Open Access. Powered by Scholars. Published by Universities.®

Other Oceanography and Atmospheric Sciences and Meteorology Commons

Open Access. Powered by Scholars. Published by Universities.®

296 Full-Text Articles 567 Authors 47,771 Downloads 36 Institutions

All Articles in Other Oceanography and Atmospheric Sciences and Meteorology

Faceted Search

296 full-text articles. Page 1 of 10.

Numerical Experiment Of Sediment Dynamics Over A Dredged Pit On The Louisiana Shelf, Nazanin Chaichitehrani 2018 Louisiana State University

Numerical Experiment Of Sediment Dynamics Over A Dredged Pit On The Louisiana Shelf, Nazanin Chaichitehrani

LSU Doctoral Dissertations

Sediment transport over Sandy Point dredge pit in the northern Gulf of Mexico was examined using field measurements and a finely resolved numerical model. Delft3D model with well-vetted computational grid and input parameters was used. Numerical experiments were performed to examine the effect of wind-generated waves, wind-driven currents and their interaction on sediment dynamics in our study area during a cold front in November 2014 and fair-weather conditions between July and August of 2015. Sediment dispersal from the lower Mississippi River, sediment resuspension, transport and deposition with high spatial and temporal resolution were simulated. A reliable satellite-derived near-surface suspended particulate ...


Spatio-Temporal Pattern Estimation Of Pm2.5 In Beijing-Tianjin-Hebei Region Based On Modis Aod And Meteorological Data Using The Back Propagation Neural Network, Xialing Ni, Chunxiang Cao, Yuke Zhou, Xianghui Cui, Ramesh Singh 2018 Chinese Academy of Sciences

Spatio-Temporal Pattern Estimation Of Pm2.5 In Beijing-Tianjin-Hebei Region Based On Modis Aod And Meteorological Data Using The Back Propagation Neural Network, Xialing Ni, Chunxiang Cao, Yuke Zhou, Xianghui Cui, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

With the economic growth and increasing urbanization in the last three decades, the air quality over China has continuously degraded, which poses a great threat to human health. The concentration of fine particulate matter (PM2.5) directly affects the mortality of people living in the polluted areas where air quality is poor. The Beijing-Tianjin-Hebei (BTH) region, one of the well organized urban regions in northern China, has suffered with poor air quality and atmospheric pollution due to recent growth of the industrial sector and vehicle emissions. In the present study, we used the back propagation neural network model approach to ...


Estimating Live Fuel Moisture From Modis Satellite Data For Wildfire Danger Assessment In Southern California Usa, Boksoon Myoung, Seung Hee Kim, Son V. Nghiem, Shenyue Jia, Kristen Whitney, Menas Kafatos 2018 APEC Climate Center

Estimating Live Fuel Moisture From Modis Satellite Data For Wildfire Danger Assessment In Southern California Usa, Boksoon Myoung, Seung Hee Kim, Son V. Nghiem, Shenyue Jia, Kristen Whitney, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The goal of the research reported here is to assess the capability of satellite vegetation indices from the Moderate Resolution Imaging Spectroradiometer onboard both Terra and Aqua satellites, in order to replicate live fuel moisture content of Southern California chaparral ecosystems. We compared seasonal and interannual characteristics of in-situ live fuel moisture with satellite vegetation indices that were averaged over different radial extents around each live fuel moisture observation site. The highest correlations are found using the Aqua Enhanced Vegetation Index for a radius of 10 km, independently verifying the validity of in-situ live fuel moisture measurements over a large ...


Investigating Marine Resources In The Gulf Of Mexico At Multiple Spatial And Temporal Scales Of Inquiry, Joshua Paul Kilborn 2017 University of South Florida

Investigating Marine Resources In The Gulf Of Mexico At Multiple Spatial And Temporal Scales Of Inquiry, Joshua Paul Kilborn

Graduate Theses and Dissertations

The work in this dissertation represents an attempt to investigate multiple temporal and spatial scales of inquiry relating to the variability of marine resources throughout the Gulf of Mexico large marine ecosystem (Gulf LME). This effort was undertaken over two spatial extents within the greater Gulf LME using two different time-series of fisheries monitoring data. Case studies demonstrating simple frameworks and best practices are presented with the aim of aiding researchers seeking to reduce errors and biases in scientific decision making. Two of the studies focused on three years of groundfish survey data collected across the West Florida Shelf (WFS ...


