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Michigan Technological University

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Articles 121 - 150 of 167

Full-Text Articles in Geological Engineering

Application Of Remote Sensing And Machine Learning Modeling To Post-Wildfire Debris Flow Risks, Priscilla Addison Jan 2018

Application Of Remote Sensing And Machine Learning Modeling To Post-Wildfire Debris Flow Risks, Priscilla Addison

Dissertations, Master's Theses and Master's Reports

Historically, post-fire debris flows (DFs) have been mostly more deadly than the fires that preceded them. Fires can transform a location that had no history of DFs to one that is primed for it. Studies have found that the higher the severity of the fire, the higher the probability of DF occurrence. Due to high fatalities associated with these events, several statistical models have been developed for use as emergency decision support tools. These previous models used linear modeling approaches that produced subpar results. Our study therefore investigated the application of nonlinear machine learning modeling as an alternative. Existing models …


Probabilistic Regional Landslide Hazard Assessment For The Enguri Dam (Jivari, Georgia), Maria Diletta Acciaro Jan 2018

Probabilistic Regional Landslide Hazard Assessment For The Enguri Dam (Jivari, Georgia), Maria Diletta Acciaro

Dissertations, Master's Theses and Master's Reports

The Enguri Dam forms a reservoir in a seismically active area in the foothills of the Caucasus Mountain range near Jvari, Georgia. The slopes are steep, highly fractured, and weathered, which make them at risk to failure during or following extreme rainfall events. Hydroelectricity produced by the water retained by the 271-m dam provides almost half of the electricity for the country. The reservoir perimeter is more than 40 km and the surrounding slopes span an area of more than 30 km2. The size of the area and paucity of slope data have made slope-failure hazard assessment of the broader …


Analyzing The Life-Cycle Of Unstable Slopes Using Applied Remote Sensing Within An Asset Management Framework, El Hachemi Y. Bouali Jan 2018

Analyzing The Life-Cycle Of Unstable Slopes Using Applied Remote Sensing Within An Asset Management Framework, El Hachemi Y. Bouali

Dissertations, Master's Theses and Master's Reports

An asset management framework provides a methodology for monitoring and maintaining assets, which include anthropogenic infrastructure (e.g., dams, embankments, and retaining structures) and natural geological features (e.g., soil and rock slopes). It is imperative that these assets operate efficiently, effectively, safely, and at a high standard since many assets are located along transportation corridors (highways, railways, and waterways) and can cause severe damage if compromised. Assets built on or around regions prone to natural hazards are at an increased risk of deterioration and failure. The objective of this study is to utilize remote sensing techniques such as InSAR, LiDAR, and …


Early Warning System For Shallow Landslides Using Rainfall Threshold And Slope Stability Analysis, Shruti Naidu, K. S. Sajinkumar, Thomas Oommen, V.J. Anuja, Rinu Samuel, C. Muraleedharan Oct 2017

Early Warning System For Shallow Landslides Using Rainfall Threshold And Slope Stability Analysis, Shruti Naidu, K. S. Sajinkumar, Thomas Oommen, V.J. Anuja, Rinu Samuel, C. Muraleedharan

Michigan Tech Publications, Part 1

A combined cluster and regression analysis were performed for the first time to identify rainfall threshold that triggers landslide events in Amboori, Kerala, India. Amboori is a tropical area that is highly vulnerable to landslides. The 2, 3, and 5-day antecedent rainfall data versus daily rainfall was clustered to identify a cluster of critical events that could potentially trigger landslides. Further, the cluster of critical events was utilized for regression analysis to develop the threshold equations. The 5-day antecedent (x-variable) vs. daily rainfall (y-variable) provided the best fit to the data with a threshold equation of …


Engineering Decision Making Under Uncertainties, Snehamoy Chatterjee Oct 2017

Engineering Decision Making Under Uncertainties, Snehamoy Chatterjee

TechTalks

Uncertainty is an inherent component of any engineering problem. Uncertainty comes at different stages of an engineering project with different level of complexities. Decision making by neglecting uncertainty may leads to an incorrect solution for a project. Our research focuses on identification and quantification of different sources of uncertainness, and bringing uncertainties within the decision making framework. We are developing algorithms for uncertainty evaluation of spatial and temporal data by integrating multiple source and multiple scale data types, and stochastic optimization models to take into account multiple objectives and constraints. We are applying our research on mining, geology, and geo-hydrology …


