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Oceanography and Atmospheric Sciences and Meteorology Commons™

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The University of Maine

2011

Articles 1 - 12 of 12

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Inferring Phytoplankton Carbon And Eco-Physiological Rates From Diel Cycles Of Spectral Particulate Beam-Attenuation Coefficient, G. Dall'olmo, E. Boss, M. J. Behrenfeld, T. K. Westberry, C. Courties, L. Prieur, M. Pujo-Pay, N. Hardman-Mountford, T. Moutin Dec 2011

Inferring Phytoplankton Carbon And Eco-Physiological Rates From Diel Cycles Of Spectral Particulate Beam-Attenuation Coefficient, G. Dall'olmo, E. Boss, M. J. Behrenfeld, T. K. Westberry, C. Courties, L. Prieur, M. Pujo-Pay, N. Hardman-Mountford, T. Moutin

Marine Sciences Faculty Scholarship

The diurnal fluctuations in solar irradiance impose a fundamental frequency on ocean biogeochemistry. Observations of the ocean carbon cycle at these frequencies are rare, but could be considerably expanded by measuring and interpreting the inherent optical properties. A method is presented to analyze diel cycles in particulate beam-attenuation coefficient (cp) measured at multiple wavelengths. The method is based on fitting observations with a size-structured population model coupled to an optical model to infer the particle size distribution and physiologically relevant parameters of the cells responsible for the measured diel cycle in cp. Results show that the information related to size …

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Collaborative Research: Microparticle/Tephra Analysis Of The Wais Divide Ice Core, Karl J. Kreutz, Andrei V. Kurbatov, Mark Wells, Paul Andrew Mayewski Sep 2011

Collaborative Research: Microparticle/Tephra Analysis Of The Wais Divide Ice Core, Karl J. Kreutz, Andrei V. Kurbatov, Mark Wells, Paul Andrew Mayewski

University of Maine Office of Research Administration: Grant Reports

This award supports a project to perform continuous microparticle concentration and size distribution measurements (using coulter counter and state-of-the-art laser detector methods), analysis of biologically relevant trace elements associated with microparticles (Fe, Zn, Co, Cd, Cu), and tephra measurements on the WAIS Divide ice core. This initial three-year project includes analysis of ice core spanning the instrumental (~1850-present) to mid- Holocene (~5000 years BP) period, with sample resolution ranging from subannual to decadal. The intellectual merit of the project is that it will help in establishing the relationships among climate, atmospheric aerosols from terrestrial and volcanic sources, ocean biogeochemistry, and …

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Effects Of Trace Metal Limitation On Oxidative Stress In Zooxanthellae And Its Role In Coral Bleaching, Mark Wells, J. Malcolm Shick, Charles G. Trick, Walter Dunlap, Paul Long Sep 2011

Effects Of Trace Metal Limitation On Oxidative Stress In Zooxanthellae And Its Role In Coral Bleaching, Mark Wells, J. Malcolm Shick, Charles G. Trick, Walter Dunlap, Paul Long

University of Maine Office of Research Administration: Grant Reports

Coral bleaching has increased dramatically in frequency, severity, and geographic extent since the 1980s and this trend is anticipated to continue, causing major environmental and economic impacts in tropical regions. This bleaching - the loss by corals of their photosynthetic endosymbiotic dinoflagellates (zooxanthellae; Symbiodinium spp.) - involves increased oxidative stress arising from the combined effects of elevated temperature at high light intensities. Although the production of reactive oxygen species (ROS) in corals and phytoplankton is routine during daylight hours, the failure of antioxidant defenses in zooxanthellae becomes catastrophic under comparatively small changes in environmental temperature, because reef corals live close …

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Rapid: A Unique Cruise Opportunity To Test The Effect Of Trace Metal Limitation On Oxidative Stress And Coral Bleaching, Mark L. Wells, J. Malcolm Shick Sep 2011

Rapid: A Unique Cruise Opportunity To Test The Effect Of Trace Metal Limitation On Oxidative Stress And Coral Bleaching, Mark L. Wells, J. Malcolm Shick

University of Maine Office of Research Administration: Grant Reports

Intellectual Merit. Coral bleaching has increased dramatically in frequency, severity, and geographic extent since the 1980's and this trend is anticipated to continue, causing major environmental and economic impacts in tropical regions. This bleaching, or loss by corals of their photosynthetic endosymbiotic dinoflagellates (zooxanthellae; Symbiodinium spp.), appears to result from increased oxidative stress arising from the combined effects of elevated temperature at high light intensities. However, the mechanisms underlying this failure are not understood. The premise of the PIs' current project entitled "Effects of Trace Metal Limitation on Oxidative Stress in Zooxanthellae and Its Role in Coral Bleaching" (OCE - …

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Collaborative Research: Centers For Ocean Science Education Excellence - Oceans In The Earth-Sun System, Annette Decharon Aug 2011

Collaborative Research: Centers For Ocean Science Education Excellence - Oceans In The Earth-Sun System, Annette Decharon

University of Maine Office of Research Administration: Grant Reports

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 …

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Collaborative Research: Asian Ice Core Array (Aica)--Reconstruction Of Past Physical And Chemical Climate Over Asia, Paul Mayewski, Karl J. Kreutz, Andrei V. Kurbatov Jul 2011

Collaborative Research: Asian Ice Core Array (Aica)--Reconstruction Of Past Physical And Chemical Climate Over Asia, Paul Mayewski, Karl J. Kreutz, Andrei V. Kurbatov

University of Maine Office of Research Administration: Grant Reports

Funding is provided to help the researchers build on success using ice cores for understanding past physical and chemical climate change from Antarctica, Arctic, North Pacific and Asia by analyzing and interpreting a new array of Asian ice cores. The researchers plan to use five existing ice cores and collect one new ice core to enhance the reconstruction of environmental conditions over Asia.

