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Old Dominion University

CCPO Publications

2016

Articles 1 - 16 of 16

Full-Text Articles in Physical Sciences and Mathematics

Impact Of Upper-Tropospheric Temperature Anomalies And Vertical Wind Shear On Tropical Cyclone Evolution Using An Idealized Version Of The Operational Gfdl Hurricane Model, Robert E. Tuleya, Morris Bender, Thomas R. Knutson, Joseph R. Sirutis, Biju Thomas, Isaac Ginis Oct 2016

Impact Of Upper-Tropospheric Temperature Anomalies And Vertical Wind Shear On Tropical Cyclone Evolution Using An Idealized Version Of The Operational Gfdl Hurricane Model, Robert E. Tuleya, Morris Bender, Thomas R. Knutson, Joseph R. Sirutis, Biju Thomas, Isaac Ginis

CCPO Publications

The GFDL hurricane modeling system, initiated in the 1970s, has progressed from a research tool to an operational system over four decades. This system is still in use today in research and operations, and its evolution will be briefly described. This study used an idealized version of the 2014 GFDL model to test its sensitivity across a wide range of three environmental factors that are often identified as key factors in tropical cyclone (TC) evolution: SST, atmospheric stability (upper-air thermal anomalies), and vertical wind shear (westerly through easterly). A wide range of minimum central pressure intensities resulted (905-980 hPa). The …

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Is The Detection Of Accelerated Sea Level Rise Imminent?, J. T. Fasullo, R. S. Nerem, B. Hamlington Aug 2016

Is The Detection Of Accelerated Sea Level Rise Imminent?, J. T. Fasullo, R. S. Nerem, B. Hamlington

CCPO Publications

Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking …

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Revisiting The Problem Of The Gulf Stream Separation: On The Representation Of Topography In Ocean Models With Different Types Of Vertical Grids, Tal Ezer Aug 2016

Revisiting The Problem Of The Gulf Stream Separation: On The Representation Of Topography In Ocean Models With Different Types Of Vertical Grids, Tal Ezer

CCPO Publications

The difficulty of simulating a realistic Gulf Stream (GS) that separates from the coast at Cape Hatteras has troubled numerical ocean modelers for a long time, and the problem is evident in different models, from the early models of the 1980s to the modern models of today. The source of the problem is not completely understood yet, since GS simulations are sensitive to many different factors, such as numerical parameterization, model grid, treatment of topography and forcing fields. A curious result of early models is that models with terrain-following vertical grids (e.g., “sigma” or “s” coordinates) seem to achieve a …

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Marine Disease Impacts, Diagnosis, Forecasting, Management And Policy, Kevin D. Lafferty, Eileen E. Hofmann Mar 2016

Marine Disease Impacts, Diagnosis, Forecasting, Management And Policy, Kevin D. Lafferty, Eileen E. Hofmann

CCPO Publications

(First paragraph) As Australians were spending millions of dollars in 2014 to remove the coraleating crown of thorns sea star from the Great Barrier Reef, sea stars started washing up dead for free along North America’s Pacific Coast. Because North American sea stars are important and iconic predators in marine communities, locals and marine scientists alike were alarmed by what proved to be the world’s most widespread marine mass mortality in geographical extent and species affected, especially given its mysterious cause. Investigative research using modern diagnostic techniques implicated a never-before-seen virus [1]. The virus inspired international attention to marine diseases, …

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Can The Gulf Stream Induce Coherent Short-Term Fluctuations In Sea Level Along The Us East Coast?: A Modeling Study, Tal Ezer Feb 2016

Can The Gulf Stream Induce Coherent Short-Term Fluctuations In Sea Level Along The Us East Coast?: A Modeling Study, Tal Ezer

CCPO Publications

Much attention has been given in recent years to observations and models that show that variations in the transport of the Atlantic Meridional Overturning Circulation (AMOC) and in the Gulf Stream (GS) can contribute to interannual, decadal, and multi-decadal variations in coastal sea level (CSL) along the US East Coast. However, less is known about the impact of short-term (time scales of days to weeks) fluctuations in the GS and their impact on CSL anomalies. Some observations suggest that these anomalies can cause unpredictable minor tidal flooding in low-lying areas when the GS suddenly weakens. Can these short-term CSL variations …

