseppe; Langer, Horst; Spampinato, Salvatore

    2016-04-01

    We analyze in-soil radon (Rn) emission and ambient parameters (barometric pressure and air temperature measurements) along with seismic activity during the longest flank eruption of this century at Mt. Etna, Italy. This eruption occurred between 14 May 2008 and 6 July 2009, from a N120-140°E eruptive fissure extending between 3050 and 2620 m above sea level. It was heralded by a short-lived (~5 hours) episode of lava fountaining three days before a dike-forming intrusion fed a lava emission, which affected the summit area of the volcano over ~15 months. The peculiar position of the station for the Rn measurement, which was at an altitude of 2950 m above sea level and near (~1 km) the summit active craters, offered us the uncommon chance: i) to explore the temporal development of the gas emission close (relationship between in-soil Rn fluxes and seismic signals (in particular, local earthquakes and volcanic tremor) during the uninterrupted lava emission. This approach reveals important details about the recharging phases characterizing the 2008-2009 eruption, which are not visible with other methods of investigation. Our study benefitted from the application of methods of pattern classification developed in the framework of the European MEDiterrranean Supersite Volcanoes (MED­SUV) project.

  2. An overview of the Icelandic Volcano Observatory response to the on-going rifting event at Bárðarbunga (Iceland) and the SO2 emergency associated with the gas-rich eruption in Holuhraun

    Science.gov (United States)

    Barsotti, Sara; Jonsdottir, Kristin; Roberts, Matthew J.; Pfeffer, Melissa A.; Ófeigsson, Benedikt G.; Vögfjord, Kristin; Stefánsdóttir, Gerður; Jónasdóttir, Elin B.

    2015-04-01

    On 16 August, 2014, Bárðarbunga volcano entered a new phase of unrest. Elevated seismicity in the area with up to thousands of earthquakes detected per day and significant deformation was observed around the Bárðarbunga caldera. A dike intrusion was monitored for almost two weeks until a small, short-lived effusive eruption began on 29 August in Holuhraun. Two days later a second, more intense, tremendously gas-rich eruption started that is still (as of writing) ongoing. The Icelandic Volcano Observatory (IVO), within the Icelandic Meteorological Office (IMO), monitors all the volcanoes in Iceland. Responsibilities include evaluating their related hazards, issuing warnings to the public and Civil Protection, and providing information regarding risks to aviation, including a weekly summary of volcanic activity provided to the Volcanic Ash Advisory Center in London. IVO has monitored the Bárðarbunga unrest phase since its beginning with the support of international colleagues and, in collaboration with the University of Iceland and the Environment Agency of Iceland, provides scientific support and interpretation of the ongoing phenomena to the local Civil Protection. The Aviation Color Code, for preventing hazards to aviation due to ash-cloud encounter, has been widely used and changed as soon as new observations and geophysical data from the monitoring network have suggested a potential evolution in the volcanic crisis. Since the onset of the eruption, IVO is monitoring the gas emission by using different and complementary instrumentations aimed at analyzing the plume composition as well as estimating the gaseous fluxes. SO2 rates have been measured with both real-time scanning DOASes and occasional mobile DOAS traveses, near the eruption site and in the far field. During the first month-and-a-half of the eruption, an average flux equal to 400 kg/s was registered, with peaks exceeding 1,000 kg/s. Along with these measurements the dispersal model CALPUFF has

  3. Formaldehyde and its relation to CO, PAN, and SO2 in the Houston-Galveston airshed

    Directory of Open Access Journals (Sweden)

    W. Luke

    2009-11-01

    Full Text Available The Houston-Galveston Airshed (HGA is one of the major metropolitan areas in the US that is classified as a nonattainment area of Federal ozone standards. Formaldehyde (HCHO is a key species in understanding ozone related air pollution; some of the highest HCHO concentrations in North America have been reported for the HGA. We report on HCHO measurements in the HGA from summer 2006. Among several sites, maximum HCHO mixing ratios were observed in the Houston Ship Channel (HSC, a region with a very high density of industrial/petrochemical operations. HCHO levels at the Moody Tower (MT site close to downtown were dependent on the wind direction: southerly maritime winds brought in background levels (0.5–1 ppbv while trajectories originating in the HSC resulted in high HCH (up to 31.5 ppbv. Based on the best multiparametric linear regression model fit, the HCHO levels at the MT site can be accounted for as follows: 38.5±12.3% from primary vehicular emissions (using CO as an index of vehicular emission, 24.1±17.7% formed photochemically (using peroxyacetic nitric anhydride (PAN as an index of photochemical activity and 8.9±11.2% from industrial emissions (using SO2 as an index of industrial emissions. The balance 28.5±12.7% constituted the residual which cannot be easily ascribed to the above categories and/or which is transported into the HGA. The CO related HCHO fraction is dominant during the morning rush hour (06:00–09:00 h, all times are given in CDT; on a carbon basis, HCHO emissions are up to 0.7% of the CO emissions. The SO2 related HCHO fraction is significant between 09:00–12:00 h. After 12:00 h HCHO is largely formed through secondary processes. The HCHO/PAN ratios are dependent on the SO2 levels. The SO2 related HCHO fraction at the downtown site originates in the ship channel. Aside from traffic-related primary HCHO emissions, HCHO of industrial origin serves as an appreciable source for OH in the morning.

  4. SAGE II Measurements of Stratospheric Aerosol Properties at Non-Volcanic Levels

    Science.gov (United States)

    Thomason, Larry W.; Burton, Sharon P.; Luo, Bei-Ping; Peter, Thomas

    2008-01-01

    Since 2000, stratospheric aerosol levels have been relatively stable and at the lowest levels observed in the historical record. Given the challenges of making satellite measurements of aerosol properties at these levels, we have performed a study of the sensitivity of the product to the major components of the processing algorithm used in the production of SAGE II aerosol extinction measurements and the retrieval process that produces the operational surface area density (SAD) product. We find that the aerosol extinction measurements, particularly at 1020 nm, remain robust and reliable at the observed aerosol levels. On the other hand, during background periods, the SAD operational product has an uncertainty of at least a factor of 2 during due to the lack of sensitivity to particles with radii less than 100 nm.

  5. [Experiment study on the aqueous removal of SO2 by Mn2+ catalytic ozonation].

    Science.gov (United States)

    Ma, Shuang-Chen; Su, Min; Ma, Jing-Xiang; Sun, Yun-Xue; Jin, Xin; Zhao, Yi

    2009-11-01

    The removal of SO2 by Mn2+ catalytic aqueous ozonation was investigated by experiment, so as to find the effects of Mn2+ for aqueous removal of SO2 by ozonation. The concentration curve of ozone was drawn by standard iodine method. The operating factors included mole ratio of ozone to sulfur dioxide and concentration of Mn2+. When absorption solution has no Mn2+, the removal efficiency of SO2 was 35% at [O3 ]/[SO2 ] = 0.5,but the efficiency was 70% when Mn2+ was put into absorption solution at the same value of [O3 ]/[SO2].With the increasing of [3O]/[SO2], the removal efficiency of SO2 increases. And as concentration of Mn2+ increases, the efficiency also increases. There is an appropriate concentration range which is 1.2 x 10(-2)-1.2 x 10(-1) mol/L for Mn2+.

  6. Effect of volcanic aerosol on stratospheric NO2 and N2O5 from 2002–2014 as measured by Odin-OSIRIS and Envisat-MIPAS

    Directory of Open Access Journals (Sweden)

    C. Adams

    2017-07-01

    Full Text Available Following the large volcanic eruptions of Pinatubo in 1991 and El Chichón in 1982, decreases in stratospheric NO2 associated with enhanced aerosol were observed. The Optical Spectrograph and Infrared Imaging Spectrometer (OSIRIS measured the widespread enhancements of stratospheric aerosol following seven volcanic eruptions between 2002 and 2014, although the magnitudes of these eruptions were all much smaller than the Pinatubo and El Chichón eruptions. In order to isolate and quantify the relationship between volcanic aerosol and NO2, NO2 anomalies were calculated using measurements from OSIRIS and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. In the tropics, variability due to the quasi-biennial oscillation was subtracted from the time series. OSIRIS profile measurements indicate that the strongest anticorrelations between NO2 and volcanic aerosol extinction were for the 5 km layer starting  ∼  3 km above the climatological mean tropopause at the given latitude. OSIRIS stratospheric NO2 partial columns in this layer were found to be smaller than background NO2 levels during these aerosol enhancements by up to  ∼  60 % with typical Pearson correlation coefficients of R ∼ −0. 7. MIPAS also observed decreases in NO2 partial columns during periods affected by volcanic aerosol, with percent differences of up to  ∼  25 % relative to background levels. An even stronger anticorrelation was observed between OSIRIS aerosol optical depth and MIPAS N2O5 partial columns, with R ∼ −0. 9, although no link with MIPAS HNO3 was observed. The variation in OSIRIS NO2 with increasing aerosol was found to be consistent with simulations from a photochemical box model within the estimated model uncertainty.

  7. An automated SO2 camera system for continuous, real-time monitoring of gas emissions from Kīlauea Volcano's summit Overlook Crater

    Science.gov (United States)

    Kern, Christoph; Sutton, Jeff; Elias, Tamar; Lee, Robert Lopaka; Kamibayashi, Kevan P.; Antolik, Loren; Werner, Cynthia A.

    2015-01-01

    SO2 camera systems allow rapid two-dimensional imaging of sulfur dioxide (SO2) emitted from volcanic vents. Here, we describe the development of an SO2 camera system specifically designed for semi-permanent field installation and continuous use. The integration of innovative but largely “off-the-shelf” components allowed us to assemble a robust and highly customizable instrument capable of continuous, long-term deployment at Kīlauea Volcano's summit Overlook Crater. Recorded imagery is telemetered to the USGS Hawaiian Volcano Observatory (HVO) where a novel automatic retrieval algorithm derives SO2 column densities and emission rates in real-time. Imagery and corresponding emission rates displayed in the HVO operations center and on the internal observatory website provide HVO staff with useful information for assessing the volcano's current activity. The ever-growing archive of continuous imagery and high-resolution emission rates in combination with continuous data from other monitoring techniques provides insight into shallow volcanic processes occurring at the Overlook Crater. An exemplary dataset from September 2013 is discussed in which a variation in the efficiency of shallow circulation and convection, the processes that transport volatile-rich magma to the surface of the summit lava lake, appears to have caused two distinctly different phases of lake activity and degassing. This first successful deployment of an SO2 camera for continuous, real-time volcano monitoring shows how this versatile technique might soon be adapted and applied to monitor SO2 degassing at other volcanoes around the world.

  8. Study of meteorological aspects and urban concentration of SO2 in atmospheric environment of La Plata, Argentina.

    Science.gov (United States)

    Ratto, Gustavo; Videla, Fabián; Almandos, J Reyna; Maronna, Ricardo; Schinca, Daniel

    2006-10-01

    This article presents and discusses SO(2) (ppbv) concentration measurements combined with meteorological data (mainly wind speed and direction) for a five-year campaign (1996 to 2000), in a site near an oil refinery plant close to the city of La Plata and surroundings (aprox. 740.000 inh.), considered one of the six most affected cities by air pollution in the country. Since there is no monitoring network in the area, the obtained results should be considered as medium term accumulated data that enables to determine trends by analyzing together gas concentrations and meteorological parameters. Preliminary characterization of the behaviour of the predominant winds of the region in relation with potential atmospheric gas pollutants from seasonal wind roses is possible to carry out from the data. These results are complemented with monthly averaged SO(2) measurements. In particular, for year 2000, pollutant roses were determined which enable predictions about contamination emission sources. As a general result we can state that there is a clear increase in annual SO(2) concentration and that the selected site should be considered as a key site for future survey monitoring network deployment. Annual SO(2) average concentration and prevailing seasonal winds determined in this work, together with the potential health impact of SO(2) reveals the need for a comprehensive and systematic study involving particulate matter an other basic pollutant gases.

