ORCID Profile
0000-0002-1860-510X
Current Organisation
Queensland Herbarium
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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 | Climate Change Processes | Information Systems Management | Oceanography Not Elsewhere Classified | Physical Oceanography | Meteorology | Atmospheric Sciences Not Elsewhere Classified | Oceanography | Atmospheric Sciences not elsewhere classified | Climatology (excl. Climate Change Processes)
ANZSRC Socio-Economic Objective (SEO)
Climate Change Models | Climate change | Land and water management | Living resources (flora and fauna) | Weather | Climate and Climate Change not elsewhere classified | Expanding Knowledge in the Environmental Sciences | Expanding Knowledge in the Information and Computing Sciences |
Related Links
Publications
Quantifying storm tide risk in Fiji due to climate variability and change
Publisher: Elsevier BV
Date: 05-2014
Recently Naturalized Paraserianthes lophantha subsp. lophantha Displays Contrasting Genetic Diversity and Climate Relationships Compared to Native Populations
Publisher: MDPI AG
Date: 10-11-2020
DOI: 10.3390/D12110422
Abstract: Paraseriantheslophantha subsp. lophantha (Leguminosae) is native to southwestern Australia, but has become naturalized in eastern Australia and in countries around the world. Previous studies have investigated the introduction sources for P. lophantha subsp. lophantha overseas, but here, we expand on the knowledge of genetic patterns in its native and naturalized range in Australia. Genetic patterns were examined using nine nuclear microsatellite loci and three chloroplast DNA markers. The native populations exhibited phylogeographic patterns, including north-south differentiation, and a genetic signal related to temperature gradients. Naturalized Australian populations displayed lower overall genetic variation and no phylogeographic patterns. Several naturalized populations separated by large distances (350–650 km) shared multi-locus genotypes, supporting the notion of a shared source of germplasm and possible inbreeding due to human-mediated introductions from a limited number of in iduals and/or source populations within the native range. We advocate that management strategies are tailored to the distinct conservation aims underpinning conservation in native or naturalized populations. Within the native distribution, management should have a long-term aim to replicate historical evolutionary processes, whereas in naturalized populations, immediate actions may be required to reduce the abundance of P. lophantha subsp. lophantha and minimize its invasive impact on the recipient vegetation.
Correction to “Numerical evaluation of subsurface soil water evaporation derived from sensible heat balance”
Publisher: American Geophysical Union (AGU)
Date: 05-2011
DOI: 10.1029/2011WR010620
Future Changes in the Occurrence of Hybrid Cyclones: The Added Value of Cyclone Classification for the East Australian Low-Pressure Systems
Publisher: American Geophysical Union (AGU)
Date: 20-03-2020
DOI: 10.1029/2019GL085751
Future Australian Severe Thunderstorm Environments. Part II: The Influence of a Strongly Warming Climate on Convective Environments
Publisher: American Meteorological Society
Date: 09-05-2014
DOI: 10.1175/JCLI-D-13-00426.1
Abstract: The influence of a warming climate on the occurrence of severe thunderstorm environments in Australia was explored using two global climate models: Commonwealth Scientific and Industrial Research Organisation Mark, version 3.6 (CSIRO Mk3.6), and the Cubic-Conformal Atmospheric Model (CCAM). These models have previously been evaluated and found to be capable of reproducing a useful climatology for the twentieth-century period (1980–2000). Analyzing the changes between the historical period and high warming climate scenarios for the period 2079–99 has allowed estimation of the potential convective future for the continent. Based on these simulations, significant increases to the frequency of severe thunderstorm environments will likely occur for northern and eastern Australia in a warmed climate. This change is a response to increasing convective available potential energy from higher continental moisture, particularly in proximity to warm sea surface temperatures. Despite decreases to the frequency of environments with high vertical wind shear, it appears unlikely that this will offset increases to thermodynamic energy. The change is most pronounced during the peak of the convective season, increasing its length and the frequency of severe thunderstorm environments therein, particularly over the eastern parts of the continent. The implications of this potential increase are significant, with the overall frequency of potential severe thunderstorm days per year likely to rise over the major population centers of the east coast by 14% for Brisbane, 22% for Melbourne, and 30% for Sydney. The limitations of this approach are then discussed in the context of ways to increase the confidence of predictions of future severe convection.
Natural hazards in Australia: storms, wind and hail
Publisher: Springer Science and Business Media LLC
Date: 22-07-2016
Climate change impacts on tropical cyclones and extreme sea levels in the South Pacific - A regional assessment
Publisher: Elsevier BV
Date: 2012
Historical biogeography of Rhododendron section Vireya and the Malesian Archipelago
Publisher: Wiley
Date: 02-08-2006
A new alpine species of Rhododendron (Ericaceae) from New Guinea
Publisher: JSTOR
Date: 2003
DOI: 10.2307/3393560
Sensitivity of the distribution of thunderstorms to sea surface temperatures in four Australian east coast lows
Publisher: Springer Science and Business Media LLC
Date: 08-05-2015
Uncertainties in runoff projections in southwestern Australian catchments using a global climate model with perturbed physics
Publisher: Elsevier BV
Date: 10-2015
Contrasting tropical cyclone and non-tropical cyclone related rainfall drop size distribution at Darwin, Australia
Publisher: Elsevier BV
Date: 11-2016
Hybrid capture of 964 nuclear genes resolves evolutionary relationships in the mimosoid legumes and reveals the polytomous origins of a large pantropical radiation
Publisher: Wiley
Date: 30-11-2020
DOI: 10.1002/AJB2.1568
Evaluation of TMPA 3B42 Precipitation Estimates during the Passage of Tropical Cyclones over New Caledonia
Publisher: Springer Science and Business Media LLC
Date: 25-04-2016
Basinwise Statistical Analysis of Factors Limiting Tropical Storm Formation From an Initial Tropical Circulation
Publisher: American Geophysical Union (AGU)
Date: 10-06-2020
DOI: 10.1029/2019JD032006
Phylogenetic connections of phyllodinous species of Acacia outside Australia are explained by geological history and human-mediated dispersal
Publisher: CSIRO Publishing
Date: 2012
DOI: 10.1071/SB12027
Abstract: Acacia sensu stricto is found predominantly in Australia however, there are 18 phyllodinous taxa that occur naturally outside Australia, north from New Guinea to Indonesia, Taiwan, the Philippines, south-western Pacific (New Caledonia to Samoa), northern Pacific (Hawaii) and Indian Ocean (Mascarene Islands). Our aim was to determine the phylogenetic position of these species within Acacia, to infer their biogeographic history. To an existing molecular dataset of 109 taxa of Acacia, we added 51 new accessions sequenced for the ITS and ETS regions of nuclear rDNA, including s les from 15 extra-Australian taxa. Data were analysed using both maximum parsimony and Bayesian methods. The phylogenetic positions of the extra-Australian taxa s led revealed four geographic connections. Connection A, i.e. northern Australia?South-east Asia?south-western Pacific, is shown by an early erging clade in section Plurinerves, which relates A. confusa from Taiwan and the Philippines (possibly Fiji) to A. simplex from Fiji and Samoa. That clade is related to A. simsii from southern New Guinea and northern Australia and other northern Australian species. Two related clades in section Juliflorae show a repeated connection (B), i.e. northern Australia?southern New Guinea?south-western Pacific. One of these is the ?A. auriculiformis clade', which includes A. spirorbis subsp. spirorbis from New Caledonia and the Loyalty Islands as sister to the Queensland species A. auriculiformis related taxa include A. mangium, A. leptocarpa and A. spirorbis subsp. solandri. The ?A. aulacocarpa clade' includes A. aulacocarpa, A. peregrinalis endemic to New Guinea, A. crassicarpa from New Guinea and Australia, and other Australian species. Acacia spirorbis (syn. A. solandri subsp. kajewskii) from Vanuatu (Melanesia) is related to these two clades but its exact position is equivocal. The third biogeographic connection (C) is Australia?Timor?Flores, represented independently by the widespread taxon A. oraria (section Plurinerves) found on Flores and Timor and in north-eastern Queensland, and the Wetar island endemic A. wetarensis (Juliflorae). The fourth biogeographic connection (D), i.e. Hawaii?Mascarene?eastern Australia, reveals an extreme disjunct distribution, consisting of the Hawaiian koa (A. koa, A. koaia and A. kaoaiensis), sister to the Mascarene (R�union Island) species A. heterophylla this clade is sister to the eastern Australian A. melanoxylon and A. implexa (all section Plurinerves), and sequence ergence between taxa is very low. Historical range expansion of acacias is inferred to have occurred several times from an Australian?southern New Guinean source. Dispersal would have been possible as the Australian land mass approached South-east Asia, and during times when sea levels were low, from the Late Miocene or Early Pliocene. The close genetic relationship of species separated by vast distances, from the Indian Ocean to the Pacific, is best explained by dispersal by Austronesians, early Homo sapiens migrants from Asia.
