Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Past Atlantic Hurricanes Linked to Climate Change

14.08.2009
Climate researchers show intense hurricanes in the Atlantic Ocean over the last 1,500 years were closely linked to long-term changes in the El Niño/Southern Oscillation (ENSO) and sea surface temperature. The finding, reported in Nature, could help with future hurricane modeling and prediction.

In the Aug. 13 issue of the journal Nature, climate researchers including Jonathan Woodruff of the University of Massachusetts Amherst show that the frequency of intense hurricanes in the Atlantic Ocean over the last 1,500 years has been closely linked to long-term changes in the El Niño/Southern Oscillation (ENSO) and sea surface temperature. The finding could help with hurricane modeling and prediction in the future.

Establishing the link between hurricane variability and climate change over these longer timescales “is a new viewpoint for us,” Woodruff explains. “There’s a randomness to hurricanes. But the fact that we can see trends that rise above that randomness is significant and a bit of a surprise. Our work indicates that hurricane activity has responded noticeably to past climate shifts. When considering future climate change over the next century, our results indicate that measurable changes in hurricane activity could occur, rising above the noise in the system.”

A relationship between ENSO, sea surface temperature and hurricane activity is seen in modern times, Woodruff says, but the historical record based on ships’ logs and other observations is not long enough to assess variability on timescales longer than a few decades at best. “Given the possible effects of continued climate warming on intense tropical cyclone activity, it’s essential that we develop an understanding of how past climate change has affected tropical cyclone frequency, intensity and track on longer timescales,” the geologist says. “This work is another step forward in understanding the complex relationship between climate variability and Atlantic hurricane activity.”

Woodruff and colleagues’ study shows that a statistical climate model and actual paleoclimate data cross-validate each other over the last 1,500 years during key intervals of climatic change.

Specifically, UMass Amherst’s Woodruff and colleagues at Penn State and Woods Hole Oceanographic Institute prepared sedimentary reconstructions of hurricane-induced flooding, preserved in coastal ponds and salt marshes and collected as core samples from eight representative sites throughout the western North Atlantic, an approach known as paleotempestology.

These environments are usually protected from the sea by barrier beach systems. They enjoy sustained quiet periods during which only fine-grained mud and organic materials build up on pond floors and marsh surfaces. But during hurricanes and other storms, these normally calm environments are overrun with ocean waves and storm surges that carry in coarser sand from the barrier beaches. The sedimentary record is thus one of fine-grained organic mud, interbedded with coarse-grained, storm-induced deposits. Such deposits serve as natural archives of past hurricanes, with storm reconstructions that can extend back for many thousands of years, Woodruff points out.

Although still limited to a few reconstructions at present, he and colleagues have now observed statistically significant trends in tropical cyclone activity emerging from paleo-hurricane records. They compared these trends to data from a statistical model which independently predicted hurricane variability using paleo-reconstructions of climate factors known to influence hurricane activity, such as sea surface temperature, ENSO and the North Atlantic Oscillation.

The model predicted similar trends to those observed in the paleo-storm reconstructions, with an observed decrease in hurricane activity during the “Little Ice Age” around 300 years ago, a time when sea surface temperatures were lower than today and El Niño events appear to have occurred more frequently. Likewise, a period of increased hurricane activity similar to present levels also occurred around 1,000 years ago during an interval known as the “Medieval Climate Anomaly,” driven predominantly by increases in both sea surface temperature and the frequency of La Niña events.

Woodruff says the new finding “is like so much in science―in hindsight it makes sense. When the evidence is supplied, it’s simple enough to see the relationships, as in this case with the two independent records telling the same story. But until we had this evidence, things were much less clear.”

Jon Woodruff | Newswise Science News
Further information:
http://www.nsm.umass