  9. Measurements of radon and chemical elements: Popocatepetl volcano; Mediciones de radon y elementos quimicos: Volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Valdes, C.; Mena, M. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L.; Monnin, M. [UMR 5569 CNRS Hydrosciences, Montpellier (France)

    2002-07-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  10. Inverse transport modeling of volcanic sulfur dioxide emissions using large-scale ensemble simulations

    Science.gov (United States)

    Heng, Y.; Hoffmann, L.; Griessbach, S.; Rößler, T.; Stein, O.

    2015-10-01

    An inverse transport modeling approach based on the concepts of sequential importance resampling and parallel computing is presented to reconstruct altitude-resolved time series of volcanic emissions, which often can not be obtained directly with current measurement techniques. A new inverse modeling and simulation system, which implements the inversion approach with the Lagrangian transport model Massive-Parallel Trajectory Calculations (MPTRAC) is developed to provide reliable transport simulations of volcanic sulfur dioxide (SO2). In the inverse modeling system MPTRAC is used to perform two types of simulations, i. e., large-scale ensemble simulations for the reconstruction of volcanic emissions and final transport simulations. The transport simulations are based on wind fields of the ERA-Interim meteorological reanalysis of the European Centre for Medium Range Weather Forecasts. The reconstruction of altitude-dependent SO2 emission time series is also based on Atmospheric Infrared Sounder (AIRS) satellite observations. A case study for the eruption of the Nabro volcano, Eritrea, in June 2011, with complex emission patterns, is considered for method validation. Meteosat Visible and InfraRed Imager (MVIRI) near-real-time imagery data are used to validate the temporal development of the reconstructed emissions. Furthermore, the altitude distributions of the emission time series are compared with top and bottom altitude measurements of aerosol layers obtained by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite instruments. The final transport simulations provide detailed spatial and temporal information on the SO2 distributions of the Nabro eruption. The SO2 column densities from the simulations are in good qualitative agreement with the AIRS observations. Our new inverse modeling and simulation system is expected to become a useful tool to also study other volcanic

  11. Inverse transport modeling of volcanic sulfur dioxide emissions using large-scale ensemble simulations

    Directory of Open Access Journals (Sweden)

    Y. Heng

    2015-10-01

    Full Text Available An inverse transport modeling approach based on the concepts of sequential importance resampling and parallel computing is presented to reconstruct altitude-resolved time series of volcanic emissions, which often can not be obtained directly with current measurement techniques. A new inverse modeling and simulation system, which implements the inversion approach with the Lagrangian transport model Massive-Parallel Trajectory Calculations (MPTRAC is developed to provide reliable transport simulations of volcanic sulfur dioxide (SO2. In the inverse modeling system MPTRAC is used to perform two types of simulations, i. e., large-scale ensemble simulations for the reconstruction of volcanic emissions and final transport simulations. The transport simulations are based on wind fields of the ERA-Interim meteorological reanalysis of the European Centre for Medium Range Weather Forecasts. The reconstruction of altitude-dependent SO2 emission time series is also based on Atmospheric Infrared Sounder (AIRS satellite observations. A case study for the eruption of the Nabro volcano, Eritrea, in June 2011, with complex emission patterns, is considered for method validation. Meteosat Visible and InfraRed Imager (MVIRI near-real-time imagery data are used to validate the temporal development of the reconstructed emissions. Furthermore, the altitude distributions of the emission time series are compared with top and bottom altitude measurements of aerosol layers obtained by the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS satellite instruments. The final transport simulations provide detailed spatial and temporal information on the SO2 distributions of the Nabro eruption. The SO2 column densities from the simulations are in good qualitative agreement with the AIRS observations. Our new inverse modeling and simulation system is expected to become a useful tool to also study

  12. Development of new measuring technique using sound velocity for CO2 concentration in Cameroonian volcanic lakes

    Science.gov (United States)

    Sanemasa, M.; Saiki, K.; Kaneko, K.; Ohba, T.; Kusakabe, M.; Tanyileke, G.; Hell, J.

    2012-12-01

    1. Introduction Limnic eruptions at Lakes Monoun and Nyos in Cameroon, which are sudden degassing of magmatic CO2 dissolved in the lake water, occurred in 1984 and 1986, respectively. The disasters killed about 1800 people around the lakes. Because of ongoing CO2 accumulation in the bottom water of the lakes, tragedy of limnic eruptions will possibly occur again. To prevent from further disasters, artificial degassing of CO2 from the lake waters has been undergoing. Additionally, CO2 monitoring of the lake waters is needed. Nevertheless, CO2 measurement is done only once or twice a year because current methods of CO2 measurement, which require chemical analysis of water samples, are not suitable for frequent measurement. In engineering field, on the other hand, a method to measure salt concentration using sound velocity has been proposed (Kleis and Sanchez, 1990). This method allows us to evaluate solute concentration fast. We applied the method to dissolved CO2 and examined the correlation between sound velocity and CO2 concentration in laboratory experiment. Furthermore, using the obtained correlation, we tried to estimate the CO2 concentration of waters in the Cameroonian lakes. 2. Laboratory experiment We examined the correlation between sound velocity and CO2 concentration. A profiler (Minos X, made by AML oceanography) and pure water were packed in cylindrical stainless vessel and high-pressure CO2 gas was injected to produce carbonated water. The profiler recorded temperature, pressure and sound velocity. Change of sound velocity was defined as difference of sound velocity between carbonated water and pure water under the same temperature and pressure conditions. CO2 concentration was calculated by Henry's law. The result indicated that the change of sound velocity [m s-1] is proportional to CO2 concentration [mmol kg-1], and the coefficient is 0.021 [m kg s-1 mmol-1]. 3. Field application Depth profiles of sound velocity, pressure, and temperature of Lakes

  13. Projection of SO2, NOx, NMVOC, particulate matter and black carbon emissions - 2015-2030

    DEFF Research Database (Denmark)

    Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt; Hjelgaard, Katja Hossy

    This report contains a description of models and background data for projection of SO2, NOX, NMVOC, PM2.5 and black carbon for Denmark. The emissions are projected to 2030 using basic scenarios together with the expected results of a few individual policy measures. Official Danish forecasts...... of activity rates are used in the models for those sectors for which the forecasts are available, i.e. the latest official forecast from the Danish Energy Agency. The emission factors refer either to international guidelines or are country-specific and refer to Danish legislation, Danish research reports...... or calculations based on emission data from a considerable number of plants. The projection models are based on the same structure and method as the Danish emission inventories in order to ensure consistency....

  14. The combined influence of SO2 and heavy metal-containing particulates on beans, carrots and parsley.

    Science.gov (United States)

    Marchwińska, E; Kucharski, R

    1987-01-01

    The effects of various concentrations of air pollutants on crop losses were investigated. Parsley, bean and carrots were fumigated using SO2 in concentrations ranging from 0.35 mg m(-3) (0.13 ppm) to 4.5 mg m(-3) (1.7 ppm) with and without lead/zinc/cadmium-containing particulate matter. It was concluded that a long-term exposure to low levels of SO2, even without visible plant injuries, resulted in more significant crop losses than short-term, high concentrations.Measurements of root and leaf weight in carrot and parsley fumigated in exposure chambers with SO2 show that the ratio of root to leaf weight is dependent on the type and concentration of pollutants. This result leads to the conclusion that a mathematical model describing the above phenomena might be an useful tool in the assessment of crop losses due to known concentrations of air pollutants during the growth period.

  15. Holocene Flows of the Cima Volcanic Field, Mojave Desert, Part 2: Flow Rheology from Laboratory Measurements

    Science.gov (United States)

    Robertson, T.; Whittington, A. G.; Soldati, A.; Sehlke, A.; Beem, J. R.; Gomez, F. G.

    2014-12-01

    Lava flow morphology is often utilized as an indicator of rheological behavior during flow emplacement. Rheological behavior can be characterized by the viscosity and yield strength of lava, which in turn are dependent on physical and chemical properties including crystallinity, vesicularity, and bulk composition. We are studying the rheology of a basaltic lava flow from a monogenetic Holocene cinder cone in the Cima lava field (Mojave Desert, California). The flow is roughly 2.5 km long and up to 700m wide, with a well-developed central channel along much of its length. Samples were collected along seven different traverses across the flow, along with real-time kinematic (RTK) GPS profiles to allow levee heights and slopes to be measured. Surface textures change from pahoehoe ropes near the vent to predominantly jagged `a`a blocks over the majority of the flow, including all levees and the toe. Chemically the lava shows little variation, plotting on the trachybasalt-basanite boundary on the total alkali-silica diagram. Mineralogically the lava is dominated by plagioclase, clinopyroxene and olivine phenocrysts, with abundant flow-aligned plagioclase microcrystals. The total crystal fraction is ~50% near the vent, with higher percentages in the distal portion of the flow. Vesicularity varies between ~10 and more than ~60%. Levees are ~10-15m high with slopes typically ~25-35˚, suggesting a yield strength at final emplacement of ~150,000 Pa. The effective emplacement temperature and yield strength of lava samples will be determined using the parallel-plate technique. We will test the hypothesis that these physical and rheological properties of the lava during final emplacement correlate with spatial patterns in flow morphology, such as average slope and levee width, which have been determined using remote sensing observations (Beem et al. 2014).

  16. Adsorption of SO2 on bituminous coal char and activated carbon fiber

    Science.gov (United States)

    DeBarr, Joseph A.; Lizzio, Anthony A.; Daley, Michael A.

    1997-01-01

    The SO2 adsorption behaviors of activated carbons produced from Illinois coal and of commercially prepared activated carbon fibers (ACFs) were compared. There was no relation between surface area of coal-based carbons and SO2 adsorption, whereas adsorption of SO2 on the series of ACFs was inversely proportional to N2 BET surface area. Higher surface area ACFs had wider pores and adsorbed less SO2; thus, pore size distribution is thought to play a significant role in SO2 adsorption for these materials. Oxidation with HNO3 and/or H2SO4, followed by heat treatment at 700−925°C to remove carbon−oxygen complexes, resulted in increased SO2 adsorption for both coal chars and ACFs. This behavior was explained by an increase in the available number of free sites, previously occupied by oxygen and now available for SO2 adsorption. The use of nitrogen-containing functional groups on ACFs of proper pore size shows promise for further increasing SO2 adsorption capacities. Knowledge of the relationship among the number of free sites, pore size, and surface chemistry on corresponding SO2 adsorption should lead to the development of more efficient adsorbents prepared from either coal or ACFs.

  17. Adsorption of SO2 on bituminous coal char and activated carbon fiber prepared from phenol formaldehyde

    Science.gov (United States)

    DeBarr, Joseph A.; Lizzio, Anthony A.; Daley, Michael A.