Phylogenetic placement and the timing of diversification in Australia's endemic Vachellia (Caesalpinioideae, Mimosoid Clade, Fabaceae) species
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/SB19013
Abstract: The genus Vachellia Wight & Arn. has a pantropical distribution, with species being distributed through Africa, the Americas, Asia and Australia. The relationships among the lineages from Africa and America are well understood, but the phylogenetic placement and evolutionary origins of the Australian species of Vachellia are not known. We, therefore, sequenced four plastid genes from representatives of each of the nine Australian species of Vachellia, and used Bayesian inference to assess the phylogenetic placement of these lineages, and a relaxed molecular clock to assess the timing of ersification. The Australian species of Vachellia form a well-supported monophyletic clade, with molecular-dating analysis suggesting a single dispersal into Australia 6.5 million years ago (95% range 13.9–2.7 million years ago). Diversification of the Australian clade commenced more recently, c. 3.1 million years ago (95% range 9.2–1.2 million years ago), perhaps driven by the increased aridification of Australia at this time. The closest relatives to the Australian Vachellia were not from the Malesian bioregion, suggesting either a long-distance dispersal from Africa, or two separate migrations through Asia. These results not only improve our understanding of the biogeography of Vachellia species, but also have significant implications for the biological control of invasive Vachellia species in Australia.
The ability of general circulation models to simulate tropical cyclones and their precursors over the North Atlantic main development region
Publisher: Springer Science and Business Media LLC
Date: 19-01-2012
Incidence of hyperaccumulation and tissue-level distribution of manganese, cobalt, and zinc in the genus Gossia (Myrtaceae)
Publisher: Oxford University Press (OUP)
Date: 25-02-2021
Abstract: The rare phenomenon of plant manganese (Mn) hyperaccumulation within the Australian flora has previously been detected in the field, which suggested that the tree genus Gossia (Myrtaceae) might contain new Mn hyperaccumulators. We conducted the first growth experiment on Gossia using a multi-factorial dosing trial to assess Mn, cobalt (Co), and zinc (Zn) (hyper)accumulation patterns in selected Gossia species (G. fragrantissima and G. punctata) after a systematic assessment of elemental profiles on all holdings of the genus Gossia at the Queensland Herbarium using handheld X-ray fluorescence spectroscopy. We then conducted detailed in situ analyses of the elemental distribution of Mn, Co, Zn and other elements at the macro (organ) and micro (cellular) levels with laboratory- and synchrotron-based X-ray fluorescence microscopy (XFM). Gossia pubiflora and Gossia hillii were newly discovered to be Mn hyperaccumulator plants. In the dosing trial, G. fragrantissima accumulated 17 400 µg g−1 Mn, 545 µg g−1 Co, and 13 000 µg g−1 Zn, without signs of toxicity. The laboratory-based XFM revealed distinct patterns of accumulation of Co, Mn, and Zn in G. fragrantissima, while the synchrotron XFM showed their localization in foliar epidermal cells, and in the cortex and phloem cells of roots. This study combined novel analytical approaches with controlled experimentation to examine metal hyperaccumulation in slow-growing tropical woody species, thereby enabling insight into the phenomenon not possible through field studies.
The Herbarium 2021 Half–Earth Challenge Dataset and Machine Learning Competition
Publisher: Frontiers Media SA
Date: 02-2022
Abstract: Herbarium sheets present a unique view of the world's botanical history, evolution, and bio ersity. This makes them an all–important data source for botanical research. With the increased digitization of herbaria worldwide and advances in the domain of fine–grained visual classification which can facilitate automatic identification of herbarium specimen images, there are many opportunities for supporting and expanding research in this field. However, existing datasets are either too small, or not erse enough, in terms of represented taxa, geographic distribution, and imaging protocols. Furthermore, aggregating datasets is difficult as taxa are recognized under a multitude of names and must be aligned to a common reference. We introduce the Herbarium 2021 Half–Earth dataset: the largest and most erse dataset of herbarium specimen images, to date, for automatic taxon recognition. We also present the results of the Herbarium 2021 Half–Earth challenge, a competition that was part of the Eighth Workshop on Fine-Grained Visual Categorization (FGVC8) and hosted by Kaggle to encourage the development of models to automatically identify taxa from herbarium sheet images.
