Charitha Pattiaratchi

University of Western Australia | UWA · Oceans Institute

Meteotsunamis are generated by meteorological events, particularly moving pressure disturbances due to squalls, thunderstorms, frontal passages and atmospheric gravity waves. Relatively small initial sea-level perturbations, of the order of a few centimetres, can increase significantly through multi-resonant phenomena to create destructive events t...

There is observational evidence that global sea level is rising and there is concern that the rate of rise will increase, significantly threatening coastal communities. However, considerable debate remains as to whether the rate of sea level rise is currently increasing and, if so, by how much. Here we provide new insights into sea level accelerati...

The incidence of major storm surges in the last decade have dramatically emphasized the immense destructive capabilities of extreme water level events, particularly when driven by severe tropical cyclones. Given this risk, it is vitally important that the exceedance probabilities of extreme water levels are accurately evaluated to inform risk-based...

Hydrological data from a repeated cross-shore transect obtained using Teledyne Webb Research Slocum Electric gliders offshore Two Rocks in south-western Australia over 13 months are presented. The data revealed that formation of dense water inshore and its transport across the shelf as a near bed gravity current (defined as Dense Shelf Water Cascad...

Open ocean boundary conditions and field measurements for model validation are essential for the operation of high resolution local numerical models. Therefore, the main objectives of this theme were to: (1) provide open ocean boundary conditions for the period 2000-2022 and future climate scenarios (to 2100) under different emission scenarios; and...

This study explores the linkage between lunar precessions, solar activity, plus their interactions, and the interannual variability of climate indices and Australian sea level. The focus is on variability longer than the lunar nodal cycle (18.6 years), but shorter than millennia, also known as orbital gap. Climate indices include the Pacific Decada...

Mesoscale eddies represent discrete, rotating fluid particles that are different compared to their ambient aquatic environment. Understanding the dynamics of mesoscale eddies requires observations, not only of their horizontal structure, such as is available through satellite data, but also of their vertical structure. This study investigates the s...

Large amounts of plastic waste from non-local sources (>200 tonnes) wash up on Christmas Island and the Cocos Keeling Islands, two remote Indian Ocean islands, every year. Local communities on these islands organize beach clean-ups regularly to tackle this problem and, because their waste systems cannot handle the enormous amounts of plastic, predo...

Continental shelves are amongst the most dynamic and vulnerable regions in the oceans, and understanding their dynamics has implications for the transport of organisms and materials in both coastal and offshore zones. Determining the circulation patterns in systems experiencing high variability is crucial, but challenging as continuous and high‐res...

There is a relative lack of research, targeted models and tools to manage beaches in estuaries and bays (BEBs). Many estuaries and bays have been highly modified and urbanised, for example port developments and coastal revetments. This paper outlines the complications and opportunities for conserving and managing BEBs in modified estuaries. To do t...

South‐west Australia has been identified as a global hotspot for the occurrence of meteotsunamis. In this study, a numerical hydrodynamic model (Regional Ocean Modelling System) was configured to investigate the generation of meteotsunamis through propagating thunderstorms. A range of simulations were performed using realistic and synthetic atmosph...

Hypersaline Hamelin Pool, with mean salinity >65, is located in Shark Bay, Western Australia. The high salinity has reduced its biodiversity, but it is home to a diverse assemblage of modern marine stromatolites. The limited exchange of water between Hamelin Pool and the rest of Shark Bay, due to the presence of the shallow Faure Sill together with...

We examine baseline water properties and bottom water patterns in hadal trench environments across the Southern Ocean, Indian Ocean, and western Pacific. Significant differences are identified in the South Fiji Basin and surrounding the Philippine Sea, primarily due to the movement of cold Lower Circumpolar Deep Water along topographic features, hi...

Background Measuring coastal-pelagic prey fields at scales relevant to the movements of marine predators is challenging due to the dynamic and ephemeral nature of these environments. Whale sharks (Rhincodon typus) are thought to aggregate in nearshore tropical waters due to seasonally enhanced foraging opportunities. This implies that the three-dim...

