Journal of Volcanology and Geothermal Research, 2008
The 1982 eruption of El Chichon inspired a new technique for monitoring volcanic clouds. Data fro... more The 1982 eruption of El Chichon inspired a new technique for monitoring volcanic clouds. Data from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite were used to measure sulfur dioxide in addition to ozone. For the first time precise data on the sulfur dioxide mass in even the largest explosive eruption plumes could be determined. The plumes could be tracked globally as they are carried by winds. Magmatic eruptions could be discriminated from phreatic eruptions. The data from El Chichon are reanalyzed in this paper using the latest version of the TOMS instrument calibration (V8). They show the shearing of the eruption cloud into a globe-circling band while still anchored over Mexico in three weeks. The measured sulfur dioxide mass in the initial March 28 eruption was 1.6 Tg; the April 3 eruption produced 0.3 Tg more, and the April 4 eruptions added 5.6 Tg, for a cumulative total of 7.5 Tg, in substantial agreement with estimates from prior data versions. TOMS Aerosol Index (absorbing aerosol) data show rapid fallout of dense ash east and south of the volcano in agreement with AVHRR ash positions.
Sulfur dioxide in volcanic eruption clouds was detected from space using data from the Total Ozon... more Sulfur dioxide in volcanic eruption clouds was detected from space using data from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus 7 satellite (Krueger, 1983) and confirmed in data from the SBUV instrument on the same satellite (McPeters and Heath, 1984). The detection was possible because sulfur dioxide has strong absorption bands in the same wavelength region of the near ultraviolet that was selected for measuring total ozone with these satellite instruments. The background levels of sulfur dioxide are so low that the measurement of ozone can normally be made without accounting for any interference from this gas. However, volcanic eruptions can produce millions of tons of sulfur dioxide in compact clouds which locally dwarf the absorption by ozone. Even as the eruption cloud is dispersing the absorption by sulfur dioxide can be comparable to that of ozone.
ABSTRACT Volcanic clouds from explosive eruptions can wreak havoc in many parts of the world, as ... more ABSTRACT Volcanic clouds from explosive eruptions can wreak havoc in many parts of the world, as exemplified by the 2010 eruption at the Eyjafjöll volcano in Iceland, which caused widespread disruption to air traffic and resulted in economic impacts across the globe. A suite of satellite-based systems offer the most effective means to monitor active volcanoes and to track the movement of volcanic clouds globally, providing critical information for aviation hazard mitigation. Satellite UV sensors, as part of this suite, have a long history of making unique near-real time (NRT) measurements of sulfur dioxide (SO2) and ash (aerosol Index) in volcanic clouds to supplement operational volcanic ash monitoring. Recently a NASA application project has shown that the use of near real-time (NRT,i.e., not older than 3 h) Aura/OMI satellite data produces a marked improvement in volcanic cloud detection using SO2 combined with Aerosol Index (AI) as a marker for ash. An operational online NRT OMI AI and SO2 image and data product distribution system was developed in collaboration with the NOAA Office of Satellite Data Processing and Distribution. Automated volcanic eruption alarms, and the production of volcanic cloud subsets for multiple regions are provided through the NOAA website. The data provide valuable information in support of the U.S. Federal Aviation Administration goal of a safe and efficient National Air Space. In this presentation, we will highlight the advantages of UV techniques and describe the advances in volcanic SO2 plume height estimation and enhanced volcanic ash detection using hyper-spectral UV measurements, illustrated with Aura/OMI observations of recent eruptions. We will share our plan to provide near-real-time volcanic cloud monitoring service using the Ozone Mapping and Profiler Suite (OMPS) on the Joint Polar Satellite System (JPSS).
