Featured Research

from universities, journals, and other organizations

El Niño Not The Driving Force Behind North Pacific Hurricanes

Date:
March 27, 1998
Source:
Ohio State University
Summary:
El Niño may be responsible for severe weather conditions across North America, but an Ohio State University study has revealed that El Niño weather systems don’t always spawn severe hurricanes in the North Pacific.

COLUMBUS, Ohio -- El Niño may be responsible for severe weather conditions across North America, but an Ohio State University study has revealed that El Niño weather systems don’t always spawn severe hurricanes in the North Pacific.

Related Articles


The current El Niño is different than most, however, and this difference may help researchers solve the mystery behind some curious atmospheric trends, like why the average intensity of North Pacific hurricanes is increasing over time.

Jay Hobgood, associate professor of geography at Ohio State, and graduate student Luke Whitney reviewed 31 years of weather data and found that hurricanes in the 7 years during which a severe El Niño visited the North Pacific were not much more intense than hurricanes during the other 24 years. Hurricanes during El Niño years averaged 49.3 percent of the maximum possible intensity, versus 48.6 percent in non-El Niño years. The work appeared in a recent issue of the Journal of Climate.

Hobgood explained that the warm surface water caused by El Niño off the west coast of South America heats the air and gives rise to stormy weather over the Pacific as far north as Southern California. The researchers expected that El Niño would intensify hurricanes in that area, but it didn’t.

“We were surprised,” said Hobgood. “But then we realized that El Niño also may generate more wind shear. In the Atlantic, wind shear keeps the storms down. We think that in the Pacific the warm water and the wind shear may cancel each other out.”

In fact, wind shear is the major reason that most hurricanes only reach 40 to 80 percent of their maximum possible intensity.

“But this El Niño is different,” said Hobgood. “Most El Niños start around Christmas, but this El Niño started in March of 1997. The warming was also greater than anything we’ve seen this century, and during the hurricane season it didn’t create much wind shear to weaken storms over the Eastern North Pacific. On the average, El Niños aren’t going to have much of an effect on hurricanes, but this one has.”

The continued warm surface temperatures and low winds aloft from this El Niño nurtured Hurricane Linda in September of 1997, allowing it to become the strongest storm ever observed in the East Pacific, with winds reaching 190 miles per hour.

Hobgood said this work represents a natural next step in the research that’s been going on for decades at the National Hurricane Center (NHC), part of the National Centers for Environmental Prediction in Miami. The work may one day help scientists predict hurricane strength.

“For the last 30 years most hurricane research has focused on prediction of where hurricanes are going to hit, and we’ve gotten pretty good at it,” said Hobgood. “We can warn people about 2 days in advance that a storm may hit their area. Now we’re trying to learn how to predict the strength of hurricanes.”

NHC scientists were already investigating hurricane strength in the Atlantic, so Hobgood and Whitney decided to look at the Pacific. When they did, they noticed that hurricanes in the North Pacific have on the average grown more intense between 1963 and 1993.

While the average intensity fluctuated year to year, it gradually increased over the 31 years. The minimum intensity of 32.6 percent occurred in 1964, then grew to about 50 percent in 1973, remained relatively stable until 1987 when it began to increase again, and then reached a maximum of 63.7 percent in 1990.

Hobgood admits that the gradual increase in intensity may be at least partially due to an overall increase in ocean surface temperature, which may be due to global warming.

“I’m not convinced that the change is entirely due to global warming,” he said. “It’s probably a combination of things, possibly including global warming.”

Hobgood was quick to point out that as satellite technology has improved over the years, analytical techniques have become more systematic, which could account for some of the increase in recorded intensity.

Now that Hobgood and Whitney have investigated ocean surface temperature, they plan to examine the influences of other atmospheric conditions on hurricanes. Currently they are studying data collected at Socorro, a tiny volcanic island off the west coast of Mexico, an area of much hurricane activity. They are examining weather balloon information such as wind speed, humidity, and temperature, all of which contribute to hurricane incidence and strength. Hobgood presented his preliminary analyses of the Socorro data at the March 1998 meeting of the Association of American Geographers meeting in Boston.

This work was supported by the Air Force Institute of Technology at Wright-Patterson Air Force Base in Ohio.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "El Niño Not The Driving Force Behind North Pacific Hurricanes." ScienceDaily. ScienceDaily, 27 March 1998. <www.sciencedaily.com/releases/1998/03/980327074151.htm>.
Ohio State University. (1998, March 27). El Niño Not The Driving Force Behind North Pacific Hurricanes. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/1998/03/980327074151.htm
Ohio State University. "El Niño Not The Driving Force Behind North Pacific Hurricanes." ScienceDaily. www.sciencedaily.com/releases/1998/03/980327074151.htm (accessed October 24, 2014).

Share This



More Earth & Climate News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) — One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
E.U. Leaders Agree To 40% CO2 Emissions Cut By 2030

E.U. Leaders Agree To 40% CO2 Emissions Cut By 2030

Newsy (Oct. 23, 2014) — The latest E.U. emissions deal calls for a 40 percent greenhouse gas cut, which leaders say sets Europe up to lead in climate negotiations next year. 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