Kelp forests may contribute substantially to ocean carbon sequestration, mainly through transporting kelp carbon away from the coast and into the deep sea. However, it is not clear if and how kelp detritus is transported across the continental shelf. Dense shelf water transport (DSWT) is associated with offshore flows along the seabed and provides...

The lack of data on distribution of juvenile marine species can limit conservation efforts. As hatchlings, marine turtles are too small to track using satellite telemetry, so their at-sea distribution remains unknown. This knowledge gap is critical, as hatchlings already experience high mortality in coastal zones. In addition, further risks to thei...

We examine baseline water properties and bottom water patterns in hadal trench environments across the Southern Ocean, Indian Ocean, and Western Pacific. Significant differences are identified in the South Fiji Basin and surrounding the Philippine Sea, primarily due to the movement of cold Lower Circumpolar Deep Water along topographic features, hi...

Meteorological tsunamis, or meteotsunamis, are similar to tsunami waves that are generated by seismic or volcanic activity, except they are forced through the atmospheric effects. The main forcing mechanism is an abrupt change in sea surface atmospheric pressure propagating over the ocean. These may be due to atmospheric effects or volcanic eruptio...

Understanding sexual reproduction and recruitment in seagrasses is crucial to their conservation and restoration. Flowering, seed production, seed recruitment, and seedling establishment data for the seagrass Posidonia australis was collected annually between 2013 and 2018 in meadows at six locations around Rottnest Island, Western Australia. Varia...

Fifteen papers are included in this PAGEOPH topical issue “Sixty Years of Modern Tsunami Science, Volume 2: Challenges.” The issue starts with a general introduction, and then briefly summarizes all contributions, first papers addressing general topics, and then articles grouped on a regional basis: Northern Pacific, Southeast Pacific, Southwest Pa...

The National Marine Science Committee (NMSC) established a working group to provide advice on establishing and supporting a national program. This report provides the working group’s advice and recommendations for establishing and supporting a national program. A national approach to the systematic collection and reporting of priority marine baseli...

Mentorship is defined as a professional relationship, whereby a mentee and mentor are matched to share professional and personal skills and experiences, as well as enhance career development. It has been in existence for many centuries, and in several South Asian cultures, mentorship took place through an ancient tradition called the guru-shishya p...

Context Spiny lobsters are critically affected by ocean current movements over their long journey from hatching to swimming post-larvae (puerulus). Methods Isolating three different larval stages of the Western rock lobster (Panulirus cygnus), we have applied three-dimensional larval-dispersal modelling techniques Aims To better understand a period...

Drivers and extent of the largest coastal upwelling region of Southern Australia: Bonney Coast

We present the outcomes of the first deep-sea remotely operated vehicle study of previously unexplored submarine canyon systems along the southwest Australian continental margin. This was conducted around: (1) the Bremer Marine Park; (2) the Mount Gabi seamount and nearby slope-shelf margin at the interface of the Southern and Indian oceans; with n...

Sri Lanka, located in the northern Indian Ocean with the Arabian Sea on its western side and the Bay of Bengal on its eastern side and experiences biannually reversing monsoon winds. This brief overview explored the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka, particularly along the southern coast, using...

Sea level exerts a fundamental influence on the intertidal zone, where organisms are subject to immersion and emersion at varying timescales and frequencies. While emersed, intertidal organisms are exposed to atmospheric stressors which show marked diurnal and seasonal variability, therefore the daily and seasonal timing of low water is a key deter...

Numerous processes can cause upwelling, but the processes that cause upwelling along the east coast of Peninsular Malaysia (ECPM) are not well understood. Therefore, the dynamics of upwelling driving processes along the ECPM were investigated in this study. During the southwest monsoon, satellite-derived sea surface temperature (SST) and cruise sur...

Offshore platforms, subsea pipelines, wells and related fixed structures supporting the oil and gas (O&G) industry are prevalent in oceans across the globe, with many approaching the end of their operational life and requiring decommissioning. Although structures can possess high ecological diversity and productivity, information on how they intera...

