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Full-Text Articles in Engineering
Adjusting Particle-Size Distributions To Account For Aggregation In Tephra-Deposit Model Forecasts, Larry G. Mastin, Alexa R. Van Eaton, Adam J. Durant
Adjusting Particle-Size Distributions To Account For Aggregation In Tephra-Deposit Model Forecasts, Larry G. Mastin, Alexa R. Van Eaton, Adam J. Durant
Michigan Tech Publications
Volcanic ash transport and dispersion (VATD) models are used to forecast tephra deposition during volcanic eruptions. Model accuracy is limited by the fact that fine-ash aggregates (clumps into clusters), thus altering patterns of deposition. In most models this is accounted for by ad hoc changes to model input, representing fine ash as aggregates with density ρagg, and a log-normal size distribution with median μagg and standard deviation σagg. Optimal values may vary between eruptions. To test the variance, we used the Ash3d tephra model to simulate four deposits: 18 May 1980 Mount St. Helens; 16-17 September 1992 Crater Peak (Mount …
Improving Automated Global Detection Of Volcanic So2 Plumes Using The Ozone Monitoring Instrument (Omi), Verity Flower, Thomas Oommen, Simon Carn
Improving Automated Global Detection Of Volcanic So2 Plumes Using The Ozone Monitoring Instrument (Omi), Verity Flower, Thomas Oommen, Simon Carn
Michigan Tech Publications
Volcanic eruptions pose an ever-present threat to human populations around the globe, but many active volcanoes remain poorly monitored. In regions where ground-based monitoring is present the effects of volcanic eruptions can be moderated through observational alerts to both local populations and service providers such as air traffic control. However, in regions where volcano monitoring is limited satellite-based remote sensing provides a global data source that can be utilized to provide near real time identification of volcanic activity. This paper details the development of an automated volcanic plume detection method utilizing daily, global observations of sulphur dioxide (SO2) by the …
Developing The Greatest Blue Economy: Water Productivity, Fresh Water Depletion, And Virtual Water Trade In The Great Lakes Basin, A. L. Mayer, Stanley Mubako, Benjamin L. Ruddell
Developing The Greatest Blue Economy: Water Productivity, Fresh Water Depletion, And Virtual Water Trade In The Great Lakes Basin, A. L. Mayer, Stanley Mubako, Benjamin L. Ruddell
Michigan Tech Publications
The Great Lakes basin hosts the world's most abundant surface fresh water reserve. Historically an industrial and natural resource powerhouse, the region has suffered economic stagnation in recent decades. Meanwhile, growing water resource scarcity around the world is creating pressure on water-intensive human activities. This situation creates the potential for the Great Lakes region to sustainably utilize its relative water wealth for economic benefit. We combine economic production and trade datasets with water consumption data and models of surface water depletion in the region. We find that, on average, the current economy does not create significant impacts on surface waters, …
Post-Eruption Deformation Processes Measured Using Alos-1 And Uavsar Insar At Pacaya Volcano, Guatemala, Lauren Schaefer, Zhong Lu, Thomas Oommen
Post-Eruption Deformation Processes Measured Using Alos-1 And Uavsar Insar At Pacaya Volcano, Guatemala, Lauren Schaefer, Zhong Lu, Thomas Oommen
Michigan Tech Publications
Pacaya volcano is a persistently active basaltic cone complex located in the Central American Volcanic Arc in Guatemala. In May of 2010, violent Volcanic Explosivity Index-3 (VEI-3) eruptions caused significant topographic changes to the edifice, including a linear collapse feature 600 m long originating from the summit, the dispersion of ~20 cm of tephra and ash on the cone, the emplacement of a 5.4 km long lava flow, and ~3 m of co-eruptive movement of the southwest flank. For this study, Interferometric Synthetic Aperture Radar (InSAR) images (interferograms) processed from both spaceborne Advanced Land Observing Satellite-1 (ALOS-1) and aerial Uninhabited …
The Impact Of Mpowir A Decade Of Investing In Mentoring Women In Physical Oceanography, Sarah Clem, Sonya Legg, Susan Lozier, Colleen B. Mouw
The Impact Of Mpowir A Decade Of Investing In Mentoring Women In Physical Oceanography, Sarah Clem, Sonya Legg, Susan Lozier, Colleen B. Mouw
Michigan Tech Publications
MPOWIR (Mentoring Physical Oceanography Women to Increase Retention) is a US communityinitiated and community-led mentoring program aimed at improving the retention of women physical oceanographers in academic and/or research positions. This article describes the MPOWIR program elements designed by the US physical oceanography community, quantifies the participation in these programs, describes MPOWIR’s impact to date, and outlines future directions. An examination of surveys to date indicates that MPOWIR, several years after its implementation, is having a positive impact on the retention of junior women in physical oceanography, primarily by giving them a broad professional network and focused mentoring.
