ORCID Profile
0000-0002-3523-6254
Current Organisations
University of Tasmania
,
University of Sydney
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Atmospheric Sciences | Physical Oceanography | Climate Change Processes | Meteorology | Ecological Applications | Atmospheric sciences | Atmospheric Dynamics | Marine and Estuarine Ecology (incl. Marine Ichthyology) | Physical oceanography | Meteorology | Ecological Impacts of Climate Change | Climate change processes | Atmospheric dynamics | Atmospheric Sciences not elsewhere classified | Physical Sciences not elsewhere classified
ANZSRC Socio-Economic Objective (SEO)
Climate Change Models | Atmospheric Processes and Dynamics | Expanding Knowledge in the Information and Computing Sciences | Ecosystem Adaptation to Climate Change | Effects of Climate Change and Variability on Australia (excl. Social Impacts) | Climate Variability (excl. Social Impacts) | Expanding Knowledge in the Environmental Sciences | Marine Flora, Fauna and Biodiversity |
Related Links
Publications
Potential applications of subseasonal-to-seasonal (S2S) predictions
Publisher: Wiley
Date: 06-04-2017
DOI: 10.1002/MET.1654
Dynamics and Predictability of El Niño–Southern Oscillation: An Australian Perspective on Progress and Challenges
Publisher: American Meteorological Society
Date: 03-2019
Abstract: El Niño and La Niña, the warm and cold phases of El Niño–Southern Oscillation (ENSO), cause significant year-to-year disruptions in global climate, including in the atmosphere, oceans, and cryosphere. Australia is one of the countries where its climate, including droughts and flooding rains, is highly sensitive to the temporal and spatial variations of ENSO. The dramatic impacts of ENSO on the environment, society, health, and economies worldwide make the application of reliable ENSO predictions a powerful way to manage risks and resources. An improved understanding of ENSO dynamics in a changing climate has the potential to lead to more accurate and reliable ENSO predictions by facilitating improved forecast systems. This motivated an Australian national workshop on ENSO dynamics and prediction that was held in Sydney, Australia, in November 2017. This workshop followed the aftermath of the 2015/16 extreme El Niño, which exhibited different characteristics to previous extreme El Niños and whose early evolution since 2014 was challenging to predict. This essay summarizes the collective workshop perspective on recent progress and challenges in understanding ENSO dynamics and predictability and improving forecast systems. While this essay discusses key issues from an Australian perspective, many of the same issues are important for other ENSO-affected countries and for the international ENSO research community.
Projected Marine Heatwaves in the 21st Century and the Potential for Ecological Impact
Publisher: Frontiers Media SA
Date: 04-12-2019
How can climate predictions improve sustainability of coastal fisheries in Pacific Small-Island Developing States?
Publisher: Elsevier BV
Date: 02-2018
Fisheries management approaches as platforms for climate change adaptation: comparing theory and practice in Australian fisheries
Publisher: Elsevier BV
Date: 09-2016
Marine heatwaves threaten global biodiversity and the provision of ecosystem services
Publisher: Springer Science and Business Media LLC
Date: 04-03-2019
Erratum: Oscillatory and propagating modes of temperature variability at the 3-3.5- and 4-4.5-yr time scales in the Upper Southwest Pacific Ocean (Journal of Climate vol. 18 (5) (719-736))
Publisher: American Meteorological Society
Date: 15-05-2005
DOI: 10.1175/JCLI9001.1
The strengthening East Australian Current, its eddies and biological effects - an introduction and overview
Publisher: Elsevier BV
Date: 03-2011
Measuring the vulnerability of marine social-ecological systems: A prerequisite for the identification of climate change adaptations
Publisher: Resilience Alliance, Inc.
Date: 2015
On the dynamics of interdecadal thermocline depth and sea surface temperature variability in the low to mid-latitude Pacific Ocean
Publisher: American Geophysical Union (AGU)
Date: 12-2004
DOI: 10.1029/2004GL021241
The Response of a stochastically forced ENSO model to observed off-equatorial wind stress forcing
Publisher: American Meteorological Society
Date: 15-05-2009
Abstract: This study investigates the response of a stochastically forced coupled atmosphere–ocean model of the equatorial Pacific to off-equatorial wind stress anomaly forcing. The intermediate-complexity coupled ENSO model comprises a linear, first baroclinic mode, ocean shallow water model with a steady-state, two–pressure level (250 and 750 mb) atmospheric component that has been linearized about a state of rest on the β plane. Estimates of observed equatorial region stochastic forcing are calculated from NCEP–NCAR reanalysis surface winds for the period 1950–2006 using singular value decomposition. The stochastic forcing is applied to the model both with and without off-equatorial region wind stress anomalies (i.e., poleward of 12.5° latitude). It is found that the multiyear changes in the equatorial Pacific thermocline depth “background state” induced by off-equatorial forcing can affect the litude of modeled sea surface temperature anomalies by up to 1°C. Moreover, off-equatorial wind stress anomalies increased the modeled litude of the two biggest El Niño events in the twentieth century (1982/83 and 1997/98) by more than 0.5°C, resulting in a more realistic modeled response. These equatorial changes driven by off-equatorial region wind stress anomalies are highly predictable to two years in advance and may be useful as a physical basis to enhance multiyear probabilistic predictions of ENSO indices.
Oceanic variability and coastal topography shape genetic structure in a long-dispersing sea urchin
Publisher: Wiley
Date: 12-2007
DOI: 10.1890/07-0091.1
Abstract: Understanding the scale of marine population connectivity is critical for the conservation and sustainable management of marine resources. For many marine species adults are benthic and relatively immobile, so patterns of larval dispersal and recruitment provide the key to understanding marine population connectivity. Contrary to previous expectations, recent studies have often detected unexpectedly low dispersal and fine-scale population structure in the sea, leading to a paradigm shift in how marine systems are viewed. Nonetheless, the link between fine-scale marine population structure and the underlying physical and biological processes has not been made. Here we show that patterns of genetic structure and population connectivity in the broadcast-spawning and long-distance dispersing sea urchin Centrostephanus rodgersii are influenced by physical oceanographic and geographic variables. Despite weak genetic differentiation and no isolation-by-distance over thousands of kilometers among s les from eastern Australia and northern New Zealand, fine-scale genetic structure was associated with sea surface temperature (SST) variability and geography along the southeastern Australian coast. The zone of high SST variability is characterized by periodic shedding of eddies from the East Australian Current, and we suggest that ocean current circulation may, through its influence on larval transport and recruitment, interact with the genetic consequences of large variance in in idual reproductive success to generate patterns of fine-scale patchy genetic structure. If proven consistent across species, our findings suggest that the optimal scale for fisheries management and reserve design should vary among localities in relation to regional oceanographic variability and coastal geography.
A synoptic bridge linking sea salt aerosol concentrations in East Antarctic snowfall to Australian rainfall
Publisher: Springer Science and Business Media LLC
Date: 04-08-2022
DOI: 10.1038/S43247-022-00502-W
Abstract: Previous research has shown that aerosol sea salt concentrations (Southern Ocean wind proxy) preserved in the Law Dome ice core (East Antarctica) correlate significantly with subtropical eastern Australian rainfall. However, physical mechanisms underpinning this connection have not been established. Here we use synoptic typing to show that an atmospheric bridge links East Antarctica to subtropical eastern Australia. Increased ice core sea salt concentrations and wetter conditions in eastern Australia are associated with a regional, asymmetric contraction of the mid-latitude westerlies. Decreased ice core sea salt concentrations and drier eastern Australia conditions are associated with an equatorward shift in the mid-latitude westerlies, suggesting greater broad-scale control of eastern Australia climate by southern hemisphere variability than previously assumed. This relationship explains double the rainfall variance compared to El Niño-Southern Oscillation during late spring-summer, highlighting the importance of the Law Dome ice core record as a 2000-year proxy of eastern Australia rainfall variability.
