Oceanography and Atmospheric Sciences and Meteorology Commons^™

Spectral Energy Transfer Of Atmospheric Gravity Waves Through Sum And Difference Nonlinear Interactions, Kaiming Huang, Alan Z. Liu, Shaodong Zhang, Fan Yi, Zhenhua Li

Zhenhua Li

No abstract provided.

Spectral Energy Transfer Of Atmospheric Gravity Waves Through Sum And Difference Nonlinear Interactions, Kaiming Huang, Alan Z. Liu, Shaodong Zhang, Fan Yi, Zhenhua Li

Alan Z Liu

No abstract provided.

Empirical Correction Of A Toy Climate Model, Nicholas A. Allgaier, Kameron D. Harris, Christopher M. Danforth

College of Engineering and Mathematical Sciences Faculty Publications

Improving the accuracy of forecast models for physical systems such as the atmosphere is a crucial ongoing effort. The primary focus of recent research on these highly nonlinear systems has been errors in state estimation, but as that error has been successfully diminished, the role of model error in forecast uncertainty has duly increased. The present study is an investigation of an empirical model correction procedure involving the comparison of short forecasts with a reference "truth" system during a training period, in order to calculate systematic (1) state-independent model bias and (2) state-dependent error patterns. An estimate of the likelihood …

Hydrographic Data Processing On A Robust, Network-Coupled Parallel Cluster, Rohit Venugopal, Brian R. Calder

Center for Coastal and Ocean Mapping

Increasing data volumes and adoption of computer-assisted hydrographic data processing algorithms necessitate higher data processing rates if gains in efficiency achieved in the last decade are to be maintained and enhanced. Recent advances in desktop computer architectures have made multi-core and multi-processor systems readily available, and some advances have been made in implementing multi-threaded versions of common hydrographic data processing algorithms. In many cases, however, although the algorithms might be ideal for parallel implementation (so called ‘embarrassingly parallel’ tasks), limitations in memory, disc and network bandwidth within a single system can have significant limitations on the scalability of these solutions. …

Statistical Challenges In Null Model Analysis, Nicholas J. Gotelli, Werner Ulrich

College of Arts and Sciences Faculty Publications

This review identifies several important challenges in null model testing in ecology: 1) developing randomization algorithms that generate appropriate patterns for a specified null hypothesis; these randomization algorithms stake out a middle ground between formal Pearson-Neyman tests (which require a fully-specified null distribution) and specific process-based models (which require parameter values that cannot be easily and independently estimated); 2) developing metrics that specify a particular pattern in a matrix, but ideally exclude other, related patterns; 3) avoiding classification schemes based on idealized matrix patterns that may prove to be inconsistent or contradictory when tested with empirical matrices that do not …

Weak Prezygotic Isolating Mechanisms In Threatened Caribbean Acropora Corals, Nicole D. Fogarty, Steven V. Vollmer, Don R. Levitan

Marine & Environmental Sciences Faculty Articles

The Caribbean corals, Acropora palmata and A. cervicornis, recently have undergone drastic declines primarily as a result of disease. Previous molecular studies have demonstrated that these species form a hybrid (A. prolifera) that varies in abundance throughout the range of the parental distribution. There is variable unidirectional introgression across loci and sites of A. palmata genes flowing into A. cervicornis. Here we examine the efficacy of prezygotic reproductive isolating mechanisms within these corals including spawning times and choice and no-choice fertilization crosses. We show that these species have subtly different mean but overlapping spawning times, suggesting …

Analysis Of Satellite-Derived Arctic Tropospheric Bro Columns In Conjunction With Aircraft Measurements During Arctas And Arcpac, S Choi, Yuhang Wang, R J. Salawitch, T Canty, J Joiner, T Zeng, T P. Kurosu, K Chance, A Richter, L Gregory Huey, J Liao, J A. Neuman, J Nowak, Jack E. Dibb, Andrew Weinheimer, Glenn Diskin, Thomas B. Ryerson, Arlindo Da Silva, J Curry, D Kinnison, S Tilmes, P F. Levelt

Earth Sciences

We derive tropospheric column BrO during the ARCTAS and ARCPAC field campaigns in spring 2008 using retrievals of total column BrO from the satellite UV nadir sensors OMI and GOME-2 using a radiative transfer model and stratospheric column BrO from a photochemical simulation. We conduct a comprehensive comparison of satellite-derived tropospheric BrO column to aircraft in-situ observations of BrO and related species. The aircraft profiles reveal that tropospheric BrO, when present during April 2008, was distributed over a broad range of altitudes rather than being confined to the planetary boundary layer (PBL). Perturbations to the total column resulting from tropospheric …

