Oceanography and Atmospheric Sciences and Meteorology Commons^™

Establishing A Multibeam Sonar Evaluation Test Bed Near Sidney, British Columbia, Rob Hare, Clay Whittaker, J.E. Hughes Clarke, Jonathan Beaudoin

Center for Coastal and Ocean Mapping

The Canadian Hydrographic Service (CHS), Naval Oceanographic Office (NAVOCEANO) and the Ocean Mapping Group of the University of New Brunswick (OMG) collaborated on establishing a multibeam sonar test bed in the vicinity of the Institute of Ocean Sciences in Sidney, British Columbia Canada. This paper describes the purpose of the sonar evaluation test bed, the trials and tribulations of two foreign governments collaborating on projects of mutual interest, the evaluation areas and their characteristics for sonar testing, and sample results of sonar evaluations using this test bed. Some target detection comparisons of several systems over a range of artificial sonar …

Beyond The Chart: The Use Of Satellite Remote Sensing For Assessing The Adequacy And Completeness Information, Shachak Pe'eri, Chukwuma Azuike, Lee Alexander, Christopher Parrish, Andy Armstrong

Center for Coastal and Ocean Mapping

Chart adequacy and completeness information consists of the symbols, abbreviations and warnings used to inform mariners of the level of confidence that should be given to data on a nautical chart. This information is derived both from the nautical chart and sailing directions. However, analysis based solely on these datasets is limited without access to the sources (e.g., smooth sheets). Publically-available, multi-spectral satellite imagery and published algorithms can be used to derive estimates of the relative bathymetry in shallow, clear waters. In this study, we evaluate the potential of these methods for supplementing the procedure to assess the adequacy of …

The Impact Of Sea State Condition On Airborne Lidar Bathymetry Measurements, Torbjorn Karlsson, Andreas Axelsson, Shachak Pe'eri

Center for Coastal and Ocean Mapping

Due to a large number of available Airborne Lidar Bathymetry (ALB) survey datasets and scheduled future surveys, there is a growing need from coastal mapping communities to estimate the accuracy of ALB as a function of the survey system and environmental conditions. Knowledge of ALB accuracy can also be used to evaluate the quality of products derived from ALB surveying. This paper presents theoretical and experimental results focused on the relationship between sea surface conditions and the accuracy of ALB measurements. The simulated environmental conditions were defined according to the typical conditions under which successful ALB surveys can be conducted. …

Develping A Methodology For The Mapping And Characterization Of The Nigerian Coastline Using Remote Sensing, Olumide Fadahunsi, Shachak Pe'eri, Lee Alexander, Christopher Parrish

Center for Coastal and Ocean Mapping

Coastline delineation is important in maritime boundary determination, as well as for analyzing coastline change rates due to coastal erosion, sea level change, storms, and other causes. Coastline change rate estimates depend on the uncertainty of the current and historical coastlines used in the analysis, which, in turn, depend on the surveying technologies and techniques that were originally used. Current techniques for coastline mapping include photogrammetric delineation using tide-coordinated aerial imagery. However, in many developing countries, the charted coastlines may have been inadequately and inconsistently mapped largely due to inadequate resources. This paper describes the use of an automated technique …

Seafloor Characterization For Trawlability Using The Simrad Me70 Multibeam Echosounder In The Gulf Of Alaska, Jodi L. Pirtle, Thomas C. Weber, Chris Rooper, Christopher D. Wilson, Brian R. Calder

Center for Coastal and Ocean Mapping

No abstract provided.

