Oceanographic Sciences Research Articles

Effective scattering phase functions for the multiple scattering regime

The propagation of light through turbid media is of fundamental interest in a number of areas of optical science including atmospheric and oceanographic science, astrophysics and medicine amongst many others. The angular distribution of photons after a single scattering event is determined by the scattering phase function of the material the light is passing through. However, in many instances photons experience multiple scattering events and there is currently no equivalent function to describe the resulting angular distribution of photons. Here we present simple analytic formulas that describe the angular distribution of photons after multiple scattering events, based only on knowledge of the single scattering albedo and the single scattering phase function.

THE 2010 JOSEPH A. CUSHMAN AWARD

ANDREW J. GOODAY The 2010 Joseph A. Cushman Award for Excellence in Foraminiferal Research was presented to Andrew J. Gooday on November 2, 2010 at the Cushman Foundation for Foraminiferal Research Reception and Award Ceremony in Denver, Colorado. Andy Gooday began his career studying ostracodes. His M.S. from the University of Wisconsin, Milwaukee was on Miocene benthic ostracodes and his Ph.D. from the University of Exeter (UK) was on Devonian ostracodes. The particular group that he studied in his dissertation, the entomozoids, is believed to have been plankton and so the logical next step was to work with the modern equivalents. This he did as a NERC Postdoctoral Fellow at the Institute of Oceanographic Sciences (Wormley, England), where he studied modern planktonic ostracodes under the direction of Dr. Martin V. Angel, the leading authority on this unusual group. As this fellowship was finishing, Dr. Tony Rice was starting a benthic biology working group at the same institution and Andy began working on the copious benthic foraminiferal material collected off northwestern Africa on a cruise in 1973. During this early stage of his career, Andy was employed …

Editorial: IV Brazilian Symposium on Oceanography

This volume of the Brazilian Journal of Oceanography publishes articles presented during the IV Brazilian Symposium on Oceanography held at the Oceanographic Institute of the University of Sao Paulo, Sao Paulo, Brazil, 8-12 December 2008. All the articles appearing in this volume have gone through the normal review process as expected for any article published in the Brazilian Journal of Oceanography. The main theme of the IV Brazilian Symposium on Oceanography was “Environmental changes: scenarios and adaptations” at their different spatial and time scales. The IVSBO was attended by 308 participants, with a total of 90 oral and 206 poster presentations. Invited scientists from various countries proferred nine keynote lectures comprehending several fields in oceanography. The Brazilian Symposium on Oceanography derived from the Symposium on Oceanography I, II and III organized in 1989, 1991 and 1996, respectively. This symposium gained national recognition and has been transformed into the Brazilian Symposium on Oceanography, maintaining its regularity since 2002, being an important forum for the discussion of different aspects of the oceanographic sciences. The IVSBO was sponsored by the Oceanographic Institute of the University of Sao Paulo (IO/USP), FAPESP, CNPq, Pro-reitoria de Cultura e Extensao Universitaria/USP, FUNDESPA, CORPLAB, CPEA and HidroMares. We are grateful to all the people involved in the organization of the symposium, especially the group of students that made sure that everything ran smoothly. We also take this opportunity to thank the referees for their valuable reviews of the submitted manuscripts. Eduardo Siegle Alexander Turra

Complete Proceedings - Single PDF Download

The Conference on Coastal Engineering at Long Beach was conceived originally as a local meeting of engineers and scientists interested in shoreline problems and was sponsored by the University of California. It early became evident that there was widespread interest in the subject and that the program should be planned on a more ambitious scale. The aim was to aid engineers by summarizing the present state of the art and science related to the design and planning of coastal works rather than to present a series of original scientific contributions. Starting from a rather comprehensive outline, invitations were issued to recognized authorities to report on specific phases of the subject, and the authors cooperated splendidly both in their treatment of the subjects assigned and in their avoidance of overlapping other subjects. Although much remains to be done in the way of developing reliable design methods, the series of papers presented at the conference and published in this volume do represent a rather thorough summary of coastal engineering as now practiced.
 Engineers engaged in the design of coastal works have had available to them a large number of papers dealing with various phases of the science related to their problems, but proper dealing with design were limited in number and scope. Only a few books on coastal engineering have been published. The quality and scope of the papers and the need for a comprehensive and modern treatment of the subject convinced the sponsors of the conference that publication in a single volume was desirable rather than piecemeal in the scientific and technical journals. The newly-formed Council on Wave Research secured funds to underwrite the publication costs from its parent organization, the Engineering Foundation.
 A word about the term "Coastal Engineering" is perhaps in order here. It is not a new or separate branch of engineering and there is no implication intended that a new breed of engineer, and a new society, is in the making. Coastal Engineering is primarily a branch of Civil Engineering which leans heavily on the sciences of oceanography, meteorology, fluid mechanics, electronics, structural mechanics, and others. However, it is also true that the design of coastal works does involve many criteria which are foreign to other phases of civil engineering and the novices in this field should proceed with caution. Along the coastlines of the world, numerous engineering works in various stages of disintegration testify to the futility and wastefulness of disregarding the tremendous destructive forces of the sea. Far worse than the destruction of insubstantial coastal works has been the damage to adjacent shorelines caused by structures planned in ignorance of, and occasionally in disregard of, the shoreline processes operative in the area.
 The Council on Wave Research takes this opportunity to thank the authors of the papers and the many others who assisted in organization of the conference and in the preparation of this volume for publication.

Deep-sea mining of seafloor massive sulfides

Abstract The potential emergence of an ocean mining industry to exploit seafloor massive sulfides could present opportunities for oceanographic science to facilitate seafloor mineral development in ways that lessen environmental harms.

Changing the tide of forecasts

This article presents a general discussion on the forecasting capabilities provided by the Integrated Ocean Observing System and its applications to oceanographic science and data collection.

The Ensemble Kalman Filter in Reservoir Engineering--a Review

Introduction and Background There has been great progress in data assimilation within atmospheric and oceanographic sciences during the last couple of decades. In data assimilation, one aims at merging the information from observations into a numerical model, typically of a geophysical system. A typical example where data assimilation is needed is in weather forecasting. Here, the atmospheric models must take into account the most recent observations of variables such as temperature and atmospheric pressure for better forecasting of the weather in the next time period. A major challenge for these models is that they contain very large numbers of variables. The progress in data assimilation is because of both increased computational power and the introduction of techniques that are capable of handling large amounts of data and more severe nonlinearities. The aim of this paper is to focus on one of these techniques, the ensemble Kalman filter (EnKF). The EnKF has been introduced to petroleum science recently (Lorentzen et al. 2001a) and, in particular, has attracted attention as a promising method for solving the history matching problem. The literature available on the EnKF is now rather overwhelming. We hope that this review will help researchers (and students) working on adapting the EnKF to petroleum applications to find valuable references and ideas, although the number of papers discussing the EnKF is too large to give a complete review. For practitioners, we have cited critical EnKF papers from weather and oceanography. We have also tried to review most of the papers dealing with the EnKF and updating of reservoir models available to the authors by the beginning of 2008. The EnKF is based on the simpler Kalman filter (Kalman 1960). We will start by introducing the Kalman filter. The Kalman filter is an efficient recursive filter that estimates the state of a linear dynamical system from a series of noisy measurements. The Kalman filter is based on a model equation, where the current state of the system is associated with an uncertainty (expressed by a covariance matrix) and an observation equation that relates a linear combination of the states to measurements. The measurements are also associated with uncertainty. The model equations are used to compute a forward step (Eqs. 1 and 2) where the state variables are computed forward in time with the current estimate of the state as initial condition. The observation equations are used in the analysis step (Eqs. 3 through 5) where the estimated value of the state and its uncertainty are corrected to take into account the most recent measurements See, e.g., Cohn (1997), Maybeck (1979), or Stengel (1994) for an introduction to the Kalman filter.

Characterization of African Dust (PM 2.5) across the Atlantic Ocean during AEROSE 2004

An Aerosol and Oceanographic Science Expedition (AEROSE) on the NOAA Ship Ronald H. Brown collected PM 2.5 particles from a Saharan dust storm in March 2004. High levels of PM 2.5 (120 μg m −3) were measured during this Saharan storm over the Atlantic Ocean. The particles were characterized for trace element content, with Al and Fe the most abundant metals. These metals were detected in high concentrations during the Saharan event and exhibited good correlations with PM 2.5, suggesting its soil origin. Other elements (Pb, Ni, Cd) did not correlate with Al and Fe, indicating their anthropogenic origin. Enrichment factor calculation conducted on these trace elements support our findings. Trace element analyses performed on particulate matter from a reference site on land in Puerto Rico (Fajardo), demonstrated similar results to those obtained in the AEROSE expedition, where high concentrations of PM 2.5 and Fe were present concomitantly with Saharan events at this station.

