- Barr, Cameron, Tibby, John, Gell, Peter, Tyler, Jonathan, Zawadzki, Atun, Jacobsen, Geraldine
- Authors: Barr, Cameron , Tibby, John , Gell, Peter , Tyler, Jonathan , Zawadzki, Atun , Jacobsen, Geraldine
- Date: 2014
- Type: Text , Journal article
- Relation: Quaternary Science Reviews Vol. 95, no. (July 2014 2014), p. 115-131
- Full Text: false
- Reviewed:
- Description: Climates of the last two millennia have been the focus of numerous studies due to the availability of high-resolution palaeoclimate records and the occurrence of divergent periods of climate, commonly referred to as the 'Medieval Climatic Anomaly' and 'The Little Ice Age'. The majority of these studies are centred in the Northern Hemisphere and, in comparison, the Southern Hemisphere is relatively under-studied. In Australia, there are few high-resolution, palaeoclimate studies spanning a millennium or more and, consequently, knowledge of long-term natural climate variability is limited for much of the continent. South-eastern Australia, which recently experienced a severe, decade-long drought, is one such region.Results are presented of investigations from two crater lakes in the south-east of mainland Australia. Fluctuations in lake-water conductivity, a proxy for effective moisture, are reconstructed at sub-decadal resolution over the past 1500 years using a statistically robust, diatom-conductivity transfer function. These data are interpreted in conjunction with diatom autecology. The records display coherent patterns of change at centennial scale, signifying that both lakes responded to regional-scale climate forcing, though the nature of that response varied between sites due to differing lake morphometry. Both sites provide evidence for a multi-decadal drought, commencing ca 650 AD, and a period of variable climate between ca 850 and 1400 AD. From ca 1400-1880 AD, coincident with the timing of the 'Little Ice Age', climates of the region are characterised by high effective moisture and a marked reduction in inter-decadal variability. The records provide context for climates of the historical period and reveal the potential for more extreme droughts and more variable climate than that experienced since European settlement of the region ca 170 years ago.
- Mills, Keely, Gell, Peter, Gergis, Joelle, Baker, Patrick J., Finlayson, C. Max, Hesse, Paul, Jones, R., Kershaw, Peter, Pearson, Stuart, Treble, Pauline, Barr, Cameron, Brookhouse, Matthew, Drysdale, Russell, McDonald, Janece, Haberle, Simon, Reid, Michael, Thoms, M., Tibby, John
- Authors: Mills, Keely , Gell, Peter , Gergis, Joelle , Baker, Patrick J. , Finlayson, C. Max , Hesse, Paul , Jones, R. , Kershaw, Peter , Pearson, Stuart , Treble, Pauline , Barr, Cameron , Brookhouse, Matthew , Drysdale, Russell , McDonald, Janece , Haberle, Simon , Reid, Michael , Thoms, M. , Tibby, John
- Date: 2013
- Type: Text , Journal article
- Relation: Australian Journal of Earth Sciences Vol. 60, no. 5 (2013), p. 561-571
- Full Text: false
- Reviewed:
- Description: The management of the water resources of the Murray-Darling Basin (MDB) has long been contested, and the effects of the recent Millennium drought and subsequent flooding events have generated acute contests over the appropriate allocation of water supplies to agricultural, domestic and environmental uses. This water-availability crisis has driven demand for improved knowledge of climate change trends, cycles of variability, the range of historical climates experienced by natural systems and the ecological health of the system relative to a past benchmark. A considerable volume of research on the past climates of southeastern Australia has been produced over recent decades, but much of this work has focused on longer geological time-scales, and is of low temporal resolution. Less evidence has been generated of recent climate change at the level of resolution that accesses the cycles of change relevant to management. Intra-decadal and near-annual resolution (high-resolution) records do exist and provide evidence of climate change and variability, and of human impact on systems, relevant to natural-resource management. There exist now many research groups using a range of proxy indicators of climate that will rapidly escalate our knowledge of management-relevant, climate change and variability. This review assembles available climate and catchment change research within, and in the vicinity of, the MDB and portrays the research activities that are responding to the knowledge need. It also discusses how paleoclimate scientists may better integrate their pursuits into the resource-management realm to enhance the utility of the science, the effectiveness of the management measures and the outcomes for the end users.