Atmospheric Processes Affecting The Separation Of Volcanic Ash And So < Inf> 2 In Volcanic Eruptions: Inferences From The May 2011 Grímsvötn Eruption, Fred Prata, Mark Woodhouse, Herbert E. Huppert, Andrew Prata, Thor Thordarson, S. Carn Sep 2017

Atmospheric Processes Affecting The Separation Of Volcanic Ash And So < Inf> 2 In Volcanic Eruptions: Inferences From The May 2011 Grímsvötn Eruption, Fred Prata, Mark Woodhouse, Herbert E. Huppert, Andrew Prata, Thor Thordarson, S. Carn

Michigan Tech Publications, Part 1

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 …


A Novel Applications Of Photogrammetry For Retaining Wall Assessment, Renee Oats, Rudiger Escobar-Wolf, Thomas Oommen Aug 2017

A Novel Applications Of Photogrammetry For Retaining Wall Assessment, Renee Oats, Rudiger Escobar-Wolf, Thomas Oommen

Michigan Tech Publications, Part 1

Retaining walls are critical geotechnical assets and their performance needs to be monitored in accordance to transportation asset management principles. Current practices for retaining wall monitoring consist mostly of qualitative approaches that provide limited engineering information or the methods include traditional geodetic surveying, which may provide high accuracy and reliability, but is costly and time-consuming. This study focuses on evaluating failure modes of a 2.43 m × 2.43 m retaining wall model using three-dimensional (3D) photogrammetry as a cost-effective quantitative alternative for retaining wall monitoring. As a remote sensing technique, photogrammetry integrates images collected from a camera and creates a …


Expanding Understanding Of Optical Variability In Lake Superior With A 4-Year Dataset, Colleen B. Mouw, Audrey B. Ciochetto, Brice Grunert, Angela W. Yu Jul 2017

Expanding Understanding Of Optical Variability In Lake Superior With A 4-Year Dataset, Colleen B. Mouw, Audrey B. Ciochetto, Brice Grunert, Angela W. Yu

Michigan Tech Publications, Part 1

Lake Superior is one of the largest freshwater lakes on our planet, but few optical observations have been made to allow for the development and validation of visible spectral satellite remote sensing products. The dataset described here focuses on coincidently observing inherent and apparent optical properties along with biogeochemical parameters. Specifically, we observe remote sensing reflectance, absorption, scattering, backscattering, attenuation, chlorophyll concentration, and suspended particulate matter over the ice-free months of 2013-2016. The dataset substantially increases the optical knowledge of the lake. In addition to visible spectral satellite algorithm development, the dataset is valuable for characterizing the variable light field, …


Spatial Variability Of Co < Inf> 2 Uptake In Polygonal Tundra: Assessing Low-Frequency Disturbances In Eddy Covariance Flux Estimates, Norbert Pirk, Jakob Sievers, Jordan Mertes, Frans Jan W. Parmentier, Mikhail Mastepanov, Torben R. Christensen Jun 2017

Spatial Variability Of Co < Inf> 2 Uptake In Polygonal Tundra: Assessing Low-Frequency Disturbances In Eddy Covariance Flux Estimates, Norbert Pirk, Jakob Sievers, Jordan Mertes, Frans Jan W. Parmentier, Mikhail Mastepanov, Torben R. Christensen

Michigan Tech Publications, Part 1

The large spatial variability in Arctic tundra complicates the representative assessment of CO2 budgets. Accurate measurements of these heterogeneous landscapes are, however, essential to understanding their vulnerability to climate change. We surveyed a polygonal tundra lowland on Svalbard with an unmanned aerial vehicle (UAV) that mapped ice-wedge morphology to complement eddy covariance (EC) flux measurements of CO2. The analysis of spectral distributions showed that conventional EC methods do not accurately capture the turbulent CO2 exchange with a spatially heterogeneous surface that typically features small flux magnitudes. Nonlocal (low-frequency) flux contributions were especially pronounced during snowmelt and introduced a large bias …