Capturing Optically Important Constituents And Properties In A Marine Biogeochemical And Ecosystem Model, S. Dutkiewicz, A. E. Hickman, O. Jahn, W. W. Gregg, C. B. Mouw, M. J. Follows, C. Mouw
Capturing Optically Important Constituents And Properties In A Marine Biogeochemical And Ecosystem Model, S. Dutkiewicz, A. E. Hickman, O. Jahn, W. W. Gregg, C. B. Mouw, M. J. Follows, C. Mouw
Michigan Tech Publications
We present a numerical model of the ocean that couples a three-stream radiative transfer component with a marine biogeochemical-ecosystem component in a dynamic three-dimensional physical framework. The radiative transfer component resolves the penetration of spectral irradiance as it is absorbed and scattered within the water column. We explicitly include the effect of several optically important water constituents (different phytoplankton functional types; detrital particles; and coloured dissolved organic matter, CDOM). The model is evaluated against in situ-observed and satellite-derived products. In particular we compare to concurrently measured biogeochemical, ecosystem, and optical data along a meridional transect of the Atlantic Ocean. The …
Seasonal Variability Of Atmospheric Nitrogen Oxides And Non-Methane Hydrocarbons At The Geosummit Station, Greenland, L. J. Kramer, D. Helmig, J. F. Burkhart, A. Stohl, S. Oltmans, R. E. Honrath
Seasonal Variability Of Atmospheric Nitrogen Oxides And Non-Methane Hydrocarbons At The Geosummit Station, Greenland, L. J. Kramer, D. Helmig, J. F. Burkhart, A. Stohl, S. Oltmans, R. E. Honrath
Michigan Tech Publications
Measurements of atmospheric nitrogen oxides NOx (NOx = NO + NO2), peroxyacetyl nitrate (PAN), NOy, and non-methane hydrocarbons (NMHC) were taken at the Greenland Environmental Observatory at Summit (GEOSummit) station, Greenland (72.34° N, 38.29° W; 3212 m a.s.l.), from July 2008 to July 2010. The data set represents the first year-round concurrent record of these compounds sampled at a high latitude Arctic site. Here, the study focused on the seasonal variability of these important ozone (O3) precursors in the Arctic troposphere and the impact from transported anthropogenic and biomass burning emissions. Our analysis shows that PAN is the dominant NOy …
Spatial Analysis Of Mount St. Helens Tephra Leachate Compositions: Implications For Future Sampling Strategies, P. M. Ayris, P. Delmelle, B. Pereira, E. C. Maters, D. E. Damby, A. J. Durant, D. B. Dingwell
Spatial Analysis Of Mount St. Helens Tephra Leachate Compositions: Implications For Future Sampling Strategies, P. M. Ayris, P. Delmelle, B. Pereira, E. C. Maters, D. E. Damby, A. J. Durant, D. B. Dingwell
Michigan Tech Publications
Tephra particles in physically and chemically evolving volcanic plumes and clouds carry soluble sulphate and halide salts to the Earth’s surface, ultimately depositing volcanogenic compounds into terrestrial or aquatic environments. Upon leaching of tephra in water, these salts dissolve rapidly. Previous studies have investigated the spatial and temporal variability of tephra leachate compositions during an eruption in order to gain insight into the mechanisms of gas-tephra interaction which emplace those salts. However, the leachate datasets analysed are typically small and may poorly represent the natural variability and complexity of tephra deposits. Here, we have conducted a retrospective analysis of published …
Stratospheric Volcanic Ash Emissions From The 13 February 2014 Kelut Eruption, N. I. Kristiansen, A. J. Prata, A. Stohl, S. A. Carn
Stratospheric Volcanic Ash Emissions From The 13 February 2014 Kelut Eruption, N. I. Kristiansen, A. J. Prata, A. Stohl, S. A. Carn
Michigan Tech Publications
