Journal articles on the topic 'Weather Effect of mountains on Australia'
To see the other types of publications on this topic, follow the link: Weather Effect of mountains on Australia.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Weather Effect of mountains on Australia.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Sharples, Jason J., Graham A. Mills, Richard H. D. McRae, and Rodney O. Weber. "Foehn-Like Winds and Elevated Fire Danger Conditions in Southeastern Australia." Journal of Applied Meteorology and Climatology 49, no. 6 (June 1, 2010): 1067–95. http://dx.doi.org/10.1175/2010jamc2219.1.
Full textAbstract:
Abstract Bushfires in southeastern Australia are a serious environmental problem, and consistently cause loss of life and damage to property and other assets. Understanding synoptic processes that can lead to dangerous fire weather conditions throughout the region is therefore an important undertaking aimed at improving community safety, protection of assets, and fire suppression tactics and strategies. In southeastern Australia severe fire weather is often associated with dry cool changes or coastally modified cold fronts. Less well known, however, are synoptic events that can occur in connection with the topography of the region, such as cross-mountain flows and foehn-like winds, which can also lead to abrupt changes in fire weather variables that ultimately result in locally elevated fire danger. This paper focuses on foehn-like occurrences over the southeastern mainland, which are characterized by warm, dry winds on the lee side of the Australian Alps. The characteristics of a number of foehn-like occurrences are analyzed based on observational data and the predictions of a numerical weather model. The analyses confirm the existence of a foehn effect over parts of southeastern Australia and suggest that its occurrence is primarily due to the partial orographic blocking of relatively moist low-level air and the subsidence of drier upper-level air in the lee of the mountains. The regions prone to foehn occurrence, the influence of the foehn on fire weather variables, and the connection between the foehn and mountain waves are also discussed.
2
Bradstock, R. A., J. S. Cohn, A. M. Gill, M. Bedward, and C. Lucas. "Prediction of the probability of large fires in the Sydney region of south-eastern Australia using fire weather." International Journal of Wildland Fire 18, no. 8 (2009): 932. http://dx.doi.org/10.1071/wf08133.
Full textAbstract:
The probability of large-fire (≥1000 ha) ignition days, in the Sydney region, was examined using historical records. Relative influences of the ambient and drought components of the Forest Fire Danger Index (FFDI) on large fire ignition probability were explored using Bayesian logistic regression. The preferred models for two areas (Blue Mountains and Central Coast) were composed of the sum of FFDI (Drought Factor, DF = 1) (ambient component) and DF as predictors. Both drought and ambient weather positively affected the chance of large fire ignitions, with large fires more probable on the Central Coast than in the Blue Mountains. The preferred, additive combination of drought and ambient weather had a marked threshold effect on large-fire ignition and total area burned in both localities. This may be due to a landscape-scale increase in the connectivity of available fuel at high values of the index. Higher probability of large fires on the Central Coast may be due to more subdued terrain or higher population density and ignitions. Climate scenarios for 2050 yielded predictions of a 20–84% increase in potential large-fire ignitions days, using the preferred model.
3
Brischke, Christian, and Vanessa Selter. "Mapping the Decay Hazard of Wooden Structures in Topographically Divergent Regions." Forests 11, no. 5 (May 1, 2020): 510. http://dx.doi.org/10.3390/f11050510.
Full textAbstract:
The service life of exposed wooden structures depends on many endogenous and exogenous factors with moisture being key for fungal degradation. Climate parameters are therefore important input variables for modelling fungal decay in wood. In recent years, different approaches aimed at modelling climate-induced dosage on the material climate (i.e., exposure models) and the effect of the latter on fungal decay (i.e., decay models). Based on maps of Europe, North America or Australia, the decay hazard can be assigned to zones and used for estimating the relative decay potential of an arbitrary location. However, especially in topographically divergent regions, the climate-induced decay hazard can vary strongly within a small area. Within this study, decay hazards were quantified and mapped for a mountainous region where topography-induced differences in local climate and corresponding exposure dosage can be expected. The area under investigation was Switzerland. In addition to the Scheffer Climate Index (SCI), two exposure models were combined with two decay models and used to quantify the relative moisture- and temperature-induced exposure dose at 75 different weather stations in Switzerland and adjacent regions. The exposure was expressed as relative dosage with Uppsala (Sweden) as a reference location. Relative dose values were calculated for locations between weather stations using an ‘inverse distance weighted (IDW)’ interpolation and displayed in maps for the entire country. A more detailed analysis was undertaken for the Lötschental area, which is the largest valley on the northern side of the Rhône valley in the canton of Valais. The relative dose differed strongly within small areas and altitude was well correlated with the average annual temperature and the resulting relative dose. It became evident that small-scale mapping with high resolution is needed to fully reflect the impact of topography and other local conditions on the moisture- and temperature-induced decay risk in wooden components.
4
Dai, Jingru, Michael J. Manton, Steven T. Siems, and Elizabeth E. Ebert. "Estimation of Daily Winter Precipitation in the Snowy Mountains of Southeastern Australia." Journal of Hydrometeorology 15, no. 3 (June 1, 2014): 909–20. http://dx.doi.org/10.1175/jhm-d-13-081.1.
Full textAbstract:
Abstract Wintertime precipitation in the Snowy Mountains provides water for agriculture, industry, and domestic use in inland southeastern Australia. Unlike most of Australia, much of this precipitation falls as snow, and it is recorded by a private network of heated tipping-bucket gauges. These observations are used in the present study to assess the accuracy of a poor man’s ensemble (PME) prediction of precipitation in the Snowy Mountains based on seven numerical weather prediction models. While the PME performs quite well, there is significant underestimation of precipitation intensity. It is shown that indicators of the synoptic environment can be used to improve the PME estimates of precipitation. Four synoptic regimes associated with different precipitation classes are identified from upper-air data. The reliability of the PME forecasts can be sharpened by considering the precipitation in each of the four synoptic classes. A linear regression, based on the synoptic classification and the PME estimate, is used to reduce the forecast errors. The potential to extend the method for forecasting purposes is discussed.
5
Falk, Martin, and Eva Hagsten. "Winter Weather Anomalies and Individual Destination Choice." Sustainability 10, no. 8 (July 26, 2018): 2630. http://dx.doi.org/10.3390/su10082630.
Full textAbstract:
Recently, several winter seasons in the European Alps have been unexpectedly warm. In the Austrian mountains, December 2015 was the warmest since weather records began, with a temperature deviation of +6.6 °C compared to the long-term average. By use of data on 6200 individual trips from the Austrian travel survey, a multinomial Logit model is employed to estimate if weather anomalies affect the choice of winter trips. A substitution for more distant trips may create additional environmental burdens, given that they require longer travels or alternative transportation modes. Estimation results reveal that the choice of a mountain destination is not yet affected by extreme winter weather conditions. The result is valid for December 2015, as well as for the total winter season 2015/2016. However, December 2015 and 2016 exhibit a separate development with a significant increase in the likelihood of trips to non-mountains in Europe (mostly city breaks), although no traces of a direct substitution effect can be found. Younger and older people, as well as women, are less likely to go on a winter trip to the mountains. Residents with a tertiary degree and students are more interested in this, as well as large travel groups.
6
HALL, G. V., I. C. HANIGAN, K. B. G. DEAR, and H. VALLY. "The influence of weather on community gastroenteritis in Australia." Epidemiology and Infection 139, no. 6 (August 9, 2010): 927–36. http://dx.doi.org/10.1017/s0950268810001901.
Full textAbstract:
SUMMARYInfectious gastroenteritis is a common illness in Australia as elsewhere. Data from a year-long national gastroenteritis survey in 2001–2002 showed that gastroenteritis was more common in the northern and hotter part of Australia. These data were used to quantify associations between local weather variables and gastroenteritis in people aged >5 years while controlling for socioeconomic status. A distributed lag model was used to examine the influence of weather over a period of days prior to an event and the maximal effect was found at a lag of 2–5 days. The total effect over the preceding week indicated a relative increase from baseline in the probability of gastroenteritis of 2·48% (95% CI 1·01–3·97) for each degree rise (°C) over that period. Given the very high burden of gastroenteritis, this represents a substantial effect at the population level and has relevance for health predictions due to climate change.
7
ABDELWAHAB, MM, A. SALAHELDIN, and Z. METWALLY. "A case of Khamsin type weather in north Africa." MAUSAM 36, no. 3 (April 6, 2022): 291–94. http://dx.doi.org/10.54302/mausam.v36i3.1912.
