Australia: The Land Where Time Began

A biography of the Australian continent 

Climate                                        Climate cycles     Climate in Aboriginal Australia     RealClimate: Climate Science from Climate Scientists 

Australia is the driest continent on Earth (if Antarctica is excluded because its millions of tonnes of water are in the form of ice or snow). Its climate is very erratic, often moving from one extreme directly to the other. It can have years of drought that is broken by devastating floods. This erratic climate has been found to be influenced very strongly by the El Nino-Southern Oscillation (ENSO) atmosphere-ocean system and Indian Ocean Dipole (IOD).

It has been said that the only thing predictable about the climate of the arid areas of Australia, 3/4 of the continent, is that it is unpredictable. In such a place the very flatness of the majority of the continent turns out to be of importance to the survival of many plants and animals in times of long droughts, which occur often and irregularly. Because of this overall flatness, any high points, from rock outcrops to desert mountain ranges, tend to collect and store more water for longer periods than the surrounding flat land, where it tends to run off, infiltrate to the deep water table or evaporate within a short time of the end of the rainfall. From rock outcrops to gorges in mountain ranges, the water collected is at least partially protected from the worst of the conditions of the surrounding flat land where any surface water  rapidly evaporates.

The plants and animals of Australia have been very strongly influenced by the climate. Both have adapted to survive, as a species if not always as individuals, in very harsh environments in many parts of the continent. The plants of a particular area may have to cope with poor soils, often low and unpredictable water availability, variable climate including droughts of variable and unpredictable length, and occasional floods, and a wide range of temperatures.

The geological feature that influences the climate of Australia most strongly is the absence of sufficiently high mountain ranges west of the Great Dividing Range running north-south near the east cost of the continent. It is not high as mountain ranges go, but is high enough to force winds crossing it to rise high enough to lose some of their moisture as rain, or in the southern states in winter, snow.

Climate change as Australia broke from Antarctica

Prior to the separation of South America and Australia from Antarctica, cold currents flowing along the Antarctic coast were diverted north to the tropics when they struck the west coasts of South America and Australia, returning south to Antarctica after they had been heated by their passage through the equatorial regions, taking that heat south to warm Antarctica. These warming currents were disrupted by the opening of the ocean between Antarctica and South America and Australia, allowing the polar regions to become a progressively colder closed climatic system. The southern parts of Australia became cooler, and the latitudinal temperature gradients steepened, and the climatic zones became more pronounced. The movement of Australia north gradually moved the central and northern parts of the continent away from the moist westerly winds, and into the region of the drier, warmer subtropical high pressure systems (Bowler, 1982; Bowman, 2000).

The zone is dominated by the belt  of high pressure around the Earth, composed of series of high pressure systems that move from west to east near the latitude of 30o S that is about 3000 km wide. In summer these high pressure systems cover the southern parts of the continent and by winter they have moved north to the central regions. The area they cover at any particular time experiences mostly clear skies, the descending air being dry. The increasing aridity of the Australian continent as it moved north is a result of this dry air.

A band or westerly winds is located immediately to the south if the high pressure zone. Fronts and depressions in this band of westerly winds are areas where the air pressures are locally lower, the air in the lower atmosphere converging and ascending, any contained water vapour then condenses as the rising air mass cools, which occurs as it rises, until the water coalesces into rain drops which fall as rain when they reach a sufficient mass to overcome the updraft tending to push them higher. In the winter rain parts of southern Australia it is these mid-latitude systems that bring the rain, usually moving from west to east.

