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Articles 6181 - 6210 of 13997

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Model Suggests Potential For Porites Coral Population Recovery After Removal Of Anthropogenic Disturbance (Luhuitou, Hainan, South China Sea), Meixia Zhao, Bernhard Riegl, Kefu Yu, Qi Shi, Qiaomin Zhang, Guohui Liu, Hongqiang Yang, Hongquiang Yan Jan 2016

Model Suggests Potential For Porites Coral Population Recovery After Removal Of Anthropogenic Disturbance (Luhuitou, Hainan, South China Sea), Meixia Zhao, Bernhard Riegl, Kefu Yu, Qi Shi, Qiaomin Zhang, Guohui Liu, Hongqiang Yang, Hongquiang Yan

Marine & Environmental Sciences Faculty Articles

Population models are important for resource management and can inform about potential trajectories useful for planning purposes, even with incomplete monitoring data. From size frequency data on Luhuitou fringing reef, Hainan, South China Sea, a matrix population model of massive corals (Porites lutea) was developed and trajectories over 100 years under no disturbance and random disturbances were projected. The model reflects a largely open population of Porites lutea, with low local recruitment and preponderance of imported recruitment. Under no further disturbance, the population of Porites lutea will grow and its size structure will change from predominance of …


Using Cleaved Amplified Polymorphic Sequence (Caps) Genetic Markers To Determine The Extent Of Hybridization Between Castilleja Affinis And Castilleja Mollis As A Mechanism For Adapting To Climate Change On Santa Rosa Island, Elizabeth Medford Jan 2016

Using Cleaved Amplified Polymorphic Sequence (Caps) Genetic Markers To Determine The Extent Of Hybridization Between Castilleja Affinis And Castilleja Mollis As A Mechanism For Adapting To Climate Change On Santa Rosa Island, Elizabeth Medford

Scripps Senior Theses

Hybridization, the process of interbreeding between individuals of different species, is one method by which plants and animals adapt to a changing environment. One example of such adaptation through hybridization may be occurring on the California Channel Islands with two species of Castilleja. While United State Geological Survey (USGS) researchers have been studying the populations of Castilleja affinis and Castilleja mollis to determine if hybridization is occurring on Santa Rosa Island since the early 1990s, up until this point primarily overt phenotypic characteristics have been used to differentiate between the two species. Genetic methods of differentiation were adopted to …


A Demonstration Project Of The Action-Oriented Stakeholder Engagement For A Resilient Tomorrow (Asert) Framework: Effectiveness, Juita-Elena (Wie) Yusuf, Michelle Covi, Carol Considine, Burton St. John Iii, Gail Nicula, Pragati Rawat, Kaitlin Giles Jan 2016

A Demonstration Project Of The Action-Oriented Stakeholder Engagement For A Resilient Tomorrow (Asert) Framework: Effectiveness, Juita-Elena (Wie) Yusuf, Michelle Covi, Carol Considine, Burton St. John Iii, Gail Nicula, Pragati Rawat, Kaitlin Giles

Presentations, Lectures, Posters, Reports

Poster presentation by the Research Team of the ODU Resilience Collaborative used from March-May, 2016


A Demonstration Project Of The Action-Oriented Stakeholder Engagement For A Resilient Tomorrow (Asert) Framework: Efficacy, Juita-Elena (Wie) Yusuf, Michelle Covi, Carol Considine, Burton St. John Iii, Gail Nicula, Pragati Rawat, Kaitlin Giles Jan 2016

A Demonstration Project Of The Action-Oriented Stakeholder Engagement For A Resilient Tomorrow (Asert) Framework: Efficacy, Juita-Elena (Wie) Yusuf, Michelle Covi, Carol Considine, Burton St. John Iii, Gail Nicula, Pragati Rawat, Kaitlin Giles

Presentations, Lectures, Posters, Reports

Poster presentation by the Research Team of the ODU Resilience Collaborative used March-May 2016. This poster focuses on efficacy of the ASERT Framework and includes charts.


