A5021771035- Marine and coastal ecosystems
- Ocean Acidification Effects and Responses
- Marine Biology and Ecology Research
- Isotope Analysis in Ecology
- Methane Hydrates and Related Phenomena
- Marine and fisheries research
- Oceanographic and Atmospheric Processes
- Atmospheric and Environmental Gas Dynamics
- Geology and Paleoclimatology Research
- Arctic and Antarctic ice dynamics
- Groundwater and Isotope Geochemistry
- Connexins and lens biology
- Marine Bivalve and Aquaculture Studies
- Identification and Quantification in Food
- Ultrasound and Hyperthermia Applications
- Dermatologic Treatments and Research
- Olfactory and Sensory Function Studies
- Marine and environmental studies
- CO2 Sequestration and Geologic Interactions
- Analytical Chemistry and Sensors
- Offshore Engineering and Technologies
- Cephalopods and Marine Biology
- Carbon Dioxide Capture Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Coastal and Marine Management
Planetary Systems (United States)
2024
Metamaterial Technologies (Canada)
2023-2024
University of Alaska Fairbanks
2019-2021
Dalhousie University
2012-2019
University of British Columbia
2016-2019
University of Oklahoma
2011
Columbia University
1971
Abstract Some of the longest and most comprehensive marine ecosystem monitoring programs were established in Gulf Alaska following environmental disaster Exxon Valdez oil spill over 30 years ago. These have been successful assessing recovery from impacts, their continuation decades later has now provided an unparalleled assessment responses to another newly emerging global threat, heatwaves. The 2014–2016 northeast Pacific heatwave (PMH) was lasting globally past decade, with some cooling,...
Carbon Dioxide Removal (CDR) from the atmosphere is unavoidable if we are to meet Paris Agreement’s goal of limiting global warming 1.5°C, and almost certainly required limit 2°C. The ocean exchanges carbon dioxide (CO 2 ) with a large repository that could either be partially emptied allow more CO absorption or have its storage capacity enhanced it remove additional atmosphere. Early-stage techniques exist utilise in atmospheric removal, but typically, removal these stimulate happens...
A multitracer approach is applied to assess the impact of boundary fluxes (e.g., benthic input from sediments or lateral inputs coastline) on acid-base buffering capacity, and overall biogeochemistry, North Sea. Analyses both basin-wide observations in Sea transects through tidal basins at North-Frisian coastline, reveal that surface distributions δ13C signature dissolved inorganic carbon (DIC) are predominantly controlled by a balance between biological production respiration. In...
Abstract We present optically derived estimates of phytoplankton carbon (C phyto ) and chlorophyll a concentration (Chl) across wide range productivity hydrographic regimes in the Subarctic Pacific Ocean. Our high‐frequency measurements capture changes C Chl regional gradients macronutrient micronutrient limitations submesoscale frontal zones. Throughout majority our survey region, to ratios :Chl) ranged between 50 100. Lower values (10–20) were constrained highly productive coastal...
Abstract Summer near‐surface seawater sampling in the Canadian Arctic revealed potential for significant errors (nearly 0.1 μmol·(m ‐2 s ‐1 )) CO 2 fluxes calculated from measured air‐sea gradients. River runoff and sea ice melt strongly stratify these waters, often resulting surface mixed layers only a few meters thick isolated waters sampled by shipboard underway systems. Samples collected with system, rosette, small boats exposed substantial gradients partial pressure ( p ) over top 7 m...
Abstract Ocean alkalinity enhancement (OAE) reduces the concentration of dissolved carbon dioxide (CO 2 ) in seawater, leading to atmospheric removal (CDR). Here we report laboratory experiments and a field-trial through addition magnesium hydroxide wastewater its subsequent discharge coastal ocean. In wastewater, 10% increase average (+0.56 mmol/kg) led 74% reduction aqueous CO (−0.41 pH 0.4 units 7.78 (efficiency 0.73 molCO /mol alkalinity). The alkalinization signal was limited within few...
Abstract Sediment‐water column exchange plays an important role in coastal biogeochemistry. We utilize short‐lived radium isotopes ( 224 Ra and 223 Ra) to understand quantify the dominant processes governing sediment‐water throughout North Sea. Our comprehensive survey, conducted September 2011, represents first of its kind find that two main sources regulate surface distributions: minor input from rivers shallow mudflats Sea sediments as source. Pore waters show 100‐fold larger activities...
