CMG Training in Spatio-Temporal Statistical Analysis of Multi-Platform Ocean Optical Observations

This project will be a five-week summer school on the topic of spatio-temporal statistical analysis and its application to multi-platform, multi-sensor bio-optical oceanic data. The summer school seeks to address some of the analysis challenges anticipated as the Integrated Ocean Observing System is established. These are associated with the very diverse range of spatial and temporal sampling afforded by the different components of such a system and contemporaneous process experiments. Statistical experts in spatial information engineering with experience in collaboration with ocean scientists will discuss some of the modern tools for statistical analysis of such data and associated challenges, while ocean scientists will introduce students to the data and the underlying science questions. The primary focus will be on analysis of the distribution of phytoplankton, which is known to be a patchy and intermittent field, the interpretation of measurements of which are complicated by advection. This should serve as a model for the study of statistical techniques that can then be applied to other environmental fields. An interdisciplinary group of approximately 16 students will be recruited, half with background in mathematical sciences and half with ocean science backgrounds. The goal is to introduce students to interdisciplinary research questions and provide stimulating ideas that they can subsequently apply in their dissertation research

Collaborative Research: Incorporation of Sensors into Autonomous Gliders for 4-D Measurement of Bio-Optical and Chemical Parameters

This research project is conducted under the auspices of the National Oceanographic Partnership Program (NOPP). Partners include the Univ. of Maine, Univ. of Washington, several commercial instrument manufacturers, and two local government agencies. The project addresses an ocean sciences requirement for new ocean observational capabilities for continuous, high-resolution measurements of oceanic processes that include characterization of distributions, mechanisms, and rates of processes involving chemical and biological variables together with physical variables in the ocean. The overall objective is to add new capabilities to a small (1.8 m, 52 kg) autonomous underwater glider that moves horizontally and vertically using variable buoyancy control and wings. It can perform hundreds of cycles per launch from surface to 2,000 m or less, report data back (including GPS location) in real time upon each surfacing, and be reprogrammed from shore. New sensors will be developed and integrated into the system for dissolved oxygen and various inherent optical properties of seawater, all measured at the same time and space scales as physical properties. The project encompasses development of new sensors, miniaturization of several extant sensors and extensive field tests. The research team includes industrial partners, local governments working on practical societal/scientific issues; biological, physical and optical oceanographers; and an education effort from 8th grade through graduate school. The specific goals of this project are: • to extend development of an autonomous, underwater glider to be capable of measuring biological, optical, physical and chemical variables on the same time and space sales, in real time, and in diverse environments;• to develop small, light-weight, low-power sensors for measuring dissolved oxygen, inherent optical properties (IOPs) of seawater, chlorophyll a fluorescence (the primary surrogate for phytoplankton biomass), and other fluorescing compounds;• to verify with ground-truth measurements the high quality data collected by the glider;• to demonstrate the glider\u27s capabilities for real-time, data-adaptive sampling;• to enhance understanding of the dynamics of key physical and biological parameters in Puget Sound that are essential to assessing human impacts on water quality;• to demonstrate the glider\u27s ability to significantly improve validation of satellite ocean color data by sampling at the appropriate scales; and • to engage undergraduates and graduate students in engineering tests and research applications. The newly developed optical sensors for IOPs and chlorophyll a fluorescence would be easily adaptable to other platforms, and hence be easily and rapidly available to the general oceanographic community. Also, the glider will be able to operate in areas beyond Puget Sound including both coastal and open-ocean environments

Estimating Particle Size in the Ocean from High-frequency Variability in In-situ Optics