The primary research questions for the Asian Ice Core Array (AICA) research include:

(1) Asian climate variability - How do major Asian circulation features (i.e., Asian monsoon, Westerlies, polar air masses, Siberian and Tibetan Highs) vary on …

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Evaluation Of A Compact Sensor For Backscattering And Absorption, Alina Gainusa Bogdan, Emmanuel S. Boss Jul 2011

Evaluation Of A Compact Sensor For Backscattering And Absorption, Alina Gainusa Bogdan, Emmanuel S. Boss

Marine Sciences Faculty Scholarship

Seawater inherent optical properties (IOPs) are key parameters in a wide range of applications in environmental studies and oceanographic research. In particular, the absorption coefficient (a) is the typical IOP used to obtain the concentration of chlorophyll-a in the water-a critical parameter in biological oceanography studies and the backscattering coefficient (bb) is used as a measure of turbidity. In this study, we test a novel instrument concept designed to obtain both the absorption and backscattering coefficients. The instrument would emit a collimated monochromatic light beam into the water retrieving the backscattered light intensity as a function of distance from the …

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Collaborative Research: Molluscan Radiocarbon As A Proxy For Upwelling In Holocene Peru, Daniel H. Sandweiss May 2011

Collaborative Research: Molluscan Radiocarbon As A Proxy For Upwelling In Holocene Peru, Daniel H. Sandweiss

University of Maine Office of Research Administration: Grant Reports

Abstract: Under this award the PI will measure 14C in independently dated Peruvian mollusks from multiple time intervals to define long-term trends in upwelling variation. Upwelling is a defining factor of El Nino-southern oscillation (ENSO) in the eastern Pacific, particularly along the coast of Peru. Historical records of this phenomenon are limited and older proxy records in this region are few. The proposal will exploit the ventilation age difference between equatorial surface and deeper upwelled waters. The detection of El Nino events will be made by screening for shell increment alteration and by sequential d18O analysis. The simultaneous excursions in …

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Event Discovery And Classification In Space-Time Series: A Case Study For Storms, Avinash Rude May 2011

Event Discovery And Classification In Space-Time Series: A Case Study For Storms, Avinash Rude

Electronic Theses and Dissertations

Recent advancement in sensor technology has enabled the deployment of wireless sensors for surveillance and monitoring of phenomenon in diverse domains such as environment and health. Data generated by these sensors are typically high-dimensional and therefore difficult to analyze and comprehend. Additionally, high level phenomenon that humans commonly recognize, such as storms, fire, traffic jams are often complex and multivariate which individual univariate sensors are incapable of detecting. This thesis describes the Event Oriented approach, which addresses these challenges by providing a way to reduce dimensionality of space-time series and a way to integrate multivariate data over space and/or time …

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Interannual Variability In American Lobster Settlement: Correlations With Sea Surface Temperature, Wind Stress And River Discharge, Mahima Jaini May 2011

Interannual Variability In American Lobster Settlement: Correlations With Sea Surface Temperature, Wind Stress And River Discharge, Mahima Jaini

Electronic Theses and Dissertations

Recruitment to benthic marine populations is fundamentally a biophysical problem. The American Lobster Settlement Index is an annual diver-based survey of the young-of-year American lobsters (Homarus americanus) found in inshore nurseries in New England, USA and Atlantic Canada at the end of the postlarval settlement season. The considerable interannual variability in the settlement index suggests that environmental factors play an important role in regulating planktonic larval supply and transport. In this study, I focused on the longest settlement time series from three oceanographically contrasting regions: Midcoast Maine, coastal Rhode Island and the lower Bay of Fundy. Sampling in these regions …

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Effects Of Particle Aggregation And Disaggregation On Their Inherent Optical Properties, Wayne H. Slade, Emmanuel Boss, Clementina Russo Apr 2011

Effects Of Particle Aggregation And Disaggregation On Their Inherent Optical Properties, Wayne H. Slade, Emmanuel Boss, Clementina Russo

Marine Sciences Faculty Scholarship

In many environments a large portion of particulate material is contained in aggregated particles; however, there is no validated framework to describe how aggregates in the ocean scatter light. Here we present the results of two experiments aiming to expose the role that aggregation plays in determining particle light scattering properties, especially in sedimentdominated coastal waters. First, in situ measurements of particle size distribution (PSD) and beam-attenuation were made with two laser particle sizing instruments (one equipped with a pump to subject the sample to aggregate-breaking shear), and measurements from the two treatments were compared. Second, clays were aggregated in …

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Collaborative Research: Interannual Variability Of Coastal Phytoplankton Blooms In The Gulf Of Maine And Their Relationships To Local And Remote Forcings, David W. Townsend Jan 2011

Collaborative Research: Interannual Variability Of Coastal Phytoplankton Blooms In The Gulf Of Maine And Their Relationships To Local And Remote Forcings, David W. Townsend

University of Maine Office of Research Administration: Grant Reports

The aim of this proposal is to explore the interaction of remote climate based forcing with local forcing to impact phytoplankton blooms in coastal and shelf regions with a coupled biological-physical model. Phytoplankton bloom dynamics are a classic example of biological-physical interactions in the ocean (Gran and Braarud, 1935; Sverdrup, 1953). Yet it is still a challenge to identify the dominant processes controlling the interannual variability of phytoplankton blooms in coastal and shelf seas where multiple-scale biological and physical processes interact. The unstructured-grid, finite-volume, coastal ocean model (FVCOM, built within the GLOBEC Georges Bank Program) bridges the multi-scale physical processes …

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