Full textAbstract:
In most cases, desert depressions over north Africa form in the lee of the Atlas mountains, Such occurrences are found when a north or northwest air stream from over the Atlantic moves toward the Atlas range, or when a northeasterly wind blows over the western Mediterranean towards these mountains, As shown in Fig. 1, these depressions may follow numerous tracks during their eastward movement. These depressions usually produce severe heat waves and sandstorms (EL Fandi, 1940, Soliman 1958). The phenomenon of Khamsin weather in spring is one of the main problems associated with weather analysis and forecasting in the area of north Africa. In recent years, several formulations of these types of desert depressions have been discussed from the point of view of their sources and supply of heat and energy.
The present paper is an attempt to identify the effect of cyc1ogenetic activity on the trajectory of these depressions.
8
Warchałowski, Marcin, Piotr Nowakowski, and Andrzej Dancewicz. "Effect of winter conditions on wild ungulates mortality in the Owl Mountains (Poland)." Folia Forestalia Polonica 57, no. 3 (September 1, 2015): 187–93. http://dx.doi.org/10.1515/ffp-2015-0018.
Full textAbstract:
Abstract Relations between climatic factors during the winter season (n days with frost <0oC and −10oC; n days with snow cover: >1 cm, >10 cm and >30 cm; maximum snow cover during season [cm]) and mortality in free-living ungulates (red deer Cervus elaphus Linnaeus, 1758, roe deer Capreolus capreolus Linnaeus, 1758 and mouflon Ovis aries musimon Linnaeus, 1758) in the Owl Mountains (Lower Silesia – Poland) in years 1998–2010 were investigated. Significant effects of all analysed climatic factors on ungulates mortality were documented. Correlations (Pearson) between such weather factors as the depth of snow cover and number of days with frost and recorded mortality in total animal populations analysed ranged from r = 0.33 to r = 0.77. The least adapted to local weather conditions was mouflon introduced to this area ca. 100 years ago from more southern parts of Europe. Roe deer species seems to be environmentally plastic, and are doing quite well in severe winters. Tolerance of red deer to the snow cover is much lower at low temperatures due to the fact that this species, during the period of snow cover, has limited access to the plants covered with snow and difficult access to food base.
9
Jensen, Christopher A., and Jessamie Yule. "Response strategies used to mitigate the effect of extreme weather on rural and remote housing in Australia." IOP Conference Series: Materials Science and Engineering 1218, no. 1 (January 1, 2022): 012049. http://dx.doi.org/10.1088/1757-899x/1218/1/012049.
Full textAbstract:
Abstract In the extreme climates of Australia, rural and remote locations have special site and dwelling requirements and therefore special design solutions. This can include construction constraints, bushfire risk, resource efficiency, comfort and respect for the surrounding environment and heritage. Existing regulations targeted at extreme weather impacts such as bushfire, flood, cyclones, and heatwaves often impact the design and material choices for rural and remote housing due to their exposed locations, including housing proposed for rebuild following damage resulting from an extreme weather event. These regulations also lead to increased costs and uncertainty about the suitability of rural land for construction, making it challenging for rebuilding communities in affected areas. Such well-intentioned regulations also create limitations on innovation through experimental / bespoke building design, such as; 1) novel solutions to extreme weather mitigation and resistance 2) material choices for construction; and 3) achievement of operational and embodied energy reductions. Experimental buildings provide significant innovation benefits to industry as is often seen in the development of sustainable and high-performance buildings. This research examines the academic and industry knowledge of current design regulations for extreme weather events and implications for experimental and innovative design, highlighting the challenges for buildings to achieve increasing standards of environmental performance whilst ensuring resilience in the face of increasing extreme weather events, with a specific focus on rural communities. Case study analysis is used to provide an understanding of the focus and strategies used by different groups in different locations to address the impacts of extreme weather.
10
Fox-Hughes, Paul. "Springtime Fire Weather in Tasmania, Australia: Two Case Studies." Weather and Forecasting 27, no. 2 (April 1, 2012): 379–95. http://dx.doi.org/10.1175/waf-d-11-00020.1.
Full textAbstract:
Abstract A number of severe springtime fire weather events have occurred in Tasmania, Australia, in recent years. Two such events are examined here in some detail, in an attempt to understand the mechanisms involved in the events. Both events exhibit strong winds and very low surface dewpoint temperatures. Associated 850-hPa wind–dewpoint depression conditions are extreme in both cases, and evaluation of these quantities against a scale of past occurrences may provide a useful early indicator of future severe events. Both events also feature the advection of air from drought-affected continental Australia ahead of cold fronts. This air reaches the surface in the lee of Tasmanian topography by the action of the föehn effect. In one event, there is good evidence of an intrusion of stratospheric, high potential vorticity (PV), air, supplementing the above mechanism and causing an additional peak in airmass dryness and wind speed.
11
Sexton, Justin, Yvette Everingham, and Bertrand Timbal. "Harvest disruption projections for the Australian sugar industry." International Journal of Climate Change Strategies and Management 7, no. 1 (March 16, 2015): 41–57. http://dx.doi.org/10.1108/ijccsm-03-2013-0018.
Full textAbstract:
Purpose – This study aims to investigate the effects of climate change on harvestability for sugarcane-growing regions situated between mountain ranges and the narrow east Australian coastline. Design/methodology/approach – Daily rainfall simulations from 11 general circulation models (GCMs) were downscaled for seven Australian sugarcane regions (1961:2000). Unharvestable days were calculated from these 11 GCMs and compared to interpolated observed data. The historical downscaled GCM simulations were then compared to simulations under low (B1) and high (A2) emissions scenarios for the period of 2046-2065. The 25th, 50th and 75th percentiles of paired model differences were assessed using 95 per cent bootstrapped confidence intervals. Findings – A decrease in the number of unharvestable days for the Burdekin (winter/spring) and Bundaberg (winter) regions and an increase for the Herbert region (spring) were plausible under the A2 scenario. Spatial plots identified variability within regions. Northern and southern regions were more variable than central regions. Practical implications – Changes to the frequency of unharvestable days may require a range of management adaptations such as modifying the harvest period and upgrading harvesting technologies. Originality/value – The application of a targeted industry rainfall parameter (unharvestable days) obtained from downscaled climate models provided a novel approach to investigate the impacts of climate change. This research forms a baseline for industry discussion and adaptation planning towards an environmentally and economically sustainable future. The methodology outlined can easily be extended to other primary industries impacted by wet weather.
12
Pallathadka, Harikumar, and Laxmi Kirana Pallathadka. "A Critical Analysis of Possible Natural Disasters in the Himalayan Region and a Detailed Study of the Consequences Thereof." Integrated Journal for Research in Arts and Humanities 2, no. 6 (November 30, 2022): 187–94. http://dx.doi.org/10.55544/ijrah.2.6.25.
Full textAbstract:
The Himalayan Mountainous region is the world's newest, fastest, and most enormous crumpled mountainous range. It is highly volatile because of the continuous geological process. The entire Himalayas range has been responding to devastating natural hazards, which reflects its fragility and susceptibility. The temperature ranges from low-lying hills and mountains to high-altitude, continuously snow-capped mountainous ranges. According to studies, the temperature revolution had a profound effect on the Mountains, and as a result, weather patterns and disasters have changed substantially. The Mountainous terrain's high frequency magnifies weather hazards, bringing everyone else in the area at risk.
Humans are no strangers to disasters. Since the beginning of civilization, they have been persistent, though unpleasant, companions of humans, leaving trails of rage and disaster of incredible magnitude.
Uttarakhand is susceptible to disasters, glaciers, river flooding, forest fires, cloudbursts, and land degradation, among other disasters.
13
Li, Xiaofei, Ninglian Wang, and Zhanhao Wu. "Terrain Effects on Regional Precipitation in a Warm Season over Qinling-Daba Mountains in Central China." Atmosphere 12, no. 12 (December 16, 2021): 1685. http://dx.doi.org/10.3390/atmos12121685.
Full textAbstract:
The terrain effects of Qinling–Daba Mountains on reginal precipitation during a warm season were investigated in a two-month day-to-day experiment using the Weather Research and Forecasting (WRF) model. According to the results from the terrain sensitivity experiment with lowered mountains, Qinling–Daba Mountains have been found to have an obvious effect on both the spatial-temporal distribution and diurnal cycle of reginal precipitation from July to August in 2019, where the Qinling Mountains mainly enhanced the precipitation around 34° N, and the Daba Mountains mainly enhanced it around 32° N at the time period of early morning and midnight. Horizontal distribution of water vapor and convective available potential energy (CAPE), as well as cross section of vertical velocity of wind and potential temperature has been studied to examine the key mechanisms for these two mountains’ effect. The existence of Qinling Mountains intercepted transportation of water vapor from South to North in the lower troposphere to across 34° N and caused an obvious enhancement of CAPE in the neighborhood, while the Daba Mountains intercepted the northward water vapor transportation to across 32° N and caused an enhanced CAPE nearby. The time period of the influence is in a good accordance with the diurnal cycle. In the cross-section, the existence of Qinling Mountains and Daba Mountains are found to stimulate the upward motion and unstable environment effectively at around 34° N and 32° N, separately. As a result, the existence of the two mountains lead to a favorable environment in water vapor, thermodynamic, and dynamic conditions for this warm season precipitation.