During this 3-year NESSF fellowship and seven-month no-cost extension, I published two papers as first author (Briggs et al. 2011; Briggs et al. 2013) and two papers as a co-author (Alkire et al. 2012; Cetinic et al. 2012). I am also co-author on one submitted paper and have worked on five additional papers that are in preparation (two as first author). I have given talks at four international oceanographic conferences: The 2012 and 2014 Ocean Sciences Meetings in Salt Lake City and Honolulu, the 2012 Ocean Optics meeting in Glasgow, Scotland, and the 2013 Liege Colloquium in Liege, Belgium. I also gave a 45-minute seminar at the Laboratoire d\u27Oceanographie Villefranche-sur-mer in France. In 2013 , I received the University of Maine’s NSFA Graduate Research Excellence Award in recognition of the research conducted under the NESSF fellowship. In addition to my research-related accomplishments, I successfully completed five graduate-level classes (paid for with NESSF funding) and passed my qualifying exams to ascend to PhD candidacy. My research focused on advancing methods for estimating two important oceanographic quantities - particle size and primary productivity (PP) - from autonomous platforms. The aim of my research is to pave the way for much greater global coverage of size and productivity estimates, both for direct application to ecological and biogeochemical studies and to validate and perhaps calibrate the growing number of global ocean color-based particle size and PP inversions

ALPS Implementation Conference

Intellectual Merit:A diverse suite of autonomous mobile platforms - including drifters, floats, underwater gliders and AUVs (autonomous underwater vehicles), and the small sensors they carry - have collectively become known as ALPS, i.e., Autonomous and Lagrangian Platforms and Sensors . A small interdisciplinary workshop is proposed as a follow-on to the Spring 2003 ALPS workshop. The first ALPS workshop convened a group of scientists and engineering, representing diverse backgrounds and interests, who met to identify new science that could best be done with ALPS alone or in conjunction with other platforms; to address technological developments needed to improve the capabilities of ALPS; to elucidate models for making the technologies more accessible to the broader community; and to assess training, education and outreach efforts. Until the first ALPS workshop, there had been no focused plan that outlined how ALPS could enable new opportunities in cross-disciplinary ocean studies. The ALPS workshop produced a report that detailed the capabilities of these mobile platforms and outlined the exciting, new scientific opportunities for using ALPS for interdisciplinary studies of the ocean; the report is available one line at www.geo-prose.com/ALPS. The follow-on workshop, to be held in Winter 2005 will focus on the details of how ALPS can be used in specific types of studies that are best suited to mobile technologies. Secondary goals are a) to outline a future scientific conference to bring together a diverse community of present and potential users of Lagrangian and autonomous platforms and b) to plan a framework for exploring implementation models to make ALPS technologies more accessible to the broader scientific community. The proposed ALPS workshop will be small, with about 20 participants representing a diverse cross section of the ocean community. A draft report will be vetted and community comment incorporated in the document; the final report will be published in Spring 2005.Broader Impacts:The primary goal of the proposed workshop is to continue advancements in ocean observations and hypothesis testing made possible by mobile platforms. The full potential for using ALPS testing has not yet been fully explored; the workshop will detail mechanisms to do that. A scientific conference will help disseminate knowledge about using ALPS and results of ALPS experiments. An increasing number of investigators wish to use ALPS, but presently have no access to the technology; the workshop will address models to facilitate access to these tools and data by a broader community. The research resulting from ALPS technologies will contribute to a more powerful capacity to observe the oceans and to address issues of major societal concern, including climate change and ocean ecosystem health

Improvements to Sampling from the Research Vessel Ira C

The University of Maine\u27s Darling Marine Center is awarded a grant to equip the 42-ft Ira C., the Center\u27s largest vessel, with a well instrumented CTD, including optical sensors and a small array of sampling bottles plus a winch with conducting cable so that CTD work from the Ira C. no longer needs to depend on users bringing their own CTD and lowering by hand. This proposal is to expand the environments and variables within effective reach of the University of Maine\u27s marine laboratory, the Ira C. Darling Marine Center (the Center) in midcoast Maine. The Center is within a day\u27s access by sea of an unparalleled range of marine environments on the East Coast depths from intertidal to \u3e 200 m and substrates from rocks to gravels to sand to mud. Environments within a day\u27s reach include the coastal seas with the strongest latitudinal thermal gradients along the U.S. coasts and the largest seasonal range of temperatures. It includes the outflows of Maine\u27s three rivers with the greatest volumetric flows, the Penobscot, the Kennebec and the Saco as well as several of the smallest. It is ideally poised to help investigators do process-, ecosystem- and species-level studies of Gulf of Maine and estuarine environments and biota in the context of environmental variability and climate change. Broader Impacts: The Center has an outstanding group of faculty and scientists including some distinguished emeritus professors. The center also has a remarkable record of visiting scientists and students, drawing researchers from all over the U.S. and internationally. Clearly an attraction is the facilities (including a first rate library) and access to a unique spectrum of marine environments, biogeographically diverse populations of marine organisms, etc. The need for the proposed improvements is easily recognized. The authors describe how the facility is used for education and how the upgrades will increase users for both science and for education. The Center currently has NSF COSEE support, and the author proposes to leverage off this program for K-grey teacher training, undergraduate, and graduate and \u27world-class\u27 web-based educational outreach