Inferred variables in data assimilation: quantifying sensitivity to inaccurate error statistics

The ability of data assimilation systems to infer unobserved variables has brought major benefits to atmospheric and oceanographic sciences. Information is transferred from observations to unobserved variables in two ways: through the temporal evolution of the predictive equations (either a forecast model or its adjoint) or through an error covariance matrix (or a parametrized approximation to the error covariance). Here, it is found that high frequency information tends to flow through the former route, low frequency through the latter. It is also noted that using the Kalman Filter analysis to estimate the correlation between the observed and unobserved variables can lead to a biased result because of an error correlation: this error correlation is absent when the Kalman Smoother is used.

Inferred variables in data assimilation: quantifying sensitivity to inaccurate error statistics

The ability of data assimilation systems to infer unobserved variables has brought major benefits to atmospheric and oceanographic sciences. Information is transferred from observations to unobserved variables in two ways: through the temporal evolution of the predictive equations (either a forecast model or its adjoint) or through an error covariance matrix (or a parametrized approximation to the error covariance). Here, it is found that high frequency information tends to flow through the former route, low frequency through the latter. It is also noted that using the Kalman Filter analysis to estimate the correlation between the observed and unobserved variables can lead to a biased result because of an error correlation: this error correlation is absent when the Kalman Smoother is used.

Patrick Michael Holligan: a short biography

Our understanding of the role of marine phytoplankton in the global biogeochemical cycles of carbon and sulphur, particularly the rates and variability of primary production and calcification, phytoplankton activity and ecology in the subsurface chlorophyll maximum, and the use of satellite remote sensing to detect coccolithophore blooms, has progressed substantially through research initiated, led and undertaken by Patrick M. Holligan. The enthusiasm and commitment of Patrick’s colleagues for both this special issue and the symposium on “Marine Plankton: From Cells to Ecosystems” held in his honour in April 2008 at Plymouth, UK are testament to the high esteem in which he is held within the international scientific community. His expertise as a scientific leader, teacher and writer has inspired students and collaborators over more than three decades. In particular, his chairmanship during the early 1990s of the Planning Committee for the “Land-Ocean Interactions in the Coastal Zone” (LOICZ) project led to the establishment of a new core project within the International Geosphere-Biosphere Programme (IGBP). As the first Head of the School of Ocean and Earth Science (SOES), University of Southampton (1998– 2002), Patrick had responsibility for substantial expansion of the School, including 13 new academic appointments. As one of the first UK Principal Investigators to propose an open-ocean latitudinal time-series study, he helped initiate the development of the Atlantic Meridional Transect (AMT) programme (www.amt-uk. org), and as the President of the Council of the Sir Alister Hardy Foundation for Ocean Science (SAHFOS), he guided the transition to a new Directorship of the Continuous Plankton Recorder programme. Patrick gained an MA in Botany from Christs College, Cambridge in 1966. He then moved to the Department of Botany at the University of Leeds where he completed his PhD in 1970 on “Carbohydrate metabolism in the fungus Dendryphiella salina“ under the supervision of David Jennings. During the first year of his PhD, Patrick assisted Ed Drew in some research on acclimations by seaweeds to changes in light intensity and quality that required summer fieldwork in Malta. It was here that Patrick practised his self-taught skills in scuba diving, met John Woods for the first time, acted as a guinea pig for behavioural research into the effects of nitrogen narcosis, and developed a serious interest in the marine environment. While doing his PhD, Patrick also met and married his wife, Sue. Patrick then undertook a postdoctoral appointment (1969–1973) with David Lewis in the Department of Botany at the University of Sheffield to work on the physiology of higher plants infected by rust fungi. In 1973, Patrick joined the staff at the Marine Biological Association (MBA) in Plymouth UK as a Research Scientist, despite his only “marine” credentials being research on a marine fungus and his hobby of scuba diving. He sought external advice from David Cushing and Tim Wyatt at Lowestoft and from Jack Talling at Windermere about developing a new research programme on marine phytoplankton and then, over morning coffee, met Robin Pingree, a physicist with an interest in biology who had come from the Institute of Oceanographic Sciences (IOS), Wormley, UK to work

Development of the DORADO mapping vehicle for multibeam, subbottom, and sidescan science missions

AbstractOceanographic science is frequently hindered by a lack of spatial and temporal resolution for most parameters oceanographic science desires to measure. This paper discusses our effort to advance the current state of bathymetric mapping as part of the Monterey Bay Aquarium Research Institute (MBARI) charter. MBARI scientists and engineers, in consultation with the external community, have produced a new multibeam mapping autonomous underwater vehicle (AUV) system. The system is intended to reduce some of the impediments encountered by science trying to resolve specific portions of the oceans bottom. Starting with the established and in‐house developed Dorado AUV technology, MBARI engineering refined the AUV into a full ocean depth capable and now operational multibeam mapping system (MBAUV). The MBAUV system conducts regular multibeam bathymetry, subbottom, and sidescan surveys for oceanographic science. MBAUV is a torpedo‐shaped, 6000 m rated vehicle operating the aforementioned sonars simultaneously. The endurance of the MBAUV is approximately 8 h at 3 kn and is designed to support 16 h operations at 3 kn by adding an additional battery section. This paper describes the basics of the MBAUV and our design trades and modifications to the Dorado AUV in support of multibeam mapping missions. The paper also reviews a sampling of the results from a series of missions that demonstrate the performance of various subsystems and the science quality data available from the MBAUV. © 2007 Wiley Periodicals, Inc.

The future of chemical in situ sensors

Many of the sampling methods used in oceanographic sciences today date back decades, if not centuries. Although there has been a marked change in how sampling for chemical oceanography is carried out it still relies on taking samples of seawater from a research vessel in most cases. Assessing processes on small timescales as well as transient events requires higher temporal and spatial resolution of measurements; long time series stations require high duration deployments of instruments. Both requirements can only be adequately satisfied by in situ sensors; for the physical parameters off the shelf instruments are available, in the field of chemical oceanography only a few parameters, such as oxygen, are covered by off the shelf instruments, for most parameters adequate instrumentation only exists in the form of prototypes, if at all. Chemical in situ sensors are needed to gain new insights in how the oceans and the life in it works. This paper will give an overview of several technologies used for developments of chemical in situ sensors over the last five years and what potential these technologies have for future sensors. The technologies covered are: optical absorption spectroscopy (e.g. for nitrate measurements from the low micromolar to high concentrations); Raman spectroscopy (demonstrated e.g. on polyaromatic aromatic hydrocarbons with detection limits (LOD) from ng l −1 to μg l −1); microelectrodes (e.g. Cu(II), Pb(II) and Cd(II) with LOD in the pM range); optodes (e.g. for oceanic oxygen measurements with accuracy of 2 μM); in situ mass spectrometry (e.g. dissolved gases, volatile organic compounds (1–5 ppb LOD)) and microelectromechanical (MEMS) analysers (that could be used in situ to measure a variety of analytes with wet-chemical methods). The paper will also evaluate how it can be assured that measurements made with new in situ sensors are consistent with proven lab analysis.

NEPTUNE Canada—status and planning

Stage 1 of the joint Canada-U.S. NEPTUNE seafloor observatory has been funded by the Canada Foundation for Innovation and the British Columbia Knowledge Development Fund with an overall budget of $62.4 million. The network is designed to provide as close to real−time data and images as possible to be distributed to the research community, government agencies, educational institutions and the public via the Internet. Covering much of the northern segment of the Juan de Fuca Plate, this first phase of the NEPTUNE project is scheduled to be installed, with an initial suite of ‘‘community experiments’’, in 2008. As part of the planning, NEPTUNE Canada held a series of three workshops to develop the science plans for these ‘‘community experiments’’; these experiments have a budget of approximately $13 million. The experiments will cover the gamut of oceanographic science themes including various aspects of: ocean climate and marine productivity, seabed environments and biological communities, fluids at ocean ridges, gas hydrates and fluids on continental margins, plate tectonics processes, associated earthquakes and tsunamis. The next three years will be spent developing and testing the necessary instrumentation for deployment on the network.

Autonomous Underwater Vehicles for Ocean Research: Current Needs and State of the Art Technologies

Research in the field of scientific Autonomous Underwater Vehicles (AUVs) has been underway for over three decades. Much of the original work was funded by the military, and the vehicles were intended for Naval Ordnance Systems Command oceanographic needs, although the payloads were for general scientific use. Over the last decade, several autonomous underwater vehicles have been purpose built for both the science community and industrial operations around the world. Because of the variety of mission requirements, AUV configurations and options available today are numerous.Beginning with a brief overview of the history of AUVs for science, the paper continues with discussion of the ocean applications that are suitable to AUVs. Highlighted are some points a potential user might consider when selecting an AUV for a particular science application. An overview of several AUVs available today has been included exploring the cross-section of capabilities offered. This leads into the emerging requirements for AUVs of the future. In conclusion, some insight is given on lessons learned by several members of the oceanographic AUV community and how these lessons might be applicable when considering AUVs as a solution to today's intriguing oceanographic science questions.

