Journal of Southern Hemisphere Earth Systems Science最新文献

{"title":"A catalogue of marine heatwave metrics and trends for the Australian region","authors":"J. Kajtar, N. Holbrook, V. Hernaman","doi":"10.1071/es21014","DOIUrl":"https://doi.org/10.1071/es21014","url":null,"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.","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74982537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Australian rainfall anomalies and Indo-Pacific driver indices: links and skill in 2-year-long forecasts","authors":"I. Watterson, T. O’Kane, V. Kitsios, M. Chamberlain","doi":"10.1071/es21008","DOIUrl":"https://doi.org/10.1071/es21008","url":null,"abstract":"","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90834980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seamless climate change projections and seasonal predictions for bushfires in Australia","authors":"A. Dowdy","doi":"10.1071/ES20001","DOIUrl":"https://doi.org/10.1071/ES20001","url":null,"abstract":"\u0000Spatio-temporal variations in fire weather conditions are presented based on various data sets, with consistent approaches applied to help enable seamless services over different time scales. Recent research on this is shown here, covering climate change projections for future years throughout this century, predictions at multi-week to seasonal lead times and historical climate records based on observations. Climate projections are presented based on extreme metrics with results shown for individual seasons. A seasonal prediction system for fire weather conditions is demonstrated here as a new capability development for Australia. To produce a more seamless set of predictions, the data sets are calibrated based on quantile-quantile matching for consistency with observations-based data sets, including to help provide details around extreme values for the model predictions (demonstrating the quantile matching for extremes method). Factors influencing the predictability of conditions are discussed, including pre-existing fuel moisture, large-scale modes of variability, sudden stratospheric warmings and climate trends. The extreme 2019–2020 summer fire season is discussed, with examples provided on how this suite of calibrated fire weather data sets was used, including long-range predictions several months ahead provided to fire agencies. These fire weather data sets are now available in a consistent form covering historical records back to 1950, long-range predictions out to several months ahead and future climate change projections throughout this century. A seamless service across different time scales is intended to enhance long-range planning capabilities and climate adaptation efforts, leading to enhanced resilience and disaster risk reduction in relation to natural hazards.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77521241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal climate summary for the southern hemisphere (spring 2018): positive Indian Ocean Dipole and Australia","authors":"B. Trewin","doi":"10.1071/es20007","DOIUrl":"https://doi.org/10.1071/es20007","url":null,"abstract":"This is a summary of the southern hemisphere atmospheric circulation patterns and meteorological indices for spring 2018; an account of seasonal rainfall and temperature for the Australian region and broader southern hemisphere is also provided. A positive phase of the Indian Ocean Dipole developed during the season, and the central and eastern equatorial Pacific were warmer than average without reaching El Niño thresholds. It was Australia’s driest September on record, before rainfall of closer to average in October and November. It was warmer than average, especially in northern Australia, with coastal Queensland affected by extreme heat and wildfires in November. It was one of the three warmest springs on record for the southern hemisphere as a whole, and was notably dry in southern and eastern Africa.","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88760953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal climate summary for the southern hemisphere (autumn 2018): a weak La Niña fades, the austral autumn remains warmer and drier","authors":"Bernard Chapman, Katie Rosemond","doi":"10.1071/es19039","DOIUrl":"https://doi.org/10.1071/es19039","url":null,"abstract":"\u0000This is a summary of the austral autumn 2018 atmospheric circulation patterns and meteorological indices for the southern hemisphere, including an exploration of the season’s rainfall and temperature for the Australian region. The weak La Niña event during summer 2017–18 was in retreat as the southern hemisphere welcomed the austral autumn, and before midseason, it had faded. With the El Niño Southern Oscillation and the Indian Ocean Dipole in neutral phases, their influence on the climate was weakened. Warmer than average sea surface temperatures dominated much of the subtropical South Pacific Ocean and provided favourable conditions for the formation of a rare subtropical cyclone over the southeast Pacific Ocean in May. The southern hemisphere sea ice extent was slightly below the autumn seasonal average. The southern hemisphere