The southeast trade winds occur immediately to the north of the high pressure belt. These winds converge with the northeast trades of the Northern Hemisphere to form the inter-tropical convergence zone (ITCZ), a belt where the rising warm air containing large amounts of moisture lead to the heavy rain of the tropics. The ITCZ moves from north to south of the equator in the Australian summer and back again in the Australian winter, as it tracks the movements of the sun in relation to the Earth, being over the latitudes of northern Australia in the Southern Hemisphere summer and over the areas to the north of the Equator in the Australian winter. During summer there is a low pressure trough that remains continuously over northern Australia, the monsoon season that is hot and wet. The southeast trade winds can bring rain to the east coast of the continent at any time of the year, the moist air rising to cross the Great Dividing Range, which runs the full length of the continent, from Cape York to Tasmania, the moisture being condensed into rain as the air rises. The amount of rain brought by these winds is the result of the water temperature along the east coast of the continent, the warmer the water the higher the evaporation rate and the warmer the air the more water vapour it can hold, hence the potential problems when the oceans are warming.

Both the tropical and mid-latitudes are subject to substantial variability, many rainy weather types being recognised. In the tropical north cyclones often bring heavy rain to the northern coast, in the south, in addition to the normal frontal systems, low pressure systems that originate in the mid-latitudes can be cut-off from the westerlies, often moving slowly while dumping large amounts of rain. The presence of hills or range in an area influences the rain it receives from rain-bearing winds, depending on the direction of flow of the winds in relation to the high ground. In southeastern Australia the western slopes of high ground receive much of their rain from bands of cloud ahead of northwesterly fronts.

The moist southwesterly streams following fronts bring rain to western Tasmania, southern Victoria and the far southwest of Western Australia. Low pressure systems, that can originate in either tropical or mid-latitude regions, situated off the east coast can bring heavy rain to the east coast of New South Wales via the associated onshore easterlies.

In the arid interior of the continent rainfall is usually connected with strong tropical systems that penetrate southward, or the passage of strong fronts, and in winter by 'cut-off' lows.

Variability of the climate

The Byrd Ice Core, the first ice core to be drilled to bedrock in Antarctica, through 2164 m of ice, 99 % of the core being recovered, was drilled through the ice at Byrd Station, Antarctica . It contained a record of atmospheric concentrations of methane that proved a picture of the fluctuations of global climate through much of the last glacial cycle (Blunier & Brook, 2001). The high concentrations are believed to have been from warm, wet periods, when methane is believed to have been produced in tropical wetlands that would be expanding at these times. The evidence from this core confirms the results from other lines of evidence that during the last glacial cycle there were many short-term fluctuations on scales of about 1,000 years. These fluctuations were most dramatic in the middle part of the last cycle, settling down as the LGM (last glacial maximum) approached, so that the climate was very stable between about 28,000 to 20,000 years ago. Sediment cores from the lake bed that formed on the Carpentaria Plain at times of low sea level also show a climatically calm period at the LGM, the fine structure of the sediments indicating that there were few intense storms to disturb them as they were being deposited (De Dekker, 2001). Reconstructions of sea surface temperatures of the ocean around Australia indicate there was little variation of temperature between seasons, seasonal variability being less than at present (Barrows & Juggins, 2005).