    1996-01-01

    Carbon-based materials are used commercially to remove SO2 from coal combustion flue gases. Historically, these materials have consisted of granular activated carbons prepared from lignite or bituminous coal. Recent studies have reported that activated carbon fibers (ACFs) may have potential in this application due to their relatively high SO2 adsorption capacity. In this paper, a comparison of SO2 adsorption for both coal-based carbons and ACFs is presented, as well as ideas on carbon properties that may influence SO2 adsorption

  18. 46. Micronuclei induced by chronical treatment of SO2 inhalation in mouse bone marrow cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the chronical experiment of treating with sulfur dioxide(SO2) inhalation, Micronuclei(MN) frequencies in the polychromatophilic erythroblasts(PCE) of mouse bone marrow and the frequencies of cells with MN were significantly increased in dose-dependent manner. There is a significant difference between the male and the female animals. The results also showed that SO2 inhibited urethone-induced MN formation, it is a antagonistic joint action to Urethone. These results furtherly confirm that SO2 inhalation is a clastogenetic and genotoxic agent to mammalian cells, and the combination roles of SO2 and other mutagens are complexity.

  19. The spatial distribution of remote sensed SO2 in China and its relationship with energy consumption

    Science.gov (United States)

    Xu, Chao; Wang, Yunpeng; Li, Lili; Liu, Yihong

    2017-07-01

    The spatial distribution of SO2 in China was analyzed using OMI-Level3 SO2 PBL (planetary boundary layer) column concentration data of 2013. At the same time, the total value of energy consumption per unit area and coal energy consumption per unit area were analyzed and compared with SO2 distribution. Results show that SO2 distribute unevenly in whole China, and even at the provincial level, SO2 concentration difference was obvious. The spatial distribution of SO2 in China displays characteristics of two highest plates as the center, sub-high regions radiate from center, as well as “The east higher than the west, and the north higher than the south”. Energy consumption per unit area and coal consumption per unit area also distribute unevenly, and the two distributions have similar characteristics but different details. The higher similar spatial distributions of SO2 and energy consumption (especially coal consumption) imply the firm connection of SO2 pollution and coal consumption. SO2 pollution in China remains acute, and the control on coal consumption remains important and emergent in recent years.

  20. Vanadia-silica and vanadia-cesium-silica catalysts for oxidation of SO2

    DEFF Research Database (Denmark)

    Pârvulescu, Vasile I.; Paun, Christina; Pârvulescu, Viorica

    2004-01-01

    of the V/Cs catalysts vanadia is dissolved in a sulfate containing molten salt. The activity of these catalysts for the oxidation of SO2 was tested in a gas containing 2% SO2, 19% O-2, 79% N-2 in the temperature range 523-823 K. Similar experiments with gases containing 10% H2O in the feed or with wet......)-based industrial catalyst, where kieselghur is used as carrier material. The high dispersion of vanadium in the studied catalysts results in an increased catalytic activity for the oxidation of SO2 contained in feed gases with low SO2 content....

  1. A Proposed Community Network For Monitoring Volcanic Emissions In Saint Lucia, Lesser Antilles

    Science.gov (United States)

    Joseph, E. P.; Beckles, D. M.; Robertson, R. E.; Latchman, J. L.; Edwards, S.

    2013-12-01

    Systematic geochemical monitoring of volcanic systems in the English-speaking islands of the Lesser Antilles was initiated by the UWI Seismic Research Centre (SRC) in 2000, as part of its volcanic surveillance programme for the English-speaking islands of the Lesser Antilles. This programme provided the first time-series observations used for the purpose of volcano monitoring in Dominica and Saint Lucia, permitted the characterization of the geothermal fluids associated with them, and established baseline studies for understanding of the hydrothermal systems during periods of quiescence (Joseph et al., 2011; Joseph et al., 2013). As part of efforts to improve and expand the capacity of SRC to provide volcanic surveillance through its geothermal monitoring programme, it is necessary to develop economically sustainable options for the monitoring of volcanic emissions/pollutants. Towards this effort we intend to work in collaboration with local authorities in Saint Lucia, to develop a monitoring network for quantifying the background exposure levels of ambient concentrations of volcanic pollutants, SO2 in air and As in waters (as health significant marker elements in the geothermal emissions) that would serve as a model for the emissions monitoring network for other volcanic islands. This programme would facilitate the building of local capacity and training to monitor the hazardous exposure, through the application and transfer of a regionally available low-cost and low-technology SO2 measurement/detection system in Saint Lucia. Existing monitoring technologies to inform evidence based health practices are too costly for small island Caribbean states, and no government policies or health services measures currently exist to address/mitigate these influences. Gases, aerosols and toxic elements from eruptive and non-eruptive volcanic activity are known to adversely affect human health and the environment (Baxter, 2000; Zhang et al., 2008). Investigations into the

  2. Aerosols upwind of Mexico City during the MILAGRO campaign: regional scale biomass burning, dust and volcanic ash from aircraft measurements

    Science.gov (United States)

    Junkermann, W.; Steinbrecher, R.

    2009-04-01

    During the MILAGRO Campaign March/April 2006 a series of aircraft flights with the FZK microlight D-MIFU were performed in the area southeast of Mexico City starting from Puebla airport, circling the national park area of Ixtachiuatl and Popocatepetl and scanning the Chalco valley down to Cuautla in the Cuernavaca province. All flights were combined with vertical profiles up to 4500 m a.s.l. in several locations, typically north of volcano Ixtachiuatl on the Puebla side, above Chalco or Tenago del Aire and south of volcano Popocatepetl, either at Cuautla or Atlixco. In Tenango del Aire a ceilometer was additionally operated continuously for characterization of the planetary boundary layer. The aircraft carried a set of aerosol instrumentation, fine and coarse particles and size distributions as well as a 7 wavelength aethalometer. Additionally meteorological parameters, temperature and dewpoint, global radiation and actinic radiation balance, respectively photolysis rates, and ozone concentrations were measured. The instrumentation allowed to characterize the aerosol according to their sources and also their impact on radiation transfer. Biomass burning aerosol, windblown dust and volcanic ash were identified within the upwind area of Mexico City with large differences between the dry season in the first weeks of the campaign and the by far cleaner situation after beginning thunderstorm activity towards the end of the campaign. Also the aerosol characteristics inside and outside the Mexico City basin were often completely different. With wind speeds of ~ 5 m/sec from southerly directions in the Chalco valley the aerosol mixture can reach the City within ~ 2 h. Rural aerosol mixtures from the Cuernavaca plain were mixed during the transport with dust from the MC basin. Very high intensity biomass burning plumes normally reached higher altitudes and produced pyrocumulus clouds. These aerosols were injected mainly into the free troposphere. Within the MC basin a large

  3. SO(2N)/U(N) Riccati-Hartree-Bogoliubov Equation Based on the SO(2N) Lie Algebra of the Fermion Operators

    CERN Document Server

    Nishiyama, Seiya

    2014-01-01

    In this paper we present the induced representation of SO(2N) canonical transformation group and introduce SO(2N)/U(N) coset variables. We give a derivation of the time dependent Hartree-Bogoliubov (TDHB) equation on the Kaehler coset space G/H=SO(2N)/U(N) from the Euler-Lagrange equation of motion for the coset variables. The TDHB wave function represents the TD behavior of Bose condensate of fermion pairs. It is a good approximation for the ground state of the fermion system with a pairing interaction, producing the spontaneous Bose condensation. To describe the classical motion on the coset manifold, we start from the local equation of motion. This equation becomes a Riccati-type equation. After giving a simple two-level model and a solution for a coset variable, we can get successfully a general solution of TDRHB equation for the coset variables. We obtain the Harish-Chandra decomposition for the SO(2N) matrix based on the nonlinear Moebius transformation together with the geodesic flow on the manifold.

  4. $\\frac{{\\rm SO}(2N)}{U(N)}$ Riccati-Hartree-Bogoliubov equation based on the SO(2N) Lie algebra of the fermion operators

    Science.gov (United States)

    Nishiyama, Seiya; da Providência, João

    2015-02-01

    In this paper we present the induced representation of SO(2N) canonical transformation group and introduce (SO(2N))/(U(N)) coset variables. We give a derivation of the time-dependent Hartree-Bogoliubov (TDHB) equation on the Kähler coset space (G)/(H) = (SO(2N))/(U(N)) from the Euler-Lagrange equation of motion for the coset variables. The TDHB wave function represents the TD behavior of Bose condensate of fermion pairs. It is a good approximation for the ground state of the fermion system with a pairing interaction, producing the spontaneous Bose condensation. To describe the classical motion on the coset manifold, we start from the local equation of motion. This equation becomes a Riccati-type equation. After giving a simple two-level model and a solution for a coset variable, we can get successfully a general solution of time-dependent Riccati-Hartree-Bogoliubov equation for the coset variables. We obtain the Harish-Chandra decomposition for the SO(2N) matrix based on the nonlinear Möbius transformation together with the geodesic flow on the manifold.

  5. 新型固体电解质SO2传感器的研制%Research on new solid-electrolyte SO2 gas sensor

    Institute of Scientific and Technical Information of China (English)

    梁喜双; 钟铁钢; 陈丽华; 王彪; 全宝富

    2008-01-01

    以sol-gel法制备的NASICON(Na3Zr2Si2PO12)为基体材料,掺杂了V2O5的TiO2为辅助电极材料,制备了一种管式结构的固体电解质SO2传感器.当工作温度为300 ℃时,以V2O5与(V2O5+TiO2)的质量比为5%的材料为辅助电极材料时,传感器对体积分数为(1~50)×10-6的SO2表现出了较好的气敏性能,传感器的电动势E值与SO2浓度的对数呈很好的线性关系,传感器的灵敏度为78 mV/decade.同时,传感器对50×10-6的SO2的响应恢复时间分别为10 s和35 s,且有较好的选择性.

  6. Impacts of some meteorological parameters on the SO2 concentrations in the City of Obrenovac, Serbia

    Directory of Open Access Journals (Sweden)

    SNEŽANA S. NENADOVIĆ

    2010-05-01

    Full Text Available In this paper, the impacts of some meteorological parameters on the SO2 concentrations in the City of Obrenovac are presented. The City of Obrenovac is located in the north-west part of Serbia on the banks of the River Sava. The observed source emission, the power plants TENT A and B are situated on the bank of the Sava River in the vicinity of Obrenovac. During the period from January to November 2006, the concentrations of sulfur dioxide in the air at 4 monitoring sites in Obrenovac were measured. It was noticed that the maximal measured daily concentrations of sulfur dioxide ranged from 1 μg m-3 (16th November, 2006 to 98 μg m-3 (29th January 2006 and lie under the maximal allowed concentration value according to the Serbian Law on Environmental Protection. The measured sulfur dioxide concentrations mostly showed characteristics usual for a daily acidification sulfur dioxide cycle, excluding the specificities influenced by the measuring site itself. Sulfur dioxide transport was recorded at increased wind speeds, primarily from the southeast direction. Based on the impact of meteorological parameters on the sulfur dioxide concentration, a validation of the monitoring sites was also performed from the aspect of their representivity.

  7. Consistent High-Quality Global SO2 and HCHO Datasets from EOS Aura/OMI and Suomi NPP/OMPS

    Science.gov (United States)

    Li, C.; Joiner, J.; Krotkov, N. A.; Fioletov, V.; McLinden, C. A.; Zhang, Y.

