A5091795805- Arctic and Antarctic ice dynamics
- Ocean Waves and Remote Sensing
- Oceanographic and Atmospheric Processes
- Cryospheric studies and observations
- Methane Hydrates and Related Phenomena
- Climate change and permafrost
- Coastal and Marine Dynamics
- Tropical and Extratropical Cyclones Research
- Underwater Acoustics Research
- Aerospace Engineering and Energy Systems
- Underwater Vehicles and Communication Systems
- Marine and Offshore Engineering Studies
- Fire Detection and Safety Systems
- Autonomous Vehicle Technology and Safety
- Climate variability and models
- Geological formations and processes
- Geophysics and Gravity Measurements
- Winter Sports Injuries and Performance
- Offshore Engineering and Technologies
- Wave and Wind Energy Systems
- Law, logistics, and international trade
- Ionosphere and magnetosphere dynamics
- Global Energy and Sustainability Research
- Oil Spill Detection and Mitigation
- Coastal wetland ecosystem dynamics
University of Cape Town
2018-2023
City of Cape Town
2017
L&S Consulting (South Africa)
1999-2009
Abstract Antarctic sea ice shows a large degree of regional variability, which is partly driven by severe weather events. Here we bring new perspective on synoptic changes presenting the first in situ observations an explosive extratropical cyclone crossing winter marginal zone (MIZ) South Atlantic. This complemented analysis subsequent cyclones and highlights rapid variations that ice‐landing cause ice: Midlatitude warm oceanic air advected onto ice, storm waves generated close to edge...
The marginal ice zone is the dynamic interface between open ocean and consolidated inner pack ice. Surface gravity waves regulate extent properties, and, hence, fluxes atmosphere ocean, advance retreat. Over past decade, seminal experimental campaigns have generated much needed measurements of wave evolution in zone, which, notwithstanding prominent knowledge gaps that remain, are underpinning major advances understanding region's role climate system. Here, we report three-dimensional...
Abstract. The size distribution of pancake ice floes is calculated from images acquired during a voyage to the Antarctic marginal zone in winter expansion season. Results show that 50 % sea area made up with diameters 2.3–4 m. floe shows two distinct slopes on either side m range, neither which conforms power law. Following relevant recent study, it conjectured growth pancakes frazil forms small (D<2.3 m), and welding large (D>4 m).
The generation and evolution of ocean waves by wind is one the most complex phenomena in geophysics, great practical significance. Predictive capabilities respective wave models, however, are impaired lack field situ observations, particularly extreme Metocean conditions. paper outlines highlights important gaps understanding processes suggests a major observational program Southern Ocean. This large, but poorly investigated part World Ocean home to weather around year. network would include...
Abstract Global wave hindcasts are developed using the third generation spectral model WAVEWATCH III with observation‐based source terms (ST6) and a hybrid rectilinear‐curvilinear, irregular‐regular‐irregular grid system (approximately at ). Three distinct global produced: (a) long‐term hindcast (1979–2019) forced by ERA5 conventional winds (b) two short‐term (2011–2019) driven NCEP climate forecast (CFS)v2 neutral , respectively. The input field for ice is sourced from Ocean Sea Ice...
Abstract. The Southern Ocean has a profound impact on the Earth's climate system. Its strong winds, intense currents, and fierce waves are critical components of air–sea interface contribute to absorbing, storing, releasing heat, moisture, gases, momentum. Owing its remoteness harsh environment, this region is significantly undersampled, hampering validation prediction models large-scale observations from satellite sensors. Here, an unprecedented data set simultaneous surface ocean...
Abstract. As part of the 2019 Southern oCean seAsonal Experiment (SCALE) Winter Cruise South African icebreaker SA Agulhas II, first-year ice was sampled at advancing outer edge Antarctic marginal zone along a 150 km Good Hope Line transect. Ice cores were extracted from four solitary pancake floes 1.83–2.95 m diameter and 0.37–0.45 thickness as well 12×4 floe 0.31–0.76 that larger consolidated pack domain. The subsequently analysed for temperature, salinity, texture, anisotropic elastic...
High temporal resolution in--situ measurements of pancake ice drift are presented, from a pair buoys deployed on floes in the Antarctic marginal zone during winter sea expansion, over nine days which region was impacted by four polar cyclones. Concomitant wave-in-ice activity is used to infer that conditions were maintained at least first seven days. Analysis data shows: (i)~unprecedentedly fast speeds Southern Ocean; (ii)~high correlation velocities with surface wind velocities, indicating...