Characteristic atmospheric states during mid-summer droughts over Central America and Mexico
Publisher: Springer Science and Business Media LLC
Date: 10-05-2020
Defining and observing stages of climate-mediated range shifts in marine systems
Publisher: Elsevier BV
Date: 05-2014
Characterizing Marine Heatwaves in the Kerguelen Plateau Region
Publisher: Frontiers Media SA
Date: 07-01-2021
DOI: 10.3389/FMARS.2020.531297
Abstract: Marine heatwaves (MHWs) are prolonged extreme oceanic warm water events. Globally, the frequency and intensity of MHWs have been increasing in recent years, and it is expected that this trend is reflected in the Kerguelen Plateau region. MHWs can negatively impact the structure of marine bio ersity, marine ecosystems, and commercial fisheries. Considering that the KP is a hot-spot for marine bio ersity, characterizing MHWs and their drivers for this region is important, but has not been performed. Here, we characterize MHWs in the KP region between January 1994 and December 2016 using a combination of remotely sensed observations and output from a publicly available model hindcast simulation. We describe a strong MHW event that starts during the 2011/2012 austral summer and persists through winter, dissipating in late 2012. During the winter months, the anomalous temperature signal deepens from the surface to a depth of at least 150 m. We show that downwelling-favorable winds occur in the region during these months. At the end of 2012, as the MHW dissipates, upwelling-favorable winds prevail. We also show that the ocean temperature on the KP is significantly correlated with key modes of climate variability. Over the KP, temperature at both the ocean surface and at a depth of 150 m correlates significantly with the Indian Ocean Dipole. To the south of the KP, temperature variations are significantly correlated with the El Niño Southern Oscillation, and to both the north and south of the KP, with the Southern Annular Mode. These results suggest there may be potential predictability in ocean temperatures, and their extremes, in the KP region. Strong MHWs, like the event in 2012, may be detrimental to the unique ecosystem of this region, including economically relevant species, such as the Patagonian Toothfish.
Understanding the changing nature of marine cold spells
Publisher: Wiley
Date: 17-11-2021
A statistical seasonal forecast model of North Indian Ocean tropical cyclones using the quasi‐biennial oscillation
Publisher: Wiley
Date: 30-09-2018
DOI: 10.1002/JOC.5853
Ability of global climate models at a regional scale over Australia
Publisher: Inderscience Publishers
Date: 2007
Drivers and impacts of the most extreme marine heatwave events
Publisher: Springer Science and Business Media LLC
Date: 09-11-2020
DOI: 10.1038/S41598-020-75445-3
Abstract: Prolonged high-temperature extreme events in the ocean, marine heatwaves, can have severe and long-lasting impacts on marine ecosystems, fisheries and associated services. This study applies a marine heatwave framework to analyse a global sea surface temperature product and identify the most extreme events, based on their intensity, duration and spatial extent. Many of these events have yet to be described in terms of their physical attributes, generation mechanisms, or ecological impacts. Our synthesis identifies commonalities between marine heatwave characteristics and seasonality, links to the El Niño-Southern Oscillation, triggering processes and impacts on ocean productivity. The most intense events preferentially occur in summer, when climatological oceanic mixed layers are shallow and winds are weak, but at a time preceding climatological maximum sea surface temperatures. Most subtropical extreme marine heatwaves were triggered by persistent atmospheric high-pressure systems and anomalously weak wind speeds, associated with increased insolation, and reduced ocean heat losses. Furthermore, the most extreme events tended to coincide with reduced chlorophyll- a concentration at low and mid-latitudes. Understanding the importance of the oceanic background state, local and remote drivers and the ocean productivity response from past events are critical steps toward improving predictions of future marine heatwaves and their impacts.
Differential vulnerability to climate change yields novel deep-reef communities
Publisher: Springer Science and Business Media LLC
Date: 24-09-2018
Seasonal Variability of the Global Spectral Wind Wave Climate
Publisher: American Geophysical Union (AGU)
Date: 04-2019
DOI: 10.1029/2018JC014620
Modelling the shelf circulation off eastern Tasmania
Publisher: Elsevier BV
Date: 11-2016
Reassessing conceptual models of ENSO
Publisher: American Meteorological Society
Date: 12-2015
DOI: 10.1175/JCLI-D-14-00812.1
Abstract: The complex nature of the El Niño–Southern Oscillation (ENSO) is often simplified through the use of conceptual models, each of which offers a different perspective on the ocean–atmosphere feedbacks underpinning the ENSO cycle. One theory, the unified oscillator, combines a variety of conceptual frameworks in the form of a coupled system of delay differential equations. The system produces a self-sustained oscillation on interannual time scales. While the unified oscillator is assumed to provide a more complete conceptual framework of ENSO behaviors than the models it incorporates, its formulation and performance have not been systematically assessed. This paper investigates the accuracy of the unified oscillator through its ability to replicate the ENSO cycle modeled by flux-forced output from the Australian Community Climate and Earth-System Simulator Ocean Model (ACCESS-OM). The anomalous sea surface temperature equation reproduces the main features of the corresponding tendency modeled by ACCESS-OM reasonably well. However, the remaining equations for the thermocline depth anomaly and zonal wind stress anomalies are unable to accurately replicate the corresponding tendencies in ACCESS-OM. Modifications to the unified oscillator, including a diagnostic form of the zonal wind stress anomaly equations, improve its ability to emulate simulated ENSO tendencies. Despite these improvements, the unified oscillator model is less adept than the delayed oscillator model it incorporates in capturing ENSO behavior in ACCESS-OM, bringing into question its usefulness as a unifying ENSO framework.
Species traits and climate velocity explain geographic range shifts in an ocean warming hotspot
Publisher: Wiley
Date: 20-07-2015
DOI: 10.1111/ELE.12474
Abstract: Species' ranges are shifting globally in response to climate warming, with substantial variability among taxa, even within regions. Relationships between range dynamics and intrinsic species traits may be particularly apparent in the ocean, where temperature more directly shapes species' distributions. Here, we test for a role of species traits and climate velocity in driving range extensions in the ocean-warming hotspot of southeast Australia. Climate velocity explained some variation in range shifts, however, including species traits more than doubled the variation explained. Swimming ability, omnivory and latitudinal range size all had positive relationships with range extension rate, supporting hypotheses that increased dispersal capacity and ecological generalism promote extensions. We find independent support for the hypothesis that species with narrow latitudinal ranges are limited by factors other than climate. Our findings suggest that small-ranging species are in double jeopardy, with limited ability to escape warming and greater intrinsic vulnerability to stochastic disturbances.
Longer and more frequent marine heatwaves over the past century
Publisher: Springer Science and Business Media LLC
Date: 10-04-2018
DOI: 10.1038/S41467-018-03732-9
Abstract: Heatwaves are important climatic extremes in atmospheric and oceanic systems that can have devastating and long-term impacts on ecosystems, with subsequent socioeconomic consequences. Recent prominent marine heatwaves have attracted considerable scientific and public interest. Despite this, a comprehensive assessment of how these ocean temperature extremes have been changing globally is missing. Using a range of ocean temperature data including global records of daily satellite observations, daily in situ measurements and gridded monthly in situ-based data sets, we identify significant increases in marine heatwaves over the past century. We find that from 1925 to 2016, global average marine heatwave frequency and duration increased by 34% and 17%, respectively, resulting in a 54% increase in annual marine heatwave days globally. Importantly, these trends can largely be explained by increases in mean ocean temperatures, suggesting that we can expect further increases in marine heatwave days under continued global warming.
Arctic warming contributes to increase in Northeast Pacific marine heatwave days over the past decades
Publisher: Springer Science and Business Media LLC
Date: 07-02-2023
DOI: 10.1038/S43247-023-00683-Y
Abstract: The frequency and duration of marine heatwaves have been increasing with ocean warming due to climate change. In particular, the Northeast Pacific has experienced intense and extensive marine heatwaves since the late 1990s – characteristically called “the Blob”. Here, an investigation of satellite-derived and reanalysis data supported by idealized coupled model experiments show that Arctic warming plays an important role in the increase in Northeast Pacific marine heatwave days during boreal summers. Strong Arctic warming has acted to change the atmospheric circulation pattern over the Northeast Pacific and reduce the low-level cloud fraction from late spring to early summer. We show that the enhancement of solar radiative heat fluxes and reduced latent heat loss over a relatively large area has favored an increase in sea surface temperatures and marine heatwave days. An idealized model experiment performed here, designed to isolate the impact of Arctic warming, supports this hypothesis. The projected changes of Arctic climate on the occurrence of marine heatwaves should be considered in climate change adaptation and mitigation plans.