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), Can Li, Nickolay A. Krotkov, Simon Carn, Yan Zhang, Robert J.D. Spurr, Joanna Joiner Feb 2017

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

Michigan Tech Publications, Part 1

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 …


Arctic Micromonas Uses Protein Pools And Non-Photochemical Quenching To Cope With Temperature Restrictions On Photosystem Ii Protein Turnover, Guangyan Ni, Gabrielle Zimbalatti, Cole D. Murphy, Audrey B. Barnett, Christopher M. Arsenault, Gang Li, Amanda M. Cockshutt, Douglas A. Campbell Feb 2017

Arctic Micromonas Uses Protein Pools And Non-Photochemical Quenching To Cope With Temperature Restrictions On Photosystem Ii Protein Turnover, Guangyan Ni, Gabrielle Zimbalatti, Cole D. Murphy, Audrey B. Barnett, Christopher M. Arsenault, Gang Li, Amanda M. Cockshutt, Douglas A. Campbell

Michigan Tech Publications, Part 1

Micromonas strains of small prasinophyte green algae are found throughout the world’s oceans, exploiting widely different niches. We grew arctic and temperate strains of Micromonas and compared their susceptibilities to photoinactivation of Photosystem II, their counteracting Photosystem II repair capacities, their Photosystem II content, and their induction and relaxation of non-photochemical quenching. In the arctic strain Micromonas NCMA 2099, the cellular content of active Photosystem II represents only about 50 % of total Photosystem II protein, as a slow rate constant for clearance of PsbA protein limits instantaneous repair. In contrast, the temperate strain NCMA 1646 shows a faster clearance …


Quantitating Active Photosystem Ii Reaction Center Content From Fluorescence Induction Transients, Cole D. Murphy, Guangyan Ni, Gang Li, Audrey Barnett, Kui Xu, Jessica Grant-Burt, Justin D. Liefer, David J. Suggett, Douglas A. Campbell Jan 2017

Quantitating Active Photosystem Ii Reaction Center Content From Fluorescence Induction Transients, Cole D. Murphy, Guangyan Ni, Gang Li, Audrey Barnett, Kui Xu, Jessica Grant-Burt, Justin D. Liefer, David J. Suggett, Douglas A. Campbell

Michigan Tech Publications, Part 1

Photosystem II (PSII) is a pigment-protein complex that photochemically extracts electrons from water, generating the reductant that supports biological productivity in all biomes. Estimating the content of active PSII reaction centers in a liquid sample is a key input for estimating aquatic photosynthesis rates, as well as for analyzing phytoplankton stress responses. Established procedures for PSII content quantification based on oxygen evolution are slow, imprecise and require dense cell suspensions, and are thus inapplicable to many laboratory or field studies. A new approach uses baseline chlorophyll fluorescence emission divided by the effective absorbance cross section for PSII photochemistry, with both …


Surface Ozone And Its Precursors At Summit, Greenland: Comparison Between Observations And Model Simulations, Yaoxian Huang, Shiliang Wu, Louisa J. Kramer, Detlev Helmig, Richard E. Honrath Jan 2017

Surface Ozone And Its Precursors At Summit, Greenland: Comparison Between Observations And Model Simulations, Yaoxian Huang, Shiliang Wu, Louisa J. Kramer, Detlev Helmig, Richard E. Honrath

Michigan Tech Publications, Part 1

Recent studies have shown significant challenges for atmospheric models to simulate tropospheric ozone (O3/and its precursors in the Arctic. In this study, ground-based data were combined with a global 3-D chemical transport model (GEOS-Chem) to examine the abundance and seasonal variations of O3 and its precursors at Summit, Greenland (72.34° N, 38.29° W; 3212 ma.s.l.). Model simulations for atmospheric nitrogen oxides (NOx/, peroxyacetyl nitrate (PAN), ethane (C2H6/, propane (C3H8/, carbon monoxide (CO), and O3 for the period July 2008-June 2010 were compared with observations. The model performed well in simulating certain species (such as CO and C3H8/, but some significant …


