A5085430202- Oceanographic and Atmospheric Processes
- Marine and coastal ecosystems
- Arctic and Antarctic ice dynamics
- Climate variability and models
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Marine Biology and Ecology Research
- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Ocean Acidification Effects and Responses
- Underwater Acoustics Research
- Marine and fisheries research
- Underwater Vehicles and Communication Systems
- Ocean Waves and Remote Sensing
- Meteorological Phenomena and Simulations
- Polar Research and Ecology
- Marine and environmental studies
- Tropical and Extratropical Cyclones Research
- Maritime Navigation and Safety
- Climate change and permafrost
- Scientific Research and Discoveries
- Isotope Analysis in Ecology
- Environmental Monitoring and Data Management
- Coastal and Marine Management
- Marine animal studies overview
University of Cape Town
2016-2025
University of Gothenburg
2016-2025
Sultan Qaboos University
2023-2024
Stellenbosch University
2011-2019
California Institute of Technology
2019
Woods Hole Oceanographic Institution
2019
Council for Scientific and Industrial Research
2012-2017
Canadian Society of Intestinal Research
2013
Editor’s note: For easy download the posted pdf of State Climate for 2016 is a very low-resolution file. A high-resolution copy report available by clicking here. Please be patient as it may take few minutes file to download.
Turbulent and radiative exchanges of heat between the ocean atmosphere (hereafter fluxes), surface wind stress, state variables used to estimate them, are Essential Ocean Variables (EOVs) Climate (ECVs) influencing weather climate. This paper describes an observational strategy for producing 3-hourly, 25-km (and aspirational goal hourly at 10-km) flux stress fields over global, ice-free with breakthrough 1-day random uncertainty 15 W m-2 a bias less than 5 m-2. At present this accuracy...
Abstract Editor’s note: For easy download the posted pdf of State Climate for 2017 is a low-resolution file. A high-resolution copy report available by clicking here. Please be patient as it may take few minutes file to download.
Abstract. Due to its importance as a limiting nutrient for phytoplankton growth in large regions of the world's oceans, ocean water column observations concentration trace-metal iron (Fe) have increased markedly over recent decades. Here we compile >13 000 global measurements dissolved Fe (dFe) and make this available community. We then conduct synthesis study focussed on Southern Ocean, where dFe plays fundamental role governing carbon cycle, using four regions, six basins five depth...
Abstract. In the Ocean, seasonal cycle is mode that couples climate forcing to ecosystem response in production, diversity and carbon export. A better characterisation of ecosystem's therefore addresses an important gap our ability estimate sensitivity biological pump change. this study, regional characteristics phytoplankton biomass Southern Ocean are examined terms timing bloom initiation, its amplitude, scale variability importance climatological explaining overall variance. The was...
The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical and ecological systems, which makes recent observed changes to this system cause for global concern. enhanced understanding improvements predictive skill needed projecting future states of require sustained observations. Over last decade, Observing System (SOOS) has established networks enhancing regional coordination research community groups advance development observing...
The subpolar Southern Ocean is a critical region where CO2 outgassing influences the global mean air-sea flux (FCO2). However, processes controlling remain elusive. We show, using multi-glider dataset combining FCO2 and ocean turbulence, that gradient of (∆pCO2) modulated by synoptic storm-driven variability (20 µatm, 1-10 days) through two processes. Ekman transport explains 60% variability, entrainment drives strong episodic events 2-4 mol m-2 yr-1. Extrapolation across process model shows...
Hydrographic transects of the Antarctic Circumpolar Current (ACC) south Africa are projected into baroclinic stream function space parameterized by pressure and dynamic height. This produces a two‐dimensional gravest empirical mode (GEM) that captures more than 97% total density temperature variance in ACC domain. Weekly maps absolute topography data, derived from satellite altimetry, combined with GEM to obtain 16 year time series salinity fields. The thermohaline fields compared...
Air-sea and air-sea-ice fluxes in the Southern Ocean play a critical role global climate through their impact on overturning circulation oceanic heat carbon uptake. The challenging conditions have led to sparse spatial temporal coverage of observations. This has 'knowledge gap' that increases uncertainty atmosphere ocean dynamics boundary-layer thermodynamic processes, impeding improvements weather models. Improvements will require both process-based research understand mechanisms governing...
Abstract Ocean stratification and the vertical extent of mixed layer influence rate at which ocean atmosphere exchange properties. This process has direct impacts for anthropogenic heat carbon uptake in Southern Ocean. Submesoscale instabilities that evolve over space (1–10 km) time (from hours to days) scales directly variability are ubiquitous Mixed eddies contribute restratification, while down-front winds, enhanced by strong synoptic storms, can erode a cross-frontal Ekman buoyancy flux....