Use (And Potential Abuse) Of Uncertainty In Hydrography, Brian R. Calder

Center for Coastal and Ocean Mapping

The evaluation and use of uncertainty as a component of hydrographic data processing systems has grown considerably in the last decade. Uncertainty models for sounding data are now common, and progress has been made in developing models, methods and implementations for preserving this uncertainty in intermediate hydrographic data products. Less progress has been made in dealing with expressing the uncertainty in hydrographic data products to the user, however, which we contend should be our ultimate aim.

We draw here a distinction between the uncertainty assessed for observed sounding (and auxiliary) data and uncertainty as expressed to the user, and observe …

Agriculture Futures: Potential Rural Land Uses On The Palusplain, Rodney Safstrom, Nicolyn Short Dr

Resource management technical reports

The purpose of this project was to identify agricultural land use options and opportunities within the Serpentine–Jarrahdale and Murray Shires, with particular focus on the Palusplain wetland section. The report will contribute to the Department of Planning’s natural resource management plan for the region and guide development of regional and local planning strategies. Historically, the Palusplain was a slowly moving, interconnected, seasonal wetland system with areas of higher ground. Extensive clearing and drainage occurred in the late 1800s through to the mid-1900s to facilitate agriculture; however, agriculture has been found to be a major contributor of nutrients to the system. …

Revisiting 3d Stereo Satellite Image Displays, Frederick R. Mosher

Applied Aviation Sciences - Daytona Beach

Over 30 years ago, there were a number of development efforts to display 3D stereo satellite images and associated weather. Dr. Fritz Hasler showed how the GOES-east and west satellites could be remapped to generate true stereo pairs for obtaining cloud heights and he also showed how artificial stereo images could be generated using derived IR cloud heights to generate parallax shifts for the visible or infrared images. While there was a flurry of interest in the 1980s, the techniques had largely fallen from routine usage until recently. However, technology advances in both satellites and display technology has allowed for …

Spatio-Temporal Variability Of Daily And Weekly Precipitation Extremes In South America, Shiraj Khan, Gabriel Kuhn, Auroop Ganguly, David Erickson Iii, George Ostrouchov

Auroop R. Ganguly

Spatial and temporal variability of precipitation extremes are investigated by utilizing daily observations available at 2.5° gridded fields in South America for the period 1940–2004. All 65 a of data from 1940–2004 are analyzed for spatial variability. The temporal variability is investigated at each spatial grid by utilizing 25-a moving windows from 1965–2004 and visualized through plots of the slope of the regression line in addition to its quality measure (R²). The Poisson-generalized Pareto (Poisson-GP) model, which is a peaks over threshold (POT) approach, is applied to weekly precipitation maxima residuals based on the 95%-quantile threshold, while daily data are …

Designing A Better Weather Display, Colin Ware, Matthew D. Plumlee

Center for Coastal and Ocean Mapping

The variables most commonly displayed on weather maps are atmospheric pressure, wind speed and direction, and surface temperature. But they are usually shown separately, not together on a single map. As a design exercise, we set the goal of finding out if it is possible to show all three variables (two 2D scalar fields and a 2D vector field) simultaneously such that values can be accurately read using keys for all variables, a reasonable level of detail is shown, and important meteorological features stand out clearly. Our solution involves employing three perceptual "channels", a color channel, a texture channel, and …

Spatial Analyses Of Benthic Habitats To Define Coral Reef Ecosystem Regions And Potential Biogeographic Boundaries Along A Latitudinal Gradient, Brian K. Walker

Marine & Environmental Sciences Faculty Articles

Marine organism diversity typically attenuates latitudinally from tropical to colder climate regimes. Since the distribution of many marine species relates to certain habitats and depth regimes, mapping data provide valuable information in the absence of detailed ecological data that can be used to identify and spatially quantify smaller scale (10 s km) coral reef ecosystem regions and potential physical biogeographic barriers. This study focused on the southeast Florida coast due to a recognized, but understudied, tropical to subtropical biogeographic gradient. GIS spatial analyses were conducted on recent, accurate, shallow-water (0–30 m) benthic habitat maps to identify and quantify specific regions …

A Paleoclimate Modeling Experiment To Calculate The Soil Carbon Respiration Flux For The Paleocene-Eocene Thermal Maximum, David M. Tracy