Decadal characterization of Indo-Pacific Ocean subsurface temperature modes in SODA reanalysis
Publisher: American Meteorological Society
Date: 30-07-2015
DOI: 10.1175/JCLI-D-14-00700.1
Abstract: Studies of decadal-to-multidecadal ocean subsurface temperature variability are fundamental to improving the understanding of low-frequency climate signals. The present study uses the Simple Ocean Data Assimilation (SODA) version 2.2.4 product for the period 1950–2007 to identify decadal modes of variability that characterize the upper Indo-Pacific Ocean temperature structure (5–466-m depth). An empirical orthogonal function (EOF) analysis of the 10-yr low-pass filtered temperature field applied across four depths shows that the dominant mode is characterized by a long-term temperature trend, with warming at the surface and cooling at the thermocline depth connecting the tropical western Pacific with the southern Indian Ocean via the Indonesian Seas. EOF analysis of the detrended 10-yr filtered temperature data and correlation analyses of the EOF time series with established large-scale climate indices identified the interdecadal Pacific oscillation as EOF1, the North Pacific Gyre Oscillation as EOF2, and the decadal component of El Niño Modoki as EOF3 (respectively, modes 2, 3, and 4 of the nondetrended data). EOF2 identifies the Atlantic multidecadal oscillation when the analysis is applied to sea surface temperature anomalies only, suggesting that the surface is forced dominantly by fluxes associated with global-scale weather patterns, while the subsurface is dominantly forced by internal dynamics of the Pacific Ocean. This paper demonstrates that the decadal-to-interdecadal temperature variability in SODA has a pronounced vertical extension through the upper ocean. The upper thermocline accounts for most of the variance in the analysis. These results reinforce the importance of examining the subsurface ocean in climate dynamics studies that seek to understand the ocean’s role.
Observed variability of the South Pacific westward sea level anomaly signal in the presence of bottom topography
Publisher: American Geophysical Union (AGU)
Date: 02-2005
DOI: 10.1029/2004GL020966
A Poisson regression model approach to predicting tropical cyclogenesis in the Australian/southwest Pacific Ocean region using the SOI and saturated equivalent potential temperature gradient as predictors
Publisher: American Geophysical Union (AGU)
Date: 10-2004
DOI: 10.1029/2004GL020843
The Southwest Pacific Ocean circulation and climate experiment (SPICE)
Publisher: American Geophysical Union (AGU)
Date: 11-2014
DOI: 10.1002/2013JC009678
Understanding the Changing Nature of Marine Cold‐Spells
Publisher: American Geophysical Union (AGU)
Date: 17-03-2022
DOI: 10.1029/2021GL097002
Abstract: Marine cold‐spell (MCS) metrics—such as frequency and intensity—are decreasing globally, while marine heatwave (MHW) metrics are increasing due to sea surface temperature (SST) warming. However, the concomitant changes in MHW and MCS metrics, and whether SST warming can similarly explain the decreasing MCS metrics remain unclear. Here, we provide a comparative global assessment of these changes based on satellite SST observations over 1982–2020. Across the globe, we find distinct differences in mean MHW and MCS metrics. Furthermore, decreasing trends in MCS metrics are not necessarily aligned with increasing trends in MHW metrics. While differences in intensity trends are mainly explained by SST variance trends, differences in trends of annual days are less clear. Overall, decreasing MCS days and intensities are found to be largely driven by warming SST, rather than SST variance changes. Therefore, it is expected that MCS days and intensity will continue diminishing under global warming.
Keeping pace with marine heatwaves
Publisher: Springer Science and Business Media LLC
Date: 28-07-2001
Joint Modulation of Intraseasonal Rainfall in Tropical Australia by the Madden‐Julian Oscillation and El Niño‐Southern Oscillation
Publisher: American Geophysical Union (AGU)
Date: 28-10-2017
DOI: 10.1002/2017GL075452
Multiple westward propagating signals in South Pacific sea level anomalies
Publisher: American Geophysical Union (AGU)
Date: 12-2009
DOI: 10.1029/2008JC004799
Climate change impacts and adaptation of commercial marine fisheries in Australia: A review of the science
Publisher: Springer Science and Business Media LLC
Date: 09-04-2014
The unprecedented 2015/16 Tasman Sea marine heatwave
Publisher: Springer Science and Business Media LLC
Date: 14-07-2017
DOI: 10.1038/NCOMMS16101
Abstract: The Tasman Sea off southeast Australia exhibited its longest and most intense marine heatwave ever recorded in 2015/16. Here we report on several inter-related aspects of this event: observed characteristics, physical drivers, ecological impacts and the role of climate change. This marine heatwave lasted for 251 days reaching a maximum intensity of 2.9 °C above climatology. The anomalous warming is dominated by anomalous convergence of heat linked to the southward flowing East Australian Current. Ecosystem impacts range from new disease outbreaks in farmed shellfish, mortality of wild molluscs and out-of-range species observations. Global climate models indicate it is very likely to be that the occurrence of an extreme warming event of this duration or intensity in this region is respectively ≥330 times and ≥6.8 times as likely to be due to the influence of anthropogenic climate change. Climate projections indicate that event likelihoods will increase in the future, due to increasing anthropogenic influences.
A statistical method for improving continental shelf and nearshore marine climate predictions
Publisher: American Meteorological Society
Date: 2014
DOI: 10.1175/JTECH-D-13-00052.1
Abstract: Spatially and temporally homogeneous measurements of ocean temperature variability at high resolution on the continental shelf are scarce. Daily estimates of large-scale ocean properties are readily available from global ocean reanalysis products. However, the ocean models that underpin these reanalysis products tend not to have been designed for the simulation of complex coastal ocean variability. Hence, across-shelf values are often poorly represented. This study involved developing a statistical approach to more accurately and robustly represent SST on the continental shelf informed by large-scale satellite observations and reanalysis data or model output. Using the southeastern Australian shelf region as a case study, this paper demonstrates that this statistical model approach generates more accurate estimates of the inshore SST using (i) offshore SST from Bluelink Reanalysis (BRAN) and (ii) the statistical relationship between inshore and offshore SST in observations from the Advanced Very High Resolution Radiometer. SST is separated into the mean, seasonal cycle, and residual variability, and separate models are developed for each component. The offshore locations used to inform the model are determined by taking into account (i) the quality of BRAN at each location, (ii) the strength between the inshore and offshore variability, and (iii) the proximity of the inshore and offshore locations. Model predictions are made for the continental shelf around southeastern Australia. The role of the mean circulation in providing connectivity between the shelf and the offshore regions is discussed, and how this information can be used to better inform the choice of model predictor locations, leading to a hybrid statistical–connectivity model.