Mount Kelut (Indonesia) erupted explosively around 15:50 UT on 13 February 2014 sending ash and gases into the stratosphere. Satellite ash retrievals and dispersion transport modeling are combined within an inversion framework to estimate the volcanic ash source term and to study ash transport. The estimated source term suggests that most of the ash was injected to altitudes of 16-17km, in agreement with space-based lidar data. Modeled ash concentrations along the flight track of a commercial aircraft that encountered the ash cloud indicate that it flew under the main ash cloud and encountered maximum ash concentrations of 9±3mgm-3, mean concentrations …
Separation Of Ash And Sulfur Dioxide During The 2011 Grímsvötn Eruption, E. D. Moxnes, N. I. Kristiansen, A. Stohl, L. Clarisse, A. J. Durant, K. Weber, A. Vogel
Separation Of Ash And Sulfur Dioxide During The 2011 Grímsvötn Eruption, E. D. Moxnes, N. I. Kristiansen, A. Stohl, L. Clarisse, A. J. Durant, K. Weber, A. Vogel
Michigan Tech Publications
Modeling the transport of volcanic ash and gases released during volcanic eruptions is crucially dependent on knowledge of the source term of the eruption, that is, the source strength as a function of altitude and time. For the first time, an inversion method is used to estimate the source terms of both volcanic sulfur dioxide (SO2) and ash. It was applied to the explosive volcanic eruption of Grímsvötn, Iceland, in May 2011. The method uses input from the particle dispersion model, FLEXPART (flexible particle dispersion model), a priori source estimates, and satellite observations of SO2 or ash total columns from …
Absorption And Fluorescence Properties Of Chromophoric Dissolved Organic Matter Of The Eastern Bering Sea In The Summer With Special Reference To The Influence Of A Cold Pool, E. J. D'Sa, J. I. Goes, H. Gomes, C. Mouw
Absorption And Fluorescence Properties Of Chromophoric Dissolved Organic Matter Of The Eastern Bering Sea In The Summer With Special Reference To The Influence Of A Cold Pool, E. J. D'Sa, J. I. Goes, H. Gomes, C. Mouw
Michigan Tech Publications
The absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) are reported for the inner shelf, slope waters and outer shelf regions of the eastern Bering Sea during the summer of 2008, when a warm, thermally stratified surface mixed layer lay over a cold pool ( < 2 °C) that occupied the entire middle shelf. CDOM absorption at 355 nm (ag355) and its spectral slope (S) in conjunction with excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) revealed large variability in the characteristics of CDOM in different regions of the Bering Sea. PARAFAC analysis aided in the identification of three humic-like (components one, two and five) and two protein-like (a tyrosine-like component three, and a tryptophan-like component four) components. In the extensive shelf region, average absorption coefficients at 355 nm (ag355, mg-1) and DOC concentrations (μM) were highest in the inner shelf (0.342 ± 0.11 mg-1, 92.67 ± 14.60 μM) and lower in the middle (0.226 ± 0.05 mg-1, 78.38 ± 10.64 μM) and outer (0.185 ± 0.05 mg-1, 79.24 ± 18.01 μM) shelves, respectively. DOC concentrations, however were not significantly different, suggesting CDOM sources and sinks to be uncoupled from DOC. Mean spectral slopes S were elevated in the middle shelf (24.38 ± 2.25 μmg-1) especially in the surface waters (26.87 ± 2.39 μmg-1) indicating high rates of photodegradation in the highly stratified surface mixed layer, which intensified northwards in the northern middle shelf likely contributing to greater light penetration and to phytoplankton blooms at deeper depths. The fluorescent humic-like components one, two, and five were most elevated in the inner shelf most likely from riverine inputs. Along the productive "green belt" in the outer shelf/slope region, absorption and fluorescence properties indicated the presence of fresh and degraded autochthonous DOM. Near the Unimak Pass region