Calibration-Free Spectrophotometric Measurements Of Carbonate Saturation States In Seawater, Erin E. Cuyler 2017 University of South Florida

Calibration-Free Spectrophotometric Measurements Of Carbonate Saturation States In Seawater, Erin E. Cuyler

Graduate Theses and Dissertations

This work describes efforts to improve methodologies and instrumentation for investigation of the marine CO2 system. In the first section of my thesis, a method was developed that provides simple, calibration-free measurements of seawater carbonate saturation states (Ωspec) based solely on the use of a laboratory spectrophotometer. Measurements of pH are made in paired optical cells, one with and one without added nitric acid. The amount of added nitric acid is determined through the direct proportionality between nitrate concentration and UV absorbance. After an initial calibration, the method is calibration-free and requires no volumetric or gravimetric analyses thereafter ...


Stable Isotopes In The Eye Lenses Of Doryteuthis Plei: Exploring Natal Origins And Migratory Patterns In The Eastern Gulf Of Mexico, Brenna A. Meath 2017 University of South Florida

Stable Isotopes In The Eye Lenses Of Doryteuthis Plei: Exploring Natal Origins And Migratory Patterns In The Eastern Gulf Of Mexico, Brenna A. Meath

Graduate Theses and Dissertations

Stable isotope analysis is an emerging tool to examine trophic pathways and migratory patterns of marine organisms. Squid are widely distributed in coastal and deep water regions of the Gulf of Mexico. Stable isotope ratios of carbon and nitrogen found within cephalopod tissues can provide information on both trophic level and habitat of their food sources. More recently, ontogenetic changes in stable isotope ratios within squid eye lenses have been documented. Concentric layers of crystallin proteins are added to the lens as the squid ages; the center of the lens contains the oldest layer and the youngest layers are on ...


Thermal Radiation Anomalies Associated With Major Earthquakes, Dimitar Ouzounov, Sergey Pulinets, Menas Kafatos, Patrick Taylor 2017 Chapman University

Thermal Radiation Anomalies Associated With Major Earthquakes, Dimitar Ouzounov, Sergey Pulinets, Menas Kafatos, Patrick Taylor

Mathematics, Physics, and Computer Science Faculty Articles and Research

Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the ...


Ocean Wind Speed Measurement Using Wideband Gnss-R Signals, Brandon J. Kozel, Han Zhang, James L. Garrison, Benjamin Nold 2017 Purdue University

Ocean Wind Speed Measurement Using Wideband Gnss-R Signals, Brandon J. Kozel, Han Zhang, James L. Garrison, Benjamin Nold

The Summer Undergraduate Research Fellowship (SURF) Symposium

The use of Global Navigation Satellite System-Reflectometry (GNSS-R) for remote sensing of ocean wind speeds has been explored for nearly two decades and has become an important passive remote sensing technique for verification of hurricane formation models. To obtain wind speed measurements, reflected GNSS signals are first cross-correlated with locally generated copies to construct delay-doppler maps (DDMs). Through statistical models, DDMs can provide information about the mean-square slope (MSS) of the ocean surface, which is related to wind speed. Previous studies have focused on legacy signals such as GPS L1. However, it is expected that the MSS relationship with ocean ...


Utilizing A Consumer-Grade Camera System To Quantify Surface Reflectance, Joseph J. Lehnert 2017 University of Nebraska - Lincoln

Utilizing A Consumer-Grade Camera System To Quantify Surface Reflectance, Joseph J. Lehnert

Theses and Dissertations in Geography

Consumer-grade camera systems are often employed in aerial remote sensing to provide insight into patterns and processes of interest to science and industry, a trend that has largely been encouraged by the rapid growth of the small unmanned aircraft system (sUAS) industry. However, little research exists on the ability of these systems to accurately measure surface reflectance in specific wavebands, a crucial consideration for many remote sensing applications. This research was conducted on the premise that with proper equipment and calibration techniques consumer-grade cameras would be capable of accurately measuring surface reflectance in user-defined wavebands of interest. A stereo-pair, Fujifilm ...


The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil Lareau, Craig Clements 2017 San Jose State University

The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil Lareau, Craig Clements

Faculty Publications

The time-mean and time-varying smoke and velocity structure of a wildfire convective plume is examined using a high-resolution scanning Doppler lidar. The mean plume is shown to exhibit the archetypal form of a bent-over plume in a crosswind, matching the well-established Briggs plume-rise equation. The plume cross section is approximately Gaussian and the plume radius increases linearly with height, consistent with plumerise theory. The Briggs plume-rise equation is subsequently inverted to estimate the mean fire-generated sensible heat flux, which is found to be 87 kW m22 . The mean radial velocity structure of the plume indicates flow convergence into the plume ...