Evaluating SODA for Indo-Pacific Ocean decadal climate variability studies
Publisher: American Geophysical Union (AGU)
Date: 11-2014
DOI: 10.1002/2014JC010175
The short history of research in a marine climate change hotspot: From anecdote to adaptation in south-east Australia
Publisher: Springer Science and Business Media LLC
Date: 29-09-2014
Sensitivity of Marine Heatwave Metrics to Ocean Model Resolution
Publisher: American Geophysical Union (AGU)
Date: 26-12-2019
DOI: 10.1029/2019GL084928
The contribution of the land surface energy balance complexity to differences in means, variances and extremes using the AMIP-II methodology
Publisher: Springer Science and Business Media LLC
Date: 21-06-2005
Understanding the double peaked El Niño in coupled GCMs
Publisher: Springer Science and Business Media LLC
Date: 02-06-2017
Interdecadal sea surface temperature variability in the equatorial Pacific Ocean. Part I: The role of off-equatorial wind stresses and oceanic Rossby waves
Publisher: American Meteorological Society
Date: 06-2007
DOI: 10.1175/JCLI4145.1
Abstract: The Australian Bureau of Meteorology Research Centre CGCM and a linear first baroclinic-mode ocean shallow-water model (SWM) are used to investigate ocean dynamic forcing mechanisms of the equatorial Pacific Ocean interdecadal sea surface temperature (SST) variability. An EOF analysis of the 13-yr low-pass Butterworth-filtered SST anomalies from a century-time-scale CGCM simulation reveals an SST anomaly spatial pattern and time variability consistent with the interdecadal Pacific oscillation. Results from an SWM simulation forced with wind stresses from the CGCM simulation are shown to compare well with the CGCM, and as such the SWM is then used to investigate the roles of “uncoupled” equatorial wind stress forcing, off-equatorial wind stress forcing (OffEqWF), and Rossby wave reflection at the western Pacific Ocean boundary, on the decadal equatorial thermocline depth anomalies. Equatorial Pacific wind stresses are shown to explain a large proportion of the overall variance in the equatorial thermocline depth anomalies. However, OffEqWF beyond 12.5° latitude produces an interdecadal signature in the Niño-4 (Niño-3) region that explains approximately 10% (1.5%) of the filtered control simulation variance. Rossby wave reflection at the western Pacific boundary is shown to underpin the OffEqWF contribution to these equatorial anomalies. The implications of this result for the predictability of the decadal variations of thermocline depth are investigated with results showing that OffEqWF generates an equatorial response in the Niño-3 region up to 3 yr after the wind stress forcing is switched off. Further, a statistically significant correlation is found between thermocline depth anomalies in the off-equatorial zone and the Niño-3 region, with the Niño-3 region lagging by approximately 2 yr. The authors conclude that there is potential predictability of the OffEqWF equatorial thermocline depth anomalies with lead times of up to 3 yr when taking into account the litudes and locations of off-equatorial region Rossby waves.
Impact of land cover change on the climate of southwest Western Australia
Publisher: American Geophysical Union (AGU)
Date: 23-09-2004
DOI: 10.1029/2003JD004347
A New Paradigm for South Pacific Climate Variability and Predictability
Publisher: Research Square Platform LLC
Date: 19-07-2021
DOI: 10.21203/RS.3.RS-602270/V1
Abstract: Pacific climate variability is largely understood based on El Niño–Southern Oscillation (ENSO), the North Pacific focused Pacific decadal oscillation (PDO) and/or the whole of Pacific region interdecadal Pacific oscillation – which respectively represent the dominant modes of interannual and decadal climate variability. However, the role of the South Pacific, including atmospheric drivers and cross-scale interactions between interannual and decadal climate variability, has received considerably less attention. Here we propose a new paradigm for South Pacific climate variability whereby the Pacific-South American (PSA) mode, characterised by two mid-tropospheric modes (PSA1 and PSA2), provides coherent noise forcing that acts to excite multiple spatiotemporal scales of oceanic responses in the upper South Pacific Ocean ranging from seasonal to decadal. While PSA1 has long been recognised as highly correlated with ENSO, we find that PSA2 is critically important in generating a sea surface temperature (SST) quadrupole pattern in the extratropical South Pacific. This sets up a precursor that optimally determines the predictability and evolution of SST 9 months in advance of the peak phases of both the leading South Pacific SST mode and ENSO. Our results show that the atmospheric PSA mode is the key driver of oceanic variability in the South Pacific subtropics.
A climatological model of North Indian Ocean tropical cyclone genesis, tracks and landfall
Publisher: Springer Science and Business Media LLC
Date: 05-12-2017
Variability and Long‐Term Trends in the Shelf Circulation Off Eastern Tasmania
Publisher: American Geophysical Union (AGU)
Date: 10-2018
DOI: 10.1029/2018JC013994
A global assessment of marine heatwaves and their drivers
Publisher: Springer Science and Business Media LLC
Date: 14-06-2019
DOI: 10.1038/S41467-019-10206-Z
Abstract: Marine heatwaves (MHWs) can cause devastating impacts to marine life. Despite the serious consequences of MHWs, our understanding of their drivers is largely based on isolated case studies rather than any systematic unifying assessment. Here we provide the first global assessment under a consistent framework by combining a confidence assessment of the historical refereed literature from 1950 to February 2016, together with the analysis of MHWs determined from daily satellite sea surface temperatures from 1982–2016, to identify the important local processes, large-scale climate modes and teleconnections that are associated with MHWs regionally. Clear patterns emerge, including coherent relationships between enhanced or suppressed MHW occurrences with the dominant climate modes across most regions of the globe – an important exception being western boundary current regions where reports of MHW events are few and ocean-climate relationships are complex. These results provide a global baseline for future MHW process and prediction studies.
Drivers, Dynamics, and Persistence of the 2017/2018 Tasman Sea Marine Heatwave
Publisher: American Geophysical Union (AGU)
Date: 08-2022
DOI: 10.1029/2022JC018931
Abstract: During the austral summer of 2017/2018, the Tasman Sea experienced an intense marine heatwave over an extensive area. It persisted for approximately 3 months and caused substantial ecological impacts. The marine heatwave was understood to have been driven primarily by increased net downward heat flux associated with a high pressure system. However, it has been unclear why the marine heatwave persisted. Using an ultra‐high‐resolution (∼1 km) regional ocean model simulation, the drivers, dynamics, and persistence of the 2017/2018 marine heatwave are explored in detail. It is found that a burst of warm water advection helped to initiate the event, but a shallower than usual mixed layer, coupled with near continuous net downward air‐sea heat flux, caused the marine heatwave to persist. Submesoscale dynamics were found to be relatively unimportant to the marine heatwave's persistence.
Marine governance to avoid tipping points: Can we adapt the adaptability envelope?
Publisher: Elsevier BV
Date: 03-2016
A pressure gradient metric capturing planetary-scale influences on eastern Australian rainfall
Publisher: American Geophysical Union (AGU)
Date: 04-2008
DOI: 10.1029/2007GL032970
Links between large-scale modes of climate variability and synoptic weather patterns in the southern Indian Ocean
Publisher: American Meteorological Society
Date: 02-2020
Abstract: Weather systems in the southern Indian Ocean (SIO) drive synoptic-scale precipitation variability in East Antarctica and southern Australia. Improved understanding of these dynamical linkages is beneficial to diagnose long-term climate changes from climate proxy records as well as informing regional weather and climate forecasts. Self-organizing maps (SOMs) are used to group daily 500-hPa geopotential height (z500 ERA-Interim) anomalies into nine regional synoptic types based on their dominant patterns over the SIO (30°–75°S, 40°–180°E) from January 1979 to October 2018. The pattern anomalies represented include four meridional, three mixed meridional–zonal, one zonal, and one transitional node. The frequency of the meridional nodes shows limited association with the phase of the southern annular mode (SAM), especially during September–November. The zonal and mixed patterns were nevertheless strongly and significantly correlated with SAM, although the regional synoptic representation of SAM+ conditions was not zonally symmetric and was represented by three separate nodes. We recommend consideration of how different synoptic conditions vary the atmospheric representation of SAM+ in any given season in the SIO. These different types of SAM+ mean a hemispheric index fails to capture the regional variability in surface weather conditions that is primarily driven by the synoptic variability rather than the absolute polarity of the SAM.
Influence of the MJO on daily surface air temperature over Iran
Publisher: Wiley
Date: 24-03-2021
DOI: 10.1002/JOC.7086
Abstract: The influence of the Madden‐Julian Oscillation (MJO) on surface air temperature over Iran is examined using daily data from meteorological stations from 1979 to 2015. Composites of daily surface air temperature anomalies are positive in MJO phases 1 and 8 and negative in MJO phases 3–4 with broader region positive tendencies also in MJO phases 2 and 7, and negative tendencies in MJO phases 5–6. This variability is associated with horizontal temperature advection, whereby the southerly (northward) winds act to heat and the northerly (southward) winds cool Iran, in association with the MJO. Further, we find that daily minimum surface air temperatures respond more strongly to the MJO than do daily maximum surface temperatures. These signals correspond to cloudy and humid conditions.