The Southern Ocean (SO) contributes most of the uncertainty in contemporary estimates mean annual flux carbon dioxide CO2 between ocean and atmosphere. Attempts to reduce this have aimed at resolving seasonal cycle fugacity (fCO2). We use hourly driver observations collected by combined deployment gliders show that is not sufficient below threshold required reveal climatic trends fluxes. This was done iteratively subsampling data set various time intervals. because storm-linked intraseasonal...
Abstract Traditionally, the mechanism driving seasonal restratification of Southern Ocean mixed layer (ML) is thought to be onset springtime warming. Recent developments in numerical modeling and North Atlantic observations have shown that submesoscale ML eddies (MLE) can drive a restratifying flux shoal deep winter prior solar heating at high latitudes. The impact processes on intraseasonal variability Subantarctic still relatively unknown. We compare 5 months glider data Zone simulations...
Conceived as a major new tool for climate studies, the Surface Water and Ocean Topography (SWOT) satellite mission will launch in late 2021 can retrieve dynamics of ocean upper layer at an unprecedented resolution few kilometers. During calibration validation (CalVal) phase 2022, be 1-day-repeat fast sampling orbit with enhanced temporal but sacrificing spatial coverage. This is ideal opportunity - unique many years to come coordinating in-situ experiments during same period focused study...
There is a growing need for operational oceanographic predictions in both the Arctic and Antarctic polar regions. In former, this driven by declining ice cover accompanied an increase maritime traffic exploitation of marine resources. Oceanographic are also important, to support operations help elucidate processes governing sea shelf stability. However, significant gap exists ocean observing system regions, compared most areas global ocean, hindering reliability forecasts. This can be seen...
Abstract. Polynyas facilitate air–sea fluxes, impacting climate-relevant properties such as sea ice formation and deep water production. Despite their importance, polynyas have been poorly represented in past generations of climate models. Here we present a method to track the presence, frequency spatial distribution Southern Ocean 27 models participating Climate Model Intercomparison Project Phase 6 (CMIP6) two satellite-based products. Only half form open-water (OWPs), most underestimate...
The Southern Ocean greatly contributes to the regulation of global climate by controlling important heat and carbon exchanges between atmosphere ocean. Rates change on decadal timescales are therefore impacted oceanic processes taking place in Ocean, yet too little is known about these processes. Limitations come both from lack observations this extreme environment its inherent sensitivity intermittent at scales that not well captured current Earth system models. Carbon Heat Impact Climate...
One approach to deriving phytoplankton carbon biomass estimates (Cphyto) at appropriate scales is through optical products. This study uses a high-resolution glider data set in the Sub-Antarctic Zone (SAZ) of Southern Ocean compare four different methods Cphyto from particulate backscattering and fluorescence-derived chlorophyll (chl-a). A comparison showed that low (<0.5 mg m-3) concentrations (e.g. early spring depth), all produced similar Cphyto, whereas when were elevated one method...
Abstract Enhanced vertical velocities associated with submesoscale motions may rapidly modify mixed layer depths and increase exchange between the ocean interior. These dynamics are of particular importance in Southern Ocean, where ventilation many density classes occurs. Here we present results from an observational field program southern Drake Passage, a region preconditioned for instability owing to its strong mesoscale eddy field, persistent fronts, down-front winds, weak stratification....
Abstract Gliders were deployed for the first time in Agulhas Current region to investigate processes of interactions between western boundary currents and shelf waters. Continuous observations from gliders water depths 100–1000 m over a period 1 month provide high‐resolution Current's inshore front. The collected nonmeandering show presence submesoscale cyclonic eddies, generated at Current. cyclones are often associated with warm plumes, which extend their edge exhibit strong northeastward...
Abstract In the Southern Ocean, there is increasing evidence that seasonal to subseasonal temporal scales, and meso- submesoscales play an important role in understanding sensitivity of ocean primary productivity climate change. This drives need for a high-resolution approach resolving biogeochemical processes. this study, 5.5 months continuous, (3 h, 2 km horizontal resolution) glider data from spring summer Atlantic Subantarctic Zone used investigate: (i) mechanisms drive bloom initiation...
Abstract Surface ocean wind datasets are required to be of high spatial and temporal resolution precision accurately force or assimilated into coupled atmosphere–ocean numerical models understand ocean–atmospheric processes. In situ observed sea surface winds from the Southern Ocean scarce and, consequently, validity simulation is often questionable. Multiple data products were compared first known high-resolution in measurements speed Wave Glider (WG) deployments with intent determine which...
The role ships play in atmospheric, oceanic, and biogeochemical observations is described with a focus on measurements made within 100 m of the ocean surface. Ships include merchant research vessels, cruise liners ferries, fishing coast guard, military, other government-operated ships, yachts, growing fleet automated surface vessels. present capabilities to measure essential climate/ocean variables requirements from broad community address operational, commercial, scientific needs are...