A5036708693- Marine and coastal ecosystems
- Microbial Community Ecology and Physiology
- Marine Biology and Ecology Research
- Oceanographic and Atmospheric Processes
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Ocean Acidification Effects and Responses
- Coral and Marine Ecosystems Studies
- Water Quality Monitoring Technologies
- Methane Hydrates and Related Phenomena
- Air Quality Monitoring and Forecasting
- Oil Spill Detection and Mitigation
- Isotope Analysis in Ecology
- Diatoms and Algae Research
- Underwater Vehicles and Communication Systems
- Spaceflight effects on biology
- Environmental DNA in Biodiversity Studies
- Marine and fisheries research
- Environmental Monitoring and Data Management
- Calibration and Measurement Techniques
- Bacteriophages and microbial interactions
- Remote Sensing in Agriculture
- Maritime Transport Emissions and Efficiency
- Marine and coastal plant biology
University of Maine
2016-2025
College of Marin
2024
Station Biologique de Roscoff
2020-2022
Abstract The Southern Ocean Carbon and Climate Observations Modeling (SOCCOM) program has begun deploying a large array of biogeochemical sensors on profiling floats in the Ocean. As February 2016, 86 have been deployed. Here focus is 56 with quality‐controlled adjusted data that water at least 6 months. carry oxygen, nitrate, pH, chlorophyll fluorescence, optical backscatter sensors. raw generated by these can suffer from inaccurate initial calibrations sensor drift over time. Procedures to...
Chlorophyll fluorometers provide the largest in situ global data set for estimating phytoplankton biomass because of their ease use, size, power consumption, and relatively low price. While chlorophyll a (Chl) fluorescence is proxy Chl concentration, hence biomass, there exist large natural variations relationship between extracted concentration. Despite this variability, we present here validation WET Labs Environmental Characterization Optics (ECO) series that suggests factor 2...
Abstract The North Atlantic phytoplankton spring bloom is the pinnacle in an annual cycle that driven by physical, chemical, and biological seasonality. Despite its important contributions to global carbon cycle, transitions plankton community composition between winter have been scarcely examined Atlantic. Phytoplankton early was compared with latitudinal transects captured subsequent climax. Amplicon sequence variants (ASVs), imaging flow cytometry, flow-cytometry provided a synoptic view...
Four North Atlantic Aerosol and Marine Ecosystems Study (NAAMES) field campaigns from winter 2015 through spring 2018 sampled an extensive set of oceanographic atmospheric parameters during the annual phytoplankton bloom cycle. This unique dataset provides four seasons open-ocean observations wind speed, sea surface temperature (SST), seawater particle attenuation at 660 nm ( c p,660 , a measure ocean particulate organic carbon), bacterial production rates, sea-spray aerosol size...
Abstract. The deep chlorophyll maximum (DCM) is a ubiquitous feature of phytoplankton vertical distribution in stratified waters that relevant to our understanding the mechanisms underpin variability photoautotroph ecophysiology across environmental gradients and has implications for remote sensing aquatic productivity. During PEACETIME (Process studies at air-sea interface after dust deposition Mediterranean Sea) cruise, carried out from 10 May 11 June 2017, we obtained 23 concurrent...
Abstract The Southern Ocean (SO) ecosystem plays a key role in the carbon cycle by sinking major part (43%) of ocean uptake anthropogenic CO 2 , and being an important source nutrients for primary producers. However, undersampling SO biogeochemical properties limits our understanding mechanisms taking place this remote area. Carbon Climate Observations Modeling (SOCCOM) project has been deploying large number autonomous floats to study (as December 2016, 74 out 200 have deployed). SOCCOM...
Abstract Phytoplankton accessory pigments are commonly used to estimate phytoplankton size classes, particularly during development and validation of biogeochemical models satellite ocean color‐based algorithms. The diagnostic pigment analysis (DPA) is based on bulk measurements concentrations relies assumptions regarding the presence specific in different taxonomic groups. Three classes defined by DPA: picoplankton, nanoplankton, microplankton. Until now, DPA has not been evaluated against...
The goal of the EXport Processes in Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding export, fate, and carbon cycle impacts global ocean net primary production. To accomplish this goal, observations export flux pathways, plankton community composition, food web processes, optical, physical, biogeochemical (BGC) properties are needed over range ecosystem states. Here we introduce first EXPORTS deployment Station Papa Northeast Pacific during summer...
Abstract Phytoplankton play a major role on Earth, impacting the global distribution and cycles of carbon, oxygen, nitrogen, sulfur, other elements, structuring marine food webs. One fundamental trait phytoplankton with direct biogeochemical implications is their size, as it governs metabolic sinking rates well prey–predator interactions. size spans approximately 3.5 orders magnitude (when expressed an equivalent spherical diameter), thus measuring full range in challenging rarely attempted....
Interactions between the ocean and atmosphere occur at air-sea interface through transfer of momentum, heat, gases particulate matter impact upper-ocean biology on composition radiative properties this boundary layer. The Tara Pacific expedition, launched in May 2016 aboard schooner Tara, was a 29-month exploration with dual goals to study ecology coral systems along ecological gradients Ocean assess inter-island open surface plankton neuston community structures. In addition, key...
Abstract Carbon export efficiency (e‐ratio) is defined as the fraction of organic carbon fixed through net primary production (NPP) that exported out surface productive layer ocean. Recent observations for Southern Ocean suggest a negative e‐ratio versus NPP relationship, and reduced dependency on temperature, different than in global domain. In this study, we complement information from passive satellite sensor with novel space‐based lidar ocean particulate backscattering to infer over...