Collaborative Proposal: Cascadia Slope Circulation Study

Intellectual Merits:This project will continue to observe and understand the physics and biology of the highly productive northeast Pacific boundary current region over the continental slope off Washington and Oregon - the Cascadia slope - with an autonomous, sustained presence. For over a year, Seagliders, long-range autonomous underwater vehicles, have been deployed to survey the temperature, salinity, dissolved, oxygen, chlorophyll fluorescence, and optical backscatter structure of the slope off. Washington. Seagliders have collected data on sections from the continental shelf edge offshore 220 km at fortnightly intervals, reporting back data after each dive, on deployments typically lasting 4-5 months. The objective of the observations has been to detect seasonal and inter-annual variability in this part of the California Current system by collecting highly spatially and temporally resolved observations. Using Seagliders makes possible extended high resolution observations that would otherwise be prohibitively expensive if carried out by ships. This three-year project will: 1) analyze more than 16 months of Seaglider observations already collected, 2) continue the Seaglider observational program to over the continental shelf, and 3) analyze the newly collected data to describe the seasonal and interannual structure of the northern California Current system. Extension in time over the existing Seaglider repeat transects is necessary to confidently describe seasonal and interannual variability in the Cascadia slope region and to resolve and understand the (primarily advective) processes that are responsible for this variability. The data in hand offer tantalizing hints at the low frequency variability, but the 1.5 year record along two cross-slope sections is too limited to support quantitative understanding.Broader Impacts:The results from this project will improve physical and biological understanding of climate change. By autonomously measuring important oceanographic parameters over a sustained period of time, it will be possible to establish an unprecedented climate record in an economically important area. By expanding the spatial coverage of the autonomous transects, we will be able to resolve and understand the contribution of advection. The results of this project will benefit resource planners by helping to understand the coastal zone ecosystem and influences of large scale ocean circulation on coastal and estuarine conditions in the Pacific Northwest. We will continue our outreach activities with presentations to local schools, open houses, public talks, and contacts with print and electronic media on local, national and international levels

Collaborative Research: Autonomous Measurements of Carbon Fluxes in the North Atlantic Bloom

Net uptake of carbon dioxide in the Atlantic Ocean north of 50 degN accounts for about 25% of the global total. The biological pump, most importantly the phytoplankton bloom occurring each spring, drives this uptake. Previous studies have shown the importance of small temporal and spatial scales, i.e. ecosystem patchiness, during the bloom, but have had limited success in resolving these scales due to the inherent limitations of ship-based research. Recent advances in autonomous platforms and sensors now enable new approaches to sustained measurement of key quantities and rates that have potentially broad impacts. In this research, PIs from the University of Washington and the University of Maine - Orono, propose a process experiment focusing on an important component of the oceanic carbon system - the North Atlantic Spring Bloom - both for its intrinsic merit and as a test-bed for developing the strategies and knowledge needed to successfully use these new methods to drive the next generation of ocean observations. The PIs will use Lagrangian floats to follow water parcels in the mixed layer, with each float coupled with roving gliders to characterize its surroundings. The floats and gliders will measure - in three dimensions over time - the vertical and horizontal mixing rates, and key carbon system components and rates. Phytoplankton and organic carbon will be quantified through a suite of optical proxies, oxygen by two different sensors, and nitrate by UV spectrometry. Redundancy of sensors, reference measurements at 250-1000m, cross-checking among platforms and water sample analysis on three cruises will be used to maintain and verify the calibration of the autonomous sensors. Two-way communication via Iridium satellite will allow sampling strategies to evolve in response to observed conditions. Measurements will be made near 60 degN from late March 2008, before the bloom, through early July when it has ended. Primary productivity and carbon fluxes will be calculated from changes in inventories of oxygen, nitrate and biomass proxies corrected for the effects of horizontal and vertical mixing. Systematic comparison of these data with a bio-physical ecosystem model guided by adjoint analysis will be used to evaluate the appropriateness of such models for predicting both small-scale patchiness and net carbon uptake through the evolution of the bloom. The most important broader impact will be on the technology of ocean carbon system measurement as described above. The proposed work will also support multidisciplinary training of four graduate students in ocean observing, as well as undergraduate interns. The PIs will collaborate with the COSEE-Ocean Systems to develop a story on the role of the North Atlantic ocean ecosystem that will resonate with non-scientists and be integrated into areas identified in the National Science Education Content Standards. Finally, the project will build international collaboration with a Canadian scientist at Dalhousie University