A Qualitative Examination Of The Perception Of Risk In Warnings For Severe Weather, Teresa Simmons Jan 2016

A Qualitative Examination Of The Perception Of Risk In Warnings For Severe Weather, Teresa Simmons

Walden Dissertations and Doctoral Studies

In the past decade, weather disasters have claimed thousands of lives and resulted in billions of dollars in damages. Awareness of a storm threats can occur hours or days in advance, but disaster assessments indicate many people do not heed storm warnings. This problem is old. Despite 50 years of research, and new technologies and training to improve responsiveness, the basic issue– understanding how people interpret and respond to weather warnings–persists. An exploratory study that incorporated human behavior theories and communication models not traditionally associated with severe weather analysis was conducted to learn how weather risks are perceived by nonscientists. …


An Assessment Of Long-Term Changes In The Characterisitcs Of Precipitation In The Upper Midwest, Blake Steven Lea Jan 2016

An Assessment Of Long-Term Changes In The Characterisitcs Of Precipitation In The Upper Midwest, Blake Steven Lea

Graduate Theses/Dissertations

As climate change progresses, many forecasts for the upper Midwest predict increases in annual precipitation, but with a shift in seasonal patterns that will leave the summer months drier with less frequent, higher magnitude storm events. Changes in precipitation patterns have the potential to alter the sediment budget and discharge patterns in watersheds. The purpose of this study was to determine the effects changes in frequency, magnitude, duration, and intensity of precipitation might have on streamflow and sediment budgets in the upper Midwest. This analysis was carried out using hourly precipitation data from 1948 to 2013 from 23 sites and …


Support For Drought Response And Community Preparedness: Filling The Gaps Between Plans And Action, Kelly Helm Smith, Crystal J. Stiles, Michael Hayes, Christopher Carparelli Jan 2016

Support For Drought Response And Community Preparedness: Filling The Gaps Between Plans And Action, Kelly Helm Smith, Crystal J. Stiles, Michael Hayes, Christopher Carparelli

High Plains Regional Climate Center: Staff Publications

This chapter examines which levels of government handle various aspects of drought, as well as interactions between levels of government, providing examples from states across the western United States. It also takes a look at aspects of drought that fall outside traditional lines of authority and disciplinary boundaries. As part of a discussion on how states support local drought response, the chapter details and contrasts how California and Colorado track public water supply restrictions, and describes Colorado’s process for incorporating input from river basins across the state into its water plan. Case studies focus on drought planning in the Klamath …


Oceans And Shorelines, John J. Renton, Thomas Repine Jan 2016

Oceans And Shorelines, John J. Renton, Thomas Repine

Readings and Notes

Until 1872 when H.M.S, Challenger, a British warship converted for research, made its historic voyage, relatively little was known about the oceans. The voyage, funded by the British government, was mandated to chart the depth of the ocean, measure the various ocean currents, amass data on the composition of the ocean's water and bottom sediments, and collect information on ocean life. At the time of the voyage, except for a few soundings, almost nothing was known about the ocean bottom. Most scientists of the day had considered the vast expanses of the deep ocean basins to be nothing more than …


Action-Oriented Stakeholder Engagement For A Resilient Tomorrow (Asert) Framework, Michelle Covi, Juita-Elena (Wie) Yusuf, Carol Considine, Burton St. John Iii, Gail Nicula Jan 2016

Action-Oriented Stakeholder Engagement For A Resilient Tomorrow (Asert) Framework, Michelle Covi, Juita-Elena (Wie) Yusuf, Carol Considine, Burton St. John Iii, Gail Nicula

Presentations, Lectures, Posters, Reports

Poster presentation from the Research Team of the ODU Resilience Collaborative.