Ignimbrites To Batholiths, Chad Deering Dec 2016

Ignimbrites To Batholiths, Chad Deering

TechTalks

Ignimbrites sample large magma reservoirs in the Earth’s upper crust, sometimes digging deep enough to link the volcanic realm with the plutonic world. Integrating textural, petrological, geochemical, and geochronological information on such deposits with geophysical signals suggest incremental growth and evolution of subvolcanic magma bodies that are dominated by high crystallinity mush zones, but sometimes remain sufficiently liquid to erupt. The eruptible upper portions are either extracted melt from the mush and constitute only a small volumetric fraction of the vertically extensive mushy batholithic magma body. The high-flux, ignimbrite flare-up phases are typically preceded by waxing magmatism that prime the …


Improving Global Detection Of Volcanic Eruptions Using The Ozone Monitoring Instrument (Omi), Verity Flower, Thomas Oommen, Simon Carn Nov 2016

Improving Global Detection Of Volcanic Eruptions Using The Ozone Monitoring Instrument (Omi), Verity Flower, Thomas Oommen, Simon Carn

Michigan Tech Publications, Part 1

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 utilised to provide near-real-time identification of volcanic activity. This paper details a volcanic plume detection method capable of identifying smaller eruptions than is currently feasible, which could potentially be incorporated into automated …


Utilizing Vegetation Indices As A Proxy To Characterize The Stability Of A Railway Embankment In A Permafrost Region, Priscilla Addison, Pasi T. Lautala, Thomas Oommen Nov 2016

Utilizing Vegetation Indices As A Proxy To Characterize The Stability Of A Railway Embankment In A Permafrost Region, Priscilla Addison, Pasi T. Lautala, Thomas Oommen

Michigan Tech Publications, Part 1

Degrading permafrost conditions around the world are posing stability issues for infrastructure constructed on them. Railway lines have exceptionally low tolerances for differential settlements associated with permafrost degradation due to the potential for train derailments. Railway owners with tracks in permafrost regions therefore make it a priority to identify potential settlement locations so that proper maintenance or embankment stabilization measures can be applied to ensure smooth and safe operations. The extensive discontinuous permafrost zone along the Hudson Bay Railway (HBR) in Northern Manitoba, Canada, has been experiencing accelerated deterioration, resulting in differential settlements that necessitate continuous annual maintenance to avoid …


Global Ocean Particulate Organic Carbon Flux Merged With Satellite Parameters, Colleen B. Mouw, Audrey Barnett, Galen A. Mckinley, Lucas Gloege, Darren Pilcher Oct 2016

Global Ocean Particulate Organic Carbon Flux Merged With Satellite Parameters, Colleen B. Mouw, Audrey Barnett, Galen A. Mckinley, Lucas Gloege, Darren Pilcher

Michigan Tech Publications, Part 1

Particulate organic carbon (POC) flux estimated from POC concentration observations from sediment traps and 234 Th are compiled across the global ocean. The compilation includes six time series locations: CARIACO, K2, OSP, BATS, OFP, and HOT. Efficiency of the biological pump of carbon to the deep ocean depends largely on biologically mediated export of carbon from the surface ocean and its remineralization with depth; thus biologically related parameters able to be estimated from satellite observations were merged at the POC observation sites. Satellite parameters include net primary production, percent microplankton, sea surface temperature, photosynthetically active radiation, diffuse attenuation coefficient at …


A Global Catalogue Of Large So < Inf> 2 Sources And Emissions Derived From The Ozone Monitoring Instrument, Vitali E. Fioletov, Chris A. Mclinden, Nickolay Krotkov, Can Li, Joanna Joiner, Nicolas Theys, S. Carn, Mike D. Moran Sep 2016

A Global Catalogue Of Large So < Inf> 2 Sources And Emissions Derived From The Ozone Monitoring Instrument, Vitali E. Fioletov, Chris A. Mclinden, Nickolay Krotkov, Can Li, Joanna Joiner, Nicolas Theys, S. Carn, Mike D. Moran