of the Aleutian Islands, low DOC and ag355 (mean 66.99 ± 7.94 μM; 0.182 ± 0.05 mg-1) and a high S (mean 25.95 ± 1.58 μmg-1) suggested substantial photobleaching of the Alaska Coastal Water, but high intensities of humic-like and protein-like fluorescence suggested sources of fluorescent DOM from coastal runoff and glacier meltwaters during the summer. The spectral slope S vs. ag355 relationship revealed terrestrial and oceanic end members along with intermediate water masses that were modeled using nonlinear regression equations that could allow water mass differentiation based on CDOM optical properties. Spectral slope S was negatively correlated (r2 = 0.79) with apparent oxygen utilization (AOU) for waters extending from the middle shelf into the deep Bering Sea indicating increasing microbial alteration of CDOM with depth. Although our data show that the CDOM photochemical environment of the Bering Sea is complex, our current information on its optical properties will aid in better understanding of the biogeochemical role of CDOM in carbon budgets in relation to the annual sea ice and phytoplankton dynamics, and to improved algorithms of ocean color remote sensing for this region.
Seasonal Variability And Long-Term Evolution Of Tropospheric Composition In The Tropics And Southern Hemisphere, K. M. Wai, S. Wu, A. Kumar, H. Liao
Seasonal Variability And Long-Term Evolution Of Tropospheric Composition In The Tropics And Southern Hemisphere, K. M. Wai, S. Wu, A. Kumar, H. Liao
Michigan Tech Publications
Impacts on tropospheric composition in the tropics and the Southern Hemisphere from biomass burning and other emission sources are studied using a global chemical transport model, surface measurements and satellite retrievals. Seasonal variations in observed CO at remote island sites are examined. Easter Island (eastern Pacific Ocean) is impacted indirectly by the hemispheric zonal transport of CO due to the burning in southern Africa/South America, via the westerlies. An increasing trend in CO by 0.33 ppb yr-1 in the past decade at Ascension Island is attributed to the combined effects of South American/southern Africa burnings and the increases in CH4 …
Effects Of Stratospheric Ozone Recovery On Photochemistry And Ozone Air Quality In The Troposphere, H. Zhang, Shiliang Wu, Y. Huang, Y. Wang
Effects Of Stratospheric Ozone Recovery On Photochemistry And Ozone Air Quality In The Troposphere, H. Zhang, Shiliang Wu, Y. Huang, Y. Wang
Michigan Tech Publications
There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor …
Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li
Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li
Michigan Tech Publications
In situ measurements of carbon monoxide (CO) and ozone (O3) at the Pico Mountain Observatory (PMO) located in the Azores, Portugal, are analyzed together with results from an atmospheric chemical transport model (GEOS-Chem) and satellite remote sensing data (AIRS (Atmospheric Infrared Sounder) for CO, and TES (Tropospheric Emission Spectrometer) for O3) to examine the evolution of free-troposphere CO and O3 over the North Atlantic for 2001-2011. GEOS-Chem captured the seasonal cycles for CO and O3 well but significantly underestimated the mixing ratios of CO, particularly in spring. Statistically significant (using a significance level of 0.05) decreasing trends were found for …
Projected Effect Of 2000-2050 Changes In Climate And Emissions On Aerosol Levels In China And Associated Transboundary Transport, H. Jiang, H. Liao, H. O.T. Pye, S. Wu, L. J. Mickley, J. H. Seinfeld, X. Y. Zhang
Projected Effect Of 2000-2050 Changes In Climate And Emissions On Aerosol Levels In China And Associated Transboundary Transport, H. Jiang, H. Liao, H. O.T. Pye, S. Wu, L. J. Mickley, J. H. Seinfeld, X. Y. Zhang
Michigan Tech Publications
