The Indian Ocean Dipole (IOD), also known as the Indian Niño, is an irregular oscillation of sea surface temperatures in which the western Indian Ocean becomes alternately warmer (positive phase) and then colder (negative phase) than the eastern part of the ocean .
How does the Indian Ocean Dipole effect Australia?
The Indian Ocean Dipole (IOD) is the difference in temperature between the western and eastern Indian Ocean. When the IOD is in positive mode, warmer waters develop off the Horn of Africa and cooler waters develop off Indonesia. This leads to hotter and drier weather in Australia .
What causes the Indian Ocean Dipole?
The Indian Ocean Dipole, or IOD, is a natural climate phenomenon that influences rainfall patterns around the Indian Ocean, including Australia. It’s brought about by the interactions between the currents along the sea surface and atmospheric circulation .
How long will Indian Ocean Dipole last?
The IOD affects rainfall and temperature patterns across the country, particularly during winter and spring (or the dry season if you’re in tropical parts of Australia). There are three phases of the IOD — positive, negative and neutral. On average, each phase lasts three to five years .
How is Indian Ocean Dipole calculated?
The index is calculated as the monthly difference between the western (10°S-10°N, 50°-70°E) and eastern Indian Ocean (10°S-0°, 90°-108°E) sea surface temperature departures from average.
What happens during La Nina?
La Niña causes the jet stream to move northward and to weaken over the eastern Pacific . During La Niña winters, the South sees warmer and drier conditions than usual. The North and Canada tend to be wetter and colder. During La Niña, waters off the Pacific coast are colder and contain more nutrients than usual.
What is positive Indian Ocean Dipole?
The Indian Ocean Dipole (IOD), also known as the Indian Niño, is an irregular oscillation of sea surface temperatures in which the western Indian Ocean becomes alternately warmer (positive phase) and then colder (negative phase) than the eastern part of the ocean.
What is El Nino effect?
El Nino is a climate pattern that describes the unusual warming of surface waters in the eastern Pacific Ocean . El Niño has an impact on ocean temperatures, the speed and strength of ocean currents, the health of coastal fisheries, and local weather from Australia to South America and beyond. ...
How cold can the Indian Ocean get?
On average the Indian Ocean has a minimum temperature of around 22 degrees Celsius/71 degree Fahrenheit . However in the southern regions, nearer to the polar regions the temperatures drop drastically below 40 degrees latitude south.
Is the Indian Ocean warmer than the Pacific?
The Pacific and Atlantic Oceans are, respectively, the world’s largest and second-largest oceans. ... The waters of the Pacific Ocean comprise the world’s largest heat reservoir, by far, and it is the warmest ocean , overall, of the world’s five oceans. (The other oceans are the Arctic, Antarctic and Indian Oceans.)
How does Indian Ocean dipole affect Indian monsoon?
The anomalous SST gradient between the west and east equatorial Indian Ocean drives a dipole in equatorial precipitation anomalies and anomalous low-level circulation that would, in isolation, lead to a wetter than normal Indian summer monsoon across the monsoon season including June and September.
What causes positive IOD?
Torrential rainfall and increased risk of landslides over the region during this period often results in widespread destruction and loss of life. It is expected that the Western Indian ocean will warm at accelerated rates due to climate change leading to an increasing occurrence of positive IODs.
When was the most recent Indian Ocean dipole negative phase?
The last time a negative dipole event was declared was in 2016 , between June and September.
Is La Niña year 2020?
The 2020-2021 La Niña event has passed its peak, but impacts on temperatures, precipitation and storm patterns continue, according to a new update from the World Meteorological Organization (WMO).
Is La Niña wet or dry?
Where El Niño is wet, La Niña is dry . While El Niño conditions and their seasonal impacts look very different from normal, La Niña conditions often bring winters that are typical — only more so.
Is La Niña warm or cold?
La Nina refers to the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. Typically, La Nina events occur every 3 to 5 years or so, but on occasion can occur over successive years. La Nina represents the cool phase of the El Nino/Southern Oscillation (ENSO) cycle.
