A5079703479- Marine and coastal ecosystems
- Oceanographic and Atmospheric Processes
- Marine Biology and Ecology Research
- Water Quality Monitoring and Analysis
- Atmospheric and Environmental Gas Dynamics
- Isotope Analysis in Ecology
- Ocean Acidification Effects and Responses
- Analytical Chemistry and Sensors
- Water Quality Monitoring Technologies
- Atmospheric Ozone and Climate
- Mercury impact and mitigation studies
- Underwater Vehicles and Communication Systems
- Calibration and Measurement Techniques
- Microbial Community Ecology and Physiology
- Geochemistry and Geologic Mapping
- Groundwater and Isotope Geochemistry
- Protist diversity and phylogeny
- Heavy metals in environment
- Hydrocarbon exploration and reservoir analysis
- Methane Hydrates and Related Phenomena
- Coastal and Marine Management
- Marine and environmental studies
- Coastal and Marine Dynamics
- Advanced SAR Imaging Techniques
- Marine and fisheries research
Monterey Bay Aquarium Research Institute
2015-2024
Oceanography Society
2017
Stanford University
2013
University of Hawaii System
2000
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...
Recently, measurements of oxygen concentration in the ocean – one most classical parameters chemical oceanography are experiencing a revival. This is not surprising, given key role for assessing status marine carbon cycle and feeling pulse biological pump. The revival, however, has to large extent been driven by availability robust optical sensors their painstakingly thorough characterization. For autonomous observations, optodes choice: They used abundantly on Biogeochemical-Argo floats,...
The Biogeochemical-Argo program (BGC-Argo) is a new profiling-float-based, ocean wide, and distributed monitoring which tightly linked to, has benefited significantly from, the Argo program. community recommended for BGC-Argo addition of six measurements in to pressure, temperature salinity measured by Argo, include oxygen, pH, nitrate, downwelling light, chlorophyll fluorescence optical backscattering coefficient. purpose this enable biogeochemistry health, particular, monitor major...
In nearly a dozen open‐ocean fertilization experiments conducted by more than 100 researchers from 20 countries, adding iron at the sea surface has led to distinct increases in photosynthesis rates and biomass. These confirmed hypothesis proposed late John Martin [ , 1990] that dissolved concentration is key variable controls phytoplankton processes ocean waters However, measurement of seawater remains difficult task Bruland Rue 2001] with significant interlaboratory differences apparent...
Abstract. Nitrite (NO2−) is a substrate for both oxidative and reductive microbial metabolism. NO2− accumulates at the base of euphotic zone in oxygenated, stratified open-ocean water columns, forming feature known as primary nitrite maximum (PNM). Potential pathways production include oxidation ammonia (NH3) by ammonia-oxidizing bacteria archaea well assimilatory nitrate (NO3−) reduction phytoplankton heterotrophic bacteria. Measurements NH3 NO3− to were conducted two stations central...
Abstract Aanderaa optode sensors for dissolved oxygen show remarkable stability when deployed on profiling floats, but these suffer from poor calibration because of an apparent drift during storage (storage drift). It has been suggested that measurement in air, the period a float is surface, can be used to improve sensor and determine magnitude while ocean. The effect air quality with 47 floats were equipped assessed. Recalibrated concentration measurements compared Winkler titrations made...
The Southern Ocean Carbon and Climate Observations Modeling (SOCCOM) project has deployed 194 profiling floats equipped with biogeochemical (BGC) sensors, making it one of the largest contributors to global BGC-Argo. Post-deployment quality control (QC) float-based oxygen, nitrate, pH data is a crucial step in processing dissemination such data, as situ chemical sensors remain early stages development. In calibration on using atmospheric reanalysis empirical algorithms can bring accuracy...
Here we report measurements of iron and aluminum in surface subsurface waters during late March May 2001 on transects between central California Hawaii. A large cloud Asian dust was detected April 2001, there a clear signal water due to aerosol deposition the transect. Iron concentrations increased synchronously by 0.5 2 nM along southern portion transect, which includes Hawaii Ocean Time series (HOT) station, from background values (0.1 0.2 Fe). These changes occurred ratio that is close...
Instrumental neutron activation and atomic absorption analyses for 31 elements in marine biogenic pyrite from carbonate concretions the Upper Lias (Lower Jurassic) of Yorkshire, England, are reported. Mo, As, and, to a lesser extent, Cu concentrated relative host sediment occur together with low concentrations (<30 ppm) Ni Zn trace amounts (<5 Mn Co. The all remaining determined sulfide at or below detection limit method used relatively enriched sediment. difference levels element sediments...