14
Penman, Trent D., Dan A. Ababei, Jane G. Cawson, Brett A. Cirulis, Thomas J. Duff, William Swedosh, and James E. Hilton. "Effect of weather forecast errors on fire growth model projections." International Journal of Wildland Fire 29, no. 11 (2020): 983. http://dx.doi.org/10.1071/wf19199.
Full textAbstract:
Fire management agencies use fire behaviour simulation tools to predict the potential spread of a fire in both risk planning and operationally during wildfires. These models are generally based on underlying empirical or quasi-empirical relations and rarely are uncertainties considered. Little attention has been given to the quality of the input data used during operational fire predictions. We examined the extent to which error in weather forecasts can affect fire simulation results. The study was conducted using data representing the State of Victoria in south-eastern Australia, including grassland and forest conditions. Two fire simulator software packages were used to compare fire growth under observed and forecast weather. We found that error in the weather forecast data significantly altered the predicted size and location of fires. Large errors in wind speed and temperature resulted in an overprediction of fire size, whereas large errors in wind direction resulted in an increased spatial error in the fire’s location. As the fire weather intensified, fire predictions using forecast weather under predicted fire size, potentially resulting in greater risks to the community. These results highlight the importance of on-ground intelligence during wildfires and the use of ensembles to improve operational fire predictions.
15
Black, Mitchell T., David J. Karoly, Suzanne M. Rosier, Sam M. Dean, Andrew D. King, Neil R. Massey, Sarah N. Sparrow, et al. "The weather@home regional climate modelling project for Australia and New Zealand." Geoscientific Model Development 9, no. 9 (September 15, 2016): 3161–76. http://dx.doi.org/10.5194/gmd-9-3161-2016.
Full textAbstract:
Abstract. A new climate modelling project has been developed for regional climate simulation and the attribution of weather and climate extremes over Australia and New Zealand. The project, known as weather@home Australia–New Zealand, uses public volunteers' home computers to run a moderate-resolution global atmospheric model with a nested regional model over the Australasian region. By harnessing the aggregated computing power of home computers, weather@home is able to generate an unprecedented number of simulations of possible weather under various climate scenarios. This combination of large ensemble sizes with high spatial resolution allows extreme events to be examined with well-constrained estimates of sampling uncertainty. This paper provides an overview of the weather@home Australia–New Zealand project, including initial evaluation of the regional model performance. The model is seen to be capable of resolving many climate features that are important for the Australian and New Zealand regions, including the influence of El Niño–Southern Oscillation on driving natural climate variability. To date, 75 model simulations of the historical climate have been successfully integrated over the period 1985–2014 in a time-slice manner. In addition, multi-thousand member ensembles have also been generated for the years 2013, 2014 and 2015 under climate scenarios with and without the effect of human influences. All data generated by the project are freely available to the broader research community.
16
Utembe, Steven, Peter Rayner, Jeremy Silver, Elise-Andree Guérette, Jenny Fisher, Kathryn Emmerson, Martin Cope, et al. "Hot Summers: Effect of Extreme Temperatures on Ozone in Sydney, Australia." Atmosphere 9, no. 12 (November 27, 2018): 466. http://dx.doi.org/10.3390/atmos9120466.
Full textAbstract:
Poor air quality is often associated with hot weather, but the quantitative attribution of high temperatures on air quality remains unclear. In this study, the effect of elevated temperatures on air quality is investigated in Greater Sydney using January 2013, a period of extreme heat during which temperatures at times exceeded 40 ∘ C, as a case study. Using observations from 17 measurement sites and the Weather Research and Forecasting Chemistry (WRF-Chem) model, we analyse the effect of elevated temperatures on ozone in Sydney by running a number of sensitivity studies in which: (1) the model is run with biogenic emissions generated by MEGAN and separately run with monthly average Model of Emissions of Gases and Aerosols from Nature ( MEGAN) biogenic emissions (for January 2013); (2) the model results from the standard run are compared with those in which average temperatures (for January 2013) are only applied to the chemistry; (3) the model is run using both averaged biogenic emissions and temperatures; and (4 and 5) the model is run with half and zero biogenic emissions. The results show that the impact on simulated ozone through the effect of temperature on reaction rates is similar to the impact via the effect of temperature on biogenic emissions and the relative impacts are largely additive when compared to the run in which both are averaged. When averaged across 17 sites in Greater Sydney, the differences between ozone simulated under standard and averaged model conditions are as high as 16 ppbv. Removing biogenic emissions in the model has the effect of removing all simulated ozone episodes during extreme heat periods, highlighting the important role of biogenic emissions in Australia, where Eucalypts are a key biogenic source.
17
Storey, Michael Anthony, and Owen F. Price. "Prediction of air quality in Sydney, Australia as a function of forest fire load and weather using Bayesian statistics." PLOS ONE 17, no. 8 (August 24, 2022): e0272774. http://dx.doi.org/10.1371/journal.pone.0272774.
Full textAbstract:
Smoke from Hazard Reduction Burns (HRBs) and wildfires contains pollutants that are harmful to human health. This includes particulate matter less than 2.5 μm in diameter (PM2.5), which affects human cardiovascular and respiratory systems and can lead to increased hospitalisations and premature deaths. Better models are needed to predict PM2.5 levels associated with HRBs so that agencies can properly assess smoke pollution risk and balance smoke risk with the wildfire mitigation benefits of HRBs. Given this need, our aim was to develop a probabilistic model of daily PM2.5 using Bayesian regression. We focused on the region around Sydney, Australia, which regularly has hazard reduction burning, wildfires and associated smoke. We developed two regional models (mean daily and maximum daily) from observed PM2.5, weather reanalysis and satellite fire hotspot data. The models predict that the worst PM2.5 in Sydney occurs when PM2.5 was high the previous day, there is low ventilation index (i.e. the product of wind speed and planetary boundary layer height), low temperature, west to northwest winds in the Blue Mountains, an afternoon sea breeze and large areas of HRBs are being conducted, particularly to the west and north of Sydney. A major benefit of our approach is that models are fast to run, require simple inputs and Bayesian predictions convey both predicted PM2.5 and associated prediction uncertainty. Future research could include the application of similar methods to other regions, collecting more data to improve model precision and developing Bayesian PM2.5 models for wildfires.
18
Schwartz, Andrew J., Hamish A. McGowan, Alison Theobald, and Nik Callow. "Quantifying the impact of synoptic weather types and patterns on energy fluxes of a marginal snowpack." Cryosphere 14, no. 8 (August 28, 2020): 2755–74. http://dx.doi.org/10.5194/tc-14-2755-2020.
Full textAbstract:
Abstract. Synoptic weather patterns are investigated for their impact on energy fluxes driving melt of a marginal snowpack in the Snowy Mountains, southeast Australia. K-means clustering applied to ECMWF ERA-Interim data identified common synoptic types and patterns that were then associated with in situ snowpack energy flux measurements. The analysis showed that the largest contribution of energy to the snowpack occurred immediately prior to the passage of cold fronts through increased sensible heat flux as a result of warm air advection (WAA) ahead of the front. Shortwave radiation was found to be the dominant control on positive energy fluxes when individual synoptic weather types were examined. As a result, cloud cover related to each synoptic type was shown to be highly influential on the energy fluxes to the snowpack through its reduction of shortwave radiation and reflection/emission of longwave fluxes. As single-site energy balance measurements of the snowpack were used for this study, caution should be exercised before applying the results to the broader Australian Alps region. However, this research is an important step towards understanding changes in surface energy flux as a result of shifts to the global atmospheric circulation as anthropogenic climate change continues to impact marginal winter snowpacks.
19
Williams, RW, RJ Lawn, BC Imrie, and DE Byth. "Studies on water damage in mungbean. I. Effect of weathering on seed quality and viability." Australian Journal of Agricultural Research 46, no. 5 (1995): 887. http://dx.doi.org/10.1071/ar9950887.