  1. A 950 Year Reconstruction of Temperature from Duckhole Lake, southern Tasmania
  2. A 6,000 Year Record of Tropical Cyclones in Western Australia
  3. The 100,000 Year Problem and the Synchronisation of the Climate System to Eccentricity Forcing
  4. The 8,200 Year Event - Links East Asian Monsoon & Climate of the North Atlantic
  5. Abnormal Upwelling and Concentration of Chlorophyll-a off South Vietnam in August 2007
  6. Abrupt Change in Atmospheric Co2 During the Last Ice Age
  7. Antarctica - Role in Global Environment
  8. Antarctic Bottom Water - Freshening and Warming 1980s-2000s
  9. Antarctic Bottom Water Produced by intense formation of Sea-Ice in the Cape Darnley Polynya
  10. Antarctic Cold Reversal - Glacier Advance in Southern Middle-latitudes
  11. Antarctic Circumpolar Current - Response to recent Climate change
  12. Antarctic and Greenland Ice Sheets - Acceleration of their Contribution to Sea Level Rise
  13. Antarctic Surface Waters - Abrupt Cooling and Sea Ice Expansion in the Southern Ocean, South Atlantic Sector at 5,000 Cal Yr BP
  14. Antarctica - Persistent Wind Scour influence on Surface Mass Balance
  15. Antarctica - Ice Flow Sensitivity of Pine Island Glacier to Geothermal Heat Flux
  16. Antarctica - Pine Island Glacier, subglacial melt channels & Fracture in Floating Part
  17. Antarctica - Pine Island Glacier, West Antarctica, Sustained Glacier Retreat
  18. East Antarctica - Abrupt Climate Warming in the Early Holocene
  19. East Antarctic Ice Sheet - Dynamic Behaviour During the Pliocene Warmth
  20. East Antarctica - Relative Sea-Level Rise During Oligocene Glaciation
  21. Antarctic and Greenland Ice Cores Directly Linked at the Toba Eruption - 74 ka BP
  22. The West Antarctic Ice Shelf warming from beneath
  23. West Antarctica - Recent Changes in Climate and Ice Sheet Compared to the Past 2000 Years
  24. Antarctic Sea-Ice Expansion - Important role of Ocean Warming and Increased Ice-Shelf Melt
  25. Antarctic Weathering and Carbonate Compensation at the Transition from the Eocene to the Oligocene
  26. Anthropogenic Contributions to the Australian Record Summer Temperatures of 2013
  27. Arctic Sea Ice Heated from Below
  28. Arctic Surface Snowpacks - Molecular Bromine, Photochemical Production
  29. Arid Australia - a Fresh Framework for its Ecology
  30. Asian Connections
  31. Arctic Surface Snowpacks - Molecular Bromine, Photochemical Production
  32. Atlantic Ocean CO2 uptake reduced by weakening meridional overturning circulation (AMOC)
  33. Atlantic Ocean - Northeast Circulation Impacted by Mesoscale Polar Storms
  34. The Atlantic Meridional Overturning Circulation (AMOC) - Driving Processes
  35. Atlantic Ocean - Multiple Causes for Equatorial Surface Interannual Temperature Variability
  36. Atlantic ocean - Tropical Warm Events
  37. North Atlantic Climate During the Last Glacial Period - Links with Tropical Rainfall
  38. North Atlantic Forcing of Amazonian Precipitation During the Last Ice Age
  39. North Atlantic Millennial-Scale Climate Variability - A 0.5 My Record
  40. Atmospheric Carbon Dioxide - A 300-Million-Year record from Plant Cuticles
  41. Atmospheric Carbon Dioxide Levels from the Distant Past to the Present
  42. Atmospheric Carbon Dioxide Linked to Climate Change in the Mesozoic and Early Cainozoic
  43. Atmospheric Susceptibility to Wildfire - the Last Glacial Maximum and Mid-Holocene
  44. Austral Summer Teleconnections of Indo-Pacific Variability - Nonlinearity and Impacts on the Climate of Australia
  45. Australian regional rainfall decline has been attributed to anthropogenic greenhouse gases and ozone
  46. Australian Temperate Zone Climate Records for the Past 30,000 years – Oz-INTIMATE Workgroup
  47. Bψlling Transition – Global climate Changes Near-Synchronous in Ice Core Record
  48. The Unique Influence of Australia on the Global Sea Level in 2010-2011
  49. Brinicles
  50. Temperature Variability on a continental scale over the Past 2 Millennia
  51. Terrestrial Carbon Cycle - Fingerprints of Changes in Response to Large Ocean Circulation Reorganisation
  52. Carbon Fluxes from Land to Ocean - Anthropic Perturbations
  53. Central Western Antarctica - One of the world's Most Rapidly Warming Regions