Abstract Annual nitrate cycles have been measured throughout the pelagic waters of Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved measurements were made using in situ ultraviolet spectrophotometer (ISUS) submersible analyzer (SUNA) optical sensors deployed on profiling floats. Thirty‐one floats returned 40 complete annual cycles. The mean profile from month highest winter minus lowest yields drawdown. This quantity was...
Abstract Six profiling floats equipped with nitrate and oxygen sensors were deployed at Ocean Station P in the Gulf of Alaska. The resulting six calendar years 10 float data used to determine an average annual cycle for net community production (NCP) top 35 m water column. NCP became positive February as soon mixing activity surface layer began weaken, but nearly 3 months before traditionally defined mixed shoal from its winter time maximum. displayed two maxima, one toward end May another...
The prasinophyte order Mamiellales contains several widespread marine picophytoplankton (≤ 2 μm diameter) taxa, including Micromonas and Ostreococcus. Complete genome sequences are available for two isolates, CCMP1545 RCC299. We performed in silico analyses of nitrogen transporters related assimilation genes RCC299 compared these with other green lineage organisms as well Chromalveolata, fungi, bacteria, archaea. Phylogenetic reconstructions ammonium transporter (AMT) revealed divergent...
The NH4‐Digiscan is an in situ analyzer designed for measuring ammonium estuarine, coastal, and shelf waters at depths of less than 3 m. This wet chemical uses micro‐solenoid pumps to propel sample reagents, a gas diffusion cell isolate the analyte from matrix, conductivity detector detection. Instrument measurements are stable deployments least 30 d. In estuarine coastal waters, capable sampling hourly has detection limit 0.2 µM. can be configured have 0.014 simple chemistry, capability,...
Abstract Carbon export out of the surface ocean via biological pump is a critical sink for atmospheric carbon dioxide. This process transports organic to deep through sinking particulate (POC) and downward transport suspended POC dissolved (DOC). Changes in relative contribution each pathway can significantly affect magnitude efficiency depth. Net community production (NCP), an analog under steady state assumptions, typically estimated using budgets biologically important chemical tracers...
An ocean observatory that consists of an array moored sensor platforms, telemetry, and data collection dissemination software was designed for monitoring the biogeochemistry physical dynamics coastal estuarine ecosystems. The Land‐Ocean Biogeochemical Observatory (LOBO) robust moorings can withstand tidal currents weather. are highly configurable, be deployed in waters as shallow 0.5 m, relatively easy to maintain, accommodate a complete standard novel sensors. sensors communicate with...
Seven years of observations surface water iron concentrations in the Monterey Bay region central California reveal a consistent annual cycle dominated by injection high particulate each spring. A companion study column near upwelling center at north end bay clearly indicates sedimentary source for iron. Local river discharge, during winter storm events, results deposition fine‐grained sediment “fluff” layer along shelf. The initial rapid shoaling isotherms onset spring brings from fluff to...
Abstract Measurements of pH and nitrate from the Southern Ocean Carbon Climate Observations Modeling array profiling floats were used to assess ratios dissolved inorganic carbon (DIC) (NO 3 ) uptake during spring summer bloom period throughout Ocean. Two hundred forty‐three periods observed by 115 30°S 70°S. Similar calculations made using Takahashi surface DIC climatology. To separate effects atmospheric CO 2 exchange mixing phytoplankton uptake, changes in waters (ΔDIC/ΔNO computed...
Abstract. Nitrite (NO2–) is a substrate for both oxidative and reductive microbial metabolism. NO2– accumulates at the base of euphotic zone in oxygenated, stratified open ocean water columns, forming feature known as primary nitrite maximum (PNM). Potential pathways production include oxidation ammonia (NH3) by ammonia-oxidizing bacteria or archaea assimilatory nitrate (NO3–) reduction phytoplankton heterotrophic bacteria. Measurements NH3 NO3– to were conducted two stations central...
Abstract Sensors that use ultraviolet (UV) light absorption to measure nitrate in seawater at situ temperatures require a correction the calibration coefficients if and sample are not identical. This is mostly due bromide molecule, which absorbs more UV as temperature increases. The current applied spectrophotometer (ISUS) submersible analyzer (SUNA) sensors generally follows Sakamoto et al. (2009, Limnol. Oceanogr. Methods 7, 132–143). For waters warmer than temperature, this model can lead...
Abstract Marine phytoplankton biomass and chlorophyll-a concentration are often estimated from pigment fluorescence measurements, which have become routine despite known variability in the fluorescent response for a given amount of chlorophyll-a. Here, we present near-global, monthly climatology measurements profiling floats combined with ocean color satellite estimates to illuminate seasonal biases expand upon previously observed regional patterns this bias. Global span over an order...