Michigan Tech Publications, Part 1

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 …


The Impact Of Satellite Sensor Viewing Geometry On Time-Series Analysis Of Volcanic Emissions, Verity Flower, Simon A. Carn, Robert Wright Sep 2016

The Impact Of Satellite Sensor Viewing Geometry On Time-Series Analysis Of Volcanic Emissions, Verity Flower, Simon A. Carn, Robert Wright

Michigan Tech Publications, Part 1

Time-series analysis techniques are being increasingly used to process satellite observations of volcanic gas emissions and heat flux, with the aim of identifying cyclic behaviour that could inform hazard assessment or elucidate volcanic processes. However, it can be difficult to distinguish cyclic variations due to geophysical processes from those that are artefacts of the observation technique. Here, we conduct a comprehensive investigation into the origin of cyclicity in volcanic observations by analysing daily, global satellite measurements of volcanic SO2 loading by the Ozone Monitoring Instrument (OMI) and thermal infrared anomalies detected by the Moderate Resolution Imaging Spectroradiometer (MODIS). We use …


Adjusting Particle-Size Distributions To Account For Aggregation In Tephra-Deposit Model Forecasts, Larry G. Mastin, Alexa R. Van Eaton, Adam J. Durant Jul 2016

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, Part 1

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 Jul 2016

Improving Automated Global Detection Of Volcanic So2 Plumes Using The Ozone Monitoring Instrument (Omi), Verity Flower, Thomas Oommen, Simon Carn

Michigan Tech Publications, Part 1

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 May 2016

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, Part 1

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, …


Multi-Decadal Satellite Measurements Of Global Volcanic Degassing, S. A. Carn, L. Clarisse, A. J. Prata Feb 2016

Multi-Decadal Satellite Measurements Of Global Volcanic Degassing, S. A. Carn, L. Clarisse, A. J. Prata

Michigan Tech Publications, Part 1

Satellite instruments have been providing measurements of global volcanic emissions of sulfur dioxide (SO2) since 1978, based on observations in the ultraviolet (UV), infrared (IR) and microwave spectral bands. We review recent advances in satellite remote sensing of volcanic gases, focusing on increased instrument sensitivity to tropospheric SO2 emissions and techniques to determine volcanic plume altitude. A synthesis of ~36 years of global UV, IR and microwave satellite measurements yields an updated assessment of the volcanic SO2 flux to the upper troposphere and lower stratosphere (UTLS) between 1978 and 2014 (~1-Tg/yr). The present availability of multiple UV and IR satellite …


Post-Eruption Deformation Processes Measured Using Alos-1 And Uavsar Insar At Pacaya Volcano, Guatemala, Lauren Schaefer, Zhong Lu, Thomas Oommen Jan 2016

Post-Eruption Deformation Processes Measured Using Alos-1 And Uavsar Insar At Pacaya Volcano, Guatemala, Lauren Schaefer, Zhong Lu, Thomas Oommen

Michigan Tech Publications, Part 1

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 Oct 2015

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, Part 1

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.


Characterising Volcanic Cycles At Soufriere Hills Volcano, Montserrat: Time Series Analysis Of Multi-Parameter Satellite Data, Verity Flower, Simon Carn Oct 2015

Characterising Volcanic Cycles At Soufriere Hills Volcano, Montserrat: Time Series Analysis Of Multi-Parameter Satellite Data, Verity Flower, Simon Carn

Michigan Tech Publications, Part 1

The identification of cyclic volcanic activity can 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 to cross-correlate cyclical signals identified using complementary measurement techniques at Soufriere Hills Volcano (SHV), Montserrat. In this paper we present a Multi-taper (MTM) Fast Fourier Transform (FFT) analysis of coincident SO2 and thermal infrared (TIR) satellite measurements at SHV facilitating the identification of cyclical volcanic behaviour. These measurements were collected by the Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer (MODIS) (respectively) in the A-Train. We identify …


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 Jul 2015

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, Part 1

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 Jun 2015

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, Part 1

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 Jun 2015

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, Part 1

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 Jan 2015

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, Part 1

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 …