Molecular phylogeny of Melaleuca, Callistemon and related genera (Myrtaceae)
Publisher: CSIRO Publishing
Date: 2001
DOI: 10.1071/SB00029
Abstract: To resolve the relationships of taxa within the Beaufortia suballiance (Myrtaceae), 72 ingroup taxa were analysed by parsimony methods and nrDNA sequence data from the 5S and ITS-1 ribosomal DNA spacer regions. Although basal nodes in the consensus tree (combined data set) are not supported by bootstrap or jackknife values, a number of clades are well supported, showing that Melaleuca is polyphyletic. Monophyletic groups include: endemic species of Melaleuca from New Caledonia (including species of Callistemon recently transferred to Melaleuca) the tropical Melaleuca leucadendra group Australian species of Callistemon, which relate to species of Melaleuca predominantly from the South-East and a group of south-western and eastern Australian melaleucas that relate to a clade of three south-western genera, Eremaea, Conothamnus and Phymatocarpus. Calothamnus, Regeliaand Beaufortiamay also relate to this latter group. Lamarchea is possibly related to northern melaleucas. The results have implications for generic revisions of the large genus Melaleuca. Biogeographic subtree analysis, based only on supported nodes of the taxon cladogram, showed New Caledonia, New Guinea, Eastern Queensland and the Northern Desert unresolved at the base of the area cladogram. The position of some of these areas is likely to be artifactual, but New Caledonia is interpreted as in the correct position. At a higher node, the monsoonal northern areas of Australia (Kimberley, Arnhem and Cape York), Atherton, the Pilbara and Western Desert relate to the southern regions, which form a group. The South-West of Australia is related to Eyre and Adelaide (designated area ‘South’) and Tasmania is related to the South-East and MacPherson–Macleay. The vicariance between northern and southern regions in Australia possibly relates to an early major climatic change (from the Early Tertiary). The biogeographic analysis helped illuminate taxon relationships.
Phylogeny of Rhododendron section Vireya (Ericaceae) based on two non-coding regions of cpDNA
Publisher: Springer Science and Business Media LLC
Date: 29-12-2006
Modeling Seasonal Tropical Cyclone Activity in the Fiji Region as a Binary Classification Problem
Publisher: American Meteorological Society
Date: 15-07-2012
DOI: 10.1175/JCLI-D-11-00507.1
Abstract: This study presents a binary classification model for the prediction of tropical cyclone (TC) activity in the Fiji, Samoa, and Tonga regions (the FST region) using the accumulated cyclone energy (ACE) as a proxy of TC activity. A probit regression model, which is a suitable probability model for describing binary response data, is developed to determine at least a few months in advance (by July in this case) the probability that an upcoming TC season may have for high or low TC activity. Years of “high TC activity” are defined as those years when ACE values exceeded the s le climatology (i.e., the 1985–2008 mean value). Model parameters are determined using the Bayesian method. Various combinations of the El Niño–Southern Oscillation (ENSO) indices and large-scale environmental conditions that are known to affect TCs in the FST region are examined as potential predictors. It was found that a set of predictors comprising low-level relative vorticity, upper-level ergence, and midtropspheric relative humidity provided the best skill in terms of minimum hindcast error. Results based on hindcast verification clearly suggest that the model predicts TC activity in the FST region with substantial skill up to the May–July preseason for all years considered in the analysis, in particular for ENSO-neutral years when TC activity is known to show large variations.
Estimation of the maximum annual number of North Atlantic tropical cyclones using climate models
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-08-2020
Abstract: Millennia-long climate model simulations suggest that the 2005 North Atlantic hurricane season produced close to the maximum number of tropical cyclones that this basin can sustain in a given year under current climate conditions.
Precipitation changes due to the introduction of eddy-resolved sea surface temperatures into simulations of the “Pasha Bulker” Australian east coast low of June 2007
Publisher: Springer Science and Business Media LLC
Date: 05-04-2014
An 18‐year climatology of hailstorm trends and related drivers across southeast Queensland, Australia
Publisher: Wiley
Date: 2017
DOI: 10.1002/QJ.2995
Influence of ENSO on Tropical Cyclone Intensity in the Fiji Region
Publisher: American Meteorological Society
Date: 08-2011
Abstract: This study examines the variation in tropical cyclone (TC) intensity for different phases of the El Niño–Southern Oscillation (ENSO) phenomenon in the Fiji, Samoa, and Tonga (FST) region. The variation in TC intensity is inferred from the accumulated cyclone energy (ACE), which is constructed from the 6-hourly Joint Typhoon Warning Center best-track data for the period 1985–2006. Overall, results suggest that ACE in the FST region is considerably influenced by the ENSO signal. A substantial contribution to this ENSO signal in ACE comes from the region equatorward of 15°S where TC numbers, lifetime, and intensity all play a significant role. However, the ACE–ENSO relationship weakens substantially poleward of 15°S where large-scale environmental variables affecting TC intensity are found to be less favorable during El Niño years than during La Niña years in the region equatorward of 15°S, the reverse is true. Therefore, TCs entering this region poleward of 15°S are able to sustain their intensity for a longer period of time during La Niña years as opposed to TCs entering the region during El Niño years, when they decay more rapidly.
Application of a synthetic cyclone method for assessment of tropical cyclone storm tides in Samoa
Publisher: Springer Science and Business Media LLC
Date: 24-09-2016
Natural hazards in Australia: sea level and coastal extremes
Publisher: Springer Science and Business Media LLC
Date: 24-03-2016
Rarity, taxonomy and genetics: the chequered history of Grevillea williamsonii (Proteaceae)
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/PC17050
Abstract: Resolving uncertainty surrounding the taxonomic and conservation status of rare plants is of utmost importance to enable effective allocation of the limited resources available for conserving bio ersity. Prioritising threatened taxa that are more appropriately regarded as synonymous with more common species represents a waste of resources. Such a scenario may apply to the Australian entity Grevillea williamsonii and consequently its taxonomic status was investigated using chloroplast DNA sequences and nuclear microsatellite data. Haplotype network and genetic structure analyses showed that G. williamsonii was not genetically distinct from, and should be synonymised with, the variable and morphologically similar but more common G. aquifolium. This study highlights the benefit of undertaking genetic analyses where questionable taxonomic status biases conservation prioritisation and management decisions.
Bipinnate acacias (Acacia subg. Phyllodineae sect. Botrycephalae) of eastern Australia are polyphyletic based on DNA sequence data
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/SB05039
Abstract: A phylogenetic analysis of Acacia subg. Phyllodineae sect. Botrycephalae, endemic to eastern Australia, is presented based on a combined dataset of ITS and ETS sequences of nrDNA. A smaller set of species was sequenced also for the cpDNA trnK region. A limited number of morphological characters was also combined with the ITS+ETS dataset for most taxa. Thirty-eight of 41 Botrycephalae species were sequenced, together with a s le of ten uninerved phyllodinous species (sect. Phyllodineae). Although these DNA regions showed limited sequence ergence, bootstrap supported nodes of the consensus ITS+ETS tree indicate that Botrycephalae as currently defined is polyphyletic. Eight bipinnate species fell outside the main clade of Botrycephalae species while seven phyllodinous species were nested within it, near the base. The few derived but homoplasious morphological characters that were discovered included: presence of appressed unicellular hairs, presence of jugary and interjugary glands, number of pinnae 7 and the funicle half–fully encircling the seed. Section Botrycephalae requires redefinition.
