A5075248695- Oceanographic and Atmospheric Processes
- Arctic and Antarctic ice dynamics
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Climate variability and models
- Geology and Paleoclimatology Research
- Marine and environmental studies
- Climate change and permafrost
- Atmospheric and Environmental Gas Dynamics
- Marine and coastal ecosystems
- Tropical and Extratropical Cyclones Research
- Geological formations and processes
- Hydrocarbon exploration and reservoir analysis
- Arctic and Russian Policy Studies
- Ocean Waves and Remote Sensing
- Ocean Acidification Effects and Responses
- Underwater Acoustics Research
- Cryospheric studies and observations
- Coastal and Marine Management
- Geological and Geophysical Studies
- Winter Sports Injuries and Performance
- Geophysics and Gravity Measurements
- Marine and fisheries research
- Ionosphere and magnetosphere dynamics
- Marine animal studies overview
Bangor University
2014-2024
University of Southampton
2023
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung
2020
Indonesian Institute of Sciences
2019
University of California, San Diego
2003-2008
Scripps Institution of Oceanography
2006-2008
The Argo Program has been implemented and sustained for almost two decades, as a global array of about 4000 profiling floats. provides continuous observations ocean temperature salinity versus pressure, from the sea surface to 2000 dbar. successful installation its innovative data management system arose opportunistically combination great scientific need technological innovation. Through system, fundamental physical with broad societally-valuable applications, built on cost-efficient robust...
Abstract Barents Sea Water (BSW) is formed from Atlantic that cooled through atmospheric heat loss and freshened seasonal sea ice melt. In the eastern Sea, BSW fresher, colder Arctic meet at surface along Polar Front (PF). Despite its importance in setting northern limit of ventilation, PF has been poorly documented, mostly eluding detection by observational surveys avoid ice. this study, satellite temperature (SST) observations are used addition to a salinity climatology examine location...
Drake Passage is the narrowest constriction of Antarctic Circumpolar Current (ACC) in Southern Ocean, with implications for global ocean circulation and climate. We review long‐term sustained monitoring programs that have been conducted at Passage, dating back to early part twentieth century. Attention drawn numerous breakthroughs made from these programs, including (1) first determinations complex ACC structure quantifications its transport; (2) realization transport remarkably steady over...
Mesoscale eddies are important to many aspects of the dynamics Arctic Ocean. Among others, they maintain halocline and interact with Atlantic Water circumpolar boundary current through lateral eddy fluxes shelf-basin exchanges. also for transporting biological material modifying sea ice distribution. Here, we review what is known about their impacts in Ocean context rapid climate change. Eddy kinetic energy (EKE) a proxy mesoscale variability ocean due eddies. We present first quantification...
No Abstract available.
Abstract Largely zonal winds in the Southern Ocean drive an equatorward Ekman transport that constitutes shallowest limb of meridional overturning circulation Antarctic Circumpolar Current (ACC). Despite its importance, there have been no direct observations open ocean balance until now. Using high-resolution repeat upper-ocean velocity Drake Passage, a mean spiral is resolved and computed. The currents decay amplitude rotate anticyclonically with depth, penetrating to ∼100-m above base...
Microstructure and hydrographic observations, during September 2007 in the boundary current on East Siberian continental slope, document upper ocean stratification along‐stream water mass changes. A thin warm surface layer overrides a shallow halocline characterized by ∼40‐m thick temperature minimum beginning at ∼30 m depth. Below halocline, well‐defined thermohaline diffusive staircases extended downwards to Atlantic Water intrusions found 200–800 Observed turbulent eddy kinetic energy...
Abstract A yearlong time series from mooring-based high-resolution profiles of water temperature and salinity the Laptev Sea slope (2003–04; 2686-m depth; 78°26′N, 125°37′E) shows six remarkably persistent staircase layers in depth range ~140–350 m encompassing upper Atlantic Water (AW) lower halocline. Despite frequent displacement isopycnal surfaces by internal waves eddies two strong AW warming pulses that passed through mooring location February late August 2004, preserved their...
Siberian river water is a first-order contribution to the Arctic freshwater budget, with Ob, Yenisey, and Lena supplying nearly half of total surface flux. However, few details are known regarding where, when, how transverses vast shelf seas. This paper investigates mechanism, variability, pathways fresh Kara Sea outflow through Vilkitsky Strait toward Laptev Sea. We utilize high-resolution ocean model recent shipboard observations characterize freshwater-laden Current (VSC), shed new light...
Abstract Recent seasonal Arctic Ocean sea ice retreat is a major indicator of polar climate change. The generally quiescent with the interior basins characterized by low levels turbulent mixing at intermediate depths. In contrast, under conditions reduced cover, there evidence energetic internal waves that have been attributed to increased momentum transfer from atmosphere ocean. New measurements made in Canada Basin during unusually ice‐free and stormy summer 2012 show previously observed...