A linear inverse model of tropical and south pacific climate variability: Optimal structure and stochastic forcing
Publisher: American Meteorological Society
Date: 2021
Abstract: A stochastically forced linear inverse model (LIM) of the combined modes of variability from the tropical and South Pacific Oceans is used to investigate the linear growth of optimal initial perturbations and to identify the spatiotemporal features of the stochastic forcing associated with the atmospheric Pacific–South American patterns 1 and 2 (PSA1 and PSA2). Optimal initial perturbations are shown to project onto El Niño–Southern Oscillation (ENSO) and South Pacific decadal oscillation (SPDO), where the inclusion of subsurface South Pacific Ocean temperature variability significantly increases the multiyear linear predictability of the deterministic system. We show that the optimal extratropical sea surface temperature (SST) precursor is associated with the South Pacific meridional mode, which takes from 7 to 9 months to linearly evolve into the final ENSO and SPDO peaks in both the observations and as simulated in an atmosphere-forced ocean model. The optimal subsurface precursor resembles its peak phase, but with a weak litude, representing oceanic Rossby waves in the extratropical South Pacific. The stochastic forcing is estimated as the residual by removing the deterministic dynamics from the actual tendency under a centered difference approximation. The resulting stochastic forcing time series satisfies the Gaussian white noise assumption of the LIM. We show that the PSA-like variability is strongly associated with stochastic SST forcing in the tropical and South Pacific Oceans and contributes not only to excite the optimal initial perturbations associated with ENSO and the SPDO but in general to activate the entire stochastic SST forcing, especially in austral summer.
Storm tracks in the Southern Hemisphere subtropical oceans
Publisher: American Geophysical Union (AGU)
Date: 09-2014
DOI: 10.1002/2014JC009990
A Linear Inverse Model of Tropical and South Pacific Seasonal Predictability
Publisher: American Meteorological Society
Date: 06-2020
Abstract: A multivariate linear inverse model (LIM) is developed to demonstrate the mechanisms and seasonal predictability of the dominant modes of variability from the tropical and South Pacific Oceans. We construct a LIM whose covariance matrix is a combination of principal components derived from tropical and extratropical sea surface temperature, and South Pacific Ocean vertically averaged temperature anomalies. Eigen-decomposition of the linear deterministic system yields stationary and/or propagating eigenmodes, of which the least d ed modes resemble El Niño–Southern Oscillation (ENSO) and the South Pacific decadal oscillation (SPDO). We show that although the oscillatory periods of ENSO and SPDO are distinct, they have very close d ing time scales, indicating that the predictive skill of the surface ENSO and SPDO is comparable. The most d ed noise modes occur in the midlatitude South Pacific Ocean, reflecting atmospheric eastward-propagating Rossby wave train variability. We argue that these ocean wave trains occur due to the high-frequency atmospheric variability of the Pacific–South American pattern imprinting onto the surface ocean. The ENSO spring predictability barrier is apparent in LIM predictions initialized in March–May (MAM) but displays a significant correlation skill of up to ~3 months. For the SPDO, the predictability barrier tends to appear in June–September (JAS), indicating remote but delayed influences from the tropics. We demonstrate that subsurface processes in the South Pacific Ocean are the main source of decadal variability and further that by characterizing the upper ocean temperature contribution in the LIM, the seasonal predictability of both ENSO and the SPDO variability is increased.
Tropical western and central Pacific marine heatwave data calculated from gridded sea surface temperature observations and CMIP6
Publisher: Elsevier BV
Date: 02-2021
Projected Tasman Sea Extremes in Sea Surface Temperature through the Twenty-First Century
Publisher: American Meteorological Society
Date: 24-02-2014
DOI: 10.1175/JCLI-D-13-00259.1
Abstract: Ocean climate extremes have received little treatment in the literature, aside from coastal sea level and temperatures affecting coral bleaching. Further, it is notable that extremes (e.g., temperature and precipitation) are typically not well represented in global climate models. Here, the authors improve dynamically downscaled ocean climate model estimates of sea surface temperature (SST) extremes in the Tasman Sea off southeastern Australia using satellite remotely sensed observed extreme SSTs and the simulated marine climate of the 1990s. This is achieved using a Bayesian hierarchical model in which the parameters of an extreme value distribution are modeled by linear regression onto the key marine climate variables (e.g., mean SST, SST variance, etc.). The authors then apply this fitted model, essentially a form of bias correction, to the marine climate projections for the 2060s under an A1B emissions scenario. They show that the extreme SSTs are projected to increase in the Tasman Sea in a nonuniform way. The 50-yr return period extreme SSTs are projected to increase by up to 2°C over the entire domain and by up to 4°C in a hotspot located in the central western portion of the Tasman Sea, centered at a latitude ~500 km farther south than the projected change in mean SST. The authors show that there is a greater than 50% chance that annual maximum SSTs will increase by at least 2°C in this hotspot and that this change is significantly different than that which might be expected because of random chance in an unchanged climate.
The Double-Peaked El Niño and Its Physical Processes
Publisher: American Meteorological Society
Date: 02-2021
Abstract: Recently, El Niño ersity has been paid much attention because of its different global impacts. However, most studies have focused on a single warm peak in sea surface temperature anomalies (SSTAs), either in the central Pacific or the eastern Pacific Ocean. Here, we demonstrate from observational analyses that several recent El Niño events show double warm peaks in SSTA—called “double-peaked (DP) El Niño”—that have only been observed since 2000. The DP El Niño has two warm centers, which grow concurrently but separately, in both the central and eastern Pacific. In general, the atmospheric and oceanic patterns of the DP El Niño are similar to those of the warm-pool (WP) El Niño from the development phase, such that the central Pacific peak is developed by the zonal advective feedback and reduced wind speed anomalies. However, a distinctive difference exists in the eastern Pacific where the DP El Niño has a second SSTA peak. In addition, the DP El Niño shows more distinctive anomalous precipitation along the Pacific intertropical convergence zone (ITCZ) when compared with the WP El Niño. We demonstrate that the peculiar precipitation anomalies along the Pacific ITCZ play a critical role in enhancing the equatorial westerly wind stress anomalies, which help to develop the eastern SSTA peak by deepening the thermocline in the eastern Pacific.
Climate, urbanisation and vulnerability to vector-borne disease in subtropical coastal Australia: sustainable policy for a changing environment
Publisher: Informa UK Limited
Date: 2005
The Modulation of ENSO Variability in CCSM3 by Extratropical Rossby Waves
Publisher: American Meteorological Society
Date: 15-11-2009
Abstract: Evidence suggests that the magnitude and frequency of the El Niño–Southern Oscillation (ENSO) changes on interdecadal time scales. This is manifest in a distinct shift in ENSO behavior during the late 1970s. This study investigates mechanisms that may force this interdecadal variability and, in particular, on modulations driven by extratropical Rossby waves. Results from oceanic shallow-water models show that the Rossby wave theory can explain small near-zonal changes in equatorial thermocline depth that can alter the litude of simulated ENSO events. However, questions remain over whether the same mechanism operates in more complex coupled general circulation models (CGCMs) and what the magnitude of the resulting change would be. Experiments carried out in a state-of-the-art z-coordinate primitive equation model confirm that the Rossby wave mechanism does indeed operate. The effects of these interactions are further investigated using a partial coupling (PC) technique. This allows for the isolation of the role of wind stress–forced oceanic exchanges between the extratropics and the tropics and the subsequent modulation of ENSO variability. It is found that changes in the background state of the equatorial Pacific thermocline depth, induced by a fixed off-equatorial wind stress anomaly, can significantly affect the probability of ENSO events occurring. This confirms the results obtained from simpler models and further validates theories that rely on oceanic wave dynamics to generate Pacific Ocean interdecadal variability. This indicates that an improved predictive capability for seasonal-to-interannual ENSO variability could be achieved through a better understanding of extratropical-to-tropical Pacific Ocean transfers and western boundary processes. Furthermore, such an understanding would provide a physical basis to enhance multiyear probabilistic predictions of ENSO indices.