It is well known that light pollution disrupts the early dispersal of marine turtles. But now, light emitting diodes (LEDs) are replacing traditional lights, however, we know little about how they influence hatchling dispersal. Here, we used acoustic telemetry to assess the early in-water dispersal and predation rates of hatchlings in response to d...

Estimating ocean processes in regions with sparse observations, and where dynamics are dominated by strong barotropic and baroclinic tides, poses a significant modelling challenge. In this study, a Four-Dimensional Variational (4D-Var) data assimilation method, incorporating remotely sensed sea surface temperature (SST) data observations only, was...

Dynamics of ocean boundary currents and associated shelf processes can influence onshore and offshore water transport, critically impacting marine organisms that release long-lived pelagic larvae into the water column. The western rock lobster, Panulirus cygnus, endemic to Western Australia, is the basis of Australia's most valuable wild-caught com...

Plastic debris is the most common and exponentially increasing human pollutant in the world's ocean. The distribution and impact of plastic in the Pacific and Atlantic oceans have been the subject of many publications but not so the Indian Ocean (IO). Some of the IO rim countries have the highest population densities globally and mismanagement of p...

Both local and international careers in the ocean sciences are largely unavailable or inaccessible to interested students and graduates from under-resourced nations. Barriers to ocean science careers result from a range of region-specific factors. Financial and infrastructural resources supporting ocean science opportunities are limited. Inter- and...

Sri Lanka experienced its worst anthropogenic marine disaster as a result of the X-Press Pearl incident. This is in addition to natural disasters such as tsunamis and extreme weather events. Together they pose significant environmental, ecological, financial, social and legal risks to coastal populations. This is highlighted through the aftermath o...

Integrated analysis of the vertical and horizontal movements of epipelagic fishes requires high-resolution data from tags that have been attached to animals for long periods. The recovery of a SPLASH tag deployed on a whale shark (Rhincodon typus) for three months enabled access to archival data of horizontal and vertical movements of the shark tha...

This study aims to investigate the interconnection between the southern South China Sea (SSCS) and Java Sea (JS) by simulating seasonal circulations and associated transports using the Regional Ocean Modelling System (ROMS). The seasonal circulation was predominantly driven by monsoonal wind stress and water exchanges between the SSCS and the JS. D...

Animals follow specific movement patterns and search strategies to maximize encounters with essential resources (e.g. prey, favourable habitat) while minimizing exposures to suboptimal conditions (e.g. competitors, predators). While describing spatiotemporal patterns in animal movement from tracking data is common, understanding the associated sear...

Subsea infrastructure of the oil and gas industry attracts commercial fish species as well as megafauna including sea lions, turtles, sharks and whales. Potential impacts of this attraction, whether positive or negative, are unknown. As part of a pilot study, we deployed acoustic telemetry equipment around offshore infrastructure to assess its effe...

The monsoon circulation in the Northern Indian Ocean (NIO) is unique since it develops in response to the bi-annual reversing monsoonal winds, with the ocean currents mirroring this change through directionality and intensity. The interaction between the reversing currents and topographic features have implications for the development of the Island...

Whale sharks off the western coast of India have suffered high levels of fishing pressure in the past, and today continue to be caught in small-scale fisheries as by-catch. Additionally, coastlines in this region host very large and growing human populations that are undergoing rapid development. This exacerbates ongoing anthropogenic threats to th...

The pelagic development stages of many marine invertebrate species dictates their spatial and temporal distribution once reaching their benthic second phase of life. This life cycle is associated with the Western Rock Lobster (Panulirus cygnus) along the coast of Western Australia. Over the past 50 years, the number of puerulus reaching the nearsho...

Dynamics of ocean boundary currents and associated shelf processes can influence onshore/offshore transport of water, critically impacting marine organisms that release long-lived pelagic larvae into the water column. The western rock lobster, Panulirus cygnus, endemic to Western Australia, is the basis of Australia's most valuable wild-caught comm...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

Millions of tons of buoyant plastic materials enter oceans annually, the majority originating from terrestrial sources and transported to oceans where oceanographic processes disperse or accumulate them. Some of these materials beach while others accumulate in convergent zones in coastal seas and the open ocean. Although accumulations associated wi...

