Featured Research

from universities, journals, and other organizations

La Nina Will Have No Effect On 2006 Atlantic Hurricanes

Date:
May 5, 2006
Source:
NASA/Goddard Space Flight Center
Summary:
NASA oceanographers agree that the recent La Nina in the eastern Pacific Ocean is not expected to have an effect on the Atlantic hurricane season this year. That is good news, because normally a La Niña tends to increase Atlantic hurricane activity and decrease Pacific Ocean hurricanes.

This image shows both the El Nino and La Nina conditions in the central equatorial Pacific Ocean, as seen by NASA's TOPEX/Poseidon and Jason-1 satellites. El Nino's warmer waters are indicated in red in this 1997 image, and La Nina's cooler waters are indicated in blue in this 1999 image.
Credit: NASA

NASA oceanographers agree that the recent La Nina in the eastern Pacific Ocean is not expected to have an effect on the Atlantic hurricane season this year. That is good news, because normally a La Nia tends to increase Atlantic hurricane activity and decrease Pacific Ocean hurricanes.

Related Articles


Although La Nina occurs in the Pacific, it affects weather in the Atlantic Ocean as well, through changes in the winds. La Nia changes the wind patterns in the upper and lower levels of the atmosphere, which make it easier for hurricanes to form in the Atlantic and harder in the eastern Pacific. In the Atlantic, the winds that would normally tear a hurricane's circular motion apart are lessened but they increase in the eastern Pacific.

The National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center is the federal agency that monitors La Nina conditions such as cooler than normal sea surface temperatures, precipitation and winds. According to their latest report on April 6, 2006, sea surface temperatures were warming back to normal. That latest report stated that during the month of April, sea surface temperatures were slightly cooler than normal in the extreme eastern equatorial Pacific, and conditions returned to near average in that region.

David Adamec, an oceanographer at NASA's Goddard Space Flight Center, Greenbelt, Md. said that "the current temperature signal at the end of April is near normal and the ocean surface temperature has not yet caused the atmosphere to respond in a La Nina-like way." Adamec used what is called a NASA coupled atmosphere-ocean land computer model. This model, developed at Goddard, is used for experimental forecasts of the ocean, land and atmosphere for periods 3-12 months in the future. The data used came from 2 NASA satellites: Jason and QuikSCAT. Jason provided sea-surface height information, and QuikSCAT provided surface wind data.

Adamec said that in order for La Nina to have an effect on the Atlantic Ocean hurricane season, it would have to exist for a much longer time, especially into peak hurricane season which is August and September.

Further, he said, another factor associated with La Nina is the Southern Oscillation Index, is also normal. The Southern Oscillation Index is an atmospheric pressure indicator of the large scale surface winds. "La Nina is already a memory," said Adamec.

According to 12 major ocean-atmosphere computer models, the equatorial Pacific will be neutral to warm in August, when it really matters for hurricanes. August and September are the peak season for hurricane formation in the Atlantic Ocean. According to scientists, the atmosphere takes about two weeks to "react" to a change in ocean surface temperature.

Forecasters and other scientists still expect a greater than average number of Atlantic Ocean hurricanes this year, but La Nina will not be a factor in that. The more active season is expected because of other environmental conditions favorable to hurricanes, such as the location of the Bermuda high removing much of the wind shear in the western Atlantic that thwarts hurricanes, warm sea surface temperatures in the Gulf of Mexico.

La Nia also influences where Atlantic hurricanes form. During La Nia more hurricanes form in the deep Tropics from African easterly waves. Easterly waves are "long waves" in the atmosphere that occur between 5-15 degrees North that start in Africa and move across the Atlantic Ocean. About 60% of the Atlantic tropical storms and minor hurricanes originate from easterly waves.

According to NOAA, these systems have a much greater likelihood of becoming major hurricanes and of eventually threatening the U.S. and Caribbean Islands.

Bill Patzert, oceanographer at NASA's Jet Propulsion Laboratory in Pasadena, Calif. noted that, "The recent increased frequency of the hurricanes is thought to be part of a larger decades-long cycle of alternating increases and decreases of hurricane activity. The current busy hurricane cycle began in 1995 and could continue for another 10 to 25 years. For the U.S. East and Gulf coasts, the fading La Nina is a real good thing, but Atlantic sea surface temperatures are still very toasty. It's the summer conditions that will dictate the fall hurricane activity, and I suspect those forecasts will be modified."



Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "La Nina Will Have No Effect On 2006 Atlantic Hurricanes." ScienceDaily. ScienceDaily, 5 May 2006. <www.sciencedaily.com/releases/2006/05/060505120655.htm>.
NASA/Goddard Space Flight Center. (2006, May 5). La Nina Will Have No Effect On 2006 Atlantic Hurricanes. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2006/05/060505120655.htm
NASA/Goddard Space Flight Center. "La Nina Will Have No Effect On 2006 Atlantic Hurricanes." ScienceDaily. www.sciencedaily.com/releases/2006/05/060505120655.htm (accessed October 25, 2014).

Share This



More Earth & Climate News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins