Flocculation, Optics and Turbulence in the Community Sediment Transport Model System: Application of OASIS Results

The goal of this research is to develop greater understanding of the how the flocculation of fine-grained sediment responds to turbulent stresses and how this packaging of sediment affects optical and acoustical properties in the water column. Achieving these goals will improve the skill of sediment transport models and hence prediction of underwater visibility

Advice for young scientists on fruitful membership in the scientific community

Off and on for the past 20 years I have been co-teaching an intense summer course in optical oceanography. During the course, graduate students and postdocs often take the opportunity to ask my colleagues and me questions about how they should comport themselves as part of a scientific community. During the most recent course, I spent a class period speaking to this issue. From the comments I received, the students clearly were appreciative, and I have since shared my notes with colleagues, many of whom found them useful and have added materials of their own. Here, I convey some of the lessons we have learned through the years about strategies for navigating within the scientific community. They are by no means comprehensive, nor have they been investigated scientifically, but I hope readers will find them useful

COLLABORATIVE RESEARCH: Centers for Ocean Science Education Excellence- Ocean in the Earth-Sun System

This award establishes a new Center for Ocean Science Education Excellence (COSEE) via awards to the Bigelow Laboratory for Ocean Sciences (0528706), the University of Maine (0528702), and the University of New Hampshire (0528686). The main goals of this thematic Center are to broaden understanding of the oceans in the context of the earth and solar systems and to help the COSEE network reach rural and inland audiences. The PIs will pioneer a system of interfaces, tools, and resources to reach underserved and underrepresented groups, and to bring ocean sciences to inland audiences by presenting it in the context of more familiar components of the earth system, including environmental and space sciences. One goal is to explore the effectiveness of expanding knowledge of the ocean\u27s role beyond being a driver of earth\u27s climate to placing the earth in the context of its unique place in the solar system. Activities include building and training educator-scientist teams to work towards specific goals, e.g., testing strategies for effective use of ocean data, training in the use of concept mapping, and the identification and evaluation of high-quality resources. Evaluation of products, models and information is integrated throughout, with continuous self-assessment. Formal education partners at the University of Maine and University of New Hampshire will test the efficacy of materials with educators whose knowledge of ocean-related content ranges from novice to expert. Maine will be a test bed for the COSEE network to start reaching inland rural populations. The team includes scientists and educators with expertise in the hydrosphere, biosphere, cryosphere, geosphere, and atmosphere. The team will develop concept maps and case studies that show application of ocean topics to the National Science Education Standards. The Center will develop a formal mechanism for scientific review of materials to ensure the products they recommend are of the highest quality and meet rigorous standards, as well as to provide feedback from educators and scientists to product developers. They will select resources from DLESE, the BRIDGE, NOAA and others and evaluate these for classroom readiness and scientific accuracy using their team of well-trained resource evaluators with first-hand knowledge of earth systems science. They also will do a gap analysis of missing resources. The Gap Analysis will also inform the science community about avoiding developing materials for well-covered topics. The review process developed by COSEE-OESS, from initial use of NASA\u27s education product review, will be disseminated nationally as a model for evaluating best practices and assessment and evaluation guidelines for education materials.In-service teacher programs will focus on expansion of University of New Hampshire\u27s Coastal Observing Center summer in-service teacher workshops to incorporate OESS content and evaluation of activities ( test bed for novel materials and activities). These workshops have annual themes focusing on ocean observing systems and the integration of buoy, shipboard, and satellite data (GoMOOS). Pre-service teachers and general science students at the University of Maine will take a new course created by OESS to learn ocean research methods by focusing on using physical principles, concepts and approaches to explain phenomena in aquatic sciences that are aligned to the NSES. The course will be developed for distribution to teachers after rigorous evaluation.Intellectual Merit of the Center: This thematic center focuses on creating and evaluating a series of interconnected tools and techniques designed to broaden understanding of the ocean in the context of the earth and solar systems. Results will be translated into innovative multimedia products that showcase the ocean in the earth-sun system. Educational resources will be evaluated for science and education impact, and gaps in these resources will be identified and filled. A new undergraduate course to teach about ocean phenomena will be developed, tested, and disseminated nationally. The proposed Center will help COSEE reach inland and rural audiences. Broader impact: This Center will serve as a learning organization to deliver excellent products, models, and information that can be applied virtually anywhere. The final products, publication of Best Practices (a document that describes the value of system context in terms of learning) and Strategies to reach inland audiences will be disseminated throughout and beyond the COSEE network

SENSORS: Collaborative Research: ALOHA Mooring Sensor Network and Adaptive Sampling

The PIs propose to develop a moored deep-ocean sensor network that will first be installed at the Hawaii Ocean Time-series (HOT)/ALOHA Observatory (AO) and then at other cabled observatory sites as they are implemented. This moored sensor network is based on a profiler that will move between near-surface and fixed abyssal sensors under program control. The PIs feel that this project will demonstrate the scientific potential of combining adaptive sampling methods with a moored series of profiling sensors. The PIs will also develop optimization software tools to maximize overall information return given the constraints of competing scientific objectives, the continually changing environment that will be observed, and the physical limitations of the observing sensors and network. The power and two-way real time communications capability provided by the recently funded cabled ALOHA Observatory is essential to the sampling improvements and sensor network proposed here

Hands-on Oceanography. Diffusion at Work: An Interactive Simulation

The goal of this activity is to help students better understand the nonintuitive concept of diffusion and introduce them to a variety of diffusion-related processes in the ocean. As part of this activity, students also practice data collection and statistical analysis (e.g., average, variance, and probability distribution functions). This activity is also used as an introduction for a subsequent lesson on stirring and mixing

Subsurface maxima of phytoplankton and chlorophyll: Steady-state solutions from a simple model

In oligotrophic lakes and oceans, the deep chlorophyll maximum may form independently of a maximum of phytoplankton biomass, because the ratio of chlorophyll to phytoplankton biomass (in units of carbon) increases with acclimation to reduced light and increased nutrient supply at depth. Optical data (beam attenuation as proxy for phytoplankton biomass and chlorophyll fluorescence and absorption as proxies for chlorophyll concentration) and conventional measurements of biovolume, particulate organic carbon, and chlorophyll from two oligotrophic systems (Crater Lake, Oregon, and Sta. ALOHA in the subtropical North Pacific Ocean) are presented and show a vertical separation of the maxima of biomass and chlorophyll by 50-80 m during stratified conditions. We use a simple mathematical framework to describe the vertical structure of phytoplankton biomass, nutrients, and chlorophyll and to explore what processes contribute to the generation of vertical maxima. Consistent with the observations, the model suggests that biomass and chlorophyll maxima in stable environments are generated by fundamentally different mechanisms. Maxima in phytoplankton biomass occur where the growth rate is balanced by losses (respiration and grazing) and the divergence in sinking velocity, whereas the vertical distribution of chlorophyll is strongly determined by photoacclimation. A deep chlorophyll maximum is predicted well below the particle maximum by the model. As an interpretation of these results, we suggest a quantitative criterion for the observed coexistence of vertically distinct phytoplankton assemblages in oligotrophic systems: the vertical position at which a species occurs in highest abundance in the water column is determined by the general compensation depth - that is, the depth at which specific growth and all loss rates, including the divergence of sinking/swimming and vertical mixing, balance. This prediction can be tested in the environment when the divergence of sinking and swimming is negligible

Inlinino: A modular software data logger for oceanography

Inlinino is an open-source software data logger whose main purpose is to log scientific measurements collected during extended periods at sea. Here, we present an application of this software to data collected with commercial instrumentation. Inlinino also provides real-time visualization of the recorded observations, which helps users troubleshoot instruments in the field and prevents the collection of bad data. Inlinino is written in Python and runs on regular computers for instruments that have a serial interface. For less than $57, we built a separate data acquisition module—a precision analog-to-serial converter—for interfacing instruments that output analog signals to Inlinino. Inlinino was designed for optical sensors but can be used with any environmental sensor that communicates through analog or serial ports. The code is sufficiently modular that anyone with moderate coding skills can add new sensors. To date, Inlinino has been deployed successfully on several research vessels and logged more than 650 days of operation

Engineering literacy for undergraduates in marine science a case for hands on

Graduates in marine sciences most often lack basic engineering skills such as programming and robotics. Once they graduate, however, many of the available jobs require them to program (e.g., set a conductivity-temperature-depth sensor to sample at a specific time for a specific interval), collect data using sensors, and interface with robots (e.g., remotely operated vehicles, gliders, and floats). In general, whatever jobs they may land, the ability to teach themselves new skills will be required. We were inspired to develop the class described in this article by Randy Pausch’s The Last Lecture (http://www.cmu.edu/randyslecture), in which he described the Carnegie Mellon University Master of Science in Entertainment Technology program, where all the classes are project based

Simplified model of spectral absorption by non-algal particles and dissolved organic materials in aquatic environments

Absorption by non-algal particles (NAP, ad) and colored dissolved organic matter (CDOM, ag) are frequently modeled by exponential functions of wavelength, either separately or as a sum. We present a new representation of NAP-plus-CDOM absorption adg based on the stretched exponential function adg(λ) = A exp{−[s(λ − λo)]β}, whose parameter β can be considered a measure of optical heterogeneity. A double exponential representation of adg can be fit extremely well by a stretched exponential for all plausible parameter combinations, despite having one fewer free parameter than a double exponential. Fitting two published compilations of in situ adg data – one at low spectral resolution (n = 5, λ = 412–555 nm) and one at high spectral resolution (n = 201, λ = 300–700 nm) – the stretched exponential outperforms the single exponential, double exponential, and a power law. We thereby conclude that the stretched exponential is the preferred model for adg absorption in circumstances when NAP and CDOM cannot be separated, such as in remote sensing inversions