- Description: C1
Evaluation of PMIP2 and PMIP3 simulations of mid-Holocene climate in the Indo-Pacific, Australasian and Southern Ocean regions
- Ackerley, Duncan, Reeves, Jessica, Barr, Cameron, Bostock, Helen, Fitzsimmons, Kathryn, Fletcher, Michael-Shawn, Gouramanis, Chris, McGregor, Helen, Mooney, Scott, Phipps, Steven, Tibby, John, Tyler, Jonathan
- Authors: Ackerley, Duncan , Reeves, Jessica , Barr, Cameron , Bostock, Helen , Fitzsimmons, Kathryn , Fletcher, Michael-Shawn , Gouramanis, Chris , McGregor, Helen , Mooney, Scott , Phipps, Steven , Tibby, John , Tyler, Jonathan
- Date: 2017
- Type: Text , Journal article
- Relation: Climate of the Past Vol. 13, no. 11 (2017), p. 1661-1684
- Full Text:
- Reviewed:
- Description:
This study uses the
simplified patterns of temperature and effective precipitation
approach from the Australian component of the international palaeoclimate synthesis effort (INTegration of Ice core, MArine and TErrestrial records - OZ-INTIMATE) to compare atmosphere-ocean general circulation model (AOGCM) simulations and proxy reconstructions. The approach is used in order to identify important properties (e.g. circulation and precipitation) of past climatic states from the models and proxies, which is a primary objective of the Southern Hemisphere Assessment of PalaeoEnvironment (SHAPE) initiative. The AOGCM data are taken from the Paleoclimate Modelling Intercomparison Project (PMIP) mid-Holocene (ca. 6000 years before present, 6 ka) and pre-industrial control (ca. 1750 CE, 0 ka) experiments. The synthesis presented here shows that the models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). The analysis shows that the lower temperatures in the Pacific at around 6 ka in the models may be the result of an enhancement of an existing systematic error. It is therefore difficult to decipher which one of the proxies and/or the models is correct. This study also shows that a reduction in the Equator-to-pole temperature difference in the Southern Hemisphere causes the mid-latitude westerly wind strength to reduce in the models; however, the simulated rainfall actually increases over the southern temperate zone of Australia as a result of higher convective precipitation. Such a mechanism (increased convection) may be useful for resolving disparities between different regional proxy records and model simulations. Finally, after assessing the available datasets (model and proxy), opportunities for better model-proxy integrated research are discussed. © Author(s) 2017.
- Authors: Ackerley, Duncan , Reeves, Jessica , Barr, Cameron , Bostock, Helen , Fitzsimmons, Kathryn , Fletcher, Michael-Shawn , Gouramanis, Chris , McGregor, Helen , Mooney, Scott , Phipps, Steven , Tibby, John , Tyler, Jonathan
- Date: 2017
- Type: Text , Journal article
- Relation: Climate of the Past Vol. 13, no. 11 (2017), p. 1661-1684
- Full Text:
- Reviewed:
- Description:
This study uses the
simplified patterns of temperature and effective precipitation
approach from the Australian component of the international palaeoclimate synthesis effort (INTegration of Ice core, MArine and TErrestrial records - OZ-INTIMATE) to compare atmosphere-ocean general circulation model (AOGCM) simulations and proxy reconstructions. The approach is used in order to identify important properties (e.g. circulation and precipitation) of past climatic states from the models and proxies, which is a primary objective of the Southern Hemisphere Assessment of PalaeoEnvironment (SHAPE) initiative. The AOGCM data are taken from the Paleoclimate Modelling Intercomparison Project (PMIP) mid-Holocene (ca. 6000 years before present, 6 ka) and pre-industrial control (ca. 1750 CE, 0 ka) experiments. The synthesis presented here shows that the models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). The analysis shows that the lower temperatures in the Pacific at around 6 ka in the models may be the result of an enhancement of an existing systematic error. It is therefore difficult to decipher which one of the proxies and/or the models is correct. This study also shows that a reduction in the Equator-to-pole temperature difference in the Southern Hemisphere causes the mid-latitude westerly wind strength to reduce in the models; however, the simulated rainfall actually increases over the southern temperate zone of Australia as a result of higher convective precipitation. Such a mechanism (increased convection) may be useful for resolving disparities between different regional proxy records and model simulations. Finally, after assessing the available datasets (model and proxy), opportunities for better model-proxy integrated research are discussed. © Author(s) 2017.
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