What weather event is associated with cooler than normal water in the Pacific Ocean?
La Niña
La Niña is caused by a build-up of cooler-than-normal waters in the tropical Pacific, the area of the Pacific Ocean between the Tropic of Cancer and the Tropic of Capricorn. Unusually strong, eastward-moving trade winds and ocean currents bring this cold water to the surface, a process known as upwelling.
What effect does this have on the temperature of surface waters in the eastern Pacific Ocean?
The effects are most immediate in the equatorial Pacific. The thicker, warmer surface layer of water in the Eastern Pacific suppresses the upwelling of cooler, nutrient-rich water from the depths. Less nutrients mean less phytoplankton, which in turn leads to hunger all around the food web.
Which phenomenon is triggered by the cooling of the eastern part of the Pacific Ocean?
El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Nino is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO)….Vocabulary.
| Term | Part of Speech | Definition |
|---|---|---|
| visualize | verb | to make visual. |
What happens to sea surface temperatures in the eastern Pacific during an El Niño?
During El Niño, the surface winds across the entire tropical Pacific are weaker than usual. Ocean temperatures in the central and eastern tropical Pacific Ocean are warmer than average, and rainfall is below average over Indonesia and above average over the central or eastern Pacific.
Is 2020 an El Nino or La Nina year?
The 2020-2021 La Niña event has concluded, according to both oceanic and atmospheric indicators. In 2021, the sea surface temperature anomalies in the eastern-central Pacific weakened, leading to the currently prevailing weak cool anomalies that are not cold enough to meet the La Niña threshold.
Does La Nina mean more rain?
Globally, La Niña often brings heavy rainfall to Indonesia, the Philippines, northern Australia and southern Africa. During La Niña, waters off the Pacific coast are colder and contain more nutrients than usual.
What is the average surface temperature of the Pacific ocean?
38.3 °F
There is a pronounced difference in temperature and salinity between the surface and deep zones of the Pacific. The deep zone, which contains about 80 percent of the ocean’s volume, has relatively stable temperature and salinity patterns; its average temperature is 38.3 °F (3.5 °C).
What happens to the surface pressure at opposite ends of the Pacific Ocean during the southern oscillation?
During the southern oscillation there a seesaw model of reversing air pressure on the surface at opposite ends of the Pacific Ocean. This constituent swings in surface air pressure between the tropical eastern ocean waters and the western Pacific Ocean waters.
What is the name given to the cooling of the water in the Pacific Ocean?
El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern equatorial Pacific Ocean. Trade winds and atmosphere are also impacted by El Niño. La Nina, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the region’s surface waters.
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.
When was the last period of La Niña?
Recent years when La Niña Modoki events occurred include 1973–1974, 1975–1976, 1983–1984, 1988–1989, 1998–1999, 2000–2001, 2008–2009, 2010–2011, and 2016–2017. The recent discovery of ENSO Modoki has some scientists believing it to be linked to global warming. However, comprehensive satellite data go back only to 1979.
What does a strong La Niña mean?
During La Niña events, trade winds are even stronger than usual, pushing more warm water toward Asia, NOAA said. These cold waters in the Pacific push the jet stream northward, which affects weather patterns in the U.S. and globally.
What happens in the equatorial Pacific during El Nino?
An El Niño condition occurs when surface water in the equatorial Pacific becomes warmer than average and east winds blow weaker than normal. The opposite condition is called La Niña. During this phase of ENSO, the water is cooler than normal and the east winds are stronger.
What’s the temperature in the equatorial Pacific Ocean?
The above graphics show monthly sea surface temperature in the equatorial Pacific (20ºN-20ºS, 100ºE-60ºW), provided by the TAO project and created by Dai McClurg. The banner graphic at the top of this page shows global ocean temperature difference from average for December 2015 compared to 1991-2010 and is from climate.gov/NNVL.
Why are the winds in the Pacific so warm?
The typically strong high-pressure systems of the eastern Pacific weaken, thus changing the balance of atmospheric pressure across the eastern, central, and western Pacific. While easterly winds tend to be dry and steady, Pacific westerlies tend to come in bursts of warmer, moister air.
Which is the neutral state of the Pacific Ocean?
In the neutral state (neither El Niño nor La Niña) trade winds blow east to west across the surface of the tropical Pacific Ocean, bringing warm moist air and warmer surface waters towards the western Pacific and keeping the central Pacific Ocean relatively cool.