  54. Climate - The Atlantic Ocean
  55. Climate - The Pacific Ocean
  56. Climate Change - The Atlantic Ocean
  57. Sea Surface Temperature in the Long-term and Climate Change in the Australian and New Zealand region
  58. Climate Change
  59. Climate Change in Australia - Vertebrates of Quaternary Rainforests Response
  60. Cooper Creek - Climate Change and Aeolian-Fluvial Interaction and Development of Source-Bordering Dunes over the Past 100 ka
  61. Climate - multiple controls
  62. Climate Change - Patterns of Tropical Warming
  63. Climate Change and Variability on a Milankovitch scale - Its Impact on Monsoonal Australasia in the Late Quaternary
  64. Climate Change Science – Attribution of Causes
  65. Climate Change Science - The Berkeley Earth Surface Temperature Study – BEST
  66. Climate Change Science - The Effects of Rising Temperatures on Human Health
  67. Climate Change Science – Energy Budget of the Earth – the Basics
  68. Climate Change Science – Energy Imbalance of the Earth
  69. Climate Change Science – Human Activities and Global Warming
  70. Climate Change Science - Increasing Temperature of the Ocean
  71. Climate Change Science – Land Temperatures – Boreholes
  72. Climate Change Science – Melting Ice
  73. Climate Change Science – Permafrost, Methane and Clathrates
  74. Climate Change Science - Plant and Animal Migration
  75. Climate Change Science - Radiation Laws Affecting the Earth
  76. Climate Change Science – Rising Sea Levels
  77. Climate Change Science – Trends
  78. Climate Change - The Roles of Physical processes in the Tropical Tropopause Layer
  79. Climate Change - Slow Feedbacks
  80. Climate Change - Very Rapid Changes
  81. Climate Controls of the Present in the Southwest Pacific
  82. Climate Variability - Natural Modes
  83. Climate Variability on a Millennial Scale During the 2 past Glacial Periods
  84. Climate Sensitivity to Cumulative Carbon Emissions Due to Ocean Heat and Carbon Uptake
  85. Projected Timing of the Departure of Climate from Recent Variability
  86. Transient Climate Response – Declining Uncertainty as CO2 Forcing Dominates Climate Change into the Future
  87. Drought, Groundwater Storage and Declining Stream Flow in Southwestern Australia
  88. Polar Amplification of Climate Change Confirmed by the Warmth of the Arctic in the Last Interglacial
  89. Climate Networks Evolving 
  90. Climate Swings of the Pleistocene in Australia
  91. The Cryogenian
  92. Calibrating the Cryogenian
  93. The Cryogenian Datangpo Formation, South China - Reconstruction of Palaeo-Redox Conditions and Early Sulphur Cycling
  94. Cryogenian-Ediacaran Transition - Organic Carbon Isotope Constraints on the Dissolved Organic Carbon (Doc) Reservoir
  95. Cryogenian Glaciation - Onset of Carbon-Isotope Decoupling
  96. The Trezona δ13C Anomaly Beneath the Glaciation of the End-Cryogenian - Constraints of the Origin and Relative Timing
  97. The Cryosphere
  98. The Cryosphere - Biosphere Interactions
  99. The Cryosphere - The Geography of Snow and Ice on Earth
  100. The Cryosphere - Glaciers & Ice Sheets
  101. The Cryosphere - Albedo of Snow and Ice
  102. The Cryosphere - Effects on the Hydrological Cycle
  103. The Cryosphere - Interaction between Ocean and Ice  
  104. The Cryosphere - Influence on Circulation of the Atmosphere
  105. The Cryosphere - As a Latent Energy Buffer
  106. The Cryosphere - Permafrost
  107. Decoupling of Air-Sea Temperature in Western Europe During the Interglacial-Glacial Transition
  108. Deep-sea CaCo3 sedimentation - Response to Shutdown of the Atlantic Meridional Overturning Circulation (AMOC)
  109. Deglacial Warming – Oceanic Denitrification Acceleration
  110. Drought, Groundwater Storage and Declining Stream Flow in Southwestern Australia
  111. Early Triassic Climate
  112. El Niρo/Southern Oscillation Influence on tornado and hail frequency in the United States
  113. A World that has Warmed by 2oC Will Not Be Safe For the European Alps Ecosystem System Services
  114. Late Permian Mass Extinction - Recovery Impeded by Multiple Greenhouse Crises in the Early Triassic
  115. Early Triassic - the Smithian - Lethally Hot Temperatures
  116. Elatina Formation