Journal of Volcanology and Geothermal Research, Nov 1, 1994
Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically... more Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically through January 1983. During its most violent period from April to October, the Cikasasah Volcano Observatory reported 32 large and 56 moderate to small eruptions. From April 5 through September 19 the Total Ozone Mapping Spectrometer (TOMS), carried on NASA's Nimbus-7 satellite, detected and measured 24 different sulfur dioxide clouds; an estimated 1730 kilotons (kt) of SO2 were outgassed by these explosive eruptions. The trajectories, and rapid dispersion rates, of the SO2 clouds were consistent with injection altitudes below the tropopause. An additional 300 kt of SO2 were estimated to have come from 64 smaller explosive eruptions, based on the detection limit of the TOMS instrument. For the first time, an extended period of volcanic activity was monitored by remote sensing techniques which enabled observations of both the entire SO2 clouds produced by large explosive eruptions (using TOMS), and the relatively lower levels of SO2 emissions during non-explosive outgassing (using the Correlation Spectrometer, or COSPEC). Based on COSPEC measurements from August 1982 to January' 1983, and on the relationship between explosive and non-explosive degassing, approximately 400 kt of SO2 were emitted during non-explosive activity. The total sulfur dioxide outgassed from Galunggung volcano from April 1982 to January. 1983 is calculated to be 2500 kt (_+ 30%) from both explosive and non-explosive activity. While Galunggung added large quantities of sulfur dioxide to the atmosphere, its sporadic emissions occurred in relatively small events distributed over several months, and reached relatively low altitudes, and are unlikely to have significantly affected aerosol loading of the stratosphere in 1982 by volcanic activity.
ABSTRACT Strong volcanic eruptions usually inject large amount ash and gas high into the atmosphe... more ABSTRACT Strong volcanic eruptions usually inject large amount ash and gas high into the atmosphere. Shearing winds can disperse and transport these emissions over long distances during the subsequent days, spreading the aviation and health hazards presented by volcanic ash and elevated sulfur dioxide beyond the immediate regions of erupting volcanoes. While volcanic ash falls out quickly within days, sulfate aerosols, converted from sulfur dioxide via chemical reaction with water vapor, can stay in the atmosphere for a much longer period time, from months to years, depending on the altitude. In this presentation, we describe the recent advances in measuring volcanic emissions using hyper-spectral satellite UV observations, including improved detection and tracking of volcanic ash, direct estimation of sulfur dioxide plume altitude, accurate quantification of sulfur dioxide loadings. These advances are illustrated with results retrieved from observations of recent eruptions by the Ozone Monitoring Instrument (OMI), including the June 2009 eruptions of Sarychev Peak Volcano (Matua Island, Russia) and August 2008 eruptions of Kasatochi Volcano (Aleutian Islands, Alaska). Both eruptions released a large amount of ash and sulfur dioxide, providing perfect opportunities to demonstrate the progresses in ultraviolet (UV) retrieval technique. Comparisons with infrared (AIRS) measurements also illustrate the clear advantages of UV technique in measuring volcanic emissions.
The Ozone Monitoring Instrument (OMI) on the NASA EOS/Aura research satellite and the Global Ozon... more The Ozone Monitoring Instrument (OMI) on the NASA EOS/Aura research satellite and the Global Ozone Monitoring Experiment-2 (GOME-2) instrument on the Metop-A satellite allow measurement of SO2 concentrations at UV wavelengths with daily global coverage. SO2 is detected from space using its strong absorption band structure in the near UV (300-320 nm) as well as in IR bands near 7.3
We discuss a technique for validation of instrument radiometric calibration using the surface of ... more We discuss a technique for validation of instrument radiometric calibration using the surface of Antarctica. The proposed method involves comparing remotely-sensed radiances with predictions from a radiative transfer model, and is applicable to polar-orbiting instruments measuring in the wavelength range 335 nm to 650 nm. Coincident ground measurements are not necessary. We have estimated uncertainties in the method using existing ground measurements and Total Ozone Mapping Spectrometers (TOMS) data. Significant sources of uncertainty include ground-measurement accuracy (1 %), seasonal and spatial surface variation (0.5 %), and radiative-transfer modelling (2 %).
Total column ozone (O3) amount and an aerosol index are among the geophysical properties currentl... more Total column ozone (O3) amount and an aerosol index are among the geophysical properties currently retrieved from Total Ozone Mapping Spectrometer (TOMS) measurements. The accuracy with which each is retrieved depends in part on the characterization of diffuser plates used in the pre-launch instrument calibration. We present here the retrieval sensitivities to errors in the measured reflectance per steradian of
... BACKSCATTERING, NIMBUS SATELLITES, OZONE, SATELLITE-BORNE INSTRUMENTS, SOLAR SPECTROMETERS, T... more ... BACKSCATTERING, NIMBUS SATELLITES, OZONE, SATELLITE-BORNE INSTRUMENTS, SOLAR SPECTROMETERS, TOTAL OZONE MAPPING SPECTROMETER, DESIGN ... TOMS instrument has noteworthy design features such as a state-of-the-art double monochromator ...