An evaluation of the classical and extended Rossby wave theories in explaining spectral estimates of the first few baroclinic modes in the South Pacific Ocean
Publisher: Springer Science and Business Media LLC
Date: 30-01-2007
Marine heatwaves off eastern Tasmania: Trends, interannual variability, and predictability
Publisher: Elsevier BV
Date: 02-2018
Anthropogenic and Natural Influences on Record 2016 Marine Heat waves
Publisher: American Meteorological Society
Date: 2018
Interdecadal sea surface temperature variability in the equatorial Pacific Ocean. Part II: The role of equatorial/off-equatorial wind stresses in a hybrid coupled model
Publisher: American Meteorological Society
Date: 09-2008
Abstract: Many modeling studies have been carried out to investigate the role of oceanic Rossby waves linking the off-equatorial and equatorial Pacific Ocean. Although the equatorial ocean response to off-equatorial wind stress forcing alone tends to be relatively small, it is clear that off-equatorial oceanic Rossby waves affect equatorial Pacific Ocean variability on interannual through to interdecadal time scales. In the present study, a hybrid coupled model (HCM) of the equatorial Pacific (between 12.5°S and 12.5°N) was developed and is used to estimate the magnitude of equatorial region variability arising from off-equatorial (poleward of 12.5° latitude) wind stress forcing. The HCM utilizes a reduced-gravity ocean shallow-water model and a statistical atmosphere derived from monthly output from a 100-yr Australian Bureau of Meteorology Research Centre (now the Centre for Australian Weather and Climate Research) coupled general circulation model integration. The equatorial region wind stress forcing is found to dominate both the interannual and interdecadal SST variability. The equatorial response to off-equatorial wind stress forcing alone is insufficient to initiate an atmospheric feedback that significantly lifies the original equatorial region variability. Consequently, the predictability of equatorial region SST anomalies (SSTAs) could be limited to ∼1 yr (the maximum time it takes an oceanic Rossby wave to cross the Pacific Ocean basin in the equatorial region). However, the results also suggest that the addition of off-equatorial wind stress forcing to the HCM leads to variations in equatorial Pacific background SSTA of up to almost one standard deviation. This off-equatorially forced portion of the equatorial SSTA could prove critical for thresholds of El Niño–Southern Oscillation (ENSO) because they can constructively interfere with equatorially forced SSTA of the same sign to produce significant equatorial region ENSO anomalies.
From physics to fish to folk: Supporting coastal regional communities to understand their vulnerability to climate change in Australia
Publisher: Wiley
Date: 30-12-2016
DOI: 10.1111/FOG.12139
South Pacific Decadal Climate Variability and Potential Predictability
Publisher: American Meteorological Society
Date: 20-08-2019
Abstract: The South Pacific decadal oscillation (SPDO) characterizes the Southern Hemisphere contribution to the Pacific-wide interdecadal Pacific oscillation (IPO) and is analogous to the Pacific decadal oscillation (PDO) centered in the North Pacific. In this study, upper ocean variability and potential predictability of the SPDO is examined in HadISST data and an atmosphere-forced ocean general circulation model. The potential predictability of the IPO-related variability is investigated in terms of both the fractional contribution made by the decadal component in the South, tropical and North Pacific Oceans and in terms of a doubly integrated first-order autoregressive (AR1) model. Despite explaining a smaller fraction of the total variance, we find larger potential predictability of the SPDO relative to the PDO. We identify distinct local drivers in the western subtropical South Pacific, where nonlinear baroclinic Rossby wave–topographic interactions act to low-pass filter decadal variability. In particular, we show that the Kermadec Ridge in the southwest Pacific enhances the decadal signature more prominently than anywhere else in the Pacific basin. Applying the doubly integrated AR1 model, we demonstrate that variability associated with the Pacific–South American pattern is a critically important atmospheric driver of the SPDO via a reddening process analogous to the relationship between the Aleutian low and PDO in the North Pacific—albeit that the relationship in the South Pacific appears to be even stronger. Our results point to the largely unrecognized importance of South Pacific processes as a key source of decadal variability and predictability.
Climate change cascades: Shifts in oceanography, species' ranges and subtidal marine community dynamics in eastern Tasmania
Publisher: Elsevier BV
Date: 04-2011
A Bayesian forecast model of Australian region tropical cyclone formation
Publisher: American Meteorological Society
Date: 12-2011
Abstract: A new and potentially skillful seasonal forecast model of tropical cyclone formation [tropical cyclogenesis (TCG)] is developed for the Australian region. The model is based on Poisson regression using the Bayesian approach. Predictor combinations are chosen using a step-by-step predictor selection. The three-predictor model based on derived indices of June–August average convective available potential energy, May–July average meridional winds at 850 hPa (V850), and July–September geopotential height at 500 hPa produces the smallest standard error (se = 0.36) and root-mean-squared error (RMSE = 5.20) for the leave-one-out cross-validated TCG hindcasts over the 40-yr record between 1968/69–2007/08. The corresponding correlation coefficient between observed annual TCG totals and cross-validated model hindcasts is r = 0.73. Using fourfold cross validation, model hindcast skill is robust, with 85% of the observed seasonal TCG totals hindcast within the model standard deviations. Seasonal TCG totals during ENSO events are typically well captured with RMSE = 5.14 during El Niño, and RMSE = 6.04 during La Niña years. The model is shown to be valuable in hindcasting seasonal TCG totals in the eastern Australian subregion (r = 0.73) and also provides some skill for the western Australian region (r = 0.42), while it not useful for the northern region. In summary, the authors find that the three-predictor Bayesian model provides substantial improvement over existing statistical TCG forecast models, with remarkably skillful hindcasts (forecasts) of Australian region and subregional seasonal TCG totals provided one month ahead of the TC season.
Impacts of marine heatwaves on tropical western and central Pacific Island nations and their communities
Publisher: Elsevier BV
Date: 2021
A catalogue of marine heatwave metrics and trends for the Australian region
Publisher: CSIRO Publishing
Date: 14-12-2021
DOI: 10.1071/ES21014
Abstract: Marine heatwaves around Australia, and globally, have been increasing in their frequency, intensity, and duration. This study reviews and catalogues marine heatwave metrics and trends around Australia since 1982, from near the beginning of the satellite sea-surface temperature observing period. The years in which the longest and strongest marine heatwaves around Australia occurred are also recorded. In addition, we analyse marine heatwaves in selected case study regions, and provide a short review of their associated impacts. These regions include: off the Western Australian coast, Torres Strait, Great Barrier Reef, Tasman Sea, and South Australian Basin. Finally, we provide a brief review of progress in understanding the potential predictability of sea surface temperature changes and marine heatwaves around Australia.
A hierarchical approach to defining marine heatwaves
Publisher: Elsevier BV
Date: 02-2016
Global implications of surface current modulation of the wind-wave field
Publisher: Elsevier BV
Date: 05-2021
Image-based continental shelf habitat mapping using novel automated data extraction techniques
Publisher: Elsevier BV
Date: 08-2012
Insights from CMIP6 for Australia's future climate
Publisher: Wiley
Date: 2020
Global Water Governance and Climate Change: Identifying Innovative Arrangements for Adaptive Transformation
Publisher: MDPI AG
Date: 02-01-2018
DOI: 10.3390/W10010029
Extending our understanding of South Pacific gyre spin-up: Modeling the East Australian Current in a future climate
Publisher: American Geophysical Union (AGU)
Date: 05-2014
DOI: 10.1002/2013JC009591
Natural hazards in Australia: sea level and coastal extremes
Publisher: Springer Science and Business Media LLC
Date: 24-03-2016
Evaluation of the AR4 Climate Models’ Simulated Daily Maximum Temperature, Minimum Temperature, and Precipitation over Australia Using Probability Density Functions
Publisher: American Meteorological Society
Date: 09-2007
DOI: 10.1175/JCLI4253.1
Abstract: The coupled climate models used in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change are evaluated. The evaluation is focused on 12 regions of Australia for the daily simulation of precipitation, minimum temperature, and maximum temperature. The evaluation is based on probability density functions and a simple quantitative measure of how well each climate model can capture the observed probability density functions for each variable and each region is introduced. Across all three variables, the coupled climate models perform better than expected. Precipitation is simulated reasonably by most and very well by a small number of models, although the problem with excessive drizzle is apparent in most models. Averaged over Australia, 3 of the 14 climate models capture more than 80% of the observed probability density functions for precipitation. Minimum temperature is simulated well, with 10 of the 13 climate models capturing more than 80% of the observed probability density functions. Maximum temperature is also reasonably simulated with 6 of 10 climate models capturing more than 80% of the observed probability density functions. An overall ranking of the climate models, for each of precipitation, maximum, and minimum temperatures, and averaged over these three variables, is presented. Those climate models that are skillful over Australia are identified, providing guidance on those climate models that should be used in impacts assessments where those impacts are based on precipitation or temperature. These results have no bearing on how well these models work elsewhere, but the methodology is potentially useful in assessing which of the many climate models should be used by impacts groups.