There is clearly no immediate answer to the question posted by title of this paper. Inasmuch as that there are not much definitively known about rogue waves and still universally accepted definition for in ocean, we think might just be even more than one kind contend with. While conventional approach has generally designated with Hmax∕Hs greater 2.2 possible waves, based on Rayleigh distribution considerations, conspicuously provision how high ratio can thus a wave be. In our analysis...
Mathematics is central to the modern discipline of economics, although there has always been some dispute about value this relationship. Leijonhufvud, in his satire economics profession, declared that the ‘Math-Econ’(mathematical economists) appeared be high priests tribe. There was debate on whether their work ‘best regarded as religious, folklore and mythology, philosophical ‘scientific’, or sports and games’. In commentary I want consider whether role mathematics goes beyond ‘sports...
Inasmuch as there is yet still no universally accepted definition for rogue waves in the ocean, we think might just be more than one kind of to contend with. While conventional approach has generally designated with Hmax/Hs greater 2.2 possible waves, based on Rayleigh distribution considerations, conspicuously provision how high ratio can be. In our analysis wave measurements made from a gas-drilling platform South Indian Ocean, offshore Mossel Bay, Africa, found number cases that indicated...
Abstract. We made an objective examination of our present state knowledge on freaque waves in the ocean and lakes from three separate perspectives: - testimonial – eyewitness account actual encounters; empirical available in-situ wave measurements; conjectural academic theoretical formulations; led to a subjective answer posted title question this paper: we do not know very much about lakes! There are really no interconnections among perspectives examined. Put them together however,...
Ocean wave data comprises either instrumentally measured or model-derived data, and the former type of is preferred in offshore industry. Instrumental can be considered to comprised both directly sea surface displacement derived from acceleration buoys. It has been found that significant differences occur between displacements, which are recorded steep waves by fixed probes lasers (Eulerian), free-floating buoys (Lagrangian). This given rise situation where buoy should not used estimate...
Accidents arising from a combination of poor visibility due to heavy fog and high vehicle speeds result in significant economic costs. A proposed detection warning system is described, together with details climatology the approach taken for sensor location.
In this paper we point out the lesser known or under-explored aspects of freaque waves. The modern study waves has been an active research field over last two decades so. There have significant advancements especially in connection with nonlinear physics. We explored what DO know, paper, would like to explore NOT know?
This paper presents a preliminary examination and analysis of small suite 4-D wave data to explore what new insight or inference we can garner — particularly toward the realm where conventional approaches have not been traversed. While caught few glimpses that might indicate need for conceptualizations, it by no means negates vast positive contributions made in past century. We feel is timely encourage further ocean measurement thereby facilitate fresh states study understanding waves.
Abstract. The size distribution of pancake ice floes is calculated from images acquired during a voyage to the Antarctic marginal zone in winter expansion season. Results show that 50 % sea area made up by with diameters 2.3–4 m. floe shows two distinct slopes on either side m range. It conjectured growth pancakes frazil forms small (D 4 m).
The effective management of oil spills and the enforcement discharge regulations are issues which have been a problem to Coastal States in past they will continue be challenges around world well into foreseeable future. Records show that current instances major from tanker accidents fairly rare, with an annual spillage some 162 000 tonnes, risks associated these considered acceptable. On other hand, flouting by sea transportation continues on regular basis. total tonnage this ongoing...
Abstract. The Southern Ocean has a profound impact on the Earth's climate system. Its strong winds, intense currents, and fierce waves are critical components of air-sea interface contribute to absorbing, storing, releasing heat, moisture, gasses, momentum. Owing its remoteness harsh environment, this region is significantly under sampled, hampering validation prediction models large scale observations from satellite sensors. Here, an unprecedented data set simultaneous surface ocean...
With the recent advancement of spatial measurements ocean waves, we are clearly facing new challenges regarding how to handle an expanded data system when it becomes widely available. In this paper wish present a preliminary attempt at confronting these prospects. Because is still very limited and also conceptually new, it’s unfamiliar, unrelenting world pursue. We need paradigm shift away from our familiar single-point conceptualization in order effective approach truly waves.
We present here a preliminary examination and analysis of small suite 3D wave data to explore what new insight or inference we can garner -particularly toward the realm where conventional approaches have not yet been.While caught few glimpses that might indicate need for conceptualizations, it by no means negates vast positive contributions allowed us make in past century.We feel is timely encourage further ocean measurement thereby facilitate fresh states study enhance our understanding waves.