Phylogenetic analysis based on nuclear DNA and morphology defines a clade of eastern Australian species of Acacia s.s. (section Juliflorae): The Acacia longifolia group
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/SB09037
Abstract: Seventeen Australian, phyllodinous species of Acacia s.s. (from sections Juliflorae and Phyllodineae) were analysed to test the monophyly and relationships of ‘the Acacia longifolia group’, an informal group recognised in the Flora of Australia. Analyses were based on both morphological and molecular data, with A. triptera as an outgroup. A total of 92 herbarium specimens was investigated, with 15 phyllode, inflorescence, flower, pod and seed characters scored. The ITS and ETS regions of nuclear rDNA were sequenced and combined with a larger dataset s led from species of all major clades of Acacia, totalling 65 accessions. Cladistic analyses provided evidence of a clade that defines the A. longifolia group as follows: A. alpina, A. axillaris, A. courtii, A. dallachiana, A. derwentiana, A. floribunda, A. longifolia subsp. longifolia and A. longifolia subsp. sophorae, A. longissima, A. maidenii, A. mucronata, A. obtusifolia, A. orites, A. oxycedrus, A. phlebophylla, A. rhigiophylla and A. riceana (all sect. Juliflorae), but excluding A. verticillata (section Juliflorae) and A. genistifolia (section Phyllodineae). The A. longifolia group is recognised as including south-eastern Australian species with cylindrically spiked inflorescences and phyllodes with prominent anastomosing venation.
Acacia s.s. and its Relationship Among Tropical Legumes, Tribe Ingeae (Leguminosae: Mimosoideae)
Publisher: American Society of Plant Taxonomists
Date: 10-2008
The effect on simulated ocean climate of a parameterization of unbroken wave‐induced mixing incorporated into the k‐epsilon mixing scheme
Publisher: American Geophysical Union (AGU)
Date: 04-2017
DOI: 10.1002/2016MS000707
Nonlinear processes reinforce extreme Indian Ocean Dipole events
Publisher: Springer Science and Business Media LLC
Date: 26-06-2015
DOI: 10.1038/SREP11697
Abstract: Under global warming, climate models show an almost three-fold increase in extreme positive Indian Ocean Dipole (pIOD) events by 2100. These extreme pIODs are characterised by a westward extension of cold sea surface temperature anomalies (SSTAs) which push the downstream atmospheric convergence further west. This induces severe drought and flooding in the surrounding countries, but the processes involved in this projected increase have not been fully examined. Here we conduct a detailed heat budget analysis of 19 models from phase 5 of the Coupled Model Intercomparison Project and show that nonlinear zonal and vertical heat advection are important for reinforcing extreme pIODs. Under greenhouse warming, these nonlinear processes do not change significantly in litude, but the frequency of occurrences surpassing a threshold increases. This is due to the projected weakening of the Walker circulation, which leads to the western tropical Indian Ocean warming faster than the east. As such, the magnitude of SSTAs required to shift convection westward is relatively smaller, allowing these convection shifts to occur more frequently in the future. The associated changes in wind and ocean current anomalies support the zonal and vertical advection terms in a positive feedback process and consequently, moderate pIODs become more extreme-like.
The role of the SST-thermocline relationship in Indian Ocean Dipole skewness and its response to global warming
Publisher: Springer Science and Business Media LLC
Date: 12-08-2014
DOI: 10.1038/SREP06034
Impact of Different ENSO Regimes on Southwest Pacific Tropical Cyclones
Publisher: American Meteorological Society
Date: 15-01-2013
DOI: 10.1175/JCLI-D-12-00114.1
Abstract: The influence of different types of ENSO on tropical cyclone (TC) interannual variability in the central southwest Pacific region (5°–25°S, 170°E–170°W) is investigated. Using empirical orthogonal function analysis and an agglomerative hierarchical clustering of early tropical cyclone season Pacific sea surface temperature, years are classified into four separate regimes (i.e., canonical El Niño, canonical La Niña, positive-neutral, and negative-neutral) for the period between 1970 and 2009. These regimes are found to have a large impact on TC genesis over the central southwest Pacific region. Both the canonical El Niño and the positive-neutral years have increased numbers of cyclones, with an average of 4.3 yr−1 for positive-neutral and 4 yr−1 for canonical El Niño. In contrast, during a La Niña and negative-neutral events, substantially fewer TCs (averages of ~2.2 and 2.4 yr−1, respectively) are observed in the central southwest Pacific. The enhancement of TC numbers in both canonical El Niño and positive-neutral years is associated with the extension of favorable low-level cyclonic relative vorticity, and low vertical wind shear eastward across the date line. Relative humidity and SST are also very conducive for genesis in this region during canonical El Niño and positive-neutral events. The patterns are quite different, however, with the favorable conditions concentrated in the date line region for the positive-neutral, as compared with conditions farther eastward for the canonical El Niño regime. A significant result of the study is the demonstration that ENSO-neutral events can be objectively clustered into two separate regimes, each with very different impacts on TC genesis.
The complete chloroplast genome sequence of Spyridium parvifolium var. parvifolium (family Rhamnaceae; tribe Pomaderreae)
Publisher: Informa UK Limited
Date: 03-07-2018
Microsatellite marker development for two species of holly-leafed Grevillea and cross-species amplification in the Aspleniifolia/Hookeriana Subgroup (Proteaceae)
Publisher: Springer Science and Business Media LLC
Date: 10-08-2011
A genome resource for Acacia, Australia’s largest plant genus
Publisher: Public Library of Science (PLoS)
Date: 14-10-2022
DOI: 10.1371/JOURNAL.PONE.0274267
Abstract: Acacia (Leguminosae, Caesalpinioideae, mimosoid clade) is the largest and most widespread genus of plants in the Australian flora, occupying and dominating a erse range of environments, with an equally erse range of forms. For a genus of its size and importance, Acacia currently has surprisingly few genomic resources. Acacia pycnantha , the golden wattle, is a woody shrub or tree occurring in south-eastern Australia and is the country’s floral emblem. To assemble a genome for A . pycnantha , we generated long-read sequences using Oxford Nanopore Technology, 10x Genomics Chromium linked reads, and short-read Illumina sequences, and produced an assembly spanning 814 Mb, with a scaffold N50 of 2.8 Mb, and 98.3% of complete Embryophyta BUSCOs. Genome annotation predicted 47,624 protein-coding genes, with 62.3% of the genome predicted to comprise transposable elements. Evolutionary analyses indicated a shared genome duplication event in the Caesalpinioideae, and conflict in the relationships between Cercis (subfamily Cercidoideae) and subfamilies Caesalpinioideae and Papilionoideae (pea-flowered legumes). Comparative genomics identified a suite of expanded and contracted gene families in A . pycnantha , and these were annotated with both GO terms and KEGG functional categories. One expanded gene family of particular interest is involved in flowering time and may be associated with the characteristic synchronous flowering of Acacia . This genome assembly and annotation will be a valuable resource for all studies involving Acacia , including the evolution, conservation, breeding, invasiveness, and physiology of the genus, and for comparative studies of legumes.