ENSO to multi-decadal time scale changes in East Australian Current transports and Fort Denison sea level: Oceanic Rossby waves as the connecting mechanism
Publisher: Elsevier BV
Date: 03-2011
Linking the Atmospheric Pacific-South American Mode with Oceanic Variability and Predictability
Publisher: Springer Science and Business Media LLC
Date: 21-10-2021
DOI: 10.1038/S43247-021-00295-4
Abstract: While Pacific climate variability is largely understood based on El Niño-Southern Oscillation (ENSO), the North Pacific focused Pacific decadal oscillation and the basin-wide interdecadal Pacific oscillation, the role of the South Pacific, including atmospheric drivers and cross-scale interactions, has received less attention. Using reanalysis data and model outputs, here we propose a paradigm for South Pacific climate variability whereby the atmospheric Pacific-South American (PSA) mode acts to excite multiscale spatiotemporal responses in the upper South Pacific Ocean. We find the second mid-troposphere PSA pattern is fundamental to stochastically generate a mid-latitude sea surface temperature quadrupole pattern that represents the optimal precursor for the predictability and evolution of both the South Pacific decadal oscillation and ENSO several seasons in advance. We find that the PSA mode is the key driver of oceanic variability in the South Pacific subtropics that generates a potentially predictable climate signal linked to the tropics.
Remote Forcing of Tasman Sea Marine Heatwaves
Publisher: American Meteorological Society
Date: 15-06-2020
Abstract: Recent marine heatwave (MHW) events in the Tasman Sea have had dramatic impacts on the ecosystems, fisheries, and aquaculture off Tasmania’s east coast. However, our understanding of the large-scale drivers (forcing) and potential predictability of MHW events in this region off southeast Australia is still in its infancy. Here, we investigate the role of oceanic Rossby waves forced in the interior South Pacific on observed MHW occurrences off southeast Australia from 1994 to 2016, including the extreme 2015/16 MHW event. First, we used an upper-ocean heat budget analysis to show that 51% of these historical Tasman Sea MHWs were primarily due to increased East Australian Current (EAC) Extension poleward transports through the region. Second, we used lagged correlation analysis to empirically connect the EAC Extension intensification to incoming westward-propagating sea surface height (SSH) anomalies from the interior South Pacific. Third, we dynamically analyzed these SSH anomalies using simple process-based baroclinic and barotropic Rossby wave models forced by wind stress curl changes across the South Pacific. Finally, we show that associated monthly SSH changes around New Zealand may be a useful index of western Tasman Sea MHW predictability, with a lead time of 2–3 years. In conclusion, our findings demonstrate that there is potential predictability of advection-dominated MHW event likelihoods in the EAC Extension region up to several years in advance, due to the deterministic contribution from baroclinic and barotropic Rossby waves in modulating the EAC Extension transports.
ENSO‐Driven Ocean Extremes and Their Ecosystem Impacts
Publisher: Wiley
Date: 23-10-2020
Resilience and signatures of tropicalization in protected reef fish communities
Publisher: Springer Science and Business Media LLC
Date: 12-2014
DOI: 10.1038/NCLIMATE2062
Oscillatory and propagating modes of temperature variability at the 3-3.5- and 4-4.5-yr. time scales in the upper southwest Pacific Ocean
Publisher: American Meteorological Society
Date: 03-2005
DOI: 10.1175/JCLI-3286.1
Abstract: This paper investigates oscillatory and propagating patterns of normalized surface and subsurface temperature anomalies (from the seasonal cycle) in the southwest Pacific Ocean using an extended empirical orthogonal function (EEOF) analysis. The temperature data (and errors) are from the Digital Atlas of Southwest Pacific upper Ocean Temperatures (DASPOT). These data are 3 monthly in time (January, April, July, and October), 2° × 2° in space, and 5 m in the vertical to 450-m depths. The temperature anomalies in the EEOF analysis are normalized by the objective mapping temperature errors at each grid point. They are also Butterworth filtered in the 3–7-yr band to examine interannual variations in the temperature field. The oscillating and propagating patterns of the modes are examined across four vertical levels: the surface, and 100-, 250-, and 450-m depths. The dominant mode EEOF (70% of the total variance of the filtered data) oscillates in a 4–4.5-yr quasi-periodic manner that is consistent with El Niño–Southern Oscillation (ENSO). Anomalies peak first at the surface in the subtropics between New Caledonia and Fiji (centered around 17°S, 177°E), then 6 months later in the tropical far west centered around the Solomon Islands (5°S, 153°–157°E), with a maximum at the base of the mixed layer (100 m) and upper thermocline (250 m), and then eastward in the northeast of the southwest Pacific region (0°–10°S, 160°E–180°). Mode 2 (25% variance of the filtered data) has a periodicity of 3–3.5 yr, with centers of action in all four vertical levels. The mode-2 patterns are consistent with variations in the subtropical gyre circulation, including the East Australian Current and its separation, and are continuous with the Tasman Front. Two spatial dipoles are apparent: (i) one in sea surface temperature (SST) at about 5°S, straddling west–east either side of the Solomon Islands, consistent with the classic Pacific-wide ENSO SST anomaly mode, and (ii) a subsurface dipole pattern, with centers in the Solomon Islands region at 100- and 250-m depths, and the western Tasman Sea (27°–33°S, 157°–161°E) at 250- and 450-m depths, consistent with dynamic changes in the gyre intensity.
Simulating scientific thinking online: an example of research-led teaching
Publisher: Informa UK Limited
Date: 08-2005
Influence of the Madden–Julian oscillation on Costa Rican mid‐summer drought timing
Publisher: Wiley
Date: 05-09-2019
DOI: 10.1002/JOC.5806
The impact of polynyas on the stability of the thermohaline circulation as simulated in a coupled ocean-atmosphere-sea ice box model
Publisher: American Geophysical Union (AGU)
Date: 03-2001
DOI: 10.1029/2000GL011982
Estimating extremes from global ocean and climate models: A Bayesian hierarchical model approach
Publisher: Elsevier BV
Date: 03-2014
Southwest Pacific subtropical mode water: A climatology
Publisher: Elsevier BV
Date: 06-2008
Modulation of wet-season rainfall over Iran by the Madden–Julian Oscillation, Indian Ocean Dipole and El Niño–Southern Oscillation
Publisher: Wiley
Date: 25-03-2019
DOI: 10.1002/JOC.6057
Effectiveness of the Bjerknes stability index in representing ocean dynamics
Publisher: Springer Science and Business Media LLC
Date: 12-02-2014
Adaptation of Australia's marine ecosystems to climate change: Using science to inform conservation management
Publisher: Hindawi Limited
Date: 2014
DOI: 10.1155/2014/140354
Abstract: The challenges that climate change poses for marine ecosystems are already manifesting in impacts at the species, population, and community levels in Australia, particularly in Tasmania and tropical northern Australia. Many species and habitats are already under threat as a result of human activities, and the additional pressure from climate change significantly increases the challenge for marine conservation and management. Climate change impacts are expected to magnify as sea surface temperatures, ocean chemistry, ocean circulation, sea level, rainfall, and storm patterns continue to change this century. In particular, keystone species that form the foundation of marine habitats, such as coral reefs, kelp beds, and temperate rocky reefs, are projected to pass thresholds with subsequent implications for communities and ecosystems. This review synthesises recent science in this field: the observed impacts and responses of marine ecosystems to climate change, ecological thresholds of change, and strategies for marine conservation to promote adaptation. Increasing observations of climate-related impacts on Australia’s marine ecosystems—both temperate and tropical—are making adaptive management more important than ever before. Our increased understanding of the impacts and responses of marine ecosystems to climate change provides a focus for “no-regrets” adaptations that can be implemented now and refined as knowledge improves.