Natural formations of rock and coral can support geologically controlled beaches, where the beach dynamics are significantly influenced by these structures. However, little is known about how alongshore variations in geological controls influence beach morphodynamics. Therefore, in this study we focus on the storm response of a beach (Yanchep in so...

Bio‐logging data obtained by tagging animals are key to addressing global conservation challenges. However, the many thousands of existing bio‐logging datasets are not easily discoverable, universally comparable, nor readily accessible through existing repositories and across platforms, slowing down ecological research and effective management. A s...

A comprehensive observational data set was used to examine shoreward propagating semidiurnal internal tides as they shoal, break and run-up as turbulent boluses across the edge of the Australian North West Shelf (NWS), offshore Dampier, during late winter 2013. The measured waveforms and wavefields supported the grouping of events into two distinct...

Plastic debris are the most common and exponentially increasing human pollutant in the world's oceans. The distribution and impact of plastics in the Pacific and Atlantic Oceans have been the subject of many studies but not so for the Indian Ocean (IO). Some of the IO rim countries have the highest population densities in the world and mis-manageme...

Waves are thought to provide an important directional cue for hatchlings of marine turtles to navigate through the nearshore zone and to facilitate dispersal to oceanic waters. As the flatback turtle (Natator depressus) is the only species of marine turtle that lacks an oceanic juvenile stage and remains on the continental shelf throughout the enti...

In this talk, I will discuss long wave motions in bays and harbors, and descirbe analysis approaches to better understand the properties of these oscillations.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/4TKOOthT6MQ

In this talk, I will discuss long wave motions in bays and harbors, and descirbe analysis approaches to better understand the properties of these oscillations. Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/4TKOOthT6MQ

Throughout history, coastal settlers have had to adapt to periodic coastal flooding. However, as a society we have become increasingly vulnerable to extreme water level events as our cities and our patterns of coastal development become more intricate, populated and interdependent. In addition to this, there is now a real and growing concern about...

Extreme sea levels result from a combination of a range of factors that include long term mean sea level variability, astronomical tides, storm surges due to atmospheric pressure and wind, wave breaking, and other regional dynamics. Numerical circulation/storm-surge models are frequently used to predict water levels over broad areas with the output...

The land-sea breeze (LSB) system, driven by the thermal contrast between the land and the adjacent ocean is a widely known atmospheric phenomenon, which occurs in coastal regions globally. Southwest Australia experiences a persistent and one of the strongest LSB systems globally with maximum wind speeds associated with the LSB system often exceedin...

A large percentage of global ocean plastic waste enters the Northern Hemisphere Indian Ocean (NIO). Despite this, it is unclear what happens to buoyant plastics in the NIO. Because the subtropics in the NIO are blocked by landmass, there is no subtropical gyre and no associated subtropical garbage patch in this region. We therefore hypothesize that...

A large percentage of global ocean plastic waste enters the Northern Hemisphere Indian Ocean (NIO). Despite this, it is unclear what happens to buoyant plastics in the NIO. Because the subtropics in the NIO are blocked by landmass, there is no subtropical gyre and no associated subtropical garbage patch in this region. We therefore hypothesize that...

Resonance is generally described as a phenomenon that results in increased response that occurs when the frequency of an applied force is equal or close to a natural frequency of the system. Under these resonance conditions, energy transfer from the atmosphere to ocean is at a maximum with the oceanic response higher than what would be expected. Tr...

Tiger sharks, Galeocerdo cuvier , are a keystone, top-order predator that are assumed to engage in cost-efficient movement and foraging patterns. To investigate the extent to which oscillatory diving by tiger sharks conform to these patterns, we used a biologging approach to model their cost of transport. High-resolution biologging tags with tri-ax...

Western Australia is susceptible to tsunamis from seismic sources that originate from distant sources including the Sunda Arc. Many surface and subsurface topographic ocean features are located between the Australian continent and locations where tsunamigenic earthquakes occur. These include the Venin Meinesz Seamounts (including Christmas Island)...