What does a positive SOI indicate?
A positive SOI indicates La Niña, while a negative SOI indicates El Niño.
What does a high SOI mean?
The Southern Oscillation Index (SOI) is a measure of the intensity or strength of the Walker Circulation. Sustained positive SOI values above about +8 indicate a La Niña event while sustained negative values below about –8 indicate an El Niño.
What is SOI and how is it calculated?
The SOI is calculated using the pressure differences between Tahiti and Darwin. Sustainted positive values of the SOI above +7 are typical of a La Niña episode. They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia.
How does El Niño affect human health?
El Niño conditions can cause a wide range of health problems, including disease outbreaks, malnutrition, heat stress, and respiratory diseases. Above-average rainfall caused by El Niño can also cause floods and increase diseases spread by mosquitoes, such as malaria, dengue, chikungunya and the Zika virus.
What is the SOI index based on?
The Southern Oscillation Index (SOI) is a standardized index based on the observed sea level pressure (SLP) differences between Tahiti and Darwin, Australia.
What is the current SOI?
Note: The SOI values are expressed as an index (i.e. no units) and are derived from the 1887–1989 base period. This information is updated daily. The new data are typically available by 7:00pm (AEST)….Latest Southern Oscillation Index values.
| Monthly average SOI values | |
|---|---|
| Nov | 11.73 |
What SOI means?
SOI
| Acronym | Definition |
|---|---|
| SOI | Statement of Intent |
| SOI | Start of Injection (engines) |
| SOI | Sphere of Influence |
| SOI | Stage of Involvement (software development) |
How does El Niño cause diseases?
In tropical regions like Brazil and Southeast Asia, drought and above-normal temperatures caused by El Niño can alter the habitat and life cycles of mosquitoes that carry dengue fever, amplifying outbreaks (check out this neat video for more information).
What is the difference between El Niño and La Niña?
El Niño events are associated with a warming of the central and eastern tropical Pacific, while La Niña events are the reverse, with a sustained cooling of these same areas. These changes in the Pacific Ocean and its overlying atmosphere occur in a cycle known as the El Niño–Southern Oscillation (ENSO).
Is La Niña positive or negative?
La Niña can have both positive and negative impacts on agriculture and food security. The main positive effect associated with La Niña is the increased likelihood of above-average rainfall. On the other hand, excessive rainfall induced by La Niña, can also result in flooding of farming land and pastures.
What happens during La Niña?
La Nina refers to the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. During a La Nina event, the changes in Pacific Ocean temperatures affect the patterns of tropical rainfall from Indonesia to the west coast of South America.