The Carrington Event Not Observed In Most Ice Core Nitrate Records, E W. Wolff, M Bigler, M. A. J. Curran, Jack E. Dibb, M M. Frey, M Legrand, J R. Mcconnell

Earth Sciences

The Carrington Event of 1859 is considered to be among the largest space weather events of the last 150 years. We show that only one out of 14 well-resolved ice core records from Greenland and Antarctica has a nitrate spike dated to 1859. No sharp spikes are observed in the Antarctic cores studied here. In Greenland numerous spikes are observed in the 40 years surrounding 1859, but where other chemistry was measured, all large spikes have the unequivocal signal, including co-located spikes in ammonium, formate, black carbon and vanillic acid, of biomass burning plumes. It seems certain that most spikes …

Extracting More Data From Lidar In Forested Areas By Analyzing Waveform Shape, Thomas Adams, Peter Beets, Christopher Parrish

Center for Coastal and Ocean Mapping

Light Detection And Ranging (LiDAR) in forested areas is used for constructing Digital Terrain Models (DTMs), estimating biomass carbon and timber volume and estimating foliage distribution as an indicator of tree growth and health. All of these purposes are hindered by the inability to distinguish the source of returns as foliage, stems, understorey and the ground except by their relative positions. The ability to separate these returns would improve all analyses significantly. Furthermore, waveform metrics providing information on foliage density could improve forest health and growth estimates. In this study, the potential to use waveform LiDAR was investigated. Aerial waveform …

Public Knowledge About Polar Regions Increases While Concerns Remain Unchanged, Lawrence C. Hamilton, Matthew J. Cutler, Andrew P. Schaefer

Carsey Publications

The authors of this brief conduct the first comparative analysis of the polar questions that were part of the National Opinion Research Center's 2006 and 2010 General Social Survey. Developed by scientists at the National Science Foundation's Office of Polar Programs, these questions covered topics such as climate change, melting ice and rising sea levels, and species extinction. The authors report that the public's knowledge about the north and south polar regions significantly improved between 2006 and 2010--before and after the International Polar Year. In addition, respondents who know more about science in general, and polar facts specifically, tend to …

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 …

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. …

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 …

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 …

The New Hampshire Greenhouse Gas Emissions Reduction Fund: Year 3 (July 2011-June 2012) Evaluation, Matthew Magnusson, Cameron P. Wake

The Sustainability Institute Publications

The Greenhouse Gas Emissions Reduction Fund (GHGERF) was created by the New Hampshire legislature in 2008 and has been administered by the New Hampshire Public Utilities Commission (PUC). The purpose of the Fund was to support energy efficiency, energy conservation, and demand response programs to reduce New Hampshire’s greenhouse gas emissions. Funding was derived from the State’s participation in the Regional Greenhouse Gas Initiative (RGGI), a cooperative effort by nine northeastern states to reduce carbon dioxide emissions in the electric power sector via a cap and trade program. As of June 2012, RGGI auctions have resulted in revenues to New …

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.

Acoustic Sensing Of Gas Seeps In The Deep Ocean With Split-Beam Echosounders, Thomas C. Weber, Kevin W. Jerram, Larry A. Mayer

Center for Coastal and Ocean Mapping

When in the form of free gas in the water column, methane seeps emanating from the seabed are strong acoustic targets that are often detectable from surface vessels using echo sounders.In addition to detecting that a seep is present at some location, it is also desirable to characterize the nature of the seep in terms of its morphology and flux rates. Here, we examine how much we can learn about seeps in the deep (> 1000 m) northern Gulf of Mexico using narrow-band split-beam echo sounders operating at fixed frequencies (18 kHz and 38 kHz).Methane seeps in this region are …

U.S. Extended Continental Shelf Cruise To Map Sections Of The Mariana Trench And The Eastern And Southern Insular Margins Of Guam And The Northern Mariana Islands, Andy Armstrong

Center for Coastal and Ocean Mapping

U.S. Extended Continental Shelf Cruise to Map Sections of the Mariana Trench and the Eastern and Southern Insular Margins of Guam and the Northern Mariana Islands

CCOM-JHC CRUISE SU10-02

Leg 2: September 24 to October 21, 2010

Apra Harbor, Guam to Apra Harbor, Guam

Do You Believe The Climate Is Changing? Answers From New Survey Research, Lawrence C. Hamilton