Nres/Metr/Bsen 479/879: Hydroclimatology—A Peer Review Of Teaching Project Benchmark Portfolio, Francisco Munoz-Arriola Jan 2016

Nres/Metr/Bsen 479/879: Hydroclimatology—A Peer Review Of Teaching Project Benchmark Portfolio, Francisco Munoz-Arriola

UNL Faculty Course Portfolios

Rising temperatures and extreme hydrometeorological and climate events are evidences of a changing climate. An increasing population together with their demands for food, energy and water make changes in climate evidence the need to train a new generation of multidisciplinary professionals with a clear understanding of the effects of a changing climate in their activities. Historically, climate sciences were used for scientific and weather operational contexts and engineers applied stationary assumptions for multi-term planning. My goal is to identify elements built from classroom experiences about (a) the suitability of a hydroclimatology course for engineers and scientists; (b) the multidisciplinary skills; …


The Conflict Resolution Case Study In Urban Life: Bull Run Watershed Case, Chang-Yu Hong Jan 2016

The Conflict Resolution Case Study In Urban Life: Bull Run Watershed Case, Chang-Yu Hong

Geography Faculty Publications and Presentations

The City of Portland and the United States Department of Agriculture (USDA) Forest Service are working together, along with citizens, to formulate a comprehensive new policy to guide joint management of the Bull Run watershed at Mt. Hood National Forest. This process has brought about four decades of conflict, resulting from differences between the federal view of multiple use and the local view of exclusive use for producing high quality water. The new policy is being formulated by the City of Portland and the Forest Service through negotiation of a comprehensive Memorandum of Understanding that structures the parties’ roles, responsibilities, …


Impact Of Climate Variations On Soybean Yield In Eastern Arkansas: 1960-2014, J. W. Magugu, S. Feng, Q. Huang, K. Luthra Jan 2016

Impact Of Climate Variations On Soybean Yield In Eastern Arkansas: 1960-2014, J. W. Magugu, S. Feng, Q. Huang, K. Luthra

Journal of the Arkansas Academy of Science

Climate is the major factor affecting crop production; therefore, various agro-meteorological indicators have been frequently used to evaluate the impact of climate on crop production. In this study, we examined the temporal variations of agrometeorological indicators (growing degree days, total precipitation, dry spells and drought indices) during 1960-2014 and their impact on soybean yields in East Arkansas. Results show an increasing trend in growing degree days (GDDs) and dry spells, though the total precipitation during the soybean growing season remained nearly unchanged during the study period. Generally, GDDs and dry spells show a strong correlation with yields. We also evaluated …


Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman Jan 2016

Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman

Cal Poly Humboldt theses and projects

The Scott and Shasta rivers, Klamath River tributaries, experience spatial disparity in habitat quality in spring and summer as a result of historical and current land-use. Juvenile Coho Salmon (Oncorhynchus kisutch) born in the upper tributary reaches often rear in natal streams before migrating to sea. However, those born in the lower reaches often encounter unsuitable habitat and emigrate during their first spring to seek non-natal rearing habitats. It is assumed that these early outmigrants are population losses. This study evaluated first-summer survival, and contribution to the adult population, of non-natal rearing juveniles in the Klamath River Basin. …


Dragon Kings Of The Deep Sea: Marine Particles Deviate Markedly From The Common Number-Size Spectrum, Alexander B. Bochdansky, Melissa A. Clouse, Gerhard J. Herndl Jan 2016

Dragon Kings Of The Deep Sea: Marine Particles Deviate Markedly From The Common Number-Size Spectrum, Alexander B. Bochdansky, Melissa A. Clouse, Gerhard J. Herndl

OES Faculty Publications

Particles are the major vector for the transfer of carbon from the upper ocean to the deep sea. However, little is known about their abundance, composition and role at depths greater than 2000 m. We present the first number-size spectrum of bathy-and abyssopelagic particles to a depth of 5500 m based on surveys performed with a custom-made holographic microscope. The particle spectrum was unusual in that particles of several millimetres in length were almost 100 times more abundant than expected from the number spectrum of smaller particles, thereby meeting the definition of "dragon kings." Marine snow particles overwhelmingly contributed to …


A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Jia-Pu Jang, Hsu-Kuang Chang, Fred C. Dobbs Jan 2016

A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Jia-Pu Jang, Hsu-Kuang Chang, Fred C. Dobbs