  117. Eemian Interglacial Reconstruction from a folded Greenland Ice Core
  118. End-Permian Mass Extinction - climatic and Biotic Upheavals 
  119. Glacial-Interglacial Bottom Water Oxygen Content Changes on the Portuguese Margin
  120. Last Glacial to Holocene Dust Changes at Talos Dome, East Antarctica - Interpretations & implications for Atmospheric Variations - Regional to Hemisphere Scales
  121. Glaciation on Baltica in the Late Neoproterozoic - the Timing Constrained by Detrital Zircon from Geochronology in the Hedmark Group, Southeast Norway
  122. Glacial Maximum in Australia
  123. Glaciers – Substantial mass Loss in the Tien Shan over the past 50 Years
  124. Global Ocean Climate Change
  125. Global Warming - Patterns of Seasonal Response of Tropical Rainfall
  126. Global Warming - the Difficulty of Recovering from Dangerous Levels
  127. Northeast Greenland Soils – Net Regional Methane Sink in the High Arctic
  128. Greenland Temperature Anomalies - Origin of Multidecadal to Centennial Scales Over the Last 800 Years  
  129. Early Oxidation - great Oxidation Event
  130. Heinrich Events, Massive Detritus Layers from the Late Pleistocene in the North Atlantic -Their Global Climate Imprint
  131. Heinrich Event 4 Characterised in Southwestern Europe by the Use of Terrestrial Proxies
  132. Holocene Changes in Australian-Indonesian Monsoon Rainfall - Stalagmite Evidence from Trace element & Stable Isotope Ratios
  133. Early Holocene – Climatic and Environmental Changes about 11.5-8 cal. ka BP
  134. Hypoxia by degrees - Establishing Definitions for Oceans that are Changing
  135. Jakobshavn Isbrae – Acceleration Triggered by Warm Subsurface Ocean Waters
  136. Possible Global Ice Volume Changes and Geomagnetic Excursions and Earth Orbital Eccentricity
  137. Trends in the Global Jet Stream Characteristics Observed in the Latter Half of the 20th Century
  138. Phanerozoic Climate Modes
  139. During the Transition from the Last Interglacial to the Last Glacial Air-Sea Decoupling Occurred in Western Europe
  140. The Last Glacial Period – Climatic and Environmental Changes 30-20 Cal. ka BP
  141. Last Glacial Period Termination – Climatic and Environmental Changes 20-11.5 Cal. ka BP
  142. Last Glacial Termination Sources of Methane - Measurements of Methane in Greenland Ice
  143. The Last Interglacial – Australian Deserts
  144. The Last Interglacial - lakes and saltlakes
  145. The Last Interglacial – Lake Eyre – A Continental Rain Gauge
  146. The Last Interglacial – Other Inland Lakes
  147. The Last Interglacial – The Arid Rivers
  148. The Last Interglacial – Desert Dunes and Dust
  149. The Last Interglacial – Inland Vegetation
  150. The Last Interglacial – Last of the Dryland Megafauna
  151. The Katapiri Fauna Collapse
  152. Overview – The Desert Before People - Interglacial Landscapes
  153. Landscape of Colonisation
  154. Early Oxidation - Great Oxidation Event (GOE)
  155. Seasonal extremes over Australia - Influence of Climate Variability
  156. Southern Ocean - Shifting Westerlies
  157. Submarine End Moraines on the Continental Shelf Off NE Greenland - Implications for Lateglacial Dynamics
  158. The Great Oxidation Event - Evolution of Multicellularity Coincided with an Increase of Cyanobacterial Diversification
  159. The Great Oxidation Event - More Oxygen Through Multicellularity
  160. Holocene Western Alps Glacier Culmination - Their hemispheric relevance
  161. Early Holocene Ice-Sheet Decay, Rising Sea Level and Abrupt Climate Change
  162. Hydrogen Peroxide Production by in planktonic microorganisms by UV-B
  163. Ice Age Australia
  164. Jet Stream
  165. Polar Wander Linked to Climate Change
  166. Possible Global Ice Volume Changes and Geomagnetic Excursions and Earth Orbital Eccentricity
  167. Indo-Pacific Warm Pool - Oscillation in its Southern Extent During the Middle Holocene
  168. PETM – Rapid, Sustained Acidification of the Ocean Surface
  169. Short-Lived Halogens – Efficiency at Influencing Climate Through Stratospheric Ozone Depletion
  170. Late Palaeocene Thermal Maximum
  171. Terminal Eocene Event
  172. Terminal Miocene Event
  173. Tropical Western Pacific - A 4 Ma record of Thermal Evolution - Implications for Climate Change
  174. Wandering Australia