Sand beach ridges record 6000 year history of extreme tropical cyclone activity in northeastern Australia
Publisher: Elsevier BV
Date: 07-2009
Sigma-coordinate calculation of topographically forced baroclinicity around Antarctica
Publisher: Elsevier BV
Date: 12-2000
Incongruent patterns of nuclear and chloroplast variation in Correa (Rutaceae): introgression and biogeography in south-eastern Australia
Publisher: Springer Science and Business Media LLC
Date: 12-02-2016
Phylogeny and classification of the Australasian and Indomalayan mimosoid legumes Archidendron and Archidendropsis (Leguminosae, subfamily Caesalpinioideae, mimosoid clade)
Publisher: Pensoft Publishers
Date: 22-08-2022
DOI: 10.3897/PHYTOKEYS.205.79381
Abstract: The morphologically variable genus Archidendron is the second largest mimosoid legume genus from the Indomalayan-Australasian region, yet it has not been well represented in phylogenetic studies. Phylogenies that have included multiple representatives of Archidendron suggest it may not be monophyletic, and the same applies to Archidendropsis , another understudied genus of the Archidendron clade. The most comprehensive phylogeny of Archidendron and Archidendropsis to date is presented, based on four nuclear markers (ITS, ETS, SHMT and RBPCO). Exemplars from all genera of the wider Archidendron clade are s led, including representatives of all series within Archidendron and the two subgenera of Archidendropsis . Our results confirm that Archidendron and Archidendropsis are not monophyletic. Within Archidendron , only one series (ser. Ptenopae) is resolved as monophyletic and species of Archidendron are ided into two primarily geographic lineages. One clade is distributed in western Malesia and mainland Asia and includes most representatives of series Clypeariae , while the other is mostly restricted to eastern Malesia and Australia and includes representatives of the seven other series plus two s les of series Clypeariae . No taxonomic changes are made for Archidendron due to the high level of topological uncertainty and the lack of discrete macromorphological characters separating these two lineages. Each of the two subgenera of Archidendropsis is monophyletic but they are not closely related. A new genus endemic to Queensland (Australia), Heliodendron Gill.K. Br. & Bayly, gen. nov. , is described for the former Archidendropsis subg. Basaltica, and combinations for its three species are proposed: Heliodendron basalticum (F. Muell.) Gill.K. Br. & Bayly, comb. nov. , Heliodendron thozetianum (F. Muell.) Gill.K. Br. & Bayly, comb. nov. , and Heliodendron xanthoxylon (C.T. White & W.D. Francis) Gill.K. Br. & Bayly, comb. nov.
Biogeography of the Australian monsoon tropics
Publisher: Wiley
Date: 02-2010
Climate change effects on snow conditions in mainland Australia and adaptation at ski resorts through snowmaking
Publisher: Inter-Research Science Center
Date: 14-02-2008
DOI: 10.3354/CR00706
The different impact of positive-neutral and negative-neutral ENSO regimes on Australian tropical cyclones
Publisher: American Meteorological Society
Date: 04-10-2013
DOI: 10.1175/JCLI-D-12-00769.1
Abstract: The number of tropical cyclones (TCs) in the Australian region exhibits a large variation between different ENSO regimes. While the difference in TC numbers and spatial distribution of genesis locations between the canonical El Niño and La Niña regimes is well known, the authors demonstrate that a statistically significant difference in TC numbers also exists between the recently identified negative-neutral and positive-neutral regimes. Compared to the negative-neutral and La Niña regimes, significantly fewer TCs form in the Australian region during the positive-neutral regime, particularly in the eastern subregion. This difference is attributed to concomitant changes in various large-scale environmental conditions such as sea level pressure, relative vorticity, vertical motion, and sea surface temperature.
Tropical Cyclone Activity in the Fiji Region: Spatial Patterns and Relationship to Large-Scale Circulation
Publisher: American Meteorological Society
Date: 15-07-2009
Abstract: This study examines the variations in tropical cyclone (TC) genesis positions and their subsequent tracks for different phases of the El Niño–Southern Oscillation (ENSO) phenomenon in the Fiji, Samoa, and Tonga region (FST region) using Joint Typhoon Warning Center best-track data. Over the 36-yr period from 1970/71 to 2005/06, 122 cyclones are observed in the FST region. A large spread in the genesis positions is noted. During El Niño years, genesis is enhanced east of the date line, extending from north of Fiji to over Samoa, with the highest density centered around 10°S, 180°. During neutral years, maximum genesis occurs immediately north of Fiji with enhanced genesis south of Samoa. In La Niña years, there are fewer cyclones forming in the region than during El Niño and neutral years. During La Niña years, the genesis positions are displaced poleward of 12°S, with maximum density centered around 15°S, 170°E and south of Fiji. The cyclone tracks over the FST region are also investigated using cluster analysis. Tracks during the period 1970/71–2005/06 are conveniently described using three separate clusters, with distinct characteristics associated with different ENSO phases. Finally, the role of large-scale environmental factors affecting interannual variability of TC genesis positions and their subsequent tracks in the FST region are investigated. Favorable genesis positions are observed where large-scale environments have the following seasonal average thresholds: (i) 850-hPa cyclonic relative vorticity between −16 and −4 (×10−6 s−1), (ii) 200-hPa ergence between 2 and 8 (×10−6 s−1), and (iii) environmental vertical wind shear between 0 and 8 m s−1. The subsequent TC tracks are observed to be steered by mean 700–500-hPa winds.
Objectively determined resolution-dependent threshold criteria for the detection of tropical cyclones in climate models and reanalyses
Publisher: American Meteorological Society
Date: 15-05-2007
DOI: 10.1175/JCLI4074.1
Abstract: Objectively derived resolution-dependent criteria are defined for the detection of tropical cyclones in model simulations and observationally based analyses. These criteria are derived from the wind profiles of observed tropical cyclones, averaged at various resolutions. Both an analytical wind profile model and two-dimensional observed wind analyses are used. The results show that the threshold wind speed of an observed tropical cyclone varies roughly linearly with resolution. The criteria derived here are compared to the numerous different criteria previously employed in climate model simulations. The resulting method provides a simple means of comparing climate model simulations and reanalyses.
Future Australian Severe Thunderstorm Environments. Part I: A Novel Evaluation and Climatology of Convective Parameters from Two Climate Models for the Late Twentieth Century
Publisher: American Meteorological Society
Date: 09-05-2014
DOI: 10.1175/JCLI-D-13-00425.1
Abstract: The influence of a warming climate on the occurrence of severe thunderstorms over Australia is, as yet, poorly understood. Based on methods used in the development of a climatology of observed severe thunderstorm environments over the continent, two climate models [Commonwealth Scientific and Industrial Research Organisation Mark, version 3.6 (CSIRO Mk3.6) and the Cubic-Conformal Atmospheric Model (CCAM)] have been used to produce simulated climatologies of ingredients and environments favorable to severe thunderstorms for the late twentieth century (1980–2000). A novel evaluation of these model climatologies against data from both the ECMWF Interim Re-Analysis (ERA-Interim) and reports of severe thunderstorms from observers is used to analyze the capability of the models to represent convective environments in the current climate. This evaluation examines the representation of thunderstorm-favorable environments in terms of their frequency, seasonal cycle, and spatial distribution, while presenting a framework for future evaluations of climate model convective parameters. Both models showed the capability to explain at least 75% of the spatial variance in both vertical wind shear and convective available potential energy (CAPE). CSIRO Mk3.6 struggled to either represent the diurnal cycle over a large portion of the continent or resolve the annual cycle, while in contrast CCAM showed a tendency to underestimate CAPE and 0–6-km bulk magnitude vertical wind shear (S06). While spatial resolution likely contributes to rendering of features such as coastal moisture and significant topography, the distribution of severe thunderstorm environments is found to have greater sensitivity to model biases. This highlights the need for a consistent approach to evaluating convective parameters and severe thunderstorm environments in present-day climate: an ex le of which is presented here.