Abstract. The distributions of carbonate system parameters in Hudson Bay, which not only receives nearly one-third Canada's river discharge but is also subject to annual cycles sea-ice formation and melt, indicate that the timing magnitude freshwater inputs play an important role carbon biogeochemistry acidification this unique Arctic ecosystem. This study uses basin-wide measurements dissolved inorganic (DIC) total alkalinity (TA), as well stable isotope tracers (δ18O δ13CDIC), provide a...
The principle, application, and assessment of the membrane‐based ProOceanus CO 2 ‐Pro sensor for partial pressure (pCO ) are presented. performance is evaluated extensively under field laboratory conditions by comparing outputs with direct measurements from calibrated pCO measuring systems thermodynamic carbonate calculation discrete samples. Under stable condition, agreed a water‐air equilibrator system at −3.0 ± 4.4 µatm during 2‐month intercomparison experiment. When applied in...
Abstract. Exchanges between sediment pore waters and the overlying water column play a significant role in chemical budgets of many important constituents. Direct quantification such benthic fluxes requires explicit knowledge properties biogeochemistry. Alternatively, changes water-column near sediment-water interface can be exploited to gain insight into biogeochemistry fluxes. Here, we apply 1-D diffusive mixing model near-bottom profiles 224Ra activity order yield vertical eddy...
Examinations of ultrasonic radiation with a Schlieren optical system have demonstrated that the characteristics beams can be significantly altered by acoustic phenomena which occur in lens and sclera. The magnitude these alterations is critically dependent upon position orientation incident ultasonic beam. Both diagnostic therapeutic piezoelectric transducers, operating at frequencies between 1 10 megahertz, were employed this study. Transmission ultrasound through bovine lenses accompanied...
Abstract The major sources of macronutrients (nitrate, ammonium, phosphate, and silicic acid) in Jakolof Bay, Alaska are submarine groundwater discharge (SGD), rivers, offshore water. We estimated SGD using natural geochemical tracers (radon radium), a salt mass balance, two-component salinity mixing equation based on the change falling lower low tide. Previous studies have hypothesized that macronutrient input into Bay is This study challenges assumption by determining relative contribution...
Abstract. Much of the variability in surface ocean's carbon cycle can be attributed to availability sunlight, triggering heat flux and photosynthesis, which turn regulate biogeochemical cycling over a wide range time scales. The critical processes this regulation, occurring at scales day or less, however, have undergone few investigations, most been limited spans several days months. Optical methods helped infer short-term biological variability, but complementing investigations oceanic CO2...
Abstract. The understanding of the seasonal variability carbon cycling on Scotian Shelf in NW Atlantic Ocean has improved recent years; however, very little information is available regarding its short-term variability. In order to shed light this aspect we investigate effects Hurricane Arthur, which passed region 5 July 2014. hurricane caused a substantial decline surface water partial pressure CO2 (pCO2), even though possesses CO2-rich deep waters. High-temporal-resolution data moored...
Abstract. Phytoplankton plays a critical role in the uptake of atmospheric carbon dioxide by ocean, and is comprised spectrum cell sizes that are strongly associated with different oceanographic conditions. Studies suggest ocean will become increasingly stratified response to warming climate, limiting nutrient exchange upper sunlit favouring small cells able grow warmer, poor Here we show that, temperate shelf sea, summertime population numerically abundant accounts for approximately 20%...
Abstract We demonstrate that signal spikes in optical backscatter measurements provide information on the diel vertical migration patterns of oceanic zooplankton. During nighttime, we observed high frequency particulate coincident with increased acoustic from vertically migrating used our to examine spatial and daily timing zooplankton migrations across eastern Subarctic Pacific Ocean, demonstrating coherence regional hydrographic features. Vertical was consistently oligotrophic offshore...
Abstract. We report results from two Lagrangian drifter surveys off the Oregon coast, using continuous shipboard sensors to estimate mixed-layer gross primary productivity (GPP), community respiration (CR), and net production (NCP) variations in biological oxygen saturation (ΔO2∕Ar) optically derived particulate organic carbon (POC). At first survey, conducted a nearshore upwelling zone during development of microplankton bloom, changes ΔO2∕Ar [POC] were significantly decoupled. Differences...
The Line Height Absorption (LHA) method uses absorption of light to estimate chlorophyll-a. While most users consider regional variability and apply corrections, the effect temporal is typically not explored. Northern Gulf Alaska (NGA) was selected for this study because there no published value its large swings in productivity would make it a good candidate evaluate on relationship. mean NGA 0.0114 obtained here should be treated with caution, as variation slope relationship (a