  175. The West Antarctic Ice Shelf warming from beneath
  176. West Antarctica Warming Rapidly
  177. The Great Journey North
  178. Timeline of Boundaries-Palaeocene to Miocene
  179. The Innamincka Regime
  180. The Potoroo Regime
  181. Australian Palaeoclimate and Palaeogeography for the Tertiary
  182. Australian Palaeoclimate and Palaeobotany for the Tertiary
  183. Cenozoic Carbon Cycle
  184. Cenozoic Climate
  185. Cause of Decoupling Between Solar Radiation and Temperature - the Evidence
  186. Mid-Cretaceous Supergreenhouse - Drastic Shrinking of the Hadley Circulation
  187. Stop-and-Go Deglaciation
  188. Collapse of Prehistoric Aboriginal Society in Northwestern Australia Triggered by an ENSO Mega-Drought 
  189. ENSO - Impact of Maximum Temperature Extremes
  190. ENSO affected by Sothern High Latitude Cooling During the Medieval Period
  191. Palaeocene climate
  192. Palaeocene-Eocene Thermal Maximum (PETM) – Palaeohydrologic Response to Continental Warming, Bighorn Basin, Wyoming
  193. Palaeocene-Eocene Thermal Maximum (PETM)
  194. Palaeocene-Eocene Thermal Maximum – 2 Massive Carbon Releases During the Onset of the PETM
  195. Pliocene El Niρo-like Atmospheric Circulation in the Western US
  196. Oceans and the Climate
  197. Oceanic Anoxic Event 2 - Lithium Isotope Evidence of Enhanced Weathering
  198. Oligocene Climate
  199. Kimberly Region, Western Australia, Glaciation in the Late Neoproterozoic - an 17O
  200. Marinoan Snowball Earth Glaciation – Ice Sheet Fluctuations that were Orbitally Forced
  201. Methane Leakage over Widespread Areas of the Seafloor on the Atlantic Margin of Northern US
  202. Miocene climate
  203. Mid-Miocene Climate Optimum (MMCO)
  204. Mountain Uplift and Global Cooling
  205. North Tropical Atlantic Surface Temperature a Trigger for Enso Events
  206. Nuccaleena Formation, South Australia - Testing Models for Post glacial Deposition of 'Cap Dolostone'
  207. The Response of Northern Hemisphere Glaciers to Past Climate Warming
  208. Palaeoproterozoic Ice Houses - Evolution Oxygen-Mediating Enzymes, Late Origin of Photosystem II
  209. Permian System of Eastern Australia - Atmospheric CO2 Response to Glacial Growth & Decay in Late Palaeozoic Ice Age
  210. Permian & Triassic Greenhouse Crises
  211. Phanerozoic Climate Modes
  212. Phanerozoic Climate Modes - The Cool and Warm Modes
  213. The Invasion of the Land by Plants in the Devonian Caused Climate Change
  214. Tectonism, Climate and Geomorphology
  215. Pliocene climate
  216. Pleistocene Climate
  217. Quaternary Climate
  218. Range Increase of Precipitation Between the Wet and Dry Season
  219. Rapid Climate Change Events
  220. Rapid Climate Change Events (RCCEs) "Rickies" in the Holocene
  221. Seafloor Grooves Record Sea Level Changes During Ice Ages
  222. Snowball Earth - Atmospheric Hydrogen Peroxide and Oxygenic Photosynthesis Origin
  223. Snowball Earth - an Interglacial? Dynamic Behaviour of Ice in the Chuos Formation, Namibia
  224. Storm activity - the Medieval Warm Period and the Little Ice Age
  225. Snowball Earth - Evidence of Low 18O Magmatism During Rifting of a Supercontinent in South China
  226. Snowball Earth - Was it Actually a Profound Wintry Mix
  227. Snowball or Slushball Earth
  228. Southern Ocean Eddies Imprint on Winds, Clouds and Rainfall
  229. The Southern Ocean - Recent Ventilation Changes
  230. A sulphidic Sea in the Late Archaean Stimulated by Early Oxidative Continental Weathering
  231. Synchronization of cycles in the Arctic and the Antarctic
  232. Teleconnections of Austral Summer in Variability in the Indo-Pacific - Nonlinearity and Impacts on the Australian Climate
  233. Toba Eruption 74 ka BP – Direct Linking between Ice Cores from Greenland and Antarctica
  234. Totten Glacier, East Antarctica - Ocean Access to a Cavity Beneath it
  235. The Younger Dryas
  236. Global Tropical Forests – Seasonality Constrained by Hydroclimate
  237. Early Younger Dryas - Variations of atmospheric 14C Derived from Tree Rings
  238. Volcano-Sedimentary Record of Africa, India and Australia - Evidence of Global and Local Sea Level and Continental Freeboard Changes
  239. Pine Island Bay, West Antarctica – Ice Cavity Water Export