General circulation model simulation of mild nuclear winter effects
Publisher: Springer Science and Business Media LLC
Date: 04-1989
DOI: 10.1007/BF01058235
Testing the Impact of Calibration on Molecular Divergence Times Using a Fossil-Rich Group: The Case of Nothofagus (Fagales)
Publisher: Oxford University Press (OUP)
Date: 26-12-2011
Abstract: Although temporal calibration is widely recognized as critical for obtaining accurate ergence-time estimates using molecular dating methods, few studies have evaluated the variation resulting from different calibration strategies. Depending on the information available, researchers have often used primary calibrations from the fossil record or secondary calibrations from previous molecular dating studies. In analyses of flowering plants, primary calibration data can be obtained from macro- and mesofossils (e.g., leaves, flowers, and fruits) or microfossils (e.g., pollen). Fossil data can vary substantially in accuracy and precision, presenting a difficult choice when selecting appropriate calibrations. Here, we test the impact of eight plausible calibration scenarios for Nothofagus (Nothofagaceae, Fagales), a plant genus with a particularly rich and well-studied fossil record. To do so, we reviewed the phylogenetic placement and geochronology of 38 fossil taxa of Nothofagus and other Fagales, and we identified minimum age constraints for up to 18 nodes of the phylogeny of Fagales. Molecular dating analyses were conducted for each scenario using maximum likelihood (RAxML + r8s) and Bayesian (BEAST) approaches on sequence data from six regions of the chloroplast and nuclear genomes. Using either ingroup or outgroup constraints, or both, led to similar age estimates, except near strongly influential calibration nodes. Using "early but risky" fossil constraints in addition to "safe but late" constraints, or using assumptions of vicariance instead of fossil constraints, led to older age estimates. In contrast, using secondary calibration points yielded drastically younger age estimates. This empirical study highlights the critical influence of calibration on molecular dating analyses. Even in a best-case situation, with many thoroughly vetted fossils available, substantial uncertainties can remain in the estimates of ergence times. For ex le, our estimates for the crown group age of Nothofagus varied from 13 to 113 Ma across our full range of calibration scenarios. We suggest that increased background research should be made at all stages of the calibration process to reduce errors wherever possible, from verifying the geochronological data on the fossils to critical reassessment of their phylogenetic position.
Nonlinear Feedbacks Associated with the Indian Ocean Dipole and Their Response to Global Warming in the GFDL-ESM2M Coupled Climate Model
Publisher: American Meteorological Society
Date: 29-05-2014
DOI: 10.1175/JCLI-D-13-00527.1
Abstract: A feature of the Indian Ocean dipole (IOD) is its positive skewness, with cold IOD east pole (IODE) sea surface temperature anomalies (SSTAs) exhibiting larger litudes than warm SSTAs. Using the coupled Geophysical Fluid Dynamics Laboratory Earth System Model with Modular Ocean Model version 4 (MOM4) component (GFDL-ESM2M), the role of nonlinear feedbacks in generating this positive skewness is investigated and their response to global warming examined. These feedbacks are a nonlinear dynamic heating process, the Bjerknes feedback, wind–evaporation–SST feedback, and SST–cloud–radiation feedback. Nonlinear dynamic heating assists IOD skewness by strongly d ing warm IODE SSTAs and reinforcing cold IODE anomalies. In a warmer climate, the d ing strengthens while the reinforcement weakens. The SST–thermocline relationship is part of the positive Bjerknes feedback and contributes strongly to IOD skewness as it is weak during the development of warm IODE SSTAs, but strong during the development of cold IODE SSTAs. In response to global warming, this relationship displays weaker asymmetry associated with weaker westerly winds over the central equatorial Indian Ocean. The negative SST–cloud–radiation feedback is also asymmetric with cold IODE SSTAs less d ed by incoming shortwave radiation. Under global warming, the d ing of cold IODE SSTAs shows little change but warm IODE SSTAs become more d ed. This stronger d ing is a symptom of negative IODs becoming stronger in litude due to the mean IODE thermocline shoaling. The wind–evaporation–SST feedback does not contribute to IOD asymmetry with cold IODE SSTAs decreasing evaporation, which in turn warms the surface. However, as this study focuses on one model, the response of these feedbacks to global warming is uncertain.
A Bayesian Regression Approach to Seasonal Prediction of Tropical Cyclones Affecting the Fiji Region
Publisher: American Meteorological Society
Date: 07-2010
Abstract: This study presents seasonal prediction schemes for tropical cyclones (TCs) affecting the Fiji, Samoa, and Tonga (FST) region. Two separate Bayesian regression models are developed: (i) for cyclones forming within the FST region (FORM) and (ii) for cyclones entering the FST region (ENT). Predictors examined include various El Niño–Southern Oscillation (ENSO) indices and large-scale environmental parameters. Only those predictors that showed significant correlations with FORM and ENT are retained. Significant preseason correlations are found as early as May–July (approximately three months in advance). Therefore, May–July predictors are used to make initial predictions, and updated predictions are issued later using October–December early-cyclone-season predictors. A number of predictor combinations are evaluated through a cross-validation technique. Results suggest that a model based on relative vorticity and the Niño-4 index is optimal to predict the annual number of TCs associated with FORM, as it has the smallest RMSE associated with its hindcasts (RMSE = 1.63). Similarly, the all-parameter-combined model, which includes the Niño-4 index and some large-scale environmental fields over the East China Sea, appears appropriate to predict the annual number of TCs associated with ENT (RMSE = 0.98). While the all-parameter-combined ENT model appears to have good skill over all years, the May–July prediction of the annual number of TCs associated with FORM has two limitations. First, it underestimates (overestimates) the formation for years where the onset of El Niño (La Niña) events is after the May–July preseason or where a previous La Niña (El Niño) event continued through May–July during its decay phase. Second, its performance in neutral conditions is quite variable. Overall, no significant skill can be achieved for neutral conditions even after an October–December update. This is contrary to the performance during El Niño or La Niña events, where model performance is improved substantially after an October–December early-cyclone-season update.
