Southern Australia’s climate is influenced by several climate drivers, which can have a significant impact on farming activities. The Climate Kelpies website depicts these climate drivers as Climatedogs. There are four major Climatedogs (Enso, Indy, Ridgy and Sam), and two minor ones (Eastie and Mojo) which affect weather on a smaller scale. It’s important to remember the Climatedogs work together to drive climate, so we need to look at the combined effect of all the indicators to get a clear idea of what to expect in the future.
What a short video about the Climatedogs at Climatedogs Roundup: these working dogs round up rainfall and drive variability across Australia
ENSO (Enso)
Enso, the El Niño Southern Oscillation (ENSO) is a climate pattern that occurs in the Pacific Ocean, which can significantly impact rainfall patterns in southern Australia. During a period of El Niño, equatorial trade winds weaken and warm surface water shifts to the eastern Pacific Ocean allowing cool water to upwell in the western Pacific Ocean, which can lead to reduced rainfall and drought conditions across southern Australia. In contrast, during a period of La Niña, the trade winds are stronger than average, moving warm surface waters to the western Pacific Ocean while cool water upwell in the eastern Pacific Ocean, which can lead to increased rainfall and flooding across southern Australia.
What a short video about ENSO at Climatedog Enso: a big influence on Australia’s climate and seasonal variability (El Nino/La Nina) – YouTube
IOD (Indy)
Indy, the Indian Ocean (IOD) is a climate pattern that occurs in the tropical Indian Ocean, which can also have a significant impact on rainfall patterns across southern Australia. During a positive IOD phase the tropical west Indian Ocean sea surface temperatures (SSTs) are warmer than usual, which can lead to reduced rainfall and drought conditions across southern Australia. In contrast, during a negative IOD phase, the tropical east Indian Ocean SSTs are warmer than average, which can lead to increased rainfall and flooding across southern Australia.
Watch a short video about Indy at Climatedog Indy: important for delivering spring rainfall in Australia (Indian Ocean Dipole)
STR (Ridgy)
Ridgy, the Sub-tropical Ridge (STR) is a semi-permanent high-pressure system that influences seasonal weather variability across Australia. During summer it is positioned to the south of the continent and brings stable dry conditions, reducing rainfall and increasing temperatures. This can have a significant impact on farming across southern Australia, as it can lead to drought conditions, water shortages and reduced crop yields. We may need to adopt strategies such as irrigation, crop rotation and soil conservation to cope with these conditions.
Watch a short video about Ridgy at Climatedog Ridgy: a major driver of southern Australia’s weather (Sub-tropical Ridge)
SAM (Sam)
The Southern Annular Mode (SAM) is a climate driver that occurs in the southern hemisphere affecting the strength and position of westerly winds which influence southern Australia’s weather patterns. During a positive SAM event, the westerly winds are stronger and positioned further south, which can lead to reduced rainfall and drought conditions across southern Australia. In contrast, during a negative SAM event, the westerly winds are weaker and positioned further north, which can lead to increased rainfall and flooding across southern Australia.
Watch a short video about Sam at Climatedog Sam: bringer of cold fronts from the Southern Ocean (Southern Annular Mode)
ECLs (Eastie)
Eastie, the East Coast Low-Pressure systems (ECLs) are intense low-pressure systems that occur off the east coast of Australia, particularly during the autumn winter months. They bring moisture-laden winds and heavy rainfall to the region, which can cause flooding and waterlogging. While ECLs can benefit agriculture, providing much-needed moisture for crops and pasture, they can also be destructive, causing damage to infrastructure, property and crops.
Watch a short video about Eastie at Climatedog Eastie: the small dog behind big weather events for south-east Australia (East Coast Low)
MJO (Mojo)
The Madden-Julian Oscillation (MJO) is a tropical weather pattern that can influence rainfall patterns across southern Australia. It is characterised by a band of clouds, rainfall and winds moving eastward across the tropical Indian Ocean into the western Pacific Ocean. When the MJO is in its enhanced phase it can increase the rainfall across southern Australia. However when the MJO is in its suppressed phase it can reduce rainfall and bring drought conditions across southern Australia.
Watch a short video about Mojo at Climatedog Mojo: big influencer in warm months for northern Australia (Madden‐Julian Oscillation)
In summary, these six climate drivers significantly impact the rainfall patterns across southern Australia. Awareness of these drivers and their potential impact on crops, livestock and land will support our management decisions.
Key message
- There are six climate drivers that work together to affect the climate.
- We need to look at the combined effect of all the drivers to get a clear idea of what to expect in the future.