We investigate projected 2000-2050 changes in concentrations of aerosols in China and the associated transboundary aerosol transport by using the chemical transport model GEOS-Chem driven by the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 at 4° × 5° resolution. Future changes in climate and emissions projected by the IPCC A1B scenario are imposed separately and together through sensitivity simulations. Accounting for sulfate, nitrate, ammonium, black carbon (BC), and organic carbon (OC) aerosols, concentrations of individual aerosol species change by -1.5 to +0.8 μg m-3, and PM2.5 levels are projected to change by about 10-20% in eastern …
Impact Of Aging Mechanism On Model Simulated Carbonaceous Aerosols, Y. Huang, S. Wu, M. K. Dubey, N. H.F. French
Impact Of Aging Mechanism On Model Simulated Carbonaceous Aerosols, Y. Huang, S. Wu, M. K. Dubey, N. H.F. French
Michigan Tech Publications
Carbonaceous aerosols including organic carbon and black carbon have significant implications for both climate and air quality. In the current global climate or chemical transport models, a fixed hydrophobic-to-hydrophilic conversion lifetime for carbonaceous aerosol (τ) is generally assumed, which is usually around one day. We have implemented a new detailed aging scheme for carbonaceous aerosols in a chemical transport model (GEOS-Chem) to account for both the chemical oxidation and the physical condensation-coagulation effects, where τ is affected by local atmospheric environment including atmospheric concentrations of water vapor, ozone, hydroxyl radical and sulfuric acid. The updated τ exhibits large spatial and …
Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, R. C. Owen, Et. Al.
Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, R. C. Owen, Et. Al.
Michigan Tech Publications
We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned …
Modeling Of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation Of Omi So < Inf> 2 Plume Height Data And Comparison With Modis And Caliop Observations, J. Wang, S. Park, J. Zeng, C. Ge, K. Yang, S. Carn, N. Krotkov, A. H. Omar
Modeling Of 2008 Kasatochi Volcanic Sulfate Direct Radiative Forcing: Assimilation Of Omi So < Inf> 2 Plume Height Data And Comparison With Modis And Caliop Observations, J. Wang, S. Park, J. Zeng, C. Ge, K. Yang, S. Carn, N. Krotkov, A. H. Omar
Michigan Tech Publications
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 …
Validation Of The Fall3d Model For The 2008 Chaitén Eruption Using Field And Satellite Data, María Soledad Osores, Arnau Folch, Estela Collini, Gustavo Villarosa, Adam J. Durant, Gloria Pujol, José G. Viramonte
Validation Of The Fall3d Model For The 2008 Chaitén Eruption Using Field And Satellite Data, María Soledad Osores, Arnau Folch, Estela Collini, Gustavo Villarosa, Adam J. Durant, Gloria Pujol, José G. Viramonte
Michigan Tech Publications
The 2008 Chaitén Volcano eruption began on 2 May 2008 with an explosive phase that injected large amounts of tephra into the atmosphere. During the first week of the eruption, volcanic ash clouds were transported for hundreds of kilometres over Argentina by the prevailing westerly winds. Tephra deposition extended to the Atlantic Ocean and severely affected the Argentinean Patagonia. Impacts included air and water quality degradation, disruption of ground transportation systems and cancellation of flights at airports more than 1,500 km apart. We use the FALL3D tephra transport model coupled with the Weather Research and Forecasting-Advanced Research Weather (WRF-ARW) meteorological …
Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob
Impacts Of Changes In Land Use And Land Cover On Atmospheric Chemistry And Air Quality Over The 21st Century, S. Wu, L. J. Mickley, J. O. Kaplan, D. J. Jacob
Michigan Tech Publications