The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil P. Lareau, Craig B. Clements 2017 San Jose State University

The Mean And Turbulent Properties Of A Wildfire Convective Plume, Neil P. Lareau, Craig B. Clements

Craig B. Clements

The time-mean and time-varying smoke and velocity structure of a wildfire convective plume is examined using a high-resolution scanning Doppler lidar. The mean plume is shown to exhibit the archetypal form of a bent-over plume in a crosswind, matching the well-established Briggs plume-rise equation. The plume cross section is approximately Gaussian and the plume radius increases linearly with height, consistent with plumerise theory. The Briggs plume-rise equation is subsequently inverted to estimate the mean fire-generated sensible heat flux, which is found to be 87 kW m22 . The mean radial velocity structure of the plume indicates flow convergence into the plume ...


Synergistic Use Of Remote Sensing And Modeling To Assess An Anomalously High Chlorophyll-A Event During Summer 2015 In The South Central Red Sea, Wenzhao Li, Hesham el-Askary, K. P. ManiKandan, Mohamed A. Qurban, Michael J. Garay, Olga V. Kalishnikova 2017 Chapman University

Synergistic Use Of Remote Sensing And Modeling To Assess An Anomalously High Chlorophyll-A Event During Summer 2015 In The South Central Red Sea, Wenzhao Li, Hesham El-Askary, K. P. Manikandan, Mohamed A. Qurban, Michael J. Garay, Olga V. Kalishnikova

Mathematics, Physics, and Computer Science Faculty Articles and Research

An anomalously high chlorophyll-a (Chl-a) event (>2 mg/m3) during June 2015 in the South Central Red Sea (17.5° to 22°N, 37° to 42°E) was observed using Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra and Aqua satellite platforms. This differs from the low Chl-a values (<0.5 mg/m3) usually encountered over the same region during summertime. To assess this anomaly and possible causes, we used a wide range of oceanographical and meteorological datasets, including Chl-a concentrations, sea surface temperature (SST), sea surface height (SSH), mixed layer depth (MLD), ocean current velocity and aerosol optical depth (AOD) obtained from different sensors and models. Findings confirmed this anomalous behavior in the spatial domain using Hovmöller data analysis techniques, while a time series analysis addressed monthly and daily variability. Our analysis suggests that a combination of factors controlling nutrient supply contributed to the anomalous phytoplankton growth. These factors include horizontal transfer of upwelling water through eddy circulation and possible mineral fertilization from atmospheric dust deposition. Coral reefs might have provided extra nutrient supply, yet this is out of the scope of our analysis. We thought that dust deposition from a coastal dust jet event in late June, coinciding with the phytoplankton blooms in the area under investigation, might have also contributed as shown by our AOD findings. However, a lag cross correlation showed a two- month lag between strong dust outbreak and the high Chl-a anomaly. The high Chl-a concentration at the edge of the eddy emphasizes the importance of horizontal advection in fertilizing oligotrophic (nutrient poor) Red Sea waters.


Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman 2017 Plymouth Marine Laboratory

Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Simultaneous air–sea fluxes and concentration differences of dimethylsulfide (DMS) and carbon dioxide (CO2/ were measured during a summertime North Atlantic cruise in 2011. This data set reveals significant differences between the gas transfer velocities of these two gases (1kw/ over a range of wind speeds up to 21ms􀀀1. These differences occur at and above the approximate wind speed threshold when waves begin breaking. Whitecap fraction (a proxy for bubbles) was also measured and has a positive relationship with 1kw, consistent with enhanced bubble-mediated transfer of the less soluble CO2 relative to that of the more soluble DMS. However ...


Nuclear Weapons In A Changing Climate: Probability, Increasing Risks, And Perception, Adam Liska, Tyler R. White, Eric Holley, Robert J. Oglesby 2017 University of Nebraska - Lincoln

Nuclear Weapons In A Changing Climate: Probability, Increasing Risks, And Perception, Adam Liska, Tyler R. White, Eric Holley, Robert J. Oglesby

Adam Liska Papers

Many people tend to think that the outcome of any nuclear weapons use today will result in an escalatory situation with apocalyptic outcomes for the countries involved. Yet many factors are increasing the probability of the limited use of nuclear weapons (e.g., 1 to 20 warheads) in a range of conflict scenarios. Previous atmospheric model simulations of regional nuclear conflicts employing many relatively small bombs have been estimated to cause a global “nuclear autumn,” with great reductions in agricultural productivity, stratospheric ozone loss, and spread of hazardous radioactive fallout. The totality of these effects would result in widespread ...


Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray 2017 Portland State University

Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the ...


Characterizing South American Mesoscale Convective Complexes Using Isotope Hydrology, Kyle J. Hogancamp 2017 Western Kentucky University

Characterizing South American Mesoscale Convective Complexes Using Isotope Hydrology, Kyle J. Hogancamp

Masters Theses & Specialist Projects

Mesoscale convective complexes (MCCs) over subtropical South America contribute an average annual volume of precipitation equal to approximately seven km3 and occur with an average regularity in the region, with more than 30 per warm season. Isotopic characteristics of precipitation, such as δ2H and δ18O values, provide information that can be used to identify unique processes and sources related to precipitation events. The largest database of isotope characteristics of precipitation within the region is the Global Network of Isotopes in Precipitation (GNIP), which provides varying temporal resolution data from stations around the world, including subtropical South America.

Using this database ...


Assessing Seasonal And Spatial Variability In The Hydrogeochemistry Of Glacial Meltwater In Iceland, Anisha Tuladhar 2017 Western Kentucky University

Assessing Seasonal And Spatial Variability In The Hydrogeochemistry Of Glacial Meltwater In Iceland, Anisha Tuladhar

Masters Theses & Specialist Projects

A detailed comparative geochemical characterization of three different types of Iceland glacial systems was conducted during June, August, and October, 2016. The study was carried out at a total of 11 outlet glacier rivers flowing from the icecaps Vatnajökull, Eyjafjallajökull, and Mýrdalsjökull. A total of 75 grab samples were collected (25 for each sampling period). The hydrogeochemical variations of Icelandic glacial meltwater are influenced by volcanic activity, temporal changes, and geographical location, which differed between the sampling sites within the glaciers and icecaps. Lower pH range, and comparatively higher and variable specific conductivity, SO4, S and F is linked to ...


On The Relationship Between Spring Nao And Snowmelt In The Upper Southwestern United States, Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos 2017 APEC Climate Center

On The Relationship Between Spring Nao And Snowmelt In The Upper Southwestern United States, Boksoon Myoung, Seung Hee Kim, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study examines the relationship between the North Atlantic Oscillation (NAO) and snowmelt in spring in the upper southwestern states of the United States (UP_SW) including California, Nevada, Utah, and Colorado, using SNOTEL datasets for 34 yr (1980–2014). Statistically significant negative correlations are found between NAO averages in the snowmelt period and timings of snowmelt (i.e., positive NAO phases in spring enhance snowmelt, and vice versa). It is also found that correlations between El Niño–Southern Oscillation and snowmelt are negligible in the region. The NAO–snowmelt relationship is most pronounced below the 2800-m level; above this level ...


Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian LaFranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer 2017 Lawrence Berkeley National Laboratory

Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian Lafranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer

Faculty Publications

We present the first sector-specific analysis of methane (CH4) emissions from the San Francisco Bay Area (SFBA) using CH4 and volatile organic compound (VOC) measurements from six sites during September – December 2015. We apply a hierarchical Bayesian inversion to separate the biological from fossil-fuel (natural gas and petroleum) sources using the measurements of CH4 and selected VOCs, a source-specific 1 km CH4 emission model, and an atmospheric transport model. We estimate that SFBA CH4 emissions are 166–289 Gg CH4/yr (at 95% confidence), 1.3–2.3 times higher than a recent inventory with much of the underestimation from ...


Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko 2017 University of Nebraska-Lincoln

Multiple Drivers Of Seasonal Change In Pri: Implications For Photosynthesis 2. Stand Level, Anatoly A. Gitelson, John A. Gamon, Alexei E. Solovchenko

Biological Systems Engineering: Papers and Publications

The goal of this study was to explore the relationships between stand-level photochemical reflectance index (PRI) and canopy structure/ pigment pools, as well as light use efficiency (LUE) of photosynthetically active vegetation focusing on seasonal or ontogenetic time frames. PRI was originally designed as a means of assessing the xanthophyll cycle and LUE over short (e.g. diurnal) time frames, and few studies have explored the drivers of PRI over longer, seasonal time frames, particularly in crops having different photosynthetic pathways or canopy structures. Consequently, our purpose was to understand and quantify the drivers of PRI responses over seasonal time ...


Digital Commons powered by bepress