Simulated ocean response to tropical cyclones: The effect of a novel parameterization of mixing from unbroken surface waves
Publisher: American Geophysical Union (AGU)
Date: 04-2017
DOI: 10.1002/2016MS000878
Big trees of small baskets: phylogeny of the Australian genus
Publisher: CSIRO Publishing
Date: 18-05-2022
DOI: 10.1071/SB21034
Abstract: Spyridium Fenzl is a genus of ~45 species endemic to south-western and south-eastern Australia. This study provides the most comprehensive phylogenies of Spyridium to date, analysing both entire chloroplast genomes and the nuclear ribosomal array (18S–5.8S–26S). There was substantial incongruence between the chloroplast and nuclear phylogenies, creating phylogenetic uncertainty, but some clear relationships and biogeographic patterns could be established. Analyses support the monophyly of Spyridium, identifying an early east–west split at the base of the nuclear phylogeny and deep ergences of New South Wales and Tasmanian endemic clades. We also found evidence of more recent dispersal events between eastern and western Australia and between Tasmania and the mainland. Eleven taxa were found to be monophyletic in the nrDNA phylogeny and two were clearly polyphyletic (S. eriocephalum Fenzl and S. phylicoides Reissek). Although the polyphyly of S. eriocephalum correlates with the two varieties, suggesting distinct taxa, further research is required on S. phylicoides.
Resolution dependence of tropical cyclone formation in CMIP3 and finer resolution models
Publisher: Springer Science and Business Media LLC
Date: 11-02-2012
Manganese (hyper)accumulation within Australian Denhamia (Celastraceae): an assessment of the trait and manganese accumulation under controlled conditions
Publisher: Springer Science and Business Media LLC
Date: 13-03-2021
Application of Contiguous Rain Area (CRA) Methods to Tropical Cyclone Rainfall Forecast Verification
Publisher: American Geophysical Union (AGU)
Date: 11-2018
DOI: 10.1029/2018EA000412
Relationships of the Australo-Malesian genus Paraserianthes (Mimosoideae: Leguminosae) identifies the sister group of Acacia sensu stricto and two biogeographical tracks
Publisher: Wiley
Date: 23-02-2011
Development of microsatellite loci in Triglochin procera (Juncaginaceae), a polyploid wetland plant
Publisher: Springer Science and Business Media LLC
Date: 29-08-2011
Isolation of microsatellites using 454-sequencing for the grassland shrub Pimelea spinescens (Thymelaeaceae)
Publisher: Springer Science and Business Media LLC
Date: 21-07-2012
Detection and attribution of climate change effects on tropical cyclones
Publisher: Springer US
Date: 21-08-2009
Distribution and chemical form of selenium in Neptunia amplexicaulis from Central Queensland, Australia
Publisher: Oxford University Press (OUP)
Date: 14-02-2020
DOI: 10.1039/C9MT00244H
Abstract: Selenium (Se), a trace element essential for human and animal biological processes, is deficient in many agricultural soils. Some extremely rare plants can naturally accumulate extraordinarily high concentrations of Se. The native legume Neptunia lexicaulis, endemic to a small area near Richmond and Hughenden in Central Queensland, Australia, is one of the strongest Se hyperaccumulators known on Earth, with foliar concentrations in excess of 4000 μg Se g−1 previously recorded. Here, we report on the Se distribution at a whole plant level using laboratory micro X-ray Fluorescence Microscopy (μXRF) and scanning electron microscopy (SEM-EDS), as well as on chemical forms of Se in various tissues using liquid chromatography-mass spectrometry (LC-MS) and synchrotron X-ray absorption spectroscopy (XAS). The results show that Se occurs in the forms of methyl-selenocysteine and seleno-methionine in the foliar tissues, with up to 13 600 μg Se g−1 total in young leaves. Selenium was found to accumulate primarily in the young leaves, flowers, pods and taproot, with lower concentrations present in the fine-roots and stem and the lowest present in the oldest leaves. Trichomes were not found to accumulate Se. We postulate that Se is (re)distributed in this plant via the phloem from older leaves to newer leaves, using the taproot as the main storage organ. High concentrations of Se in the nodes (pulvini) indicate this structure may play an important a role in Se (re)distribution. The overall pattern of Se distribution was similar in a non-Se tolerant closely related species (Neptunia gracilis), although the prevailing Se concentrations were substantially lower than in N. lexicaulis.
The contribution of tropical cyclones to rainfall in northwest Australia
Publisher: Wiley
Date: 09-09-2014
DOI: 10.1002/JOC.4148
Phylogenetic relationships of Rhododendron section Vireya (Ericaceae) inferred from the ITS nrDNA region
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/SB05019
Abstract: Rhododendron L. taxonomy has been tested in recent times by molecular phylogenies based on several DNA regions. Most of these studies have aimed at higher-level relationships, despite the importance of lower ranks, such as sections, to most workers on the genus. Almost one-third of the species of Rhododendron are placed in one of the lepidote (scaly) sections, section Vireya (Blume) Copel.f. Results of phylogenetic analyses of the ITS region (ITS-1, 5.8S and ITS-2) for the genus Rhododendron, with s ling concentrated on section Vireya, are presented. The results of Bayesian and parsimony analyses were predominantly congruent. Subgenus Rhododendron is inferred to be monophyletic, while two of the three sections, Rhododendron and Vireya, are polyphyletic the monophyly of section Pogonanthum Aitch. & Hemsl. was not tested in this study. Relationships between the species of section Vireya do not correspond to the traditional classification based on morphology, instead correlating strongly with geographic areas, with a disjunction between an Australian–New Guinea clade and clades of west and middle Malesian taxa. The phylogeny also indicates that the ITS region may not undergo complete homogenisation in all species of Rhododendron.
Constraints on drag and exchange coefficients at extreme wind speeds
Publisher: American Geophysical Union (AGU)
Date: 09-09-2010
DOI: 10.1029/2009JC005876
Assessing the genetic legacy of a rare, clonal Australian shrub Grevillea infecunda (Proteaceae)
Publisher: Springer Science and Business Media LLC
Date: 17-01-2017
Phylogeography and classification of Dusty Miller (Spyridium parvifolium; Rhamnaceae): a morphologically variable shrub from south-east Australia
Publisher: Springer Science and Business Media LLC
Date: 15-04-2023
DOI: 10.1007/S00606-023-01851-5
Abstract: Spyridium parvifolium is a widespread and morphologically variable shrub from south-eastern Australia. Several varieties have been recognised, and there is disagreement on the accepted taxonomy between Australian states. This study investigated the phylogeography of the species and assessed genetic distinctiveness of its morphological variants. Nuclear ribosomal DNA and complete chloroplast genomes from seventy-two s les of S. parvifolium and seven s les from closely related species were sequenced and analysed using both Bayesian and maximum likelihood phylogenetic methods. The results showed incongruence in the placement of several associated taxa ( S. cinereum , S. obcordatum and S. daltonii ), plausibly due to long branch attraction, introgression or incomplete lineage sorting. Spyridium parvifolium was resolved as paraphyletic in both phylogenies, with accessions from west of the Murray Darling Depression ergent from those east of the Depression. We found evidence of isolation within S. parvifolium on the inland side of the Great Dividing Range and recent gene flow across Bass Strait. The variants of S. parvifolium were not supported as genetically distinct, and with the prevalence of several variants at single sites and morphological intergrades between variants, we conclude that the taxon is a single, morphologically variable species and that no infraspecific classification is warranted.