Full textAbstract:
The expansion of mungbean production in Australia is severely limited by the susceptibility of current cultivars to weather damage in the field. The aim of this research was to describe the causes, process, and effects of weathering in mungbean as the first step toward the breeding of resistant cultivars. Symptoms of weather damage were produced by exposing plants to simulated rainfall/high humidity and by subjecting seeds to cycles of wetting and drying. In both cases, symptoms progressed from discolouration, wrinkling, and cracking of the testa, to germination of the seed. Symptoms produced in controlled experiments were the same as those observed in the field. Only seeds that imbibed during the wetting phase developed symptoms of weather damage on drying. Exposure to one cycle of weathering also advanced the timing and degree of damage to seeds during subsequent cycles. This was associated with an increased rate of water absorption in weathered seeds. The lowering of apparent resistance to weather damage with prior exposure to rainfall suggested that only protected material be screened for weathering resistance. The death of seeds remained the ultimate expression of the changes induced by weathering.
20
Clarke, Hamish G., Peter L. Smith, and Andrew J. Pitman. "Regional signatures of future fire weather over eastern Australia from global climate models." International Journal of Wildland Fire 20, no. 4 (2011): 550. http://dx.doi.org/10.1071/wf10070.
Full textAbstract:
Skill-selected global climate models were used to explore the effect of future climate change on regional bushfire weather in eastern Australia. Daily Forest Fire Danger Index (FFDI) was calculated in four regions of differing rainfall seasonality for the 20th century, 2050 and 2100 using the A2 scenario from the Special Report on Emissions Scenarios. Projected changes in FFDI vary along a latitudinal gradient. In summer rainfall-dominated tropical north-east Australia, mean and extreme FFDI are projected to decrease or remain close to 20th century levels. In the uniform and winter rainfall regions, which occupy south-east continental Australia, FFDI is projected to increase strongly by 2100. Projections fall between these two extremes for the summer rainfall region, which lies between the uniform and summer tropical rainfall zones. Based on these changes in fire weather, the fire season is projected to start earlier in the uniform and winter rainfall regions, potentially leading to a longer overall fire season.
21
Williams, Richard J., Carl-Henrik Wahren, Arn D. Tolsma, Glenn M. Sanecki, Warwick A. Papst, Bronwyn A. Myers, Keith L. McDougall, Dean A. Heinze, and Ken Green. "Large fires in Australian alpine landscapes: their part in the historical fire regime and their impacts on alpine biodiversity." International Journal of Wildland Fire 17, no. 6 (2008): 793. http://dx.doi.org/10.1071/wf07154.
Full textAbstract:
The fires of summer 2003 in south-eastern Australia burnt tens of thousands of hectares of treeless alpine landscape. Here, we examine the environmental impact of these fires, using data from the Bogong High Plains area of Victoria, and the Snowy Mountains region of New South Wales. Historical and biophysical evidence suggests that in Australian alpine environments, extensive fires occur only in periods of extended regional drought, and when severe local fire weather coincides with multiple ignitions in the surrounding montane forests. Dendrochronological evidence indicates that large fires have occurred approximately every 50–100 years over the past 400 years. Post-fire monitoring of vegetation in grasslands and heathlands indicates that most alpine species regenerate rapidly after fire, with >90% of species present 1 year after fire. Some keystone species in some plant communities, however, had not regenerated after 3 years. The responses of alpine fauna to the 2003 fires were variable. The core habitat (closed heathland) of several vulnerable small mammals was extensively burnt. Some mammals experienced substantial falls in populations, others experienced substantial increases. Unburnt patches of vegetation are critical to faunal recovery from fire. There was, however, no evidence of local extinction. We conclude that infrequent extensive fires are a feature of alpine Australia. For both the flora and fauna, there is no quantitative evidence that the 2003 fires were an ecological disaster, and we conclude that the flora and fauna of alpine Australia are highly resilient to infrequent, large, intense fires.
22
Collins, L., R. A. Bradstock, and T. D. Penman. "Can precipitation influence landscape controls on wildfire severity? A case study within temperate eucalypt forests of south-eastern Australia." International Journal of Wildland Fire 23, no. 1 (2014): 9. http://dx.doi.org/10.1071/wf12184.
Full textAbstract:
The environmental, economic and social impacts of wildfires depend on spatial patterns of fire severity. An understanding as to how drivers of fire severity vary across broad vegetation communities exists. However, examination of variation within communities in response to gradients of moisture has received little attention so far. This study examined whether relationships between environmental variables (i.e. fire weather, topography and fuel age) and fire severity were modified by increasing mean annual precipitation. Understorey fires were more likely to occur in young fuels (i.e. <5 years since fire) in drier sites, although this effect diminished as precipitation increased. The probability of occurrence of understorey fires under non-extreme weather and on steep slopes was reduced in wetter areas. Relationships between crown fire and weather, topography and fuel age were largely unaltered by the precipitation gradient, with only a marginally significant interaction occurring between weather and mean annual precipitation. Greater fine fuel accumulation associated with increased precipitation presumably reduced fuel limitations imposed by environmental factors (i.e. fire weather, slope, fuel age), altering their relative control on the probability of understorey fire. The probability of crown fires is predominantly driven by fire weather and is consequently less sensitive to precipitation gradients. Consideration of precipitation gradients will be necessary when identifying controls of fire severity and devising effective fire management strategies.
23
Wang, Enli, Malcolm Ryley, and Holger Meinke. "Effect of climate variability on event frequency of sorghum ergot in Australia." Australian Journal of Agricultural Research 54, no. 6 (2003): 599. http://dx.doi.org/10.1071/ar02198.
Full textAbstract:
The significant effect of ergot, caused by Claviceps africana, on the Australian sorghum industry, has led to considerable research on the identification of resistant genotypes and on the climatic conditions that are conducive to ergot outbreaks. Here we show that the potential number of monthly ergot events differs strongly from year to year in accordance with ENSO (El Niño–Southern Oscillation)-related climate variability. The analysis is based on long-term weather records from 50 locations throughout the sorghum-growing areas of Australia and predicts the potential number of monthly ergot events based on phases of the Southern Oscillation Index (SOI). For a given location, we found a significant difference in the number of potential ergot events based on SOI phases in the preceding month, with a consistently positive SOI phase providing the greatest risk for the occurrence of ergot for most months and locations. This analysis provides a relative risk assessment for ergot outbreaks based on location and prevailing climatic conditions, thereby assisting in responsive decision-making to reduce the negative effect of sorghum ergot.
24
Dorph, Annalie, Erica Marshall, Kate A. Parkins, and Trent D. Penman. "Modelling ignition probability for human- and lightning-caused wildfires in Victoria, Australia." Natural Hazards and Earth System Sciences 22, no. 10 (October 24, 2022): 3487–99. http://dx.doi.org/10.5194/nhess-22-3487-2022.
Full textAbstract:
Abstract. Wildfires pose a significant risk to people and property, which is expected to grow with urban expansion into fire-prone landscapes and climate change causing increases in fire extent, severity and frequency. Identifying spatial patterns associated with wildfire activity is important for assessing the potential impacts of wildfires on human life, property and other values. Here, we model the probability of fire ignitions in vegetation across Victoria, Australia, to determine the key drivers of human- and lightning-caused wildfire ignitions. In particular, we extend previous research to consider the role that fuel moisture has in predicting ignition probability while accounting for environmental and local conditions previously identified as important. We used Random Forests to test the effect of variables measuring infrastructure, topography, climate, fuel and soil moisture, fire history, and local weather conditions to investigate what factors drove ignition probability for human- and lightning-caused ignitions. Human-caused ignitions were predominantly influenced by measures of infrastructure and local weather. Lightning-sourced ignitions were driven by fuel moisture, average annual rainfall and local weather. Both human- and lightning-caused ignitions were influenced by dead fuel moisture with ignitions more likely to occur when dead fuel moisture dropped below 20 %. In future, these models of ignition probability may be used to produce spatial likelihood maps, which will improve our models of future wildfire risk and enable land managers to better allocate resources to areas of increased fire risk during the fire season.
25
Elvidge, Andrew D., and Ian A. Renfrew. "The Causes of Foehn Warming in the Lee of Mountains." Bulletin of the American Meteorological Society 97, no. 3 (March 1, 2016): 455–66. http://dx.doi.org/10.1175/bams-d-14-00194.1.
Full textAbstract:
Abstract The foehn effect is well known as the warming, drying, and cloud clearance experienced on the lee side of mountain ranges during “flow over” conditions. Foehn flows were first described more than a century ago when two mechanisms for this warming effect were postulated: an isentropic drawdown mechanism, where potentially warmer air from aloft is brought down adiabatically, and a latent heating and precipitation mechanism, where air cools less on ascent—owing to condensation and latent heat release—than on its dry descent on the lee side. Here, for the first time, the direct quantitative contribution of these and other foehn warming mechanisms is shown. The results suggest a new paradigm is required after it is demonstrated that a third mechanism, mechanical mixing of the foehn flow by turbulence, is significant. In fact, depending on the flow dynamics, any of the three warming mechanisms can dominate. A novel Lagrangian heat budget model, back trajectories, high-resolution numerical model output, and aircraft observations are all employed. The study focuses on a unique natural laboratory—one that allows unambiguous quantification of the leeside warming—namely, the Antarctic Peninsula and Larsen C Ice Shelf. The demonstration that three foehn warming mechanisms are important has ramifications for weather forecasting in mountainous areas and associated hazards such as ice shelf melt and wildfires.