The Climate Now

The Australian climate is influenced by several main weather systems related to regular patterns in the oceans and the atmosphere.

Rainfall is brought to northern Australia by the north-west monsoon, and in most years, by cyclones that deliver large amounts of water to mostly coastal areas. Along the east coast rain increases when La Nina is active, when the trade winds in the Pacific ocean push warm water towards the Australian coast, and decreases when El Nino events slow or stop the trade winds, sending the warm water east away from the Australian coast. This is why El Nino brings drought to eastern Australia. It has been assumed that the La Nina events would bring drought-breaking rain to the southern parts of Australia as well. But it has now been realised that this hasn't been happening. While the coasts of New South Wales and Queensland were being deluged by rain brought by La Nina, large areas of Victoria were still in drought.

Queensland weather forecasters have been watching what they believed to be the return of El Nino, but an unexpected finding recently has been that unlike previous El Nino events in which the warm water moves to the east towards South America, it appears that the accumulating warm water stretches across the equatorial Pacific, a confusing situation for forecasters, being unable to predict with confidence what the weather is likely to be, wet or dry.

Indian Ocean Dipole - IOD

Researchers are finding that the trade winds in the Pacific seem to be weakening. If they do weaken further that would lead to a lowering of pressure in the western Pacific, so less power to force the warm water that feeds the Leeuwin Current. They are also seeing what they believe is a change in the IOD that could be leading to a state in which the cool positive phase could be the dominant condition. As if that wasn't enough, the temperatures over Australia have risen by 1o C, drying the continent out even more.

Whether part of a natural cycle or man-made, climate change is beginning to bite in Australia, and the continent is set to be affected more significantly and earlier than other continents. Yet another first for Australia.

Climate Cycles

Tropical Cyclones

Looking at the past to see the future

Climate scientists have been studying ocean sediments searching for C13/C12 isotope ratio anomalies which indicate times when increased amounts of C12-rich carbon is added to the oceans/atmosphere. The correlation of such an anomaly with the Late Palaeocene Thermal Maximum about 55 Ma has been found. It is known that there are many places on the continental shelves around the world where there are large deposits of methane clathrate that has the potential to cause catastrophic climate change if released in sufficient quantities over a sufficiently short time.