One-half of the total ozone column is predominantly under photochemical control under all conditi... more One-half of the total ozone column is predominantly under photochemical control under all conditions except polar winter. The other half is dynamically controlled. Since the photochemical forcing is phased with the solar declination and modulated by air temperature variations in the upper stratosphere and the dynamic forcing is tied to wave activity in the upper troposphere, the total ozone column is a mixture of the two drivers. If we want to use the total ozone to infer a property of the dynamic field, namely the tropopause height, it is necessary to correct for the photochemical variations.
The Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite provides the pri... more The Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite provides the primary source of total ozone data for the study of total ozone in the polar regions of the earth. There are two types of instrument related errors: a slowly developing drift in the instrument calibration since the launch of the instrument in October 1978 and an increase in the measurement noise beginning April, 1984. It is estimated that by October 1987, the accumulated error in the TOMS total ozone measurement due to instrument drift is about 6 m-atm-cm. The sign of the error is such that the TOMS is slightly overpredicting the long-term decrease of the Antarctica ozone. The increase in the measurement noise is more difficult to quantify, affecting some measurements by as much as 10 D.U. and others not at all. A detailed analysis of this error and its potential impact on the studies of total ozone from TOMS will be provided. There are three categories of algorithmic errors: (1) error due the unusual shape of the ozone profile in the ozone hole; (2) error caused by very low atmospheric temperatures in the ozone hole affecting the ozone absorption cross-sections at the TOMS wavelengths; and (3) errors resulting from occasionally thick stratospheric clouds that sometimes reach to 20 km in the ozone hole.
Data from the TOMS instrument has been used to follow the course of development of tile Antarctic... more Data from the TOMS instrument has been used to follow the course of development of tile Antarctic ozone springtime minimum since 1979. This paper addresses the question of possible north polar region changes
Journal of Volcanology and Geothermal Research, 2008
The 1982 eruption of El Chichon inspired a new technique for monitoring volcanic clouds. Data fro... more The 1982 eruption of El Chichon inspired a new technique for monitoring volcanic clouds. Data from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite were used to measure sulfur dioxide in addition to ozone. For the first time precise data on the sulfur dioxide mass in even the largest explosive eruption plumes could be determined. The plumes could be tracked globally as they are carried by winds. Magmatic eruptions could be discriminated from phreatic eruptions. The data from El Chichon are reanalyzed in this paper using the latest version of the TOMS instrument calibration (V8). They show the shearing of the eruption cloud into a globe-circling band while still anchored over Mexico in three weeks. The measured sulfur dioxide mass in the initial March 28 eruption was 1.6 Tg; the April 3 eruption produced 0.3 Tg more, and the April 4 eruptions added 5.6 Tg, for a cumulative total of 7.5 Tg, in substantial agreement with estimates from prior data versions. TOMS Aerosol Index (absorbing aerosol) data show rapid fallout of dense ash east and south of the volcano in agreement with AVHRR ash positions.
Sulfur dioxide in volcanic eruption clouds was detected from space using data from the Total Ozon... more Sulfur dioxide in volcanic eruption clouds was detected from space using data from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus 7 satellite (Krueger, 1983) and confirmed in data from the SBUV instrument on the same satellite (McPeters and Heath, 1984). The detection was possible because sulfur dioxide has strong absorption bands in the same wavelength region of the near ultraviolet that was selected for measuring total ozone with these satellite instruments. The background levels of sulfur dioxide are so low that the measurement of ozone can normally be made without accounting for any interference from this gas. However, volcanic eruptions can produce millions of tons of sulfur dioxide in compact clouds which locally dwarf the absorption by ozone. Even as the eruption cloud is dispersing the absorption by sulfur dioxide can be comparable to that of ozone.