26
Penman, T. D., R. A. Bradstock, and O. Price. "Modelling the determinants of ignition in the Sydney Basin, Australia: implications for future management." International Journal of Wildland Fire 22, no. 4 (2013): 469. http://dx.doi.org/10.1071/wf12027.
Full textAbstract:
Variations in area burnt by fire are governed by four processes: biomass growth, availability to burn, fire weather and ignitions. Insight into these how these processes are shaped by biophysical and human influences is required to underpin the development of effective management strategies. Patterns of natural and arson ignitions were examined within the densely populated Sydney region of south-eastern Australia to determine the extent to which management can alter the risk of ignition. Arson ignitions were more likely on ridges in association with human infrastructure, i.e. roads and houses. Lightning ignitions also occurred more frequently on ridges, but at greater distances from human infrastructure. These patterns are consistent with those reported in studies from forested regions in the northern hemisphere. Fuel age had a variable effect with lightning more likely in older fuels (>25 years) and arson more likely in younger fuels (<10 years). Probability of both ignition types increased under more severe fire weather. Climate change is predicted to increase the severity of fire weather and is therefore likely to result in an increase in ignition frequency in the Sydney Basin. Urban expansion is also likely to have significant effects on ignitions and resultant risks to people and property via an increase in the probability of arson ignitions.
27
Yeates, S. J., R. J. Lawn, and S. W. Adkins. "Prediction of weather damage of mungbean seed in tropical Australia. I. Relation between seed quality, weather, and reproductive development." Australian Journal of Agricultural Research 51, no. 5 (2000): 637. http://dx.doi.org/10.1071/ar99062.
Full textAbstract:
Assessment of the potential for mungbean cropping in the Australian monsoon tropics required a model that could predict pre-harvest seed quality from long-term climatic data. Empirical relations between seed quality and pre-harvest weather were developed from field-grown mungbean using 22 sowings over 3 seasons. Seed quality reflected visual symptoms of weather damage expressed as the percentage of undamaged seed. A minimum exposure to rainfall was required before seed quality was reduced. After this minimum was exceeded, the effect of additional rainfall was cumulative and the percentage of unweathered seed decreased proportionally until a maximum was reached whereby all susceptible seed was weather damaged. The percentage of unweathered seed was best predicted as a function of the cumulative duration of rainfall events. Exposure to at least 300 min of rainfall was required before seed quality was downgraded. Exposure to 4000 min of rainfall was required to reach the maximum threshold. The linear decline in the percentage of unweathered seed was accurately predicted with independent data (r2 = 0.84) by a function that combined the cumulative duration of rainfall and the standard deviation of evaporation. This function reflected the weathering process, that is, cumulative exposure to moisture and the extent of drying of the atmosphere between rainfall events. Alternatively, where pluviograph data were unavailable, combining the sum of rainfall events (>0.5mm) with the standard deviation of evaporation and mean daily solar radiation was also highly correlated with the proportion of unweathered seed; accurate predictions were made using independent data during crop ripening (r2 = 0.93) and after ripening (r2 = 0.72). Weather damage was sensitive to the timing of reproductive development relative to rainfall; adjusting climate variables for cohort-specific exposure removed the confounding effects caused by the daily ripening of pods. Time to flowering was accurately predicted, 2–3 days from observed, using mean daily photoperiod and temperature. As expected, rate of progress from flowering to the first ripe pod and crop maturity was dependent on photoperiod, temperature, and moisture availability. The proportion of pods ripe on any day was highly (P < 0.01) correlated with the proportion of the pod-ripening phase completed.
28
McRae, R. H. D., J. J. Sharples, and M. Fromm. "Linking local wildfire dynamics to pyroCb development." Natural Hazards and Earth System Sciences 15, no. 3 (March 5, 2015): 417–28. http://dx.doi.org/10.5194/nhess-15-417-2015.
Full textAbstract:
Abstract. Extreme wildfires are global phenomena that consistently result in loss of life and property and further impact the cultural, economic and political stability of communities. In their most severe form they cause widespread devastation of environmental assets and are capable of impacting the upper troposphere/lower stratosphere through the formation of a thunderstorm within the plume. Such fires are now often observed by a range of remote-sensing technologies, which together allow a greater understanding of a fire's complex dynamics. This paper considers one such fire that burnt in the Blue Mountains region of Australia in late November 2006, which is known to have generated significant pyrocumulonimbus clouds in a series of blow-up events. Observations of this fire are analysed in detail to investigate the localised processes contributing to extreme fire development. In particular, it has been possible to demonstrate for the first time that the most violent instances of pyroconvection were driven by, and not just associated with, atypical local fire dynamics, especially the fire channelling phenomenon, which arises due to an interaction between an active fire, local terrain attributes and critical fire weather and causes the fire to rapidly transition from a frontal to an areal burning pattern. The impacts of local variations in fire weather and of the atmospheric profile are also discussed, and the ability to predict extreme fire development with state-of-the-art tools is explored.
29
McRae, R. H. D., J. J. Sharples, and M. Fromm. "Linking local wildfire dynamics to pyroCb development." Natural Hazards and Earth System Sciences Discussions 2, no. 12 (December 2, 2014): 7269–92. http://dx.doi.org/10.5194/nhessd-2-7269-2014.
Full textAbstract:
Abstract. Extreme wildfires are global phenomena that consistently result in loss of life and property, and further impact the cultural, economic and political stability of communities. In their most extreme form they cause widespread devastation of environmental assets and are capable of impacting the upper troposphere–lower stratosphere through the formation of a thunderstorm within the plume. Such fires are now often observed by a range of remote sensing technologies, which together allow a greater understanding of a fire's complex dynamics. This paper considers one such fire that burnt in the Blue Mountains region of Australia in late-November 2006, that is known to have generated significant pyrocumulonimbus clouds in a series of blow-up events. Observations of this fire are analysed in detail to investigate the localised processes contributing to extreme fire development. In particular, it has been possible to demonstrate for the first time that the most severe instances of pyroconvection were driven by, and not just associated with, extreme local fire dynamics, especially the fire channelling phenomenon, which arises due to an interaction between an active fire, local terrain attributes and critical fire weather, and causes the fire to rapidly transition from a frontal to an areal burning pattern. The impacts of local variations in fire weather and of the atmospheric profile are also discussed, and the ability to predict extreme fire development with state-of-the-art tools is explored.
30
Green, K. "Effect of variation in snowpack on timing of bird migration in the Snowy Mountains of south-eastern Australia." Emu - Austral Ornithology 106, no. 3 (September 2006): 187–92. http://dx.doi.org/10.1071/mu05060.
Full text
31
Horton, Brian, and Ross Corkrey. "A weighted coefficient model for estimation of Australian daily soil temperature at depths of 5cm to 100cm based on air temperature and rainfall." Soil Research 49, no. 4 (2011): 305. http://dx.doi.org/10.1071/sr10151.
Full textAbstract:
Soil temperatures are related to air temperature and rainfall on the current day and preceding days, and this can be expressed in a non-linear relationship to provide a weighted value for the effect of air temperature or rainfall based on days lag and soil depth. The weighted minimum and maximum air temperatures and weighted rainfall can then be combined with latitude and a seasonal function to estimate soil temperature at any depth in the range 5–100 cm. The model had a root mean square deviation of 1.21–1.85°C for minimum, average, and maximum soil temperature for all weather stations in Australia (mainland and Tasmania), except for maximum soil temperature at 5 and 10 cm, where the model was less precise (3.39° and 2.52°, respectively). Data for this analysis were obtained from 32–40 Bureau of Meteorology weather stations throughout Australia and the proposed model was validated using 5-fold cross-validation.
32
Aryal, Rupak, Bivek Baral, Saravanamuthu Vigneswaran, Ravi Naidu, and Paripurnanda Loganathan. "Seasonal influence on urban dust PAH profile and toxicity in Sydney, Australia." Water Science and Technology 63, no. 10 (May 1, 2011): 2238–43. http://dx.doi.org/10.2166/wst.2011.504.