Carsey Publications

This brief explores how political views influence Americans’ understanding and perception of science. The research is based on a national version of the Community and Environment in Rural America survey called NCERA, and on New Hampshire’s statewide Granite State Poll. Author Lawrence Hamilton reports that most people on both surveys feel that they understand either a great deal or a moderate amount about global warming or climate change. However, deep partisan divisions affect both personal beliefs about climate change and perceptions of agreement among scientists. Democrats are much more likely to state they believe that climate change is happening, caused …

Estimating Oil Concentration And Flow Rate With Calibrated Vessel-Mounted Acoustic Echo Sounders, Thomas C. Weber, Alex De Robertis, Shep Smith, Samuel F. Greenaway, Larry A. Mayer, Glen Rice

Center for Coastal and Ocean Mapping

As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, …

Climate Change In The Piscataqua/Great Bay Region: Past, Present, And Future, Cameron P. Wake, Elizabeth Burakowski, Eric Kelsey, Katharine Hayhoe, Anne Stoner, Chris Watson, Ellen Douglas

The Sustainability Institute Publications

Earth ’s climate changes. It always has and always will. However, an extensive body of scientific evidence indicates that human activities are now a significant force driving change in the Earth’s climate system. This report describes how the climate of the Piscataqua/Great Bay region of coastal New Hampshire in the United States has changed over the past century and how the future climate of the region will be affected by human activities that are warming the planet.

Overall, the region has been getting warmer and wetter over the last century, and the rate of change has increased over the last …

Consistency In Statistical Moments As A Test For Bubble Cloud Clustering, Thomas C. Weber, Anthony P. Lyons, David L. Bradley

Center for Coastal and Ocean Mapping

Frequency dependent measurements of attenuation and/or sound speed through clouds of gas bubbles in liquids are often inverted to find the bubble size distribution and the void fraction of gas. The inversions are often done using an effective medium theory as a forward model under the assumption that the bubble positions are Poisson distributed (i.e., statistically independent). Under circumstances in which single scattering does not adequately describe the pressure field, the assumption of independence in position can yield large errors when clustering is present, leading to errors in the inverted bubble size distribution. It is difficult, however, to determine the …

Another Dimension From Lidar – Obtaining Foliage Density From Full Waveform Data, Thomas Adams, Peter Beets, Christopher Parrish

Center for Coastal and Ocean Mapping

LiDAR tells the user where surfaces are, not what they are. In this study we investigate the potential for waveform LiDAR to provide more information on the nature of the returns over forestry. Waveform LiDAR was acquired for ten Pinus radiata plots in a New Zealand plantation, along with comprehensive leaf area sampling in 2m vertical bands. The decay rate of each waveform peak was shown to be a useful tool for estimating foliage density, and has potential for identifying regions containing ground and understorey. Leaf Area Density (LAD) is an expression of foliage density per unit height, and a …

U.S. Law Of The Sea Cruise To Map The Foot Of The Slope And 2500-M Isobath Of The U.S. Arctic Ocean Margin, Larry A. Mayer, Andy Armstrong

Center for Coastal and Ocean Mapping

U.S. Law of the Sea cruise to map the foot of the slope and 2500-m isobath of the US Arctic Ocean margin

CRUISE HEALY 1102

August 15 to September 28, 2011

Barrow, AK to Dutch Harbor, AK

Longpath Doas Observations Of Surface Bro At Summit, Greenland, J Stutz, J L. Thomas, S C. Hurlock, M Schneider, R Von Glasow, M Piot, K Gorham, John F. Burkhart, Luke D. Ziemba, Jack E. Dibb, Barry Lefer

Earth Sciences

Reactive halogens, and in particular bromine oxide (BrO), have frequently been observed in regions with large halide reservoirs, for example during bromine catalyzed coastal polar ozone depletion events. Much less is known about the presence and impact of reactive halogens in areas without obvious halide reservoirs, such as the polar ice sheets or continental snow.