    2015-12-01

    We report on recent effort and progress at NASA Goddard Space Flight Center in developing consistent SO2 and HCHO retrieval products from Aura/Ozone Monitoring Instrument (OMI) and Suomi National Polar-orbiting Partnership (S-NPP)/Ozone Mapping and Profiler Suite (OMPS) nadir mapper. Given the substantial differences between OMI and OMPS in several key aspects, such as spatial and spectral resolution and signal-to-noise ratio, a major challenge in ensuring data continuity between the two instruments is to properly account for different instrument characteristics as well as instruments' degradation over time. To this end, we have developed an innovative approach based on principal component analysis (PCA) of measured Earthshine radiances. We utilize a PCA technique to extract a series of spectral features (principal components or PCs) explaining the variance of measured reflectance spectra, associated with both physical processes (e.g., ozone absorption, rotational Raman scattering) and measurement details (e.g., wavelength shift). By fitting these PCs along with pre-computed Jacobians for our target species (SO2 or HCHO) to the measured radiance spectra, we can estimate the atmospheric loading of SO2 or HCHO while minimizing the impacts of interfering processes and measurement imperfection on retrievals. Since no explicit instrument-specific radiance data correction scheme is required, the PCA method is easily implemented with both OMI and OMPS and maximizes data continuity. The PCA algorithm currently runs operationally in the production of the new generation NASA standard OMI planetary boundary layer (PBL) SO2 data that have been shown to improve the detection limit of anthropogenic SO2 emission sources by a factor of two, as compared with the previous generation product. In this presentation, we will demonstrate that the PCA algorithm can produce SO2 and HCHO retrievals from OMPS that have comparable data quality with our OMI retrievals. We will also demonstrate

  8. Volcanic hazards to airports

    Science.gov (United States)

    Guffanti, M.; Mayberry, G.C.; Casadevall, T.J.; Wunderman, R.

    2009-01-01

    , Tungurahua in Ecuador, Mt. Etna in Italy, Rabaul caldera in Papua New Guinea, Mt. Spurr and Mt. St. Helens in the USA, Ruapehu in New Zealand, Mt. Pinatubo in the Philippines, and Anatahan in the Commonwealth of the Northern Mariana Islands (part of the USA). Ten countries - USA, Indonesia, Ecuador, Papua New Guinea, Italy, New Zealand, Philippines, Mexico, Japan, and United Kingdom - have the highest volcanic hazard and/or vulnerability measures for airports. The adverse impacts of volcanic eruptions on airports can be mitigated by preparedness and forewarning. Methods that have been used to forewarn airports of volcanic activity include real-time detection of explosive volcanic activity, forecasts of ash dispersion and deposition, and detection of approaching ash clouds using ground-based Doppler radar. Given the demonstrated vulnerability of airports to disruption from volcanic activity, at-risk airports should develop operational plans for ashfall events, and volcano-monitoring agencies should provide timely forewarning of imminent volcanic-ash hazards directly to airport operators. ?? Springer Science+Business Media B.V. 2008.

  9. An experimental investigation of multiple sulfur isotope fractionations during heterogenous reactions between SO2 and activated carbon

    Science.gov (United States)

    Hamasaki, H.; Watanabe, Y.; Ohmoto, H.

    2010-12-01

    Watanabe et al. (2009) reported that the reduced-S species produced from reactions between solid organic compounds and aqueous sulfate at 150-200 °C possessed anomalous isotopic fractionation (AIF) of S: Δ33S = 0.1 to 2.1 ‰. Based partly on these data, they suggested that the AIF-S signatures in some sedimentary rocks were produced during thermochemical sulfate reduction by solid organic compounds during the early stage of sediment diagenesis, rather than by atmospheric UV photolysis of volcanic SO2. Theoretical study by Lasaga et al. (2008) also suggested that variable AIF-S signatures could be generated during chemisorption of aqueous (or gaseous) S species on a solid surface (e.g., kerogen) under certain conditions. The main objective of this study was, therefore, to evaluate S isotope effects during different stages of reactions (e.g., adsorption, redox reactions) between a solid organic compound and SO2. We have conducted several series of experiments in a closed pyrex-glass system. About 1.8 gm (0.15 moles) of activated C (0.25-1.0 mm in diameter) was first evacuated at 300 °C for 5 days. Then 2.5 mmoles of pure SO2 gas was introduced in the system to react with activated carbon at 200 or 250 °C. Once the pSO2 became stabilized (typically after ~1 day), an aliquot of the SO2 gas (0.1 to 1.5 mmoles) was withdrawn into a pyrex-glass tube containing 20 % H2O2 solution to collect the SO2 as sulfate. After the pSO2 reached to a new steady value, another aliquot of SO2 was withdrawn from the system; sampling was continued until the amount of SO2 gas in the system decreased to 5 % of the initial value. The collected sulfate was converted to Ag2S for isotope analysis. After a series of experiment at 200 °C and another at 250 °C, the activated carbon was removed from the reaction system, treated sequentially by different chemical solutions to extract different forms of S compounds; the extracted S compounds were analyzed for their contents and isotopic ratios

  10. Variation in response of Arabidopsis thaliana lines to atmospheric SO2 exposure

    NARCIS (Netherlands)

    Van der Kooij, T.A W.; De Kok, L.J.

    2000-01-01

    Thirteen lines of Arabidopsis thaliana L. of world-wide origin were exposed to 0.65 mul l(-1) SO2 for 11 days. Shoot growth of most lines was hardly affected. Growth of one line, originating from Tadjikistan, was negatively affected upon SO2 exposure and this line developed acute injury symptoms as

  11. Effect of activated NH3 on SO2 removal by pulse coronadischarge plasma in flue gas

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    NH3-activated electrode is placed in front of the electrode system of pulse corona discharge plasma. There are nozzles on the electrode. Positive DC high-voltage is applied on the nozzle-plate gap. NH3 is injected into the reactor through nozzles, at the same time, activated and treated. Tbese nozzles were proposed in order to make the additional gas pass through corona discharge regions near the tip of nozzles and increase the mount of radicals. The aim is to improve the De-SO2 efficiency by pulse discharge plasma in flue gas. The following topics are investigated and discussed in the paper: De-SO2 effect of single NH3-activated electrode, De-SO2 effect of activated NH3, the relationship between stoichiometric ratio of NH3 to SO2 and De-SO2 effect of activated NH3, mechanism of activated NH3 De-SO2 effect. The experimental result indicates that the De-SO2 efficiency can be increased 5 %-10 96 by activated NH3 on the original base of De-SO2 efficiency.

  12. Variation in response of Arabidopsis thaliana lines to atmospheric SO2 exposure

    NARCIS (Netherlands)

    Van der Kooij, T.A W.; De Kok, L.J.

    2000-01-01

    Thirteen lines of Arabidopsis thaliana L. of world-wide origin were exposed to 0.65 mul l(-1) SO2 for 11 days. Shoot growth of most lines was hardly affected. Growth of one line, originating from Tadjikistan, was negatively affected upon SO2 exposure and this line developed acute injury symptoms as

  13. Effect of SO 2 on CO 2 Capture Using Liquid-like Nanoparticle Organic Hybrid Materials

    KAUST Repository

    Lin, Kun-Yi Andrew

    2013-08-15

    Liquid-like nanoparticle organic hybrid materials (NOHMs), consisting of silica nanoparticles with a grafted polymeric canopy, were synthesized. Previous work on NOHMs has revealed that CO2 capture behaviors in these hybrid materials can be tuned by modifying the structure of the polymeric canopy. Because SO2, which is another acidic gas found in flue gas, would also interact with NOHMs, this study was designed to investigate its effect on CO2 capture in NOHMs. In particular, CO2 capture capacities as well as swelling and CO2 packing behaviors of NOHMs were analyzed using thermogravimetric analyses and Raman and attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopies before and after exposure of NOHMs to SO2. It was found that the SO2 absorption in NOHMs was only prominent at high SO2 levels (i.e., 3010 ppm; Ptot = 0.4 MPa) far exceeding the typical SO2 concentration in flue gas. As expected, the competitive absorption between SO2 and CO2 for the same absorption sites (i.e., ether and amine groups) resulted in a decreased CO2 capture capacity of NOHMs. The swelling of NOHMs was not notably affected by the presence of SO 2 within the given concentration range (Ptot = 0-0.68 MPa). On the other hand, SO2, owing to its Lewis acidic nature, interacted with the ether groups of the polymeric canopy and, thus, changed the CO2 packing behaviors in NOHMs. © 2013 American Chemical Society.

  14. Possibility of Reducing Formations of NOx and SO2 Simultaneously during Coal Combustion

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Comparing with other NOx and SO2 control technologies, in-bed reducing NOx and SO2 simultaneously during coal combustion may lower the investment and operation cost. However, there are several possible contradictions between the reduction of NOx and the capture of SO2 during combustion: 1) CO rich atmosphere is favorable for the reduction of NOx, whereas O2 rich favorable for the capture of SO2; 2) higher preheating temperature of coal is favorable for reducing NOx, but unfavorable for reducing SO2; 3) sulphation of some minerals may deactivate their catalytic effect on the reduction of NOx. The attempts to eliminate such contradictions by coating coal granules with thin layer of monometallic oxides and mixed oxides were proposed. Ni2O3 and Fe2O3 showed high activity on NOx reduction and CaO and Cr2O3 showed good effect on sulfur capture. The mixed metallic oxides, e.g., Fe2O3NiO, etc., showed effective for both NOx reduction and SO2 retention. It is possible to in-bed reduce NOx and SO2 simultaneously if the adhering materials are properly chosen to be difunctional materials of both active catalysts for NOx reduction reactions and better sorbents for SO2 retention.

  15. Molecular Photoabsorption Cross Sections In The Ultraviolet: N2, SO2, S2, CO2

    Science.gov (United States)

    Smith, Peter L.; Stark, G.; Blackie, D.; Pickering, J. C.; Lewis, B. R.; Heays, A. N.

    2011-05-01

    Our research program focuses on the measurement of ultraviolet molecular photoabsorption cross sections with the highest practical resolution. It supports efforts to interpret and model observations of planetary atmospheres. Measurement efforts on molecular nitrogen, sulfur dioxide, diatomic sulfur, and carbon dioxide are in progress. N2: We focus on the measurement of line f-values and line widths within the complex spectrum between 80 and 100 nm. Our measurements are incorporated into a theoretical model of N2 which has established the mechanisms responsible for predissociation and reproduces all observed absorption features in 14N2 and its isotopologues as a function of temperature. SO2: Using the Imperial College UV Fourier transform spectrometer, we have completed and published cross sections at room temperature from 198 to 325 nm, at 198 K from 213 to 325 nm, and at 160 K from 199 to 220 nm. S2: Interpretations of atmospheric (Io, Jupiter, cometary comae) S2 absorption features are hindered by a complete lack of laboratory cross section data in the ultraviolet. We are working to quantify the photoabsorption spectrum of S2 from 200 to 300 nm based on laboratory measurements and theoretical calculations. We have designed an experimental apparatus to produce a stable column of S2 vapor. Measurements of the absorption spectrum of S2 at high resolution will be complemented by coupled-channel calculations. CO2: The photodissociation of CO2 is a fundamental photochemical process in the atmospheres of Mars and Venus. Our research centers on the measurement of high resolution cross sections from 87 to 120 nm. We have completed measurements at 295 K and 195 K over the 106 to 120 nm region, and we have recorded preliminary data of the room temperature spectrum in the 87 to 106 nm region.

  16. Volcanic Eruptions and Climate

    Science.gov (United States)

    LeGrande, Allegra N.; Anchukaitis, Kevin J.