Slow westward movement of salinity anomalies across the tropical South Indian Ocean
Publisher: American Geophysical Union (AGU)
Date: 08-2015
DOI: 10.1002/2015JC010933
Projected changes to Tasman Sea eddies in a future climate
Publisher: American Geophysical Union (AGU)
Date: 11-2015
DOI: 10.1002/2015JC010993
The Quasi-Biennial Oscillation and Ross River virus incidence in Queensland, Australia
Publisher: Springer Science and Business Media LLC
Date: 09-2002
DOI: 10.1007/S00484-002-0137-Z
Abstract: Ross River virus (RRV) is the most important vector-borne disease in Australia. The National Notifiable Diseases Surveillance System has confirmed that its incidence is often greatest in the state of Queensland, where there is a clear seasonal pattern as well as interannual variability. Previous studies have examined relationships between large-scale climate fluctuations (such as El Niño Southern Oscillation) and vector-borne disease. No previous study has examined such relationships with the Quasi-Biennial Oscillation (QBO), another large-scale climate fluctuation. We employ time-series analysis techniques to investigate cycles inherent in monthly RRV incidence in Queensland, Australia, from January 1991 to December 1997 inclusive. The presence of a quasi-biennial cycle in the RRV time series that is out of phase with the climatic QBO is described. Quantitative analyses using correlograms and periodograms demonstrate that the quasi-biennial cycle in the RRV time series is statistically significant, at the 95% level, above the noise. Together with the seasonal cycle, the quasi-biennial cycle accounts for 77% of the variance in Queensland RRV cases. Regression analysis of QBO and summer rainfall in three climatic zones of Queensland indicates a significant association between QBO and rainfall in the subtropical southeastern part of the state. These results suggest an indirect influence of the QBO on RRV incidence in Queensland, via its influence on climate in this region. Our findings indicate that the QBO may be a useful predictor of RRV at several months lead, and might be used by public health authorities in the management and prevention of this disease.
Decadal climate variability in Australia during the twentieth century
Publisher: Wiley
Date: 02-1999
DOI: 10.1002/(SICI)1097-0088(199902)19:2<169::AID-JOC356>3.0.CO;2-Y
The role of natural variability and anthropogenic climate change in the 2017/18 Tasman Sea marine heatwave
Publisher: American Meteorological Society
Date: 2018
Mechanisms of tropical Pacific decadal variability
Publisher: Springer Science and Business Media LLC
Date: 18-10-2023
Research priorities for natural ecosystems in a changing global climate
Publisher: Wiley
Date: 20-11-2020
DOI: 10.1111/GCB.14856
Abstract: Climate change poses significant emerging risks to bio ersity, ecosystem function and associated socioecological systems. Adaptation responses must be initiated in parallel with mitigation efforts, but resources are limited. As climate risks are not distributed equally across taxa, ecosystems and processes, strategic prioritization of research that addresses stakeholder‐relevant knowledge gaps will accelerate effective uptake into adaptation policy and management action. After a decade of climate change adaptation research within the Australian National Climate Change Adaptation Research Facility, we synthesize the National Adaptation Research Plans for marine, terrestrial and freshwater ecosystems. We identify the key, globally relevant priorities for ongoing research relevant to informing adaptation policy and environmental management aimed at maximizing the resilience of natural ecosystems to climate change. Informed by both global literature and an extensive stakeholder consultation across all ecosystems, sectors and regions in Australia, involving thousands of participants, we suggest 18 priority research topics based on their significance, urgency, technical and economic feasibility, existing knowledge gaps and potential for cobenefits across multiple sectors. These research priorities provide a unified guide for policymakers, funding organizations and researchers to strategically direct resources, maximize stakeholder uptake of resulting knowledge and minimize the impacts of climate change on natural ecosystems. Given the pace of climate change, it is imperative that we inform and accelerate adaptation progress in all regions around the world.
Categorizing and Naming Marine Heatwaves
Publisher: The Oceanography Society
Date: 06-2018
Insights From CMIP6 for Australia's Future Climate
Publisher: American Geophysical Union (AGU)
Date: 05-2020
DOI: 10.1029/2019EF001469
Influence of the Pacific‐South American Modes on the Global Spectral Wind‐Wave Climate
Publisher: American Geophysical Union (AGU)
Date: 08-2020
DOI: 10.1029/2020JC016354
Interrogating resilience: Toward a typology to improve its operationalization
Publisher: Resilience Alliance, Inc.
Date: 2016
Tropical cyclone contribution to extreme rainfall over southwest Pacific Island nations
Publisher: Springer Science and Business Media LLC
Date: 18-03-2021
DOI: 10.1007/S00382-021-05680-5
Abstract: Southwest Pacific nations are among some of the worst impacted and most vulnerable globally in terms of tropical cyclone (TC)-induced flooding and accompanying risks. This study objectively quantifies the fractional contribution of TCs to extreme rainfall (hereafter, TC contributions) in the context of climate variability and change. We show that TC contributions to extreme rainfall are substantially enhanced during active phases of the Madden–Julian Oscillation and by El Niño conditions (particularly over the eastern southwest Pacific region) this enhancement is primarily attributed to increased TC activity during these event periods. There are also indications of increasing intensities of TC-induced extreme rainfall events over the past few decades. A key part of this work involves development of sophisticated Bayesian regression models for in idual island nations in order to better understand the synergistic relationships between TC-induced extreme rainfall and combinations of various climatic drivers that modulate the relationship. Such models are found to be very useful for not only assessing probabilities of TC- and non-TC induced extreme rainfall events but also evaluating probabilities of extreme rainfall for cases with different underlying climatic conditions. For ex le, TC-induced extreme rainfall probability over Samoa can vary from ~ 95 to ~ 75% during a La Niña period, if it coincides with an active or inactive phase of the MJO, and can be reduced to ~ 30% during a combination of El Niño period and inactive phase of the MJO. Several other such cases have been assessed for different island nations, providing information that have potentially important implications for planning and preparing for TC risks in vulnerable Pacific Island nations.
The Pacific Decadal Oscillation modulated marine heatwaves in the Northeast Pacific during past decades
Publisher: Springer Science and Business Media LLC
Date: 19-06-2023
DOI: 10.1038/S43247-023-00863-W
Abstract: The Pacific Decadal Oscillation has been suggested to play an important role in driving marine heatwaves in the Northeast Pacific during recent decades. Here we combine observations and climate model simulations to show that marine heatwaves became longer, stronger and more frequent off the Northeast Pacific coast under a positive Pacific Decadal Oscillation scenario, unlike what is found during a negative Pacific Decadal Oscillation scenario. This primarily results from the different mean-state sea surface temperatures between the two Pacific Decadal Oscillation phases. Compared to the cool (negative) phase of the Pacific Decadal Oscillation, warmer coastal sea surface temperatures occur during the positive Pacific Decadal Oscillation phase due to reduced coastal cold upwelling and increased net downward surface heat flux. Model results show that, relative to the background anthropogenic global warming, the positive Pacific Decadal Oscillation in the period 2013–2022 prolongs marine heatwaves duration by up to 43% and acts to increase marine heatwaves annual frequency by up to 32% off the Northeast Pacific coast.
Marine Heatwaves
Publisher: Annual Reviews
Date: 03-01-2021
DOI: 10.1146/ANNUREV-MARINE-032720-095144
Abstract: Ocean temperature variability is a fundamental component of the Earth's climate system, and extremes in this variability affect the health of marine ecosystems around the world. The study of marine heatwaves has emerged as a rapidly growing field of research, given notable extreme warm-water events that have occurred against a background trend of global ocean warming. This review summarizes the latest physical and statistical understanding of marine heatwaves based on how they are identified, defined, characterized, and monitored through remotely sensed and in situ data sets. We describe the physical mechanisms that cause marine heatwaves, along with their global distribution, variability, and trends. Finally, we discuss current issues in this developing research area, including considerations related to thechoice of climatological baseline periods in defining extremes and how to communicate findings in the context of societal needs.
Assessing an indirect health implication of a changing climate: Ross River Virus in a temperate island state
Publisher: Elsevier BV
Date: 2015
Toward operationalizing resilience concepts in Australian marine sectors coping with climate change
Publisher: Resilience Alliance, Inc.
Date: 2013
A new method for extracting the ENSO-independent Indian Ocean Dipole: application to Australian region tropical cyclone counts
Publisher: Springer Science and Business Media LLC
Date: 30-06-2012
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