OES Faculty Publications

The turbid, low-light waters characteristic of aquaculture ponds have made it difficult or impossible for previous video cameras to provide clear imagery of the ponds' benthic habitat. We developed a highly sensitive, underwater video system (UVS) for this particular application and tested it in shrimp ponds having turbidities typical of those in southern Taiwan. The system's high-quality video stream and images, together with its camera capacity (up to nine cameras), permit in situ observations of shrimp feeding behavior, shrimp size and internal anatomy, and organic matter residues on pond sediments. The UVS can operate continuously and be focused remotely, a …


Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan Jan 2016

Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan

OES Faculty Publications

Environmental factors such as temp erature, irradiance, and nitrogen (N) supply affect the growth of Prorocentrum donghaiense, but the interactive effects of these physical factors and the effects of atmospheric CO2 (pCO2) on growth and N uptake have not been examined. We compared growth kinetics of P. donghaiense grown on 4 different N substrates (nitrate [NO3 -], ammonium [NH4 +], urea, and glutamic acid [glu]) with respect to temperature, irradiance, and pCO2. Temperature (15 to 30°C) had a positive effect on growth (max. growth rates: 0.17 to 0.65 d …


Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick Jan 2016

Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick

OES Faculty Publications

Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, …


A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Hsu-Kunag Chang, Fred C. Dobbs Jan 2016

A Highly Sensitive Underwater Video System For Use In Turbid Aquaculture Ponds, Chin-Chang Hung, Shih-Chieh Tsao, Kuo-Hao Huang, Hsu-Kunag Chang, Fred C. Dobbs

OES Faculty Publications

The turbid, low-light waters characteristic of aquaculture ponds have made it difficult or impossible for previous video cameras to provide clear imagery of the ponds' benthic habitat. We developed a highly sensitive, underwater video system (UVS) for this particular application and tested it in shrimp ponds having turbidities typical of those in southern Taiwan. The system's high-quality video stream and images, together with its camera capacity (up to nine cameras), permit in situ observations of shrimp feeding behavior, shrimp size and internal anatomy, and organic matter residues on pond sediments. The UVS can operate continuously and be focused remotely, a …


The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce Jan 2016

The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce

OES Faculty Publications

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …


An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble Jan 2016

An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble

OES Faculty Publications

In principle, tandem mass spectrometry can be used to detect and quantify the peptides present in a microbiome sample, enabling functional and taxonomic insight into microbiome metabolic activity. However, the phylogenetic diversity constituting a particular microbiome is often unknown, and many of the organisms present may not have assembled genomes. In ocean microbiome samples, with particularly diverse and uncultured bacterial communities, it is difficult to construct protein databases that contain the bulk of the peptides in the sample without losing detection sensitivity due to the overwhelming number of candidate peptides for each tandem mass spectrum. We describe a method for …


Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton Jan 2016

Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton

OES Faculty Publications

The primary input of organic matter to almost all marine sediments comes from deposition at the sediment surface. However, in many continental margin settings, reduced carbon can also be added to sediments from below—for example, from “deep” geologic hydrocarbon reservoirs derived from ancient source rocks or from the decomposition of deeply buried gas hydrate deposits. To examine the impact of these two differing reduced carbon inputs on sediment biogeochemistry, a modified reaction-transport model for anoxic marine sediments is described here and applied to data from sediment cores in Santa Barbara Basin to a depth of 4.6 m. Excellent model fits …


Intercomparison And Evaluation Of Satellite Peroxyacetyl Nitrate Observations In The Upper Troposphere-Lower Stratosphere, Richard J. Pope, Nigel A. D. Richards, Martyn P. Chipperfield, David P. Moore, Sarah A. Monks, Stephen R. Arnold, Norbert Glatthor, Michael Kiefer, Tom J. Breider, Jeremy J. Harrison, Peter F. Bernath Jan 2016