Masters Theses 1911 - February 2014

The Paleocene-Eocene Thermal Maximum (PETM) (55 million years ago) stands as the largest in a series of extreme warming (hyperthermal) climatic events, which are analogous to the modern day increase in greenhouse gas concentrations. Orbitally triggered (Lourens et al., 2005, Galeotti et al., 2010), the PETM is marked by a large (-3‰) carbon isotope excursion (CIE). Hypothesized to be methane driven, Zeebe et al., (2009) noted that a methane based release would only account for 3.5°C of warming. An isotopically heavier carbon, such as that of soil and C3 plants, has the potential to account for the …

Holocene Climate And Environmental Changes: Disentangling Natural And Anthropogenic Signals In The Sedimentary Record Of Lake Lilandsvatnet (Nw Norway), Robert M. D'Anjou

Masters Theses 1911 - February 2014

This thesis presents a multi-proxy paleoenvironmental reconstruction from the sedimentary archives of Lilandsvatnet, a small arctic lake on Vestvågøy, in the Lofoten Islands, Norway. Lofoten has a rich history of human settlements existing throughout the Holocene. The catchment of Lilandsvatnet was the location of a prominent Viking chieftain farm that existed throughout the Iron Age, and the sedimentary archive contains a strong signal of prehistoric and historic human settlements and land-use practices. Paleoenvironmental reconstructions in this thesis show evidence for Holocene environmental variability in response to both natural and anthropogenic forcing. Cryptotephra deposits from Icelandic eruptions further contrain sediment chronology …

Using A Low-Cost Spectrometer To Analyze The Optical Depth Of Atmospheric Aerosols, Michael Yurovchak

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

2012 Chesapeake Bay Bridge Tunnel Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Submarine Landslides On The Upper Southeast Australian Passive Continental Margin – Preliminary Findings, S L. Clarke, T Hubble, D Airey, Phyllis Yu, R Boyd, J Keene, N Exon, James V. Gardner

Center for Coastal and Ocean Mapping

The southeast Australian passive continental margin is narrow, steep and sediment-deficient, and characterized by relatively low rates of modern sedimentation. Upper slope (<1200m) sediments comprise mixtures of calcareous and terrigenous sand and mud. Three of twelve sediment cores recovered from geologically-recent, submarine landslides located offshore New South Wales/Queensland (NSW/QLD) are interpreted to have sampled failure surfaces at depths of between 85 cm and 220 cm below the present-day seabed. Differences in sediment physical properties are recorded above and below the three slide-plane boundaries. Sediment taken directly above the inferred submarine landslide failure surfaces and presumed to be post-landslide, returned radiocarbon ages of 15.8 ka, 20.7 ka and 20.1 ka. The last two ages correspond to adjacent slide features, which are inferred to be consistent with their being triggered by a single event such as an earthquake. Slope stability models based on classical soil mechanics and measured sediment shearstrengths indicate that the upper slope sediments should be stable. However, multibeam sonar data reveal that many upper slope landslides occur across the margin and that submarine landsliding is a common process. We infer from these results that: a) an unidentified mechanism regularly acts to reduce the shear resistance of these sediments to the very low values required to enable slope failure, and/or b) the margin experiences seismic events that act to destabilise the slope sediments.

Evaluation Of Rockfish Abundance In Untrawlable Habitat: Combining Acoustic And Complementary Sampling Tools, Darin Jones, Christopher D. Wilson, Alex De Robertis, Chris Rooper, Thomas C. Weber, John L. Butler

Center for Coastal and Ocean Mapping

—Rockfishes (Sebastes spp.) are an important component of North Pacific marine ecosystems and commercial fisheries. Because the rocky, high-relief substrate that rockfishes often inhabit is inaccessible to standard survey trawls, population abundance assessments for many rockfish species are difficult. As part of a large study to classify substrate and compare complementary sampling tools, we investigated the feasibility of using an acoustic survey in conjunction with a lowered stereo-video camera, a remotely operated vehicle, and a modified bottom trawl to estimate rockfish biomass in untrawlable habitat. The Snakehead Bank south of Kodiak Island, Alaska, was surveyed repeatedly over 4 days and …

Mapping Gas Seeps With The Deepwater Multibeam Echosounder On Okeanos Explorer, Thomas C. Weber, Larry A. Mayer, Jonathan Beaudoin, Kevin W. Jerram, Mashkoor A. Malik, Bill Shedd, Glen Rice

Center for Coastal and Ocean Mapping

No abstract provided.