Full textAbstract:
Road dust is one of the major threats to the urban environment due to wash-off of dust to the surrounding catchments during wet weather period. The dust contains wide range of toxic contaminants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and endocrine disrupting chemicals. Among the toxic contaminants, PAHs are of environmental concern due to their potential carcinogenic and mutagenic effect besides endocrine disruptive behaviour. Eighteen road dust samples from Sydney were collected in different time periods for a year and analysed for 16 US EPA PAHs. Total PAHs content range in the dust was 9–105 μg/g. Total and individual PAH contents were highest in the finest size fraction (<75 μm) and in winter compared to the other seasons. The PAH profiles in the different particle sizes were similar but different between the four seasons. The concentrations of higher molecular weight PAHs (4- and 5-rings) were much greater than the concentrations of lower molecular weight PAHs (2- and 3-rings). Toxicity equivalency factor application showed that the longer the dry weather period the higher the total PAHs content and toxicity in the dust.
33
Price, Owen F., and Ross A. Bradstock. "The effect of fuel age on the spread of fire in sclerophyll forest in the Sydney region of Australia." International Journal of Wildland Fire 19, no. 1 (2010): 35. http://dx.doi.org/10.1071/wf08167.
Full textAbstract:
We investigated the effect of fuel age on the truncation of spread of unplanned fires using a set of 1473 patches in the Sydney region of Australia. Twenty-two percent of patches derived from prescribed fire experienced a subsequent unplanned fire within 5 years, compared with 42% of patches derived from unplanned fires. Among those encounters, the subsequent unplanned fire stopped at the leading edge of 18% of prescribed patches and 11% of unplanned patches. In comparison, the subsequent fire stopped somewhere in the patch for 44% of both prescribed and unplanned fires. Overall, there was a 10% chance that a prescribed burn patch would experience an unplanned fire that stops within the patch. Statistical modelling revealed that the presence of a road barrier was the best predictor of the likelihood of stopping on the leading edge, but fuel age and weather also had an influence. Stopping on the trailing edge was less influenced by the variables analysed. In extreme weather, even 1-year-old patches have a low likelihood of stopping unplanned fires. Fuel age had little influence on the spread of unplanned fires. Consequently, prescribed fires will be most effective when sited at the urban interface where resultant reduced unplanned fire intensity will be a benefit.
34
Holmlund, Per, and Thomas Schneider. "The effect of continentality on glacier response and mass balance." Annals of Glaciology 24 (1997): 272–76. http://dx.doi.org/10.3189/s0260305500012295.
Full textAbstract:
The continentality index is a good measure of the nature of the climate in a region, as it reflects not only the temperature but also the large-scale circulation. It correlates well with glacier mass-balance parameters. The climate along the west–east transect slightly north of the Arctic Circle across the Scandinavian Caledonides is governed by the prevailing westerlies; however, during winter the eastern part of the Caledonides is influenced by weather systems from the southeast. The differences in continentality meant by temperature and precipitation have a major impact on the response times of glaciers. The climatic change in this area has been dominated by increased summer mean temperatures (1910–20) and increased maritime influence since the 1980s. The slower-reacting glaciers on the Swedish side of the mountains are still adapting to the temperature increase at the beginning of the 20th century, and the increase in maritime influence gradually becomes less important towards the west. Thus, differences in the behaviour of glacier fronts along the west–east transect mirror differences in continentality.
35
Holmlund, Per, and Thomas Schneider. "The effect of continentality on glacier response and mass balance." Annals of Glaciology 24 (1997): 272–76. http://dx.doi.org/10.1017/s0260305500012295.
Full textAbstract:
The continentality index is a good measure of the nature of the climate in a region, as it reflects not only the temperature but also the large-scale circulation. It correlates well with glacier mass-balance parameters. The climate along the west–east transect slightly north of the Arctic Circle across the Scandinavian Caledonides is governed by the prevailing westerlies; however, during winter the eastern part of the Caledonides is influenced by weather systems from the southeast. The differences in continentality meant by temperature and precipitation have a major impact on the response times of glaciers. The climatic change in this area has been dominated by increased summer mean temperatures (1910–20) and increased maritime influence since the 1980s. The slower-reacting glaciers on the Swedish side of the mountains are still adapting to the temperature increase at the beginning of the 20th century, and the increase in maritime influence gradually becomes less important towards the west. Thus, differences in the behaviour of glacier fronts along the west–east transect mirror differences in continentality.
36
Anas, Osama, Una Jean Harrison, Phillip M. Brannen, and Turner B. Sutton. "The Effect of Warming Winter Temperatures on the Severity of Pierce's Disease in the Appalachian Mountains and Piedmont of the Southeastern United States." Plant Health Progress 9, no. 1 (January 2008): 13. http://dx.doi.org/10.1094/php-2008-0718-01-rs.
Full textAbstract:
Pierce's disease (PD) caused by Xylella fastidiosa (Xf) is a major threat to the rapidly growing Vitis vinifera/French-American hybrid winegrape industry in the southeastern United States. The bacterium, which is transmitted by xylemfeeding insects, is unable to survive low winter temperatures, and infected vines often recover the next year. Maps available from the 1970s indicate that PD is not a serious threat in the southeastern US, where the average minimum January temperature is ≤ 1.7°C. However PD symptoms developed in many vineyards planted in the late 1990s in areas identified as low risk. Surveys conducted in North Carolina and Georgia confirmed the presence of Xf in symptomatic vines using ELISA kits. Weather data for November to March from 84 weather stations from 1972-2005 for Alabama, Georgia, North Carolina, South Carolina, Tennessee, and Virginia were used to construct new maps using ArcGIS 9.1, and PD survey data from vineyards were superimposed on the maps. Areas for low risk for PD corresponded most closely with a minimum winter temperature of ≤ -12.2°C for 2 to 3 days or ≤ -9.4°C for 4 to 5 days. Warm winter temperatures during the last 8 years have resulted in a significant shift in the isotherms towards the north and west, increasing the risk of PD in the Piedmont region of the Southeast, and have extended the threat into Virginia and Tennessee. Accepted for publication 11 March 2008. Published 18 July 2008.
37
Plăiaşu, Rodica, Arpat Ozgul, Benedikt R. Schmidt, and Raluca I. Băncilă. "Estimation of apparent survival probability of the harvestman Paranemastoma sillii sillii (Herman, 1871) from two caves." Animal Biology 67, no. 2 (2017): 165–76. http://dx.doi.org/10.1163/15707563-00002529.
Full textAbstract:
Reliable estimates of population parameters are lacking for most cave-dwelling species. This lack of knowledge may hinder the appropriate management of caves and populations of cave-dwelling species. Using monthly capture-recapture data and Cormack-Jolly-Seber models, we (i) estimated the apparent survival of individuals in two cave populations of the harvestman Paranemastoma sillii sillii (Herman, 1871) from the Mehedinti Mountains in south-western Romania; (ii) investigated temporal variation in apparent survival; (iii) tested if surface weather conditions affect apparent survival of cave-dwelling harvestmen through their influence upon cave environmental conditions and (iv) tested for sex differences in apparent survival. Our results show that the apparent monthly survival estimates were high for both studied cave populations and there was a significant sex effect on survival. Males had lower survival than females, and the survival difference between caves was larger in males than in females. Temporal (i.e., monthly) variation in apparent survival was low and the weather conditions at the surface had little influence on apparent survival as the environment inside the caves is well buffered against weather fluctuations outside the caves. Our results indicate that caves stabilize survival of facultative cave-dwelling species and may serve as microrefugia for epigean species. We suggest that caves should be considered for conservation because they may serve as a refuge for some epigean species during harsh weather conditions.
38
Lenart, Elizabeth A., R. Terry Bowyer, Jay Ver Hoef, and Roger W. Ruess. "Climate change and caribou: effects of summer weather on forage." Canadian Journal of Zoology 80, no. 4 (April 1, 2002): 664–78. http://dx.doi.org/10.1139/z02-034.
Full textAbstract:
In 1989, the Chisana caribou (Rangifer tarandus) herd in the northern Wrangell Mountains, Alaska, U.S.A., declined substantially in population size and productivity. Grasses, sedges, forbs, and willows (Salix spp.) are critical components of the diet of caribou in spring and summer, and the abundance and quality of forage are influenced by climate. To evaluate effects of climatic variation on caribou forage we conducted a field experiment in subarctic tundra where light, air temperature, and precipitation were manipulated. We used a plastic tarpaulin to increase air temperature and decrease precipitation. We also decreased light intensity with a shade cloth and increased precipitation by adding water to determine climatic effects on nutrient content and biomass of forage for caribou during the summers of 1994 and 1995. The most notable treatment effect on aboveground biomass was that shading resulted in higher nitrogen concentrations in all plant growth forms. In addition, shading consistently reduced biomass in forbs during mid and late season. Water treatment increased total plant biomass in the greenhouse plots during midseason in 1994 and in late spring in 1995. Water treatment also increased late-season biomass in control plots during 1994 but had no effect on biomass in shaded plots in either 1994 or 1995. A decline in nitrogen concentration in plants occurred throughout summer, a pattern that was not evident in in vitro dry matter digestibility. Climate variation and subsequent effects on forage plants have the potential to influence the population dynamics of caribou through effects on their food supply.
