State of the Environment

2006

Indicator: A-01 Annual variation in the Southern Oscillation Index

Data

Southern Oscillation Index - annual

Southern Oscillation Index - annual

Source: Bureau of Meteorology 2005, Monthly and annual Southern Oscillation Index data.

What the data mean

El Nino events are shown on the graph as the area below zero. La Nina events are shown by the area above zero. The data shows that Australia has been experiencing an El Nino event since 2001. The data also shows that there have been more frequent and severe El Nino events since the mid 1970s than the previous periods. Furthermore, La Nina events are less pronounced.

Data Limitations

Nil

Issues for which this is an indicator and why

Atmosphere — Climate variability and change - Weather 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate.

Other indicators for this issue:

Land — Contributions and pressures between the land and the atmosphere - Climate 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on the land.

Other indicators for this issue:

Inland Waters — Catchment scale influences - Influence of climate variability and change 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on inland waters.

Other indicators for this issue:

Biodiversity — Pressures on biodiversity - Climate variability 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on biodiversity.

Other indicators for this issue:

Coasts and Oceans — Condition of the ocean and coastal waters - Climatic and carbon dioxide factors 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on coasts and oceans, especially coastal and marine biodiversity.

Other indicators for this issue:

Coasts and Oceans — Contributions and pressures between the coasts and oceans and the atmosphere - Climate and carbon dioxide 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on coasts and oceans, especially coastal and marine biodiversity.

Other indicators for this issue:

Australian Antarctic Territory — Environment - Atmosphere, climate and oceans 

A number of studies indicate that the El Nino-Southern Oscillation (ENSO) explains 30 - 40% of the year-to-year variability of Australia’s climate, particularly rainfall. The Southern Oscillation Index (SOI) is a well-established measure of this phenomenon. El Nino events are associated with below-normal rainfall and often drought over much of northern and eastern Australia. They generally occur every two to seven years and are generally followed by La Nina events, which are associated with higher rainfall. Changes in the timing of these events may be indicative of longer term changes in climate which may have significant impacts on the Antarctic continent.

Other indicators for this issue:

Further Information

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