Unprecedented quantities of heat are entering the Pacific sector Arctic Ocean through Bering Strait, particularly during summer months. Though some is lost to atmosphere autumn cooling, a significant fraction incoming warm, salty water subducts (dives beneath) below cooler fresher layer near-surface water, subsequently extending hundreds kilometers into Beaufort Gyre. Upward turbulent mixing these sub-surface pockets likely accelerating sea ice melt in region. This Pacific-origin brings both...
The northwards transport of heat through the North Atlantic Ocean is a crucial part present climate system. loss at high latitudes warms atmosphere and cryosphere, influencing weather melting ice, while simultaneously contributing to deep water formation integral Meridional Overturning Circulation. Farther north, rising temperatures influenced by this oceanic has also driven Arctic atlantification.  Thus accurate knowledge ocean pathways will enable us identify hotspots air-sea...
Agulhas Current meanders, also known as Natal Pulses, are the dominant modes of variability within Current. These meanders significantly impact local hydrological dynamics and ecosystems. Previous observations model outputs suggest that influence these on ring shedding is limited, while their effect retroflection remains unclear. Models imply Southern Ocean supergyre has more leakage than upstream drivers. Here, we developed an algorithm based 28 years daily-averaged Global Physics...
Abstract Recent observations taken at four principal latitudes in the Agulhas Current show that watermass properties on either side of its dynamical core are significantly different. Inshore velocity found waters predominantly Arabian Sea, Red and equatorial Indian Ocean origin, while offshore generally from Atlantic Ocean, Southern southeast Ocean. For most part, inshore approach through Mozambique Channel, those circulated within southern subtropical gyre before joining current. These...
Abstract Vertical mixing in the bottom boundary layer and pycnocline of Laptev Sea is evaluated from a rapidly sampled 12-h time series microstructure temperature, conductivity, shear observations collected under 100% sea ice during October 2008. The turbulent kinetic energy dissipation was observed to be enhanced (ε ∼ 10−4 W m−3) beyond background levels 10−6 m−3), extending up 10 m above seabed when simulated tidal currents were directed on slope. Upward heat fluxes into halocline-class...
Abstract The Arctic continental shelf seas hold a globally significant source of freshwater that impacts Ocean stratification, circulation, and climate. This can be injected below the surface mixed layer by intense turbulent kinetic energy dissipation events, as resolved Laptev Sea microstructure observations. tides provide major dissipated hence drive diapycnal mixing in Sea. Multiyear ADCP mooring records from locations across reveal semidiurnal are dominated M2 S2 constituents, with...
Abstract The diffusive layering (DL) form of double-diffusive convection cools the Atlantic Water (AW) as it circulates around Arctic Ocean. Large DL steps, with heights homogeneous layers often greater than 10 m, have been found above AW core in Eurasian Basin (EB) eastern Arctic. Within these staircases, heat and salt fluxes are determined by mechanisms for vertical transport through high-gradient regions (HGRs) between layers. These HGRs can be thick (up to 5 m more) frequently complex,...
Enhanced semidiurnal‐band velocity shear across the shelf halocline layer (SHL) was found during land‐fast ice edge mooring‐based acoustic Doppler current profiler (ADCP) and conductivity‐temperature‐depth (CTD) observations over eastern Laptev Sea (∼74°N, 128°E) in April–May 2008 April 2009. In 2008, major axis amplitude for lunar semidiurnal M 2 tidal ellipses demonstrated intermediate maximum SHL at 11–13 m (15 ± 3 cm/s), gradually decreasing to subice near‐bottom layers ∼9 cm/s (at 7 m)...
Abstract In the Southern Ocean, small‐scale turbulence causes diapycnal mixing which influences important water mass transformations, in turn impacting large‐scale ocean transports such as Meridional Overturning Circulation (MOC), a key controller of Earth's climate. We present direct observations over Antarctic continental slope between masses that are part Ocean MOC. A 12 h time series microstructure measurements, hydrography, and velocity off Elephant Island, north Peninsula, reveals two...
Abstract Ekman's theory of the wind-driven ocean surface boundary layer assumes a constant eddy viscosity and predicts that current rotates with depth at same rate as it decays in amplitude. Despite its wide acceptance, Ekman spirals are difficult to observe. This is primarily because small signals easily masked by variability cannot readily be separated from geostrophic component. study presents method for estimating ageostrophic currents shipboard acoustic Doppler profiler data Drake...
Abstract The authors present new estimates of the eddy momentum and heat fluxes from repeated high-resolution upper-ocean velocity temperature observations in Drake Passage interpret their role regional Antarctic Circumpolar Current (ACC) balance. span 7 yr are compared to estimated a 3-yr set output archived an eddy-resolving global Parallel Ocean Program (POP) numerical simulation. In both POP observations, stream-averaged cross-stream correspond forcing consistent with potential vorticity...
Abstract Observations are used to evaluate a simple theoretical model for the generation of near-inertial shear spikes at base open ocean mixed layer when upper displays two-layer structure. The predicts that large changes in squared can be produced by alignment wind and vectors. A climatology stratification variance Drake Passage is presented, which shows these assumptions most applicable summer, fall, spring but not highly winter. Temperature, salinity, velocity data from high spatial...