39
Read, DG. "Weather and Trap Response of the Dasyurid Marsupials Sminthopsis-Crassicaudata, Planigale-Gilesi and Planigale-Tenuirostris." Wildlife Research 15, no. 2 (1988): 139. http://dx.doi.org/10.1071/wr9880139.
Full textAbstract:
Daily captures of Sminthopsis crassicaudata, Planigale gilesi and P. tenuirostris have been analysed with respect to weather variables in an arid environment. Numbers of S. crassicaudata caught in traps were not affected by changes in air pressure but more (P=0.01) P. gilesi and P. tenuirostris were trapped when the air pressure was increasing from a level below the monthly mean. Light rain increased the numbers of all species trapped (P=0.05) but moonlight had no effect. A canonical correlation analysis separated Sminthopsis from Planigale on the basis of responses to temperature and relative humidity variables. It is not clear if the trap responses of the dasyurids are directly related to the weather or other contemporary factors, particularly food availability. Results indicate that weather has a strong influence on the trap success of small mammal studies in arid Australia.
40
Ladbrook, Megan, Eddie J. B. van Etten, and William D. Stock. "Contemporary Fire Regimes of the Arid Carnarvon Basin Region of Western Australia." Fire 1, no. 3 (December 14, 2018): 51. http://dx.doi.org/10.3390/fire1030051.
Full textAbstract:
This study investigates the fire regime for the arid Carnarvon Basin region of Western Australia using remotely sensed imagery. A fire history database was constructed from satellite images to characterise the general fire regime and determine any effect of vegetation types and pre-fire weather and climate. The study area was divided into two sections (northern and southern) due to their inherently different vegetation and climate. A total of 23.8% (15,646 km2) of the study area was burnt during the 39-year study period. Heathland vegetation (54%) burnt the most extensively in the southern study area, and hummock grasslands (68%) in the northern. A single, unusually large fire in 2012 followed exceptional rains in the previous 12 months and accounted for 55% of the total burnt area. This fire burnt mainly through Acacia shrublands and woodlands rather than hummock grasslands, as normally experienced in the northern study area. Antecedent rainfall and fire weather were found to be the main meteorological factors driving fire size. Both study areas showed a moderate to strong correlation between fire size and increased pre-fire rainfall in the year preceding the fire. Predicted future changes in climate may lead to more frequent and higher intensity fires.
41
Duke, Norman C., John M. Kovacs, Anthony D. Griffiths, Luke Preece, Duncan J. E. Hill, Penny van Oosterzee, Jock Mackenzie, Hailey S. Morning, and Damien Burrows. "Large-scale dieback of mangroves in Australia." Marine and Freshwater Research 68, no. 10 (2017): 1816. http://dx.doi.org/10.1071/mf16322.
Full textAbstract:
This study records and documents the most severe and notable instance ever reported of sudden and widespread dieback of mangrove vegetation. Between late 2015 and early 2016, extensive areas of mangrove tidal wetland vegetation died back along 1000km of the shoreline of Australia’s remote Gulf of Carpentaria. The cause is not fully explained, but the timing was coincident with an extreme weather event; notably one of high temperatures and low precipitation lacking storm winds. The dieback was severe and widespread, affecting more than 7400ha or 6% of mangrove vegetation in the affected area from Roper River estuary in the Northern Territory, east to Karumba in Queensland. At the time, there was an unusually lengthy period of severe drought conditions, unprecedented high temperatures and a temporary drop in sea level. Although consequential moisture stress appears to have contributed to the cause, this occurrence was further coincidental with heat-stressed coral bleaching. This article describes the effect and diagnostic features of this severe dieback event in the Gulf, and considers potential causal factors.
42
Tomašević, Ivana Čavlina, Kevin K. W. Cheung, Višnjica Vučetić, and Paul Fox-Hughes. "Comparison of Wildfire Meteorology and Climate at the Adriatic Coast and Southeast Australia." Atmosphere 13, no. 5 (May 7, 2022): 755. http://dx.doi.org/10.3390/atmos13050755.
Full textAbstract:
Wildfire is one of the most complex natural hazards. Its origin is a combination of anthropogenic factors, urban development and weather plus climate factors. In particular, weather and climate factors possess many spatiotemporal scales and various degrees of predictability. Due to the complex synergy of the human and natural factors behind the events, every wildfire is unique. However, there are indeed common meteorological and climate factors leading to the high fire risk before certain ignition mechanismfigures occur. From a scientific point of view, a better understanding of the meteorological and climate drivers of wildfire in every region would enable more effective seasonal to annual outlook of fire risk, and in the long term, better applications of climate projections to estimate future scenarios of wildfire. This review has performed a comparison study of two fire-prone regions: southeast Australia including Tasmania, and the Adriatic coast in Europe, especially events in Croatia. The former is well known as part of the ‘fire continent’, and major resources have been put into wildfire research and forecasting. The Adriatic coast is a region where some of the highest surface wind speeds, under strong topographic effect, have been recorded and, over the years, have coincided with wildfire ignitions. Similar synoptic background and dynamic origins of the meso-micro-scale meteorological conditions of these high wind events as well as the accompanied dryness have been identified between some of the events in the two regions. We have also reviewed how the researchers from these two regions have applied different weather indices and numerical models. The status of estimating fire potential under climate change for both regions has been evaluated. This review aims to promote a global network of information exchange to study the changing anthropogenic and natural factors we have to confront in order to mitigate and adapt the impacts and consequences from wildfire.
43
Butler, Don William, Russell James Fairfax, and Roderick John Fensham. "Impacts of tree invasion on floristic composition of subtropical grasslands on the Bunya Mountains, Australia." Australian Journal of Botany 54, no. 3 (2006): 261. http://dx.doi.org/10.1071/bt05070.
Full textAbstract:
The effect of ongoing forest invasion on floristic composition of subtropical montane grasslands was considered by examining vascular plant species frequencies across 13 adjoining areas of grassland, invaded grassland (eucalypt forest <50 years old) and eucalypt forest (>50 years old) on the Bunya Mountains in subtropical eastern Australia. Tree invasion of grasslands over the last 50 years has had substantial facilitative or antagonistic net impacts on populations of many plant species. Increases in species frequency, indicating net facilitation, generally appear to occur earlier in forest development than do decreases in frequency, indicative of net antagonism. Although more than 20% of the flora showed substantial association with either grassland or forest, the dominant ground-stratum species in each habitat were quite similar and very few grassland species were not recorded in grassy forests. Forb species composition appears to change more rapidly after tree invasion than grass species composition. Relatively few forbs preferred forest to grassland, whereas shrubs, trees or lianes were substantially more frequent in forests. Replacement of grasslands by grassy forests would reduce landscape diversity and impact on other values in the Bunya Mountains. However, this study suggests that most, if not all, vascular plants that currently occur on the grasslands will persist in the area provided the grassy character of the eucalypt forests is maintained.
44
Richter, H., A. W. Western, and F. H. S. Chiew. "The Effect of Soil and Vegetation Parameters in the ECMWF Land Surface Scheme." Journal of Hydrometeorology 5, no. 6 (December 1, 2004): 1131–46. http://dx.doi.org/10.1175/jhm-362.1.
Full textAbstract:
Abstract Numerical Weather Prediction (NWP) and climate models are sensitive to evapotranspiration at the land surface. This sensitivity requires the prediction of realistic surface moisture and heat fluxes by land surface models that provide the lower boundary condition for the atmospheric models. This paper compares simulations of a stand-alone version of the European Centre for Medium-Range Weather Forecasts (ECMWF) land surface scheme, or the Viterbo and Beljaars scheme (VB95), with various soil and vegetation parameter sets against soil moisture observations across the Murrumbidgee River catchment in southeast Australia. The study is, in part, motivated by the adoption of VB95 as the operational land surface scheme by the Australian Bureau of Meteorology in 1999. VB95 can model the temporal fluctuations in soil moisture, and therefore the moisture fluxes, fairly realistically. The monthly model latent heat flux is also fairly insensitive to soil or vegetation parameters. The VB95 soil moisture is sensitive to the soil and, to a lesser degree, the vegetation parameters. The model exhibits a significant (generally wet) bias in the absolute soil moisture that varies spatially. The use of the best Australia-wide available soils and vegetation information did not improve VB95 simulations consistently, compared with the original model parameters. Comparisons of model and observed soil moistures revealed that more realistic soil parameters are needed to reduce the model soil moisture bias. Given currently available continent-wide soils parameters, any initialization of soil moisture with observed values would likely result in significant flux errors. The soil moisture bias could be largely eliminated by using soil parameters that were derived directly from the actual soil moisture observations. Such parameters, however, are only available at very few point locations.