overall during autumn was drier and warmer than the seasonal average. The season brought warmer than average temperatures and average rains to parts of the continents of Africa and South America. Australia recorded its fourth-warmest autumn, partly due to an intense, extensive and persistent heatwave, which occurred during the midseason. An extraordinary and record-breaking rainfall event occurred over Tasmania’s southeast, under the influence of a negative Southern Annular Mode. The mainland’s northeastern tropical region was wetter than average as a result of tropical cyclones, which formed during an active monsoon. These areas, however, were in contrast to the rest of the continent, which followed the trend of the previous season and remained drier than average; consequently, rainfall deficiencies emerged across the southern half of Australia, and some areas witnessed an increase in extent and severity of these deficiencies.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79963655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate services in the UK Met Office – challenges and solutions","authors":"C. Hewitt","doi":"10.1071/es19030","DOIUrl":"https://doi.org/10.1071/es19030","url":null,"abstract":"\u0000The development, delivery, uptake and use of climate services face numerous challenges including the fact that decision-makers often need information that is beyond the current scientific capability, insufficient capacity amongst climate service providers to be able to meet the demands from decision-makers, shortcomings in the awareness and understanding of available knowledge, and insufficient understanding by climate service providers of the needs of decision-makers. This article provides examples of the UK Met Office’s international climate service activities in Commonwealth small island states, China and Europe, highlighting specific challenges. Based on experiences developing and delivering climate services and collaborating with a range of actors, some approaches that help overcome, or at least reduce, these challenges include undertaking focused user engagement, collaboration and partnerships, developing prototypes and conducting trials of these prototypes with the users, evolving the science and the services based on the users’ needs to better serve societal needs.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73020420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Configuration and spin-up of ACCESS-CM2, the new generation Australian Community Climate and Earth System Simulator Coupled Model","authors":"Daohua Bi, M. Dix, S. Marsland, S. O’Farrell, Arnold Sullivan, R. Bodman, R. Law, I. Harman, J. Srbinovsky, H. Rashid, P. Dobrohotoff, C. Mackallah, Hailin Yan, A. Hirst, A. Savita, Fabio Boeira Dias, M. Woodhouse, R. Fiedler, A. Heerdegen","doi":"10.1071/es19040","DOIUrl":"https://doi.org/10.1071/es19040","url":null,"abstract":"\u0000A new version of the Australian Community Climate and Earth System Simulator coupled model, ACCESS-CM2, has been developed for a wide range of climate modelling research and applications. In particular, ACCESS-CM2 is one of Australia’s contributions to the World Climate Research Programme’s Coupled Model Intercomparison Project Phase 6 (CMIP6). Compared with the ACCESS1.3 model used for our CMIP5 submission, all model components have been upgraded as well as the coupling framework (OASIS3-MCT) and experiment control system (Rose/Cylc). The component models are: UM10.6 GA7.1 for the atmosphere, CABLE2.5 for the land surface, MOM5 for the ocean, and CICE5.1.2 for the sea ice. This paper describes the model configuration of ACCESS-CM2, documents the experimental set up, and assesses the model performance for the preindustrial spin-up simulation in comparison against (reconstructed) observations and ACCESS1.3 results. While the performance of the two generations of the ACCESS coupled model is largely comparable, ACCESS-CM2 shows better global hydrological balance, more realistic ocean water properties (in terms of spatial distribution) and meridional overturning circulation in the Southern Ocean but a poorer simulation of the Antarctic sea ice and a larger energy imbalance at the top of atmosphere. This energy imbalance reflects a noticeable warming trend of the global ocean over the spin-up period.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89179563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sea surface height trends in the southern hemisphere oceans simulated by the Brazilian Earth System Model under RCP4.5 and RCP8.5 scenarios","authors":"E. Giarolla, Sandro F. Veiga, P. Nobre, Manoel B DA Silva, V. Capistrano, Andyara O. Callegare","doi":"10.1071/es19042","DOIUrl":"https://doi.org/10.1071/es19042","url":null,"abstract":"\u0000The Brazilian Earth System Model (BESM-OA2.5), while simulating the historical period proposed by the fifth phase of the Coupled Model Intercomparison Project (CMIP5), detects an increasing trend in the sea surface height (SSH) on the southern hemisphere oceans relative to that of the pre-industrial era. The increasing trend is accentuated in the CMIP5 RCP4.5 and RCP8.5 future scenarios with higher concentrations