The evolution and phylogenetic placement of invasive Australian Acacia species
Publisher: Wiley
Date: 08-08-2011
A preliminary survey of nickel, manganese and zinc (hyper)accumulation in the flora of Papua New Guinea from herbarium X-ray fluorescence scanning
Publisher: Springer Science and Business Media LLC
Date: 03-01-2020
The Influence of the Madden–Julian Oscillation on Tropical Cyclone Activity in the Fiji Region
Publisher: American Meteorological Society
Date: 15-02-2010
Abstract: This study examines the modulation of tropical cyclone (TC) activity by the Madden–Julian oscillation (MJO) in the Fiji, Samoa, and Tonga regions (FST region), using Joint Typhoon Warning Center best-track cyclone data and the MJO index developed by Wheeler and Hendon. Results suggest strong MJO–TC relationships in the FST region. The TC genesis patterns are significantly altered over the FST region with approximately 5 times more cyclones forming in the active phase than in the inactive phase of the MJO. This modulation is further strengthened during El Niño periods. The large-scale environmental conditions (i.e., low-level relative vorticity, upper-level ergence, and vertical wind shear) associated with TC genesis show a distinct patterns of variability for the active and inactive MJO phases. The MJO also has a significant effect on hurricane category and combined gale and storm category cyclones in the FST region. The occurrences of both these cyclone categories are increased in the active phase of the MJO, which is associated with enhanced convective activity. The TCs in the other MJO phases where convective activity is relatively low, however, show a consistent pattern of increase in hurricane category cyclones and a concomitant decrease in gale and storm category cyclones. Finally, TC tracks in different MJO phases are also objectively described using a cluster analysis technique. Patterns seen in the clustered track regimes are well explained here in terms of 700–500-hPa mean steering flow.
Phylogeographic consequences of different introduction histories of invasive Australian Acacia species and Paraserianthes lophantha (Fabaceae) in South Africa
Publisher: Wiley
Date: 08-08-2011
Forecasting Tropical Cyclone Formation in the Fiji Region: A Probit Regression Approach Using Bayesian Fitting
Publisher: American Meteorological Society
Date: 04-2011
Abstract: An objective methodology for forecasting the probability of tropical cyclone (TC) formation in the Fiji, Samoa, and Tonga regions (collectively the FST region) using antecedent large-scale environmental conditions is investigated. Three separate probabilistic forecast schemes are developed using a probit regression approach where model parameters are determined via Bayesian fitting. These schemes provide forecasts of TC formation from an existing system (i) within the next 24 h (W24h), (ii) within the next 48 h (W48h), and (iii) within the next 72 h (W72h). To assess the performance of the three forecast schemes in practice, verification methods such as the posterior expected error, Brier skill scores, and relative operating characteristic skill scores are applied. Results suggest that the W24h scheme, which is formulated using large-scale environmental parameters, on average, performs better than that formulated using climatology and persistence (CLIPER) variables. In contrast, the W48h (W72h) scheme formulated using large-scale environmental parameters performs similar to (poorer than) that formulated using CLIPER variables. Therefore, large-scale environmental parameters (CLIPER variables) are preferred as predictors when forecasting TC formation in the FST region within 24 h (at least 48 h) using models formulated in the present investigation.
Using Sea Level Rise Projections for Urban Planning in Australia
Publisher: Coastal Education and Research Foundation
Date: 04-2004
Tropical cyclone trends in the Australian region
Publisher: American Geophysical Union (AGU)
Date: 07-2008
DOI: 10.1029/2007GC001804
Sensitivity of Tropical Cyclone Formation to Resolution‐Dependent and Independent Tracking Schemes in High‐Resolution Climate Model Simulations
Publisher: American Geophysical Union (AGU)
Date: 03-2020
DOI: 10.1029/2019EA000906
Abstract: In the present study, global tropical cyclone (TC) formation characteristics are estimated using two fundamentally different Commonwealth Scientific and Industrial Research Organisation (CSIRO) and Okubo‐Weiss zeta parameter (OWZP) tracking schemes in the reanalysis data and in a high‐resolution climate model with interannually varying sea surface temperatures. Both the schemes have a reasonable global geographical distribution of TC genesis locations with under simulation in the eastern North Atlantic and northwestern Australian regions. The mean annual TC frequency in the model is similar to observations using the CSIRO scheme but higher using the OWZP scheme, whereas the annual frequency in reanalysis using the OWZP scheme is similar to observations but halved using the CSIRO scheme. In the CSIRO scheme, both the resolution‐dependent thresholds and large‐scale climate may play a role for skilful TC formation statistics. In contrast, large‐scale climate leads to changes in OWZP TC detections. This highlights the importance of the large‐scale environment for TC detections in both the tracking schemes. The OWZP scheme can differentiate the monsoon lows from the actual TCs in the north Indian Ocean compared to the CSIRO scheme, which incorrectly detects them as TCs in the monsoon season. The distribution of TC lifetime in the model using the OWZP scheme is similar to observations. Conversely, the CSIRO scheme detected TCs have shorter lifetimes, perhaps due to intrinsic tracking scheme differences. Although the tracking schemes are fundamentally different, the study shows that there exist some similarities between them and for certain TC formation characteristics the OWZP scheme performs better compared to the CSIRO scheme.
Tracking Scheme Dependence of Simulated Tropical Cyclone Response to Idealized Climate Simulations
Publisher: American Meteorological Society
Date: 10-12-2014
DOI: 10.1175/JCLI-D-14-00200.1
Abstract: Future tropical cyclone activity is a topic of great scientific and societal interest. In the absence of a climate theory of tropical cyclogenesis, general circulation models are the primary tool available for investigating the issue. However, the identification of tropical cyclones in model data at moderate resolution is complex, and numerous schemes have been developed for their detection. The influence of different tracking schemes on detected tropical cyclone activity and responses in the Hurricane Working Group experiments is examined herein. These are idealized atmospheric general circulation model experiments aimed at determining and distinguishing the effects of increased sea surface temperature and other increased CO2 effects on tropical cyclone activity. Two tracking schemes are applied to these data and the tracks provided by each modeling group are analyzed. The results herein indicate moderate agreement between the different tracking methods, with some models and experiments showing better agreement across schemes than others. When comparing responses between experiments, it is found that much of the disagreement between schemes is due to differences in duration, wind speed, and formation-latitude thresholds. After homogenization in these thresholds, agreement between different tracking methods is improved. However, much disagreement remains, accountable for by more fundamental differences between the tracking schemes. The results indicate that sensitivity testing and selection of objective thresholds are the key factors in obtaining meaningful, reproducible results when tracking tropical cyclones in climate model data at these resolutions, but that more fundamental differences between tracking methods can also have a significant impact on the responses in activity detected.
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