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Marine Infectious Disease Dynamics And Outbreak Thresholds: Contact Transmission, Pandemic Infection, And The Potential Role Of Filter Feeders, Gorka Bidegain, Eric N. Powell, John M. Klinck, Tal Ben-Horin, Eileen E. Hofmann Jan 2016

Marine Infectious Disease Dynamics And Outbreak Thresholds: Contact Transmission, Pandemic Infection, And The Potential Role Of Filter Feeders, Gorka Bidegain, Eric N. Powell, John M. Klinck, Tal Ben-Horin, Eileen E. Hofmann

CCPO Publications

Disease-causing organisms can have significant impacts on marine species and communities. However, the dynamics that underlie the emergence of disease outbreaks in marine ecosystems still lack the equivalent level of description, conceptual understanding, and modeling context routinely present in the terrestrial systems. Here, we propose a theoretical basis for modeling the transmission of marine infectious diseases (MIDs) developed from simple models of the spread of infectious disease. The models represent the dynamics of a variety of host-pathogen systems including those unique to marine systems where transmission of disease is by contact with waterborne pathogens both directly and through filter-feeding processes. …

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Understanding The Structure And Functioning Of Polar Pelagic Ecosystems To Predict The Impacts Of Change, E. E. Murphy, R. D. Cavanagh, K. F. Drinkwater, S. M. Grant, J. J. Heymans, E. E. Hofmann, G. L. Hunt Jr., N. M. Johnston Jan 2016

Understanding The Structure And Functioning Of Polar Pelagic Ecosystems To Predict The Impacts Of Change, E. E. Murphy, R. D. Cavanagh, K. F. Drinkwater, S. M. Grant, J. J. Heymans, E. E. Hofmann, G. L. Hunt Jr., N. M. Johnston

CCPO Publications

The determinants of the structure, functioning and resilience of pelagic ecosystems across most of the polar regions are not well known. Improved understanding is essential for assessing the value of biodiversity and predicting the effects of change (including in biodiversity) on these ecosystems and the services they maintain. Here we focus on the trophic interactions that underpin ecosystem structure, developing comparative analyses of how polar pelagic food webs vary in relation to the environment. We highlight that there is not a singular, generic Arctic or Antarctic pelagic food web, and, although there are characteristic pathways of energy flow dominated by …

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Assessing The Impact Of Vertical Land Motion On Twentieth Century Global Mean Sea Level Estimates, B. D. Hamlington, P. Thompson, W. C. Hammond, G. Blewitt, R. D. Ray Jan 2016

Assessing The Impact Of Vertical Land Motion On Twentieth Century Global Mean Sea Level Estimates, B. D. Hamlington, P. Thompson, W. C. Hammond, G. Blewitt, R. D. Ray

CCPO Publications

Near-global and continuous measurements from satellite altimetry have provided accurate estimates of global mean sea level in the past two decades. Extending these estimates further into the past is a challenge using the historical tide gauge records. Not only is sampling nonuniform in both space and time, but tide gauges are also affected by vertical land motion (VLM) that creates a relative sea level change not representative of ocean variability. To allow for comparisons to the satellite altimetry estimated global mean sea level (GMSL), typically the tide gauges are corrected using glacial isostatic adjustment (GIA) models. This approach, however, does …

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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 …

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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 …

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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 …

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Mechanism Of Seasonal Arctic Sea Ice Evolution And Arctic Amplification, Kwang-Yul Kim, Benjamin D. Hamlington, Hanna Na, Jinju Kim Jan 2016

Mechanism Of Seasonal Arctic Sea Ice Evolution And Arctic Amplification, Kwang-Yul Kim, Benjamin D. Hamlington, Hanna Na, Jinju Kim

CCPO Publications

Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents-Kara seas. Excessive turbulent heat flux through the sea …

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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 …

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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). …

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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 …

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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 …

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