    2015-01-01

    Volcanic eruptions represent some of the most climatically important and societally disruptive short-term events in human history. Large eruptions inject ash, dust, sulfurous gases (e.g. SO2, H2S), halogens (e.g. Hcl and Hbr), and water vapor into the Earth's atmosphere. Sulfurous emissions principally interact with the climate by converting into sulfate aerosols that reduce incoming solar radiation, warming the stratosphere and altering ozone creation, reducing global mean surface temperature, and suppressing the hydrological cycle. In this issue, we focus on the history, processes, and consequences of these large eruptions that inject enough material into the stratosphere to significantly affect the climate system. In terms of the changes wrought on the energy balance of the Earth System, these transient events can temporarily have a radiative forcing magnitude larger than the range of solar, greenhouse gas, and land use variability over the last millennium. In simulations as well as modern and paleoclimate observations, volcanic eruptions cause large inter-annual to decadal-scale changes in climate. Active debates persist concerning their role in longer-term (multi-decadal to centennial) modification of the Earth System, however.

  17. Tolerance to SO2, NO2 and their mixture in Plantago major L. populations.

    Science.gov (United States)

    Taylor, H J; Bell, J N

    1992-01-01

    The possible evolution of tolerance to NO2, alone or in combination with SO2 was investigated in three populations of Plantago major L., originating from Hyde Park in central London (polluted site), Ascot (clean site) and The Netherlands. Screening for sensitivity to the pollutants was carried out by means of chronic fumigations with NO2 or NO2 plus SO2 and acute fumigations with SO2, NO2 or their mixture. The Hyde Park population showed smaller growth reductions induced by the pollutant mixture, than did the other populations. In contrast no differential response in terms of foliar injury was observed after an acute fumigation with SO2+ NO2, but the Hyde Park population was the most sensitive to NO2 alone. The results indicate that selection for tolerance to SO2 does not confer tolerance to NO2 alone or the pollutant mixture.

  18. Standard practice for monitoring atmospheric SO2 using the sulfation plate technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    1.1 This practice covers a weighted average effective SO2 level for a 30-day interval through the use of the sulfation plate method, a technique for estimating the effective SO2 content of the atmosphere, and especially with regard to the atmospheric corrosion of stationary structures or panels. This practice is aimed at determining SO2 levels rather than sulfuric acid aerosol or acid precipitation. 1.2 The results of this practice correlate approximately with volumetric SO2 concentrations, although the presence of dew or condensed moisture tends to enhance the capture of SO2 into the plate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  19. Effect of SO2 concentration on SOA formation in a photorreactor from a mixture of anthropogenic hydrocarbons and HONO

    Science.gov (United States)

    García Vivanco, Marta; Santiago, Manuel; García Diego, Cristina; Borrás, Esther; Ródenas, Milagros; Martínez-Tarifa, Adela

    2010-05-01

    Sulfur dioxide (SO2) is an important urban atmospheric pollutant, mainly produced by the combustion of fossil fuels containing sulfur. In the atmosphere, SO2 can react with OH radicals to form sulfuric acid, which can condense to form acidic aerosol. Sulfuric acid particles act as an acid catalyst for some heterogeneous carbonyl reactions like hydration, polymerization or acetals formation, which may lead to a large increase on SOA mass. In order to evaluate the effect of the SO2 concentration on SOA formation, 3 experiments were performed during the campaign carried out by CIEMAT on the EUPHORE facility (CEAM, Valencia, Spain) during June- July 2008. The objective of the campaign was to evaluate the effect of different experimental conditions on SOA formation from the photooxidation of some anthropogenic and biogenic VOCs using HONO as oxidant. Experiment on 6/17/08 was selected as base case (no SO2 was introduced) and experiments 6/26/08 and 7/1/08 were selected as high SO2 (2600 ug/m3) and low SO2 (60 ug/m3) concentration experiments respectively. In the three experiments a mixture of toluene, 1,3,5-TMB (trimethylbenzene), o-xylene and octane was selected as the parent VOCs. Single and coupled to mass spectroscopy gas cromatography (GC and GC/MS), as well as high performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR) were used to measure the initial VOCs and oxidant concentrations decay and the formation of gas phase oxidation products through the experiments. Aerosol size distribution and concentration were measured with SMPS (scanning mobility particle sizer) and TEOM (tapered element oscillating monitor) respectively. In addition, analysis of the organic and inorganic aerosol content was also performed via filter sampling followed by GC/MS and ionic chromatography (for organic and inrganic content respectively). Comparing the filters collected in the three experiments, clearly the largest mass aerosol formation is observed

  20. Seasonal characteristics of SO2, NO2, and CO emissions in and around the Indo-Gangetic Plain.

    Science.gov (United States)

    Mallik, C; Lal, S

    2014-02-01

    Anthropogenic emissions of sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) exert significant influence on local and regional atmospheric chemistry. Temporal and spatial variability of these gases are investigated using surface measurements by the Central Pollution Control Board (India) during 2005-2009 over six urban locations in and around the Indo-Gangetic Plain (IGP) and supported using the satellite measurements of these gases. The stations chosen are Jodhpur (west of IGP), Delhi (central IGP), Kolkata and Durgapur (eastern IGP), Guwahati (east of IGP), and Nagpur (south of IGP). Among the stations studied, SO2 concentrations are found to be the highest over Kolkata megacity. Elevated levels of NO2 occur over the IGP stations of Durgapur, Kolkata, and Delhi. Columnar NO2 values are also found to be elevated over these regions during winter due to high surface concentrations while columnar SO2 values show a monsoon maximum. Elevated columnar CO over Guwahati during pre-monsoon are attributed to biomass burning. Statistically significant correlations between columnar NO2 and surface NO2 obtained for Delhi, Kolkata, and Durgapur along with very low SO2 to NO2 ratios (≤0.2) indicate fossil fuel combustion from mobile sources as major contributors to the ambient air over these regions.

  1. Decomposition treatment of SO2F2 using packed bed DBD plasma followed by chemical absorption.

    Science.gov (United States)

    Nie, Yong; Zheng, Qifeng; Liang, Xiaojiang; Gu, Dayong; Lu, Meizhen; Min, Min; Ji, Jianbing

    2013-07-16

    The technology of packed bed dielectric barrier discharge (DBD) plasma followed by a chemical absorption has been developed and was found to be an efficient way for decomposition treatment of sulfuryl fluoride (SO2F2) in simulated residual fumigant. The effects of energy density, initial SO2F2 concentration, and residence time on the removal efficiency of SO2F2 for the DBD plasma treatment alone were investigated. It was found that the SO2F2 could be removed completely when initial volume concentration, energy density, and residence time were 0.5%, 33.9 kJ/L, and 5.1 s, respectively. The removal mechanism of SO2F2 in the packed bed DBD reactor was discussed. Based on the detailed analysis of SO2F2 molecular stability and its exhaust products in the DBD plasma reactor, it was concluded that the energetic electrons generated in the packed bed DBD reactor played a key role on the removal of SO2F2, and the major decomposition products of SO2F2 detected were SO2, SiF4, and S (Sulfur). Among these products, SiF4 was formed by the F atom reacted with the filler-quartz glass beads (SiO2) in the packed bed DBD reactor. Aqueous NaOH solution was used as the chemical absorbent for the gaseous products of SO2F2 after plasma pretreatment. It was found that the gaseous products in the plasma exhaust could be absorbed and fixed by the subsequent aqueous NaOH solution.

  2. Volcanic gas

    Science.gov (United States)

    McGee, Kenneth A.; Gerlach, Terrance M.

    1995-01-01

    In Roman mythology, Vulcan, the god of fire, was said to have made tools and weapons for the other gods in his workshop at Olympus. Throughout history, volcanoes have frequently been identified with Vulcan and other mythological figures. Scientists now know that the “smoke" from volcanoes, once attributed by poets to be from Vulcan’s forge, is actually volcanic gas naturally released from both active and many inactive volcanoes. The molten rock, or magma, that lies beneath volcanoes and fuels eruptions, contains abundant gases that are released to the surface before, during, and after eruptions. These gases range from relatively benign low-temperature steam to thick hot clouds of choking sulfurous fume jetting from the earth. Water vapor is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide. Other volcanic gases are hydrogen sulfide, hydrochloric acid, hydrogen, carbon monoxide, hydrofluoric acid, and other trace gases and volatile metals. The concentrations of these gas species can vary considerably from one volcano to the next.

  3. Mapping Weak, Altered Zones and Perched Water With Aerogeophysical Measurements at Mount Adams, Washington: Implications for Volcanic Instability

    Science.gov (United States)

    Finn, C. A.; Deszcz-Pan, M.; Anderson, E. D.; Horton, R.

    2006-12-01

    Hydrothermally altered rocks, particularly if water saturated, can weaken stratovolcanoes. This increases the potential for catastrophic sector collapses that can lead to destructive debris flows. Evaluating the hazards associated with such alteration is difficult, because alteration has been mapped on few active volcanoes and the distribution and intensity of subsurface alteration and location of perched water tables are largely unknown on any active volcano. At Mount Adams, some Holocene debris flows contain abundant hydrothermal minerals derived from collapse of an altered edifice. Intense hydrothermal alteration can significantly reduce the resistivity (from hundreds to tens ohm-m) and magnetization of volcanic rocks. These changes can be identified with helicopter electromagnetic and magnetic measurements and visualized in 3D. 100 m is the greatest depth that the lowest frequency electromagnetic data could penetrate into the low resistivity, altered zones; outside the altered zones, the depth of penetration was up to 300 m. Total-field magnetic data can detect magnetization variations to several thousand meters depth. Electromagnetic and magnetic data, combined with geological mapping and rock property measurements, indicate the presence of appreciable thicknesses of hydrothermally altered rock in the central core of Mount Adams north of the summit. We identify steep cliffs at the western edge of this zone as the likely source for future large debris flows. Water, and perhaps melted ice, is needed as a lubricant to transform debris avalanches into lahars. Therefore, knowing the distribution of both is important for hazard assessments. Over the low resistivity summit, the electromagnetic data detected ice with a thickness of 0 to about 80 m and an estimated volume of up to 0.1 km3. Over resistive ridges ice thicknesses could not be determined. The electromagnetic data also identified perched water tables in the brecciated core of the upper 300 m of the volcano

  4. Transport of gaseous NO2 and SO2 by MAX-DOAS in Beijing and surrounding area

    Science.gov (United States)

    Xu, Jin; Li, Ang; Xie, Pinhua; Liu, Jianguo; Liu, Wenqing

    2016-04-01

    With the development of industry and urbanization, regional pollution is increasing seriously, and the cross influence between cities is becoming more frequently. Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) has been successfully applied in the remote sensing of gaseous pollutants during the past decade, it is based on scattered light of the sun, and can measure spectral in different directions, measure tropospheric and the whole atmospheric column densities of trace gases combining with radiative transfer model (RTM). This approach is very useful for the investigation of the main path of air pollution transportation. Fifteen MAX-DOAS stations which are in urban and in the path of pollution transport are set up in Beijing and surrounding area including Tianjin and Hebei province to observe the spatial and temporal distributions and regional transport of gaseous NO2 and SO2. The NO2 VCDs and profiles and SO2 VCDs are obtained. The results show that the NO2 column densities in urban are higher than surroundings, it shows that the NO2 in Beijing is mainly from the local; The SO2 column densities in other cities to the south of Beijing are obviously higher than in Beijing, so regional transport from the south of Hebei province will have a significant impact on Beijing. From the results of NO2 and SO2, the whole pollution process including incubation, generation, duration, and dispersion was observed. The vertical distribution show that NO2 concentration is mainly near the surface from 0 to 400m, and SO2 is higher in the transport process.