ABSTRACT Volcanic clouds from explosive eruptions can wreak havoc in many parts of the world, as ... more ABSTRACT Volcanic clouds from explosive eruptions can wreak havoc in many parts of the world, as exemplified by the 2010 eruption at the Eyjafjöll volcano in Iceland, which caused widespread disruption to air traffic and resulted in economic impacts across the globe. A suite of satellite-based systems offer the most effective means to monitor active volcanoes and to track the movement of volcanic clouds globally, providing critical information for aviation hazard mitigation. Satellite UV sensors, as part of this suite, have a long history of making unique near-real time (NRT) measurements of sulfur dioxide (SO2) and ash (aerosol Index) in volcanic clouds to supplement operational volcanic ash monitoring. Recently a NASA application project has shown that the use of near real-time (NRT,i.e., not older than 3 h) Aura/OMI satellite data produces a marked improvement in volcanic cloud detection using SO2 combined with Aerosol Index (AI) as a marker for ash. An operational online NRT OMI AI and SO2 image and data product distribution system was developed in collaboration with the NOAA Office of Satellite Data Processing and Distribution. Automated volcanic eruption alarms, and the production of volcanic cloud subsets for multiple regions are provided through the NOAA website. The data provide valuable information in support of the U.S. Federal Aviation Administration goal of a safe and efficient National Air Space. In this presentation, we will highlight the advantages of UV techniques and describe the advances in volcanic SO2 plume height estimation and enhanced volcanic ash detection using hyper-spectral UV measurements, illustrated with Aura/OMI observations of recent eruptions. We will share our plan to provide near-real-time volcanic cloud monitoring service using the Ozone Mapping and Profiler Suite (OMPS) on the Joint Polar Satellite System (JPSS).
Journal of Volcanology and Geothermal Research, Nov 1, 1994
Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically... more Galunggung volcano, Java, awoke from a 63-year quiescence in April 1982, and erupted sporadically through January 1983. During its most violent period from April to October, the Cikasasah Volcano Observatory reported 32 large and 56 moderate to small eruptions. From April 5 through September 19 the Total Ozone Mapping Spectrometer (TOMS), carried on NASA's Nimbus-7 satellite, detected and measured 24 different sulfur dioxide clouds; an estimated 1730 kilotons (kt) of SO2 were outgassed by these explosive eruptions. The trajectories, and rapid dispersion rates, of the SO2 clouds were consistent with injection altitudes below the tropopause. An additional 300 kt of SO2 were estimated to have come from 64 smaller explosive eruptions, based on the detection limit of the TOMS instrument. For the first time, an extended period of volcanic activity was monitored by remote sensing techniques which enabled observations of both the entire SO2 clouds produced by large explosive eruptions (using TOMS), and the relatively lower levels of SO2 emissions during non-explosive outgassing (using the Correlation Spectrometer, or COSPEC). Based on COSPEC measurements from August 1982 to January' 1983, and on the relationship between explosive and non-explosive degassing, approximately 400 kt of SO2 were emitted during non-explosive activity. The total sulfur dioxide outgassed from Galunggung volcano from April 1982 to January. 1983 is calculated to be 2500 kt (_+ 30%) from both explosive and non-explosive activity. While Galunggung added large quantities of sulfur dioxide to the atmosphere, its sporadic emissions occurred in relatively small events distributed over several months, and reached relatively low altitudes, and are unlikely to have significantly affected aerosol loading of the stratosphere in 1982 by volcanic activity.
ABSTRACT Strong volcanic eruptions usually inject large amount ash and gas high into the atmosphe... more ABSTRACT Strong volcanic eruptions usually inject large amount ash and gas high into the atmosphere. Shearing winds can disperse and transport these emissions over long distances during the subsequent days, spreading the aviation and health hazards presented by volcanic ash and elevated sulfur dioxide beyond the immediate regions of erupting volcanoes. While volcanic ash falls out quickly within days, sulfate aerosols, converted from sulfur dioxide via chemical reaction with water vapor, can stay in the atmosphere for a much longer period time, from months to years, depending on the altitude. In this presentation, we describe the recent advances in measuring volcanic emissions using hyper-spectral satellite UV observations, including improved detection and tracking of volcanic ash, direct estimation of sulfur dioxide plume altitude, accurate quantification of sulfur dioxide loadings. These advances are illustrated with results retrieved from observations of recent eruptions by the Ozone Monitoring Instrument (OMI), including the June 2009 eruptions of Sarychev Peak Volcano (Matua Island, Russia) and August 2008 eruptions of Kasatochi Volcano (Aleutian Islands, Alaska). Both eruptions released a large amount of ash and sulfur dioxide, providing perfect opportunities to demonstrate the progresses in ultraviolet (UV) retrieval technique. Comparisons with infrared (AIRS) measurements also illustrate the clear advantages of UV technique in measuring volcanic emissions.