The Southern Annular Mode (SAM)

This is a weather system based in Antarctica that has been found to affect the climate of southern Australia, by controlling the strength of the westerly winds that cover the ocean to the south of the Southern Hemisphere continents, including Australia. The SAM determines how far north the westerly winds reach, the further north, the greater the winter rainfall over southern parts of Australia.

The belt of strong westerly winds contracts towards Antarctica in the positive part of the cycle, expanding north, hopefully over southern Australia, in the negative mode. In the positive mode there is reduced autumn and winter rainfall over southern Australia, especially the southern part of Western Australia. The resulting higher pressures over the southern parts of Australia lead to fewer storm systems reaching Australia.

This weather pattern has been found to be conspiring with the IOD to bring the long severe drought to southern Western Australia and western Victoria.

Sources & Further reading

  1. Mary E. White, After the Greening, The Browning of Australia, Kangaroo Press, 1994
  2. Chris Johnson, Australia's Mammal Extinctions, a 50,000 year history, Cambridge University Press, 2006
  3. Peter Whetton in Webb, Eric K, (1997), Windows on Meteorology, Australian Perspective, CSIRO Publishing.


  1. Methane Leaks off the East Siberian Coast, Speeding Climate Change
  2. Hey, Permafrost: Put a Lid on It
  3. Ice Once Covered the Equator
  4. LiveScience Image Gallery
  5. Bird Ice Core Microparticle and Chemistry Data
  6. CO2 record in the Byrd ice core 50,000-5,000 BP
  7. Ice Core Paleoclimatology Research Group
  8. Ice-core evidence of abrupt climate changes
  9. A 25,000-Year Tropical Climate History from Bolivian Ice Cores
  10. Abrupt tropical climate change-past and present
  11. Geochronology and stratigraphy of late Pleistocene lake cycles on the southern Bolivian altoplano-implications for causes of tropical climate change
  12. Abrupt Climate Change at the End of the Last Glacial Period Inferred from Tropical Air in Polar Ice
  13. Climate change and the tropical Pacific-the sleeping dragon wakes
  14. Fine-resolution pollen record of late-glacial climate reversal from New Zealand
  15. As climate changes, so do glaciers
  16. Global enhancement of ocean anoxia during Oceanic Anoxic Event 2-a quantitative approach using U isotopes
  17. Clouds may hold the key to why the early earth didn't freeze over
  18. Quiet sun puts Europe on ice
  19. Glacier melt threatens West Antarctic ice sheet
  20. Global Warming Part 1 - Ignore the debate, look at the Earth
  21. Climate Kelpie
  22. Wind speed and ocean wave height rising
  23. Cosmic Rays and Climate 
  24. Target Atmospheric CO2: Where Should Humanity Aim?
  25. Supporting Material for Target Atmospheric CO2: Where Should Humanity Aim?
  26. Target Atmospheric CO2: Where Should Humanity Aim? + Supplementary Material
  27. PETM Weirdness
  28. A millennial proxy record of ENSO and eastern Australian rainfall from the Law Dome ice core, East Antarctica
  29. Evolving Climate Networks
  30. Rapid Variability of Seawater Chemistry Over the Past 130 Million Years
  31. Evidence of Recent Causal Decoupling between Solar Radiation and Global Temperature
Author: M. H. Monroe
Last updated:

Catalyst - 100 years of Australian climate records


Aridification of Australia
Glacial Maximum
Runaway Greenhouse
Ice Ages
Climate cycles
Global warming to global freezing
Indian Ocean Dipole-IOD
Late Carboniferous Glaciation
Carboniferous Glaciation
Precambrian Ice Age
Early Palaeozoic Icehouse
Pleistocene Ice Age
Aerobacter spp. and cloud formation
Terminal Eocene Event


Journey Back Through Time
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Aboriginal Australia
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                                                                                           Author: M.H.Monroe  Email:     Sources & Further reading