  5. Aura OMI observations of changes in SO2 and NO2 emissions at local, regional and global scales

    Science.gov (United States)

    Krotkov, N. A.; McLinden, C. A.; Li, C.; Lamsal, L. N.; Celarier, E. A.; Marchenko, S. V.; Swartz, W.; Bucsela, E. J.; Joiner, J.; Duncan, B. N.; Boersma, K. F.; Veefkind, P.; Levelt, P.; Fioletov, V.; Dickerson, R. R.; He, H.; Lu, Z.; Streets, D. G.

    2015-12-01

    Space-based pollution monitoring from current and planned satellite UV-Vis spectrometers play an increasingly important role in studies of tropospheric chemistry and also air quality applications to help mitigate anthropogenic and natural impacts on sensitive ecosystems, and human health. We present long-term changes in tropospheric SO2 and NO2 over some of the most polluted industrialized regions of the world observed by the Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite. Using OMI data, we identified about 400 SO2 "hot spots" and estimated emissions from them. In many regions emissions and their ambient pollution levels have decreased significantly, such as over eastern US, Europe and China. OMI observed about 50% reduction in SO2 and NO2 pollution over the North China plain in 2012-2014 that can be attributed to both government efforts to restrain emissions from the power and industrial sectors and the economic slowdown. While much smaller, India's SO2 and NO2 emissions from coal power plants and smelters are growing at a fast pace, increasing by about 200% and 50% from 2005 to 2014. Over Europe and the US OMI-observed trends agree well with those from available in situ measurements of surface concentrations, deposition and emissions data. However, for some regions (e.g., Mexico, Middle East) the emission inventories may be incomplete and OMI can provide emission estimates for missing sources, such as SO2 sources observed over the Persian Gulf. It is essential to continue long-term overlapping satellite data records of air quality with increased spatial and temporal resolution to resolve point pollution sources using oversampling technique. We discuss how Aura OMI pollution measurements and emission estimates will be continued with the US JPSS and European Sentinel series for the next 20 years and further enhanced by the addition of three geostationary UV-VIS instruments.

  6. Life cycle inventory analysis of CO2 and SO2 emission of imperial smelting process for Pb-Zn smelter

    Institute of Scientific and Technical Information of China (English)

    李启厚; 郭学益; 肖松文; 黄凯; 张多默

    2003-01-01

    Based on the principle of life cycle assessment, CO2 and SO2 emission of Imperial Smelting Process in a certain zinc-lead smelter was analyzed by life cycle inventory method. According to the system expansion and substitution method, the environmental impacts of co-products were allocated among the main products of zinc, lead and sulfuric acid. The related impacts were assessed by use of Global Warming Potential (GWP) and Acidification Potential (ACP). The results show that the GWP index from 1998 to 2000 is 11.53, 11.65, 10.93 tCO2-eq/tZn respectively, the ACP index decreases from 14.88 kgSO2-eq/tZn in 1998 to 10.99 kgSO2-eq/tZn in 2000. Power and electricity generation, followed by smelting and zinc distillation, are mainly responsible for GWP. Sintering individually affects ACP. Reduction in greenhouse gas emissions of the ISP may come from energy conservation measures rather than from technological developments. And recycling more secondary Pb and Zn materials effectively treated by ISP, and reducing the amount of primary metal are the main ways to put SO2 emission under control.

  7. The condensation and vaporization behavior of ices containing SO2, H2S, and CO2: Implications for Io

    Science.gov (United States)

    Sandford, Scott A.; Allamandola, Louis J.

    1993-01-01

    In an extension of previously reported work on ices containing CO, CO2, H2O, CH3OH, NH3, and H2, measurements of the physical and infrared spectral properties of ices containing molecules relevant to Jupiter's moon Io are presented. These include studies on ice systems containing SO2, H2S, and CO2. The condensation and sublimation behaviors of each ice system and surface binding energies of their components are discussed. The surface binding energies can be used to calculate the residence times of the molecules on a surface as a function of temperature and thus represent important parameters for any calculation that attempts to model the transport of these molecules on Io's surface. The derived values indicate that SO2 frosts on Io are likely to anneal rapidly, resulting in less fluffy, 'glassy' ices and that H2S can be trapped in the SO2 ices of Io during night-time hours provided that SO2 deposition rates are on the order of 5 micrometers/hr or larger.

  8. Analysis on Effectiveness of SO2 Emission Reduction in Shanxi, China by Satellite Remote Sensing

    Directory of Open Access Journals (Sweden)

    Huaxiang Song

    2014-11-01

    Full Text Available The SO2 emissions from coal-fired power plants in China have been regulated since 2005 by a mandatory installation of flue gas desulfurization (FGD devices. In order to verify the effectiveness of FGD systems applied in power plants, Shanxi (a province well-known for the largest coal reserves in China was selected, and the characteristic and evolution of SO2 densities over 22 regions with large coal-fired power plants during 2005–2012 were investigated by using the satellite remote sensing data from the Ozone Monitoring Instrument (OMI. A unit-based inventory was also employed to study the trend of SO2 emissions from coal-fired power plants in Shanxi. The results show that the operation of FGD systems was successful in reducing SO2 emissions from power plants during 2005–2010: the mean SO2 densities satellite-observed over those regions with power plants operated before 2005 showed a notable decrease of approximate 0.4 DU; the mean SO2 densities over other regions with power plants newly built behind 2006 did not show a statistical increasing trend overall; the mean SO2 density over the whole Shanxi also showed a moderate decline from 2008 to 2010. However, the polluted conditions over Shanxi during 2011–2012 rebounded and the declining trend in mean SO2 density over the whole Shanxi disappeared again. In comparison of unit-based emission inventory, the emissions calculated show a similar trend with SO2 densities satellite-observed during 2005–2010 and still maintain at a lower volume during 2011–2012. By investigating the developments of other emission sources in Shanxi during 2005–2012, it is considered that the rapid expansion of industries with high coal-consumption has played an important role for the increment rise of SO2 emissions. Lack of an independent air quality monitoring network and the purposeful reduced operation rate of FGD systems occurring in some coal-fired power plants have reduced the effectiveness of SO2

  9. Reliability Analysis on Data of SO2 Emissions from Thermal Power Plants

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Since the atmospheric pollutants from thermal power plants accounl for a large proportion of lhe national total, knowing well the status of SO2 emissions of power industry is of great significance for making control strategies and related environmental policies concerning SO2 and acid rain.Through introduction and analysis to some key links, such as the existing monitoring network, data sources, examining methods and procedures for statistic data and calculating methods of total national emissions, it is concluded that the data of SO2 emissions from the statistic database for power environment is reliable and can be a reference for decision-making both on power development and environmental protection.

  10. Regional differences in Chinese SO2 emission control efficiency and policy implications

    Science.gov (United States)

    Zhang, Q. Q.; Wang, Y.; Ma, Q.; Yao, Y.; Xie, Y.; He, K.

    2015-06-01

    SO2 emission control has been one of the most important air pollution policies in China since 2000. In this study, we assess regional differences in SO2 emission control efficiencies in China through the modeling analysis of four scenarios of SO2 emissions, all of which aim to reduce the national total SO2 emissions by 8% or 2.3 Tg below the 2010 emissions level, the target set by the current twelfth Five-Year Plan (FYP; 2011-2015), but differ in spatial implementation. The GEOS-Chem chemical transport model is used to evaluate the efficiency of each scenario on the basis of four impact metrics: surface SO2 and sulfate concentrations, population-weighted sulfate concentration (PWC), and sulfur export flux from China to the western Pacific. The efficiency of SO2 control (β) is defined as the relative change of each impact metric to a 1% reduction in SO2 emissions from the 2010 baseline. The S1 scenario, which adopts a spatially uniform reduction in SO2 emissions in China, gives a β of 0.99, 0.71, 0.83, and 0.67 for SO2 and sulfate concentrations, PWC, and export flux, respectively. By comparison, the S2 scenario, which implements all the SO2 emissions reduction over North China (NC), is found most effective in reducing national mean surface SO2 and sulfate concentrations and sulfur export fluxes, with β being 1.0, 0.76, and 0.95 respectively. The S3 scenario of implementing all the SO2 emission reduction over South China (SC) has the highest β in reducing PWC (β = 0.98) because SC has the highest correlation between population density and sulfate concentration. Reducing SO2 emissions over Southwest China (SWC) is found to be least efficient on the national scale, albeit with large benefits within the region. The difference in β by scenario is attributable to the regional difference in SO2 oxidation pathways and the source-receptor relationship. Among the three regions examined here, NC shows the largest proportion of sulfate formation through gas

  11. Continuous in-situ measurements of volcanic gases at Pisciarelli-Phelgrean Field (Italy): a new experimental approach

    Science.gov (United States)

    Wiersberg, T.; Somma, R.; Rocco, A.; Quattrocchi, F.; Zimmer, M.; de Natale, G.; de Natale, P.; Boschi, E.

    2009-04-01

    We present a new experimental approach for continuous real-time monitoring of volcanic gases. The realization of this new set-up based on the experience derived from several earlier short-time gas monitoring campaigns carried out in 2006, 2007 and 2008 at different sites (Tor Caldara, Latium Region, Central Italy; Solfatara and Pisciarelli, Campania Region, Souther Italy). The monitoring station is now implemented at a fumarole field in Pisciarelli, about 1 km SE of the Solfatara volcano. Fumarolic gas is continuously pumped through 200m Teflon © tube with a membrane pump (pumping rate 400cc/min) into a small field laboratory, where the gas phase is analyzed minutely by means of a quadrupole mass spectrometer for H2, H2S, CH4, N2, O2, Ar, He, and CO2 and with a tuneable diode laser spectrometer. Further analytical devices may be added in the future. Off-line gas samples are taken regularly to crosscheck the gas composition with a gas chromatograph and for noble gas analysis. Prior to gas analysis, gaseous water is condensed in a water trap placed in a cooling box in close vicinity to the fumarole. The water is removed from the trap in regular intervals (2 h) by a peristaltic pump. The amount of water is determined directly in the trap by measuring the rise of the water level in intervals of 5 minutes. Knowledge of the gas flow and the amount of water would enables us to determine the gas/water ratio of fumarolic gases, however, the actual fumarole temperature (December 2008) at Pisciarelli is 95.8°C, thus water condensation has already occurred prior to gas sampling. The gas from the Pisciarelli fumarole is dominated by CO2 (>98.5 vol.-%), followed by N2, H2S, O2, H2, Ar, CH4 and He. O2 and partly N2 and Ar are due to atmospheric contamination of the system. The air-free calculated gas composition is in good agreement with already published gas composition data. Within the time of investigation, no significant variations were detected in the composition of the

  12. Spatio-Temporal Analyses of CH4 and SO2 over Pakistan

    Science.gov (United States)

    Mahmood, Irfan; Imran Shahzad, Muhammad; Farooq Iqbal, Muhammad

    2016-07-01

    SO2 and associated compounds are one of main atmospheric pollutant. Moreover, methane - a potent greenhouse gas can also deteriorate the air quality of the region under certain chemical and meteorological conditions. Role of such gases in regional air quality of Pakistan have not been significantly studied. This study involves the analyses of CH4 and SO2 in terms of spatio-temporal distribution over Pakistan from the period 2004 - 2014 using space borne sensors namely Ozone Monitoring Instrument (OMI) and Advanced Infrared Sounder Instrument (AIRS) respectively. Results show an increase in SO2 concentration attributed to trans-boundary sources. Monthly Methane total column results show an increase in atmospheric concentration of methane for the period 2004-2014. Results of the study are complimented by calculating the back trajectories to identify the transport paths. The study significantly describes the regional description and convection phenomenon for SO2 and CH4.