of greenhouse gases in the atmosphere. This study sheds light on the sources of such trends in these regions. The results suggest an association with the thermal expansion of the oceans in the upper 700m due to a gradual warming inflicted by those future scenarios. BESM-OA2.5 presents a surface height increase of 0.11m in the historical period of 1850–2005. Concerning future projections, BESM-OA2.5 projects SSH increases of 0.14 and 0.23m (relative to the historical 2005 value) for RCP4.5 and RCP8.5, respectively, by the end of 2100. These increases are predominantly in a band of latitude within 35–60°S in the Atlantic and Indian oceans. The reproducibility of the trend signal detected in the BESM-OA2.5 simulations is confirmed by the results of three other CMIP5 models.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90323877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response time of temperature measurements at automatic weather stations in Australia","authors":"G. Ayers, J. Warne","doi":"10.1071/es19032","DOIUrl":"https://doi.org/10.1071/es19032","url":null,"abstract":"\u0000Bureau of Meteorology automatic weather stations (AWS) are employed to record 1-min air temperature data in accord with World Meteorological Organization recommendations. These 1-min values are logged as the value measured for the last second in each minute. The Bureau explains that this is appropriate because the inherent measurement system time constant means the 1-s data are not instantaneous, but are an average smoothed over the previous 40–80s. To test this proposition in the field air temperature data were measured at 1-Hz at two Bureau AWS sites between April and June 2018. The frequency distribution of the differences between each 1-s value and the 60-s average centred on that value provided information on the overall measurement system response time constant. Expressed in terms of an e-folding measurement system response time, the data from the two measurement systems studied yielded response times in the range 50–150s, largely consistent with the Bureau’s explanation.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74533100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric rivers in the Australia–Asian region under current and future climate in CMIP5 models","authors":"Ying Xu, Huqiang Zhang, Yanju Liu, Zhenyu Han, Botao Zhou","doi":"10.1071/es19044","DOIUrl":"https://doi.org/10.1071/es19044","url":null,"abstract":"\u0000Atmospheric rivers (ARs), as long and narrow bands of strong water vapour transport in the lower troposphere, have drawn increasing scientific attention in recent years. Results from a collaborative project between the Australian Bureau of Meteorology and China Meteorological Administration have shown some unique AR characteristics embedded within the Australia–Asian monsoon based on observational analyses. As part of the project, this study focused on assessing the skill of global climate models for simulating ARs in the region under current climate and their projected changes due to global warming. Daily data from 17 Coupled Model Intercomparison Project Phase 5 (CMIP5) models in their historical and Representative Concentration Pathway (RCP) 8.5 simulations were analysed for the periods of 1981–2005 and 2081–2100 respectively. Compared with results derived from European Centre for Medium-Range Weather Forecasts ERA-interim reanalysis data, these model ensemble results showed significant seasonal variations of horizontal water vapour transport as observed, but their magnitudes measured by vertically integrated water vapour transport (IVT) were weaker, particularly for the East Asian summer monsoon. Using an objective AR detection algorithm based on 85th percentile IVT magnitude and its geometry, we showed that multi-model-ensemble (MME) averaged AR occurrence agreed well with the results derived from the reanalysis for their spatial distributions and seasonal variations. Under the RCP8.5 global warming scenario, the model ensembles, overall, showed an enhanced water vapour transport, primarily due to increased atmospheric humidity associated with a warmed atmosphere. Consequently, they simulated increased AR frequency and bigger AR size in most of the region, particularly over north and northeast China and southern Australia. However, the MME results showed a reduced AR frequency and size in July/August in southern and eastern part of China and its adjacent waters. We attributed these results to the response of the Western North Pacific Subtropical High (WNPSH) to global warming. Our analysis showed that westward expansion of WNPSH lead to the shift of ARs more inland in East Asia. In this case, eastern China was directly under the control of WNPSH, which did not favour AR development and penetration into the region. Our analyses of ARs in the A–A monsoon system offers new insight in understanding potential climate changes in the monsoon region under warmed climate.\u0000","PeriodicalId":55419,"journal":{"name":"Journal of Southern Hemisphere Earth Systems Science","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88117087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}