The ability to quantify spatio-temporal variability in phytoplankton growth and productivity is essential improving our understanding of global carbon dynamics trophic energy flow. Satellite-based observations offered the first opportunity estimate depth-integrated net primary production (NPP) at a scale, but early modeling approaches could not effectively address algal physiology, particularly effects photoacclimation on changes cellular chlorophyll. Here, previously developed model was...
Abstract Seasonal shifts in phytoplankton accumulation and loss largely follow changes mixed layer depth, but the impact of depth on cell physiology remains unexplored. Here, we investigate physiological state populations associated with distinct bloom phases mixing regimes North Atlantic. Stratification deep alter community viral production, effectively shaping rates. Communities relatively deep, early-spring layers are characterized by low levels stress high rates, while those recently...
Abstract One pathway by which the oceans influence climate is via emission of sea spray that may subsequently cloud properties. Sea emissions are known to be dependent on atmospheric and oceanic physicochemical parameters, but potential role ocean biology fluxes remains poorly characterized. Here we show a consistent significant relationship between seawater nanophytoplankton cell abundances sea-spray derived Cloud Condensation Nuclei (CCN) number fluxes, generated using water from three...
Estimating the biomass of phytoplankton communities via remote sensing is a key requirement for understanding global ocean ecosystems. Of particular interest carbon associated with diatoms given their unequivocal ecological and biogeochemical roles. Satellite-based algorithms often rely on accessory pigment proxies to define diatom biomass, despite lack validation against independent measurements. We used imaging-in-flow cytometry quantify in western North Atlantic, compared results those...
Abstract While a rich history of patchiness research has explored spatial structure in the ocean, there is no consensus over controls on biological and how physical-ecological-biogeochemical processes relate. The prevailing thought that physics structures biology, but this not been tested at basin scale with consistent situ measurements. Here we use slope relationship between variance vs to quantify ~650,000 nearly continuous ( dx ~ 200 m) measurements - representing Atlantic, Pacific,...
System vicarious calibration (SVC) of satellite ocean-color sensors involves comparing retrievals water-leaving radiance (Lw) with in-situ measurements at the time overpass and adjusting coefficients to ensure agreement between retrieved measured quantities. This approach is designed reduce uncertainties associated purely radiometric techniques, which lack accuracy required for science applications, minimize biases introduced by atmospheric correction. For recently launched PACE Ocean Color...
The ocean is brimming with mostly invisible, highly diverse forms of life: plankton. These microscopic organisms play a key role in the health and stability aquatic ecosystems, growing body evidence highlights their significant impact on global biogeochemical processes climate regulation. Tracking plankton biodiversity at local, regional levels therefore essential to understand distribution, evolution responses environmental changes, as well influence However, planetary microbiology remains...
Today, the only way we can observe surface ocean state on a daily basis is via remote sensing by satellites. These sensors have revolutionized our understanding of biology, biophysics and biochemistry, much their data available, free charge, to all. However, biological information content signals measured from space very limited, further, are not necessarily what interested in. For example, measure spectral radiance (e.g. color ocean) in order help us learn about underlying phytoplankton...
The 14C incubation method for net primary production (NPP) has limited spatial/temporal resolution, while satellite approaches cannot provide direct information at depth. With chlorophyll-a and backscatter measurements from BGC-Argo floats, we quantified year-round NPP in the western North Atlantic Ocean using both Carbon-based Productivity Model (CbPM) Photoacclimation (PPM). Comparison with profiles showed advantages limitations of models. CbPM reproduced magnitude most cases. However,...
Abstract During the North Atlantic Aerosols and Marine Ecosystems Study in western Atlantic, float‐based profiles of fluorescent dissolved organic matter backscattering exhibited distinct spike layers at 300 m. The locations spikes were depths similar or shallower to where a ship‐based scientific echo sounder identified acoustic backscatter, an Underwater Vision Profiler detected elevated concentration zooplankton, mesopelagic fish sampled by net tow. collocation bio‐optical properties with...
Phytoplankton division rate (µ), loss (l), and specific accumulation (r) were calculated using Chlorophyll-a (Chl) phytoplankton carbon (Cphyto) derived from bio-optical measurements on 12 Argo profiling floats in a north-south section of the western North Atlantic Ocean (40° N to 60° N). The float results used quantify seasonal phenology bloom dynamics for region. Latitudinally varying observed. In north, CPhyto peak was higher, occurred later, accompanied by higher total annual...
Hyperspectral optical observations of the Earth’s surface oceans from space offer a means to improve our understanding ocean biology and biogeochemistry. NASA’s Plankton, Aerosol, Cloud, Ecosystem (PACE) satellite mission, which includes hyperspectral color instrument (OCI), will provide radiometric with near continuous spectral resolution across UV NIR range. Maintaining sufficient accuracy over lifetime missions requires robust program for system vicarious calibration (SVC) product...
Abstract. The organic mass fraction from sea spray aerosol (SSA) is currently a subject of intense research. majority this research dedicated to measurements in ambient air. However number studies have recently started focus on nascent aerosol. This work presents collected during 5-week cruise May and June 2017 the central western Mediterranean Sea, an oligotrophic marine region with low phytoplankton biomass. Surface seawater was continuously pumped into bubble-bursting apparatus generate...
Abstract The use of autonomous profiling floats for observational estimates radiometric quantities in the ocean is explored, and this platform validation satellite-based remote sensing reflectance examined. This effort includes comparing estimated from float satellite data at nominal wavelengths 412, 443, 488, 555 nm, examining sources magnitudes uncertainty estimates. study had 65 occurrences coincident high-quality observations MODIS Aqua 15 Visible Infrared Imaging Radiometer Suite...