  13. Adsorption behavior of SO2 on vacancy-defected graphene: A DFT study

    Science.gov (United States)

    Zhou, Qingxiao; Ju, Weiwei; Su, Xiangying; Yong, Yongliang; Li, Xiaohong

    2017-10-01

    The adsorption of an SO2 molecule on the perfect and point-defective graphene surfaces were investigated using density functional theory (DFT). The geometric structure, adsorption energy, charge transfer, and electronic properties were calculated and analyzed to characterize the effect of vacancy on the adsorption process of SO2 on the graphene. The result indicated that the presence of vacancy enhanced the adsorption stability with the larger adsorption energy and net charge transfer compared to that of perfect graphene. Moreover, the SO2 molecule on different adsorption sites exhibited dissimilar states because of the adsorption. Furthermore, the results of the electronic properties revealed that the adsorption of SO2 induced an opening of the band gap.

  14. Atmospheric Environmental Capacity of SO2 in Winter over Lanzhou in China: A Case Study

    Institute of Scientific and Technical Information of China (English)

    AN Xingqin; ZUO Hongchao; CHEN Lijuan

    2007-01-01

    The total emission control method based on atmospheric environmental capacity is the most effective in air pollution mitigation. The atmospheric environmental capacities of SO2 on representative days over Lanzhou are estimated using the numerical models RAMS, HYPACT and a linear programming model,according to the national ambient air quality standard of China (NAAQSCHN). The results show that the fields of meteorological elements and SO2 simulated by the models agree reasonably well with observations.The atmospheric environmental capacity of SO2 over Lanzhou is around 111.7×103 kg d-1, and in order to meet the air quality level Ⅱ of the NAAQSCHN, SO2 emissions need to be reduced by 20%.

  15. US EPA Nonattainment Areas and Designations-SO2 (2010 NAAQS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This web service contains the following layer: SO2 2010 NAAQS State Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the...

  16. Volcanic Catastrophes

    Science.gov (United States)

    Eichelberger, J. C.

    2003-12-01

    The big news from 20th century geophysics may not be plate tectonics but rather the surprise return of catastrophism, following its apparent 19th century defeat to uniformitarianism. Divine miracles and plagues had yielded to the logic of integrating observations of everyday change over time. Yet the brilliant interpretation of the Cretaceous-Tertiary Boundary iridium anomaly introduced an empirically based catastrophism. Undoubtedly, decades of contemplating our own nuclear self-destruction played a role in this. Concepts of nuclear winter, volcanic winter, and meteor impact winter are closely allied. And once the veil of threat of all-out nuclear exchange began to lift, we could begin to imagine slower routes to destruction as "global change". As a way to end our world, fire is a good one. Three-dimensional magma chambers do not have as severe a magnitude limitation as essentially two-dimensional faults. Thus, while we have experienced earthquakes that are as big as they get, we have not experienced volcanic eruptions nearly as great as those preserved in the geologic record. The range extends to events almost three orders of magnitude greater than any eruptions of the 20th century. Such a calamity now would at the very least bring society to a temporary halt globally, and cause death and destruction on a continental scale. At maximum, there is the possibility of hindering photosynthesis and threatening life more generally. It has even been speculated that the relative genetic homogeneity of humankind derives from an evolutionary "bottleneck" from near-extinction in a volcanic cataclysm. This is somewhat more palatable to contemplate than a return to a form of Original Sin, in which we arrived at homogeneity by a sort of "ethnic cleansing". Lacking a written record of truly great eruptions, our sense of human impact must necessarily be aided by archeological and anthropological investigations. For example, there is much to be learned about the influence of

  17. Physiological responses of Norway spruce trees to elevated CO2 and SO2

    NARCIS (Netherlands)

    Tausz, M.; De Kok, L.J.; Stulen, I.

    1996-01-01

    Young Norway spruce (Picea abies (L.) Karst.) trees were exposed to elevated CO2 (0.8 mL L(-1)), SO2 (0.06 mu L L(-1)), and elevated CO2 and SO2 (0.8 mL L(-1) and 0.06 mu L L(-1), respectively) for three months. Exposure to elevated CO2 resulted in an increased biomass production of the needles, whi

  18. INVESTIGASI PENGARUH KONDISI LALU LINTAS DAN ASPEK METEOROLOGI TERHADAP KONSENTRASI PENCEMAR SO2 DI KOTA SEMARANG

    Directory of Open Access Journals (Sweden)

    Titik Istirokhatun

    2016-03-01

    Full Text Available The presence of air pollution in ambient air is closely related to the incidence of adverse reactions affecting human health. One of harmful pollutants and potentially major cause health problems is sulfur dioxide (SO2. The number of vehicles that are passing and queuing on the crossroads because of traffic light can affect the concentration of SO2. Besides, in these locations there are a lot of road users which are potentially exposed by contaminants, so information about the concentration of SO2 is important to know. This study aimed to investigate the impact of meteorological factors and the number of vehicles on SO2 concentrations. Impinger was used for air sampling, and pararosaniline method was used for determining SO2 concentration. Sampling and calculation of the number of passing vehicles were performed 3 times ie in the morning, afternoon and evening. Based on the results of the study, the highest concentrations of SO2 were on the range of 15-21 mg/Nm3. .

  19. Adsorption equilibrium and kinetics for SO2, NO, CO2 on zeolites FAU and LTA.

    Science.gov (United States)

    Yi, Honghong; Deng, Hua; Tang, Xiaolong; Yu, Qiongfen; Zhou, Xuan; Liu, Haiyan

    2012-02-15

    In order to develop a single-step process for removing SO(2), NO, CO(2) in flue gas simultaneously by co-adsorption method. Pure component adsorption equilibrium and kinetics of SO(2), NO, and CO(2) on zeolite NaY, NaX, CaA were obtained respectively. Equilibrium data were analyzed by equilibrium model and Henry's law constant. The results suggest that Adsorption affinity follows the trend SO(2)>CO(2)>NO for the same adsorbent. Zeolite with stronger polar surface is a more promising adsorbent candidate. Kinetics behavior was investigated using the breakthrough curve method. The overall mass transfer coefficient and diffusivity factor were determined by a linear driving force model. The results are indicative of micropore diffusion controlling mechanism. NaY zeolite has the minimum resistance of mass transfer duo to the wide pore distribution and large pore amount. CaA zeolite exhibits the highest spatial hindered effect. Finally, co-adsorption effect of SO(2), NO, and CO(2) were investigated by multi-components breakthrough method. SO(2) and NO may form new adsorbed species, however, CO(2) presents a fast breakthrough. Chemical adsorption causes SO(2) transforms to SO(4)(2-), however, element N and C are not detected in adsorbed zeolites.

  20. Mineralization of Basalts in the CO2-H2O-SO2-O2 System

    Energy Technology Data Exchange (ETDEWEB)

    Schaef, Herbert T.; Horner, Jacob A.; Owen, Antionette T.; Thompson, Christopher J.; Loring, John S.; McGrail, B. Peter

    2014-05-01

    Sequestering carbon dioxide (CO2) containing minor amounts of co-contaminants in geologic formations was investigated in the laboratory through the use of high pressure static experiments. Five different basalt samples were immersed in water equilibrated with supercritical CO2 containing 1wt% sulfur dioxide (SO2) and 1wt% oxygen (O2) at reservoir conditions (~100 bar, 90°C) for 49 and 98 days. Gypsum (CaSO4) was a common precipitate, occurred early as elongated blades with striations, and served as substrates for other mineral products. Bimodal pulses of water released during dehydroxylation were key indicators along with X-ray diffraction for verifying the presences of jarosite-alunite group minerals. Well-developed pseudocubic jarosite crystals formed surface coatings, and in some instances mixtures of natrojarosite and natroalunite aggregated into spherically shaped structures measuring 100 μm in diameter. Reaction products were also characterized using infrared spectroscopy, which indicated OH and Fe-O stretching modes. The presences of jarosite-alunite group minerals were found in the lower wavenumber region from 700–400 cm-1. A strong preferential incorporation of Fe(III) into natrojarosite was attributed to the oxidation potential of O2. Evidence of CO2 was detected during thermal decomposition of precipitates, suggesting the onset of mineral carbonation.

  1. Electrochemical study on the cationic promotion of the catalytic SO2 oxidation in pyrosulfate melts

    DEFF Research Database (Denmark)

    Petrushina, Irina; Bjerrum, Niels; Cappeln, Frederik Vilhelm

    1998-01-01

    The electrochemical behavior of the molten V2O5-M2S2O7 (M = K, Cs, or Na) system was studied using a gold working electrode at 440 degrees C in argon and air atmosphere. The aim of the present investigation was to find a possible correlation between the promoting effect of Cs+ and Na+ ions...... on the catalytic oxidation of SO2 in the V2O5-M2S2O7 system and the effect of these alkali cations on the electrochemical behavior of V2O5 in the alkali pyrosulfate melts It has been shown that Na+ ions had a promoting effect on the V(V) reversible arrow V(IV) electrochemical reaction. Sodium ions accelerate both...... in the catalytic SO, oxidation most likely is the oxidation of V(IV) to V(V) and the Na+ and Cs+ promoting effect is based on the acceleration of this stage. It has also been proposed that voltammetric measurements can be used for fast optimization of the composition of the vanadium catalyst (which...

  2. Continuation of long-term global SO2 pollution monitoring from OMI to OMPS

    Science.gov (United States)

    Zhang, Y.; Li, C.; Krotkov, N. A.; Joiner, J.

    2016-12-01

    In the past 12+ years, Ozone Monitoring Instrument (OMI) on board NASA EOS Aura satellite has pioneered the first high-resolution global SO2 pollution monitoring, which enabled new studies of atmospheric chemistry and applications for air quality management. Such long-term SO2 record will be continued with other satellite instruments, i.e., the Ozone Mapping and Profiler Suite (OMPS) Nadir Mapper on board NASA-NOAA Suomi National Polar-orbiting Partnership (S-NPP) satellite and the follow up JPSS series satellites. In this presentation, we demonstrate the first comparison between OMI and OMPS SO2 retrievals from the OMI operational SO2 algorithm, which is our state-of-the-art principal component analysis (PCA) approach. The PCA technique does not use any sort of "soft calibration" corrections required in concurrent satellite SO2 algorithms and enables seamless merging of different satellite datasets. We demonstrate a very good consistency of the retrievals from OMI and OMPS. Four full years of OMI and OMPS SO2 retrievals during 2012-2015 have been analyzed over some of the world's most polluted regions: eastern China, Mexico, and South Africa. In general, the comparisons show high correlations (r =0.79-0.96) of SO2 mass between the two instruments on a daily basis and less than unity regression slopes (0.76-0.97) indicating slightly lower OMPS SO2 mass as compared with OMI. The annual averaged SO2 loading difference between OMI and OMPS is negligible (instruments also show generally good agreement in terms of the daily spatial distribution in SO2. For example, over the Mexico region for 82% of the days, the two instruments have a spatial correlation coefficient of 0.6 or better. Such consistent retrievals were achieved without any explicit adjustment to OMI or OMPS radiance data. We will further improve the retrieval agreement in the next versions of the OMI and OMPS retrievals by applying a more comprehensive Jacobian lookup table that properly accounts for

  3. Higher air quality through cleaner maritime shipping. IMO decree for less SO2, but more CO2; Gezondere lucht door schoner varen op zee. IMO-besluit betekent minder SO2, maar meer CO2

    Energy Technology Data Exchange (ETDEWEB)

    Dame, E. [Department Energy and Environment, Directorate-General Environment, European Commission, Brussels (Belgium); Meijer, H. [Department Clean Air and Transport, Directorate-General Environment, European Commission, Brussels (Belgium)

    2008-07-01

    In October, the International Maritime Organisation (IMO) will take the definitive decision that maritime shipping must decrease their emissions of sulphur dioxide (SO2) and nitrous oxides (NOx). At the same time this will also lead to less particulate matter. This article addresses the environmental consequences of this radical IMO decision. The total CO2 emission will increase, for example. The health benefits for European citizens, the cost of these measures and the influence on European legislation will also be addressed. [mk]. [Dutch] De Internationale Maritieme Organisatie (IMO) zal in oktober definitieve besluiten dat de zeescheepvaart minder zwaveldioxide (SO2) en stikstofoxiden (NOx) gaat uitstoten. En passant levert dit ook minder fijn stof op. Dit artikel gaat in op de milieugevolgen die verband houden met het ingrijpende IMO-besluit. Zo zal bijvoorbeeld de totale uitstoot van CO2 omhoog gaan. Ook de gezondheidswinst voor de Europese burgers, de kosten van de maatregelen en de invloed op Europese regelgeving worden belicht.