We report the first LP-DOAS measurements of BrO at Summit research station in the center of the Greenland ice sheet at an altitude of 3200 m. BrO mixing ratios in May 2007 and June 2008 were typically between 1–3 pmol mol⁻¹, with maxima …

A Method For Field Calibration Of A Multibeam Echo Sounder, Carlo Lanzoni, Thomas C. Weber

Center for Coastal and Ocean Mapping

The use of multibeam echo sounders (MBES) has grown more frequent in applications like seafloor imaging, fisheries, and habitat mapping. Calibration of these instruments is important for understanding and validating the performance of MBES. For echo sounders in general, different calibration methodologies have been developed in controlled environments such as a fresh water tank and in the actual field of operation. While calibration in an indoor tank facility can bring excellent results in terms of accuracy, the amount of time required for a complete calibration can become prohibitively large. A field calibration can reveal the actual radiation beam pattern for …

Multi-Touch 3d Exploratory Analysis Of Ocean Flow Models, Thomas J. Butkiewicz, Colin Ware

Center for Coastal and Ocean Mapping

Modern ocean flow simulations are generating increasingly complex, multi-layer 3D ocean flow models. However, most researchers are still using traditional 2D visualizations to visualize these models one slice at a time. Properly designed 3D visualization tools can be highly effective for revealing the complex, dynamic flow patterns and structures present in these models. However, the transition from visualizing ocean flow patterns in 2D to 3D presents many challenges, including occlusion and depth ambiguity. Further complications arise from the interaction methods required to navigate, explore, and interact with these 3D datasets. We present a system that employs a combination of stereoscopic …

Observations Of Hydroxyl And Peroxy Radicals And The Impact Of Bro At Summit, Greenland In 2007 And 2008, J Liao, L Gregory Huey, D Tanner, N Brough, Steve Brooks, Jack E. Dibb, J Stutz, J L. Thomas, Barry Lefer, C Haman, K Gorham

Earth Sciences

The Greenland Summit Halogen-HO_x (GSHOX) Campaign was performed in spring 2007 and summer 2008 to investigate the impact of halogens on HO_x (= OH + HO₂) cycling above the Greenland Ice Sheet. Chemical species including hydroxyl and peroxy radicals (OH and HO₂+ RO₂), ozone (O₃), nitrogen oxide (NO), nitric acid (HNO₃), nitrous acid (HONO), reactive gaseous mercury (RGM), and bromine oxide (BrO) were measured during the campaign. The median midday values of HO₂ + RO₂ and OH concentrations observed by chemical ionization mass spectrometry (CIMS) were …

Remote Characterization Of Seafloor Adjacent To Shipwrecks Using Mosaicking And Analysis Of Backscatter Response, Giuseppe Masetti, Roberto Sacile, Andrea Trucco

Center for Coastal and Ocean Mapping

The paper’s aim is to evaluate mosaicking and analysis of backscatter angular responses as adequate techniques to quickly characterize the seafloor adjacent to shipwrecks, extending the results of a limited number of grabs. Both techniques have been applied to the casestudy of the VLCC Haven shipwreck site, applying the approach known as Geocoder among the available methods. From these results, the development of the research activities will attempt to improve techniques and to generalize a methodological approach for the analysis of backscatter coming from an area of seafloor with the presence of one or more anthropic objects.

In Situ Measurements Of Tropospheric Volcanic Plumes In Ecuador And Colombia During Tc, S A. Carn, K D. Froyd, B E. Anderson, Paul Wennberg, John D. Crounse, K Spencer, Jack E. Dibb, N A. Krotkov, E V. Browell, Jonathan Hair, Glenn S. Diskin, G W. Sachse

Earth Sciences

A NASA DC‐8 research aircraft penetrated tropospheric gas and aerosol plumes sourced from active volcanoes in Ecuador and Colombia during the Tropical Composition, Cloud and Climate Coupling (TC4 ) mission in July–August 2007. The likely source volcanoes were Tungurahua (Ecuador) and Nevado del Huila (Colombia). The TC4 data provide rare insight into the chemistry of volcanic plumes in the tropical troposphere and permit a comparison of SO2 column amounts measured by the Ozone Monitoring Instrument (OMI) on the Aura satellite with in situ SO2 measurements. Elevated concentrations of SO2, sulfate aerosol, and particles were measured by DC‐8 instrumentation in volcanic …