Intercomparison And Evaluation Of Satellite Peroxyacetyl Nitrate Observations In The Upper Troposphere-Lower Stratosphere, Richard J. Pope, Nigel A. D. Richards, Martyn P. Chipperfield, David P. Moore, Sarah A. Monks, Stephen R. Arnold, Norbert Glatthor, Michael Kiefer, Tom J. Breider, Jeremy J. Harrison, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Peroxyacetyl nitrate (PAN) is an important chemical species in the troposphere as it aids the long-range transport of NOx and subsequent formation of O3 in relatively clean remote regions. Over the past few decades observations from aircraft campaigns and surface sites have been used to better understand the regional distribution of PAN. However, recent measurements made by satellites allow for a global assessment of PAN in the upper troposphere-lower stratosphere (UTLS). In this study, we investigate global PAN distributions from two independent retrieval methodologies, based on measurements from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument, on …


The Use Of Remote Sensing Technologies And Models To Study Pollutants In Pdn Region, Suhail Mahmud Jan 2016

The Use Of Remote Sensing Technologies And Models To Study Pollutants In Pdn Region, Suhail Mahmud

Open Access Theses & Dissertations

Using a suite of modeling techniques and instrumentation we study the atmospheric pollutants in the PdN Region. The first objective of this work was to measure hemi-spherically integrated, spectrally resolved solar photon flux (actinic flux) between the wavelengths 300 and 700 nm, and use the measured actinic flux to improve air quality simulations. Actinic flux was measured in the PdN region in order to calculate photolysis rate coefficients for different pollutants. The improved photolysis rate coefficients were then integrated into a photochemical air quality model (CAMx) in order to improve air quality forecasting. We present the simulations performed for a …


Sea Level Acceleration In The China Seas, Yongcun Cheng, Tal Ezer, Benjamin D. Hamlington Jan 2016

Sea Level Acceleration In The China Seas, Yongcun Cheng, Tal Ezer, Benjamin D. Hamlington

CCPO Publications

While global mean sea level rise (SLR) and acceleration (SLA) are indicators of climate change and are informative regarding the current state of the climate, assessments of regional and local SLR are essential for policy makers responding to, and preparing for, changes in sea level. In this work, three acceleration detection techniques are used to demonstrate the robust SLA in the China Seas. Interannual to multidecadal sea level variations (periods >2 years), which are mainly related to natural internal climate variability and significantly affect estimation of sea level acceleration, are removed with empirical mode decomposition (EMD) analysis prior to the …


Are Long Tide Gauge Records In The Wrong Place To Measure Global Mean Sea Level Rise?, P. R. Thompson, B. D. Hamlington, F. W. Landerer, S. Adhikari Jan 2016

Are Long Tide Gauge Records In The Wrong Place To Measure Global Mean Sea Level Rise?, P. R. Thompson, B. D. Hamlington, F. W. Landerer, S. Adhikari

CCPO Publications

Ocean dynamics, land motion, and changes in Earth's gravitational and rotational fields cause local sea level change to deviate from the rate of global mean sea level rise. Here we use observations and simulations of spatial structure in sea level change to estimate the likelihood that these processes cause sea level trends in the longest and highest-quality tide gauge records to be systematically biased relative to the true global mean rate. The analyzed records have an average twentieth century rate of approximately 1.6 mm/yr, but based on the locations of these gauges, we show that the simple average underestimates the …


Developing Priority Variables (“Ecosystem Essential Ocean Variables” — Eeovs) For Observing Dynamics And Change In Southern Ocean Ecosystems, Andrew J. Constable, Daniel P. Costa, Oscar Schofield, Louise Newman, Edward R. Urban Jr., Elizabeth A. Fulton, Jessica Melbourne-Thomas, Tosca Ballerini, Philip W. Boyd, Angelika Brandt, Eileen E. Hofmann Jan 2016

Developing Priority Variables (“Ecosystem Essential Ocean Variables” — Eeovs) For Observing Dynamics And Change In Southern Ocean Ecosystems, Andrew J. Constable, Daniel P. Costa, Oscar Schofield, Louise Newman, Edward R. Urban Jr., Elizabeth A. Fulton, Jessica Melbourne-Thomas, Tosca Ballerini, Philip W. Boyd, Angelika Brandt, Eileen E. Hofmann