45
Huang, Xiaodong, Kerrie Mengersen, Gabriel Milinovich, and Wenbiao Hu. "Effect of Weather Variability on Seasonal Influenza Among Different Age Groups in Queensland, Australia: A Bayesian Spatiotemporal Analysis." Journal of Infectious Diseases 215, no. 11 (April 12, 2017): 1695–701. http://dx.doi.org/10.1093/infdis/jix181.
Full text
46
Bai, Xuesong, Zhengkun Qin, Zhaohui Lin, and Wangbin Shen. "Effect of Radio Frequency Interference-Contaminated AMSR2 Signal Restoration on Soil Moisture Retrieval." Remote Sensing 14, no. 19 (September 26, 2022): 4796. http://dx.doi.org/10.3390/rs14194796.
Full textAbstract:
Soil moisture is a key variable of the climate system. Microwave remote sensing has become an essential means of obtaining soil moisture because of the unique advantages of its all-day and all-weather observation capability. Theoretically, low-frequency C-band observations are highly suitable for soil moisture retrieval because of their high sensitivity to soil moisture at vegetation roots. However, the quality of C-band observations suffers from radio frequency interference (RFI) over the United States. This paper used the iterative principal component analysis (PCA) method to repair RFI-contaminated second-generation Advanced Microwave Scanning Radiometer (AMSR-2) C-band observations, and the results of soil moisture retrieval based on restored data were evaluated. It was found that RFI could lead to nonconvergence in the retrieval of a large amount of data, and the application of repaired data in retrieval could result in the recovery of more than 80% of nonconvergent data, especially in spring and autumn. The retrieval results based on restored data attained a satisfactory correlation with ERA5 reanalysis data and European Space Agency Climate Change Initiative (ESA-CCI) soil moisture data and suitably agreed with precipitation observation data. Soil moisture generally exhibited a gradual increase from west to north and east. This feature was weakened due to the influence of monsoons in the east in summer. The western side of the Cascade Mountains is the wettest area of the United States, with soil moisture exceeding 0.4 m3 m−3. The driest region of the United States is located between the Rockies and Cordillera Mountains, and the soil moisture value is lower than 0.1 m3 m−3.
47
Furlaud, James M., Grant J. Williamson, and David M. J. S. Bowman. "Simulating the effectiveness of prescribed burning at altering wildfire behaviour in Tasmania, Australia." International Journal of Wildland Fire 27, no. 1 (2018): 15. http://dx.doi.org/10.1071/wf17061.
Full textAbstract:
Prescribed burning is a widely accepted wildfire hazard reduction technique; however, knowledge of its effectiveness remains limited. To address this, we employ simulations of a widely used fire behaviour model across the ecologically diverse Australian island state of Tasmania. We simulate three broad scenarios: (1) no fuel treatment, (2) a maximal treatment, with the most possible prescribed burning within ecological constraints, and (3) 12 hypothetically more implementable state-wide prescribed-burning plans. In all simulations, we standardised fire-weather inputs to represent regionally typical dangerous fire-weather conditions. Statistical modelling showed that an unrealistically large maximal treatment scenario could reduce fire intensity in three flammable vegetation types, and reduce fire probability in almost every vegetation type. However, leverage analysis of the 12 more-realistic implementable plans indicated that such prescribed burning would have only a minimal effect, if any, on fire extent and that none of these prescribed-burning plans substantially reduced fire intensity. The study highlights that prescribed burning can theoretically mitigate wildfire, but that an unrealistically large area would need to be treated to affect fire behaviour across the island. Rather, optimisation of prescribed burning requires careful landscape design at the local scale. Such designs should be based on improved fire behaviour modelling, empirical measurement of fuels and analysis of actual wildfires.
48
Fontaine, Joseph B., Vanessa C. Westcott, Neal J. Enright, Janneke C. Lade, and Ben P. Miller. "Fire behaviour in south-western Australian shrublands: evaluating the influence of fuel age and fire weather." International Journal of Wildland Fire 21, no. 4 (2012): 385. http://dx.doi.org/10.1071/wf11065.
Full textAbstract:
Fuel age (time since last fire) is often used to approximate fire hazard and informs decisions on placement of shrubland management burns worldwide. However, uncertainty remains concerning the relative importance of fuel age and weather conditions as predictors of fire hazard and behaviour. Using data from 35 experimental burns across three types of shrublands in Western Australia, we evaluated importance of fuel age and fire weather on probability of fire propagation (hazard) and four metrics of fire behaviour (rate of spread, fireline intensity, residence time, surface temperature) under moderate to high fire danger weather conditions. We found significant support for a threshold effect of fuel age for fire propagation but limited evidence for an effect of fuel age or fire weather on rates of spread or fireline intensity, although surface heating and heating duration were significantly related to fuel age and shrubland type. Further analysis suggested that dead fuel mass and accumulation rate rather than live fuels were responsible for this relationship. Using BEHAVE, predicted spread rates and intensities were consistently lower than observed values, suggesting further refinement is needed in modelling shrubland fire behaviour. These data provide important insight into fire behaviour in globally significant, fire-adapted shrublands, informing fire management and relationships between fire frequency and fire intensity.
49
Evers, Cody, Andrés Holz, Sebastian Busby, and Max Nielsen-Pincus. "Extreme Winds Alter Influence of Fuels and Topography on Megafire Burn Severity in Seasonal Temperate Rainforests under Record Fuel Aridity." Fire 5, no. 2 (March 22, 2022): 41. http://dx.doi.org/10.3390/fire5020041.
Full textAbstract:
Nearly 0.8 million hectares of land were burned in the North American Pacific Northwest (PNW) over two weeks under record-breaking fuel aridity and winds during the extraordinary 2020 fire season, representing a rare example of megafires in forests west of the Cascade Mountains. We quantified the relative influence of weather, vegetation, and topography on patterns of high burn severity (>75% tree mortality) among five synchronous megafires in the western Cascade Mountains. Despite the conventional wisdom in climate-limited fire regimes that regional drivers (e.g., extreme aridity, and synoptic winds) overwhelm local controls on vegetation mortality patterns (e.g., vegetation structure and topography), we hypothesized that local controls remain important influences on burn severity patterns in these rugged forested landscapes. To study these influences, we developed remotely sensed fire extent and burn severity maps for two distinct weather periods, thereby isolating the effect of extreme east winds on drivers of burn severity. Our results confirm that wind was the major driver of the 2020 megafires, but also that both vegetation structure and topography significantly affect burn severity patterns even under extreme fuel aridity and winds. Early-seral forests primarily concentrated on private lands, burned more severely than their older and taller counterparts, over the entire megafire event regardless of topography. Meanwhile, mature stands burned severely only under extreme winds and especially on steeper slopes. Although climate change and land-use legacies may prime temperate rainforests to burn more frequently and at higher severities than has been historically observed, our work suggests that future high-severity megafires are only likely to occur during coinciding periods of heat, fuel aridity, and extreme winds.
50
Clark, S. G., E. A. Austen, T. Prance, and P. D. Ball. "Climate variability effects on simulated pasture and animal production in the perennial pasture zone of south-eastern Australia.1. Between year variability in pasture and animal production." Australian Journal of Experimental Agriculture 43, no. 10 (2003): 1211. http://dx.doi.org/10.1071/ea02101.
Full textAbstract:
Climate variability is a major constraint to farming in south-eastern Australia and one that is out of the farmers' control. However, a better understanding of long-term climate variability would be beneficial for on-farm management decisions. A series of long-term simulations were undertaken with the GrassGro decision support tool to determine the effect of climate variability on pasture and animal production at 6 locations in south-eastern Australia. The simulations ran from 89 to 119 years using daily weather records from each location. All simulations were for spring-lambing flocks of medium sized Merino ewes stocked at above-average district stocking rates, grazing well-fertilised, perennial grass–subterranean clover pastures. Annual rainfall total and, in particular, the distribution of rainfall during the year, were found to be more important than other weather variables in determining the amount of pasture grown in a year. The timing of the season opening rains (autumn break) was most important. The localities varied in their responses to climate variability, particularly in the timing of the autumn break; the pasture growth response to winter rainfall; and the relationship between rainfall and animal production.