The Nurturing of Seagliders By the National Oceanographic Partnership Program

The National Oceanographic Partnership Program provided critical support to the development of Seaglider long-range autonomous underwater vehicles. This support enabled: (1) development and integration of chemical and biological sensors, (2) transition to low-power, bi-directional satellite communication, and (3) software upgrades to enhance capability and reliability. Sponsored improvements led to setting the mission endurance and range records for autonomous underwater vehicles, wide use by the oceanographic community and licensing for commercialization

Light Scattering by Pure Seawater: Effect of Pressure

The Zhang et al. model [Optics Express,17, 5698-5710 (2009)] for calculating light scattering by seawater doesnot account for pressure, which should, theoretically, affect molecular scattering. While negligible in nearsurface waters, the error associated with this approximation could be significant when backscattering is mea-sured directly in the deep ocean, by deep CTD casts or biogeochemical-Argo floats, for example. We updated theparameterization in the Zhang et al. model using (1) the Millard and Seaver equation for the refractive index ofseawater [Deep Sea Research Part A,37, 1909-1926 (1990)] and (2) the Feistel equation for Gibbs free energyfor seawater thermodynamics [Deep-Sea Research I,55, 1639-1671 (2008)]. As these equations include theeffect of pressure as well as salinity and temperature, our new parameterization allows us to investigate thepotential effect of pressure on scattering. Increasing pressure suppresses the random motion of molecules, re-ducing the fluctuations in both density and concentration, which in turn causes an overall decrease in lightscattering by seawater. For pure water and seawater with a salinity of 34 PSU, the decreases are approximately13% and 12%, respectively, with a 100-MPa (approximately the pressure of seawater at 10000 m) increase inpressure. Below the thermocline and/or halocline where temperature and salinity change slowly, the steadyincrease of pressure is the dominant factor affecting the light scattering by seawater. At depths where back-scattering is typically dominated by molecular scattering by seawater, particulate backscattering would beunderestimated if the effect of pressure on molecular scattering were not considered

Collaborative Research: The Effect of Iron-Complexing Ligands on Iron Availability to Phytoplankton in HNLC Waters of the Subarctic Pacific Ocean

Scientists from the University of Maine and San Francisco State University propose to do deck-board incubation experiments in high nutrient, low chlorophyll (HNLC) waters of the eastern (Ocean Station PAPA) and the western (Ocean Station KNOT) Subarctic Pacific Ocean to determine how Fe supply affects phytoplankton species composition. Specifically, this team of scientists plans to address the following specific objectives: (1) assess how the relative availability of Fe bound to weaker and stronger classes of ligands differs among different phytoplankton groups (cyanobacteria, diatoms, dinoflagellates, prymnesiophytes) and how these differences influence the evolution of the phytoplankton community after Fe enrichment in HNLC waters; (2) ascertain if new ligands produced in response to Fe enrichment of HNLC waters behave similarly to ambient ligands, or if they have significantly different effect on regulating how an ecosystem evolves over the long term; and (3) determine whether phytoplankton assemblages in HNLC waters having different proximity or history of Fe inputs respond differently to the same suite of Fe ligand blends, or whether conditioning has led to their adaptation of alternate uptake capabilities. In addition, measurements of growth rates, macronutrient utilization rates, fluorescence, cell size determinations, Fe use efficiencies, rates of Fe and carbon uptake and flow cytometry sorting will be done to assess how specific organisms will respond to Fe supplied in different chemical forms