Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

El Niño's 'remote control' on hurricanes in the Northeastern Pacific

05.12.2014

El Niño, the abnormal warming of sea surface temperatures in the Pacific Ocean, is a well-studied tropical climate phenomenon that occurs every few years. It has major impacts on society and Earth's climate - inducing intense droughts and floods in multiple regions of the globe.

Further, scientists have observed that El Niño greatly influences the yearly variations of tropical cyclones (a general term which includes hurricanes, typhoons and cyclones) in the Pacific and Atlantic Oceans. However, there is a mismatch in both timing and location between this climate disturbance and the Northern Hemisphere hurricane season:


The discharge of heat, occurring in the boreal summer, followed the peak of El Niño (August-September 1998). Historical tracks of Category 3 to 5 hurricanes that developed after the peak of strong El Niños in 1991/92, 1997/98, 2008/09 and 2014 are shown in black.

Credit: Jin, et al. (2014)

El Niño peaks in winter and its surface ocean warming occurs mostly along the equator, i.e. a season and region without tropical cyclone (TC) activity. This prompted scientists to investigate El Niño's influence on hurricanes via its remote ability to alter atmospheric conditions such as stability and vertical wind shear rather than the local oceanic environment.

Fei-Fei Jin and Julien Boucharel at the University of Hawai'i School of Ocean and Earth Science and Technology (SOEST) and I-I Lin at the National Taiwan University published a paper today in Nature that uncovers what's behind this "remote control."

Jin and colleagues uncovered an oceanic pathway that brings El Niño's heat into the Northeastern Pacific basin two or three seasons after its winter peak - right in time to directly fuel intense hurricanes in that region.

El Niño develops as the equatorial Pacific Ocean builds up a huge amount of heat underneath the surface and it turns into La Niña when this heat is discharged out of the equatorial region.

"This recharge/discharge of heat makes El Niño/La Niña evolve somewhat like a swing," said lead author of the study Jin.

Prior to Jin and colleagues' recent work, researchers had largely ignored the huge accumulation of heat occurring underneath the ocean surface during every El Niño event as a potential culprit for fueling hurricane activity.

"We did not connect the discharged heat of El Niño to the fueling of hurricanes until recently, when we noticed another line of active research in the tropical cyclone community that clearly demonstrated that a strong hurricane is able to get its energy not only from the warm surface water, but also by causing warm, deep water - up to 100 meters deep - to upwell to the surface," Jin continued.

Co-author Lin had been studying how heat beneath the ocean surface adds energy to intensify typhoons (tropical cyclones that occur in the western Pacific).

"The super Typhoon Hainan last year, for instance, reached strength way beyond normal category 5," said Lin. "This led to a proposed consideration to extend the scale to category 6, to be able to grasp more properly its intensity. The heat stored underneath the ocean surface can provide additional energy to fuel such extraordinarily intense tropical cyclones."

"The North-Eastern Pacific is a region normally without abundant subsurface heat," said Boucharel, a post-doctoral researcher at UH SOEST. "El Niño's heat discharged into this region provides conditions to generate abnormal amount of intense hurricanes that may threaten Mexico, the southwest of the US and the Hawaiian islands."

Furthermore, caution the authors, most climate models predict a slow down of the tropical atmospheric circulation as the mean global climate warms up. This will result in extra heat stored underneath the North-eastern Pacific and thus greatly increase the probability for this region to experience more frequent intense hurricanes.

Viewed more optimistically, the authors point out that their findings may provide a skillful method to anticipate the activeness of the coming hurricane season by monitoring the El Niño conditions two to three seasons ahead of potentially powerful hurricane that may result.

The School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa was established by the Board of Regents of the University of Hawai'i in 1988 in recognition of the need to realign and further strengthen the excellent education and research resources available within the University. SOEST brings together four academic departments, three research institutes, several federal cooperative programs, and support facilities of the highest quality in the nation to meet challenges in the ocean, earth and planetary sciences and technologies.

Marcie Grabowski | EurekAlert!
Further information:
http://www.hawaii.edu

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>