CCPO Publications

Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect …


Modelling The Response Of Ice Shelf Basal Melting To Different Ocean Cavity Environmental Regimes, David E. Gwyther, Eva A. Cougnon, Benjamin K. Galton-Fenzi, Jason L. Roberts, John R. Hunter, Michael S. Dinniman Jan 2016

Modelling The Response Of Ice Shelf Basal Melting To Different Ocean Cavity Environmental Regimes, David E. Gwyther, Eva A. Cougnon, Benjamin K. Galton-Fenzi, Jason L. Roberts, John R. Hunter, Michael S. Dinniman

CCPO Publications

We present simulation results from a version of the Regional Ocean Modeling System modified for ice shelf/ocean interaction, including the parameterisation of basal melting by molecular diffusion alone. Simulations investigate the differences in melting for an idealised ice shelf experiencing a range of cold to hot ocean cavity conditions. Both the pattern of melt and the location of maximum melt shift due to changes in the buoyancy-driven circulation, in a different way to previous studies. Tidal forcing increases both the circulation strength and melting, with the strongest impact on the cold cavity case. Our results highlight the importance of including …


Modeling Ice Shelf/Ocean Interaction In Antarctica: A Review, Michael S. Dinniman, Xylar S. Asay-Davis, Benjamin K. Galton-Fenzi, Paul R. Holland, Adrian Jenkins, Ralph Timmerman Jan 2016

Modeling Ice Shelf/Ocean Interaction In Antarctica: A Review, Michael S. Dinniman, Xylar S. Asay-Davis, Benjamin K. Galton-Fenzi, Paul R. Holland, Adrian Jenkins, Ralph Timmerman

CCPO Publications

The most rapid loss of ice from the Antarctic Ice Sheet is observed where ice streams flow into the ocean and begin to float, forming the great Antarctic ice shelves that surround much of the continent. Because these ice shelves are floating, their thinning does not greatly influence sea level. However, they also buttress the ice streams draining the ice sheet, and so ice shelf changes do significantly influence sea level by altering the discharge of grounded ice. Currently, the most significant loss of mass from the ice shelves is from melting at the base (although iceberg calving is a …


An Ongoing Shift In Pacific Ocean Sea Level, B. D. Hamlington, S. H. Cheon, P. R. Thompson, M. A. Merrifield, R. S. Nerem, R. R. Leben, K.-Y. Kim Jan 2016

An Ongoing Shift In Pacific Ocean Sea Level, B. D. Hamlington, S. H. Cheon, P. R. Thompson, M. A. Merrifield, R. S. Nerem, R. R. Leben, K.-Y. Kim

CCPO Publications

Based on the satellite altimeter data, sea level off the west coast of the United States has increased over the past 5 years, while sea level in the western tropical Pacific has declined. Understanding whether this is a short‐term shift or the beginning of a longer‐term change in sea level has important implications for coastal planning efforts in the coming decades. Here, we identify and quantify the recent shift in Pacific Ocean sea level, and also seek to describe the variability in a manner consistent with recent descriptions of El Nino‐Southern Oscillation (ENSO) and particularly the Pacific Decadal Oscillation (PDO). …


Impact Of Model Resolution For On-Shelf Heat Transport Along The West Antarctic Peninsula, Jennifer A. Graham, Michael S. Dinniman, John M. Klinck Jan 2016

Impact Of Model Resolution For On-Shelf Heat Transport Along The West Antarctic Peninsula, Jennifer A. Graham, Michael S. Dinniman, John M. Klinck

CCPO Publications

The flux of warm deep water onto Antarctic continental shelves plays a vital role in determining water mass properties adjacent to the continent. A regional model, with two different grid resolutions, has been used to simulate ocean processes along the West Antarctic Peninsula. At both 4 km and 1.5 km resolution, the model reproduces the locations of warm intrusions, as shown through comparison with observations from instrumented seals. However, the 1.5 km simulation shows greater on-shelf heat transport, leading to improved representation of heat content on the shelf. This increased heat transport is associated with increased eddy activity, both at …