The effects of future land use and land cover change on the chemical composition of the atmosphere and air quality are largely unknown. To investigate the potential effects associated with future changes in vegetation driven by atmospheric CO 2 concentrations, climate, and anthropogenic land use over the 21st century, we performed a series of model experiments combining a general circulation model with a dynamic global vegetation model and an atmospheric chemical-transport model. Our results indicate that climate-and CO 2-induced changes in vegetation composition and density between 2100 and 2000 could lead to decreases in summer afternoon surface ozone of up …
Ethane, Ethyne And Carbon Monoxide Concentrations In The Upper Troposphere And Lower Stratosphere From Ace And Geos-Chem: A Comparison Study, G. González Abad, N. D.C. Allen, P. F. Bernath, C. D. Boone, S. D. Mcleod, G. L. Manney, G. C. Toon, C. Carouge, Y. Wang, Shiliang Wu, X
Ethane, Ethyne And Carbon Monoxide Concentrations In The Upper Troposphere And Lower Stratosphere From Ace And Geos-Chem: A Comparison Study, G. González Abad, N. D.C. Allen, P. F. Bernath, C. D. Boone, S. D. Mcleod, G. L. Manney, G. C. Toon, C. Carouge, Y. Wang, Shiliang Wu, X
Michigan Tech Publications
Near global upper tropospheric concentrations of carbon monoxide (CO), ethane (C2H6) and ethyne (C2H2) from ACE (Atmospheric Chemistry Experiment) Fourier transform spectrometer on board the Canadian satellite SCISAT-1 are presented and compared with the output from the Chemical Transport Model (CTM) GEOS-Chem. The retrievals of ethane and ethyne from ACE have been improved for this paper by using new sets of microwindows compared with those for previous versions of ACE data. With the improved ethyne retrieval we have been able to produce a near global upper tropospheric distribution of C2H2 from space. Carbon monoxide, ethane and ethyne concentrations retrieved using …
Opportunistic Validation Of Sulfur Dioxide In The Sarychev Peak Volcanic Eruption Cloud, S. Carn, T. M. Lopez
Opportunistic Validation Of Sulfur Dioxide In The Sarychev Peak Volcanic Eruption Cloud, S. Carn, T. M. Lopez
Michigan Tech Publications
We report attempted validation of Ozone Monitoring Instrument (OMI) sulfur dioxide (SO 2) retrievals in the stratospheric volcanic cloud from Sarychev Peak (Kurile Islands) in June 2009, through opportunistic deployment of a ground-based ultraviolet (UV) spectrometer (FLYSPEC) as the volcanic cloud drifted over central Alaska. The volcanic cloud altitude (∼12-14 km) was constrained using coincident CALIPSO lidar observations. By invoking some assumptions about the spatial distribution of SO 2, we derive averages of FLYSPEC vertical SO 2 columns for comparison with OMI SO 2 measurements. Despite limited data, we find minimum OMI-FLYSPEC differences within measurement uncertainties, which support the validity …
Sulphur Dioxide As A Volcanic Ash Proxy During The April-May 2010 Eruption Of Eyjafjallajökull Volcano, Iceland, H. E. Thomas, A. J. Prata
Sulphur Dioxide As A Volcanic Ash Proxy During The April-May 2010 Eruption Of Eyjafjallajökull Volcano, Iceland, H. E. Thomas, A. J. Prata
Michigan Tech Publications
The volcanic ash cloud from the eruption of Eyjafjallajökull volcano in April and May 2010 resulted in unprecedented disruption to air traffic in Western Europe causing significant financial losses and highlighting the importance of efficient volcanic cloud monitoring. The feasibility of using SO2 as a tracer for the ash released during the eruption is investigated here through comparison of ash retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) with SO2 measurements from a number of infrared and ultraviolet satellite-based sensors. Results demonstrate that the eruption can be divided into an initial ash-rich phase, a lower intensity middle phase …
Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley
Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley
Michigan Tech Publications
Simulations of present and future average regional ozone and PM 2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared …
Determination Of Time-And Height-Resolved Volcanic Ash Emissions And Their Use For Quantitative Ash Dispersion Modeling: The 2010 Eyjafjallajökull Eruption, A. Stohl, A. J. Prata, S. Eckhardt, L. Clarisse, A. Durant, S. Henne, N. I. Kristiansen, A. Minikin, U. Schumann, P. Seibert, K. Stebel, H. E. Thomas, T. Thorsteinsson, K. Tørseth, B. Weinzierl
Determination Of Time-And Height-Resolved Volcanic Ash Emissions And Their Use For Quantitative Ash Dispersion Modeling: The 2010 Eyjafjallajökull Eruption, A. Stohl, A. J. Prata, S. Eckhardt, L. Clarisse, A. Durant, S. Henne, N. I. Kristiansen, A. Minikin, U. Schumann, P. Seibert, K. Stebel, H. E. Thomas, T. Thorsteinsson, K. Tørseth, B. Weinzierl
Michigan Tech Publications
The Aprilg-May, 2010 volcanic eruptions of Eyjafjallajökull, Iceland caused significant economic and social disruption in Europe whilst state of the art measurements and ash dispersion forecasts were heavily criticized by the aviation industry. Here we demonstrate for the first time that large improvements can be made in quantitative predictions of the fate of volcanic ash emissions, by using an inversion scheme that couples a priori source information and the output of a Lagrangian dispersion model with satellite data to estimate the volcanic ash source strength as a function of altitude and time. From the inversion, we obtain a total fine …
Source Attribution And Interannual Variability Of Arctic Pollution In Spring Constrained By Aircraft (Arctas, Arcpac) And Satellite (Airs) Observations Of Carbon Monoxide, J. A. Fisher, D. J. Jacob, M. T. Purdy, M. Kopacz, P. Le Sager, Shiliang Wu, Et. Al.
Source Attribution And Interannual Variability Of Arctic Pollution In Spring Constrained By Aircraft (Arctas, Arcpac) And Satellite (Airs) Observations Of Carbon Monoxide, J. A. Fisher, D. J. Jacob, M. T. Purdy, M. Kopacz, P. Le Sager, Shiliang Wu, Et. Al.
Michigan Tech Publications
We use aircraft observations of carbon monoxide (CO) from the NASA ARCTAS and NOAA ARCPAC campaigns in April 2008 together with multiyear (2003–2008) CO satellite data from the AIRS instrument and a global chemical transport model (GEOS-Chem) to better understand the sources, transport, and interannual variability of pollution in the Arctic in spring. Model simulation of the aircraft data gives best estimates of CO emissions in April 2008 of 26 Tg month−1 for Asian anthropogenic, 9.4 for European anthropogenic, 4.1 for North American anthropogenic, 15 for Russian biomass burning (anomalously large that year), and 23 for Southeast Asian biomass burning. …
Technical Note: A New Method For The Lagrangian Tracking Of Pollution Plumes From Source To Receptor Using Gridded Model Output, R. C. Owen, R. E. Honrath
Technical Note: A New Method For The Lagrangian Tracking Of Pollution Plumes From Source To Receptor Using Gridded Model Output, R. C. Owen, R. E. Honrath
Michigan Tech Publications
Lagrangian particle dispersion models (LPDMs) are powerful and popular tools used for the analysis of atmospheric trace gas measurements. However, it can be difficult to determine the transport pathway of emissions from their source to a receptor using the standard gridded model output, particularly during complex meteorological scenarios. In this paper we present a method to clearly and easily identify the pathway taken by only those emissions that arrive at a receptor at a particular time, by combining the standard gridded output from forward (e.g., concentration) and backward (e.g., residence time) LPDM simulations. By comparing the pathway determined from this …