Reply [to “Comment on ‘Righting the balance: Gender diversity in the geosciences’”] by Floyd Herbert

In our article “On Gender Equity in the Geosciences,” we are not advocating a quota of 50% women in the geosciences, but rather, suggesting that the field would be strengthened if all the individuals with doctorates in the geosciences (including the 28% of all Ph.D.s who are women) were to remain active in these fields [National Science Board, 2002; Kastens, 2003].Currently, only about 13% of employed Ph.D.s in these fields are women, which means that there is a considerable loss of trained scientists in the Earth, atmospheric, and oceanographic sciences. Even the entry‐level hires at Ph.D.‐granting institutions are only 20% female [Holmes et al, 2003].

Building digital libraries through collaboration within and between nations (SIG DL, III)

Building digital libraries through collaboration within and between nations (SIG DL, III)

Righting the balance: Gender diversity in the geosciences

The blatant barriers are down. Women are now routinely chief scientists on major cruises, lead field parties to all continents, and have risen to leadership positions in professional organizations, academic departments, and funding agencies. Nonetheless, barriers remain. Women continue to be under‐represented in the Earth, ocean, and atmospheric sciences. Let's do the numbers: As of 1997, women received 41% of all Ph.D.s in science and engineering, but only 29% of the doctorates in the Earth, atmospheric, and oceanographic sciences [NSF, 1999a]. Women were 23% of employed Ph.D.s across all fields of science, but only accounted for 13% in the geosciences. Women's salaries also lag: the median salary for all Ph.D. geoscientists was $60,000; for women, the figure is $47,000 [NSF, 1999b]. The growing number of women students is a step in the right direction, but only a step.

Sea surface salinity from space: Science goals and measurement approach

Aquarius is a NASA/Earth System Science Pathfinder (ESSP) mission that proposes to make the first‐ever global measurements of sea surface salinity. These measurements will enable improved understanding of oceanic thermohaline circulation and of the changes in oceanic circulation that are related to seasonal to interannual climate variability. Aquarius science goals also address tropical ocean‐climate feedbacks and freshwater budget components of the coupled ocean‐atmosphere system. These oceanographic science requirements for Aquarius dictate measurements of global sea surface salinity that are accurate to 0.2–0.3 psu, as averaged monthly and over 100–200 km areas. Key aspects of the Aquarius salinity mission design include the instrument with its high‐stability L‐band radiometers, the precise calibration of the measurements, and the salinity retrieval algorithm. The Aquarius mission will meet the science needs by providing complete global coverage of ocean surface salinity, with an 8 day cycle of observations using a three beam, L‐band radiometer/scatterometer flying in a 6 am/6 pm polar orbit. This conceptual design has been verified using observations from aircraft flight instruments. The radiometer design for the instrument and the needed precise calibration is based on proven, temperature‐stabilized radiometer designs with internal references, plus vicarious calibration approaches developed in the course of previous space missions.

Autonomous underwater vehicles: future platforms for fisheries acoustics

Abstract Autonomous underwater vehicles (AUVs) are unmanned submersibles that can be pre-programmed to navigate in three dimensions under water. The technological advances required for reliable deployment, mission control, performance, and recovery of AUVs have developed considerably over the past 10 years. Currently, there are several vehicles operating successfully in the offshore industries as well as in the applied and academic oceanographic sciences. This article reviews the application of AUVs to fisheries- and plankton-acoustics research. Specifications of the main AUVs currently in operation are given. Compared to traditional platforms for acoustic instruments, AUVs can sample previously impenetrable environments such as the sea surface, the deep sea, and under-sea ice. Furthermore, AUVs are typically small, quiet, and have the potential to operate at low cost and be unconstrained by the vagaries of weather. Examples of how these traits may be utilized in fisheries-acoustics science are given with reference to previous work in the North Sea and Southern Ocean and to potential future applications. Concurrent advances in multi-beam sonar technology and species identification, using multi-frequency and broadband sonars, will further enhance the utility of AUVs for fisheries acoustics. However, before many of the more prospective applications can be accomplished, advances in power-source technology are required to increase the range of operation. The paper ends by considering developments that may turn AUVs from objects sometimes perceived as science fiction into instruments used routinely to gather scientific facts.