The Ozone Monitoring Instrument (OMI) on the NASA EOS/Aura research satellite and the Global Ozon... more The Ozone Monitoring Instrument (OMI) on the NASA EOS/Aura research satellite and the Global Ozone Monitoring Experiment-2 (GOME-2) instrument on the Metop-A satellite allow measurement of SO2 concentrations at UV wavelengths with daily global coverage. SO2 is detected from space using its strong absorption band structure in the near UV (300-320 nm) as well as in IR bands near 7.3
We discuss a technique for validation of instrument radiometric calibration using the surface of ... more We discuss a technique for validation of instrument radiometric calibration using the surface of Antarctica. The proposed method involves comparing remotely-sensed radiances with predictions from a radiative transfer model, and is applicable to polar-orbiting instruments measuring in the wavelength range 335 nm to 650 nm. Coincident ground measurements are not necessary. We have estimated uncertainties in the method using existing ground measurements and Total Ozone Mapping Spectrometers (TOMS) data. Significant sources of uncertainty include ground-measurement accuracy (1 %), seasonal and spatial surface variation (0.5 %), and radiative-transfer modelling (2 %).
Total column ozone (O3) amount and an aerosol index are among the geophysical properties currentl... more Total column ozone (O3) amount and an aerosol index are among the geophysical properties currently retrieved from Total Ozone Mapping Spectrometer (TOMS) measurements. The accuracy with which each is retrieved depends in part on the characterization of diffuser plates used in the pre-launch instrument calibration. We present here the retrieval sensitivities to errors in the measured reflectance per steradian of
... BACKSCATTERING, NIMBUS SATELLITES, OZONE, SATELLITE-BORNE INSTRUMENTS, SOLAR SPECTROMETERS, T... more ... BACKSCATTERING, NIMBUS SATELLITES, OZONE, SATELLITE-BORNE INSTRUMENTS, SOLAR SPECTROMETERS, TOTAL OZONE MAPPING SPECTROMETER, DESIGN ... TOMS instrument has noteworthy design features such as a state-of-the-art double monochromator ...
One-half of the total ozone column is predominantly under photochemical control under all conditi... more One-half of the total ozone column is predominantly under photochemical control under all conditions except polar winter. The other half is dynamically controlled. Since the photochemical forcing is phased with the solar declination and modulated by air temperature variations in the upper stratosphere and the dynamic forcing is tied to wave activity in the upper troposphere, the total ozone column is a mixture of the two drivers. If we want to use the total ozone to infer a property of the dynamic field, namely the tropopause height, it is necessary to correct for the photochemical variations.
The Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite provides the pri... more The Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite provides the primary source of total ozone data for the study of total ozone in the polar regions of the earth. There are two types of instrument related errors: a slowly developing drift in the instrument calibration since the launch of the instrument in October 1978 and an increase in the measurement noise beginning April, 1984. It is estimated that by October 1987, the accumulated error in the TOMS total ozone measurement due to instrument drift is about 6 m-atm-cm. The sign of the error is such that the TOMS is slightly overpredicting the long-term decrease of the Antarctica ozone. The increase in the measurement noise is more difficult to quantify, affecting some measurements by as much as 10 D.U. and others not at all. A detailed analysis of this error and its potential impact on the studies of total ozone from TOMS will be provided. There are three categories of algorithmic errors: (1) error due the unusual shape of the ozone profile in the ozone hole; (2) error caused by very low atmospheric temperatures in the ozone hole affecting the ozone absorption cross-sections at the TOMS wavelengths; and (3) errors resulting from occasionally thick stratospheric clouds that sometimes reach to 20 km in the ozone hole.
Data from the TOMS instrument has been used to follow the course of development of tile Antarctic... more Data from the TOMS instrument has been used to follow the course of development of tile Antarctic ozone springtime minimum since 1979. This paper addresses the question of possible north polar region changes
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Papers by Arlin Krueger