  4. Volcanic gas impacts on vegetation at Turrialba Volcano, Costa Rica

    Science.gov (United States)

    Teasdale, R.; Jenkins, M.; Pushnik, J.; Houpis, J. L.; Brown, D. L.

    2010-12-01

    Turrialba volcano is an active composite stratovolcano that is located approximately 40 km east of San Jose, Costa Rica. Seismic activity and degassing have increased since 2005, and gas compositions reflect further increased activity since 2007 peaking in January 2010 with a phreatic eruption. Gas fumes dispersed by trade winds toward the west, northwest, and southwest flanks of Turrialba volcano have caused significant vegetation kill zones, in areas important to local agriculture, including dairy pastures and potato fields, wildlife and human populations. In addition to extensive vegetative degradation is the potential for soil and water contamination and soil erosion. Summit fumarole temperatures have been measured over 200 degrees C and gas emissions are dominated by SO2; gas and vapor plumes reach up to 2 km (fumaroles and gases are measured regularly by OVSICORI-UNA). A recent network of passive air sampling, monitoring of water temperatures of hydrothermal systems, and soil pH measurements coupled with measurement of the physiological status of surrounding plants using gas exchange and fluorescence measurements to: (1) identify physiological correlations between leaf-level gas exchange and chlorophyll fluorescence measurements of plants under long term stress induced by the volcanic gas emissions, and (2) use measurements in tandem with remotely sensed reflectance-derived fluorescence ratio indices to track natural photo inhibition caused by volcanic gas emissions, for use in monitoring plant stress and photosynthetic function. Results may prove helpful in developing potential land management strategies to maintain the biological health of the area.

  5. Did the Nabro volcanic eruption directly overshoot the tropopause?

    Science.gov (United States)

    Biondi, Riccardo; Steiner, Andrea K.; Kirchengast, Gottfried; Brenot, Hugues; Rieckh, Therese

    2015-04-01

    During the night of 12 to 13 June 2011 an explosive eruption occurred at the Nabro volcano located in Eritrea (13.4°N, 41.7°E). This has been recognized as the largest volcanic eruption since Pinatubo 1991, ejecting ash and sulfur dioxide (SO2) into the atmosphere, spreading over more than 60 degrees in latitude and more than 100 degrees in longitude within a few days and lasting for more than 15 days. While there is agreement on the fact that the eruptive mass reached the stratosphere, the processes bringing the cloud to the lower stratosphere are still much debated. For solving this issue we used about 300 atmospheric profiles from Global Positioning System (GPS) Radio Occultation (RO) observations and analyzed the pre-eruption conditions and the impact of the eruption itself on the tropospheric and stratospheric thermal structure. The GPS RO technique enables measurements of the atmospheric parameters in nearly any meteorological condition, with global coverage, high vertical resolution and high accuracy, making RO data well suited to study the thermodynamic structure of volcanic clouds and their impact on climate. In the Nabro area there are no ground based measurements that can be used for such kind of studies and, in the period of the eruption, there are no acquisitions by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. By analyzing the RO bending angle anomaly in the volcanic cloud area, we evaluated the cloud top altitude and compared it to the tropopause altitude (also derived from RO) in the same area. Moreover, we analyzed the RO temperature profiles before and after the eruption. Our results show that the volcanic cloud directly overshoot the tropopause and that the injected SO2 warmed the lower stratosphere in an area of about 10x10 degrees in latitude and longitude for 6 months, which is consistent with the effect found on a larger scale for the Pinatubo eruption in 1991. This study shows the capabilities

  6. Impact of Manufacturing Transfer on SO2 Emissions in Jiangsu Province, China

    Directory of Open Access Journals (Sweden)

    Ying Peng

    2016-05-01

    Full Text Available The impact of manufacturing transfer in Jiangsu province, China, on the spatial-temporal variations of SO2 emissions is investigated using estimated sector-specific SO2 emissions, and emissions in the different transfer-in and transfer-out regions were quantified during 2000–2011. Our results show that SO2 emissions had undergone three phases: an increase in the period of 2000–2005, a rapid decline in 2005–2008 and a slow decline in 2008–2011. Emissions from the south dominated the total emissions in the province. Cleaner production generally contributed to the reduced emissions, but rather, at the industrial scale. Pollution abatement was occasional and industrial structure was negligible in some years. The three phases also coincided with the three periods of the manufacturing transfer: transferred to the south from outside the province during 2000–2005, to the central from the south within the province during 2005–2008 and to the north from the south or partly from the inner central within the province during 2008–2011. With the manufacturing transfer, SO2 emission magnitudes and distributions were also changed. In the south, −12.36 and −5.62 Mt of SO2 emissions were transferred out during 2005–2008 and 2008–2011, respectively. Forty-three-point-four percent and 56.4% of the SO2 emissions in the south were transferred to the central and north during 2005–2008, respectively. The north region received 77.7% and 22.1% of SO2 emissions from the south and the central region during 2008–2011, respectively. The paper reveals that structure adjustments should be executed in a timely manner in the manufacturing transfer-in process so that the transfer-in regions can benefit from the economic boom without bearing a deteriorated environment.

  7. Investigating the Impacts of Winds on SO2 Concentrations in Bor, Serbia

    Directory of Open Access Journals (Sweden)

    Viša Tasić

    2013-06-01

    Full Text Available Air pollution is one of the most important environmental problems in the town of Bor, situated in the eastern of Serbia. The main source of air pollution with sulphur dioxide, heavy metals and other toxic and carcinogenic elements present in particulate matter (PM and aero sediments is the Copper Mining and Smelting Complex Bor. The distribution of air pollutants is mainly determined by the copper smelter operation mode, as well as by meteorological parameters such as wind speed and direction. While information on air pollution with heavy metals and carcinogenic elements in the form of PM has been monitored and reported for longer period, availability of data related to the relationship between air pollutants and meteorological parameters in the Republic of Serbia is still limited. In the present study, the relationships between daily mean concentrations of SO2 and the speed and wind direction were analysed. The analysis includes data collected in 2011 from the four monitoring stations (Park, Jugopetrol, Institute, and Brezonik situated in a wider town area. Pearson correlation coefficients between daily average SO2 and daily average speed and direction of winds are calculated. High wind speed reduces SO2 concentration due to the dilution effect. Hence, correlations between SO2 and the speed and direction of winds at almost all monitoring stations were negative, with one exception (Jugopetrol. This could be explained by the fact that winds, blowing from the north-west (NW direction, carry polluted air towards this station. Moderate negative correlation found between SO2 and wind direction at monitoring station Park. Generally, the observed correlations between SO2 and wind speed and direction are weak, due to frequent changes in SO2 emissions, wind speed and direction during the day.

  8. 7-year temporal trend of anthropogenic SO2 emissions over China identified from GOME observations

    Science.gov (United States)

    Khokhar, M. F.; Beirle, S.; Platt, U.; Wagner, T.

    Fossil fuels such as coal and oil contain significant amounts of sulfur When burned this sulfur is generally converted to SO2 The GOME observations showed enhancements of SO2 column amounts due to anthropogenic emission sources These enhancements are identified from the regions with extensive burning of coal smelting of metal ores and heavy industrial activities such as from China Eastern USA the Arabian Peninsula Eastern Europe South Africa and particularly Norilsk Russia Also a comparison with GOME observations of anthropogenic NO2 column amounts is presented In this paper we present time series of SO2 SCDs over China We analyzed GOME data for the time period 1996-2002 Time series over the highly industrialized regions Beijing and Shanghai showed a slight increase in the SO2 SCD attributable to the increased use of coal for power generation in China Zhou 2001 Especially during the GOME-period 1996-2001 coal consumption and SO2 time series reflect similar behaviour However Richter et al 2005 calculated a significant increase in the NO2 concentrations over the industrial areas of China for the time period of 1996-2004 Additionally preliminary results of atmospheric SO2 from SCIAMACHY on board EnviSAT-1 since March 2002 instrument with broader spectral and better spatial resolution is presented The better spatial resolution will help to study and localize the impacts of SO2 emissions on a finer spatial scale References Richter A J P Burrows H Nuess C Granier and U Niemeier Increase in tropospheric nitrogen

  9. Variability of H2O and SO2 on Venus between 2012 and 2016

    Science.gov (United States)

    Encrenaz, Therese A.; Greathouse, Thomas K.; Richter, Matthew; DeWitt, Curtis; Widemann, Thomas; Bézard, Bruno; Fouchet, Thierry; Atreya, Sushil K.; Sagawa, Hideo

    2016-10-01

    Since January 2012, we have been using the TEXES high-resolution imaging spectrometer at the NASA Infrared Telescope Facility to map sulfur dioxide and deuterated water over the disk of Venus. Data have been recorded in two spectral ranges around 1348 cm-1 (7.4 microns) and 530 cm-1 (19 microns), in order to probe the cloudtop at an altitude of about 64 km (SO2 and HDO at 7 microns) and a few kilometers below (SO2 at 19 microns). Observations took place during six runs between January 2012 and January 2016. The diameter of Venus ranged between 12 and 33 arcsec. Data were recorded with a spectral resolving power as high as 80000 and a spatial resolution of about 1 arcsec (at 7 microns) and 2.5 arcsec (at 19 microns). Mixing ratios have been estimated from HDO/CO2 and SO2/CO2 line depth ratios, using weak neighboring transitions of comparable depths. All data show that the two molecules have a very different behavior. The HDO maps are globally uniform over the disk. The variations of the disk-integrated H2O mixing ratio (estimated assuming a D/H of 200 VSMOW in the mesosphere of Venus) varies by about a factor 1.5 over the four-year period. A constant value of 1.0 - 1.5 pppmv is obtained in most of the cases. The SO2 maps, in contrast, show strong variations over the disk of Venus, by a factor as high as 5. Long-term variations of SO2 show that the disk-integrated SO2 mixing ratio varies between 2012 and 2016 by a factor as high as 10, with a minimum value of 30 +/- 5 ppbv in February 2014 an a maximum value of 300 +/- 50 ppbv in January 2016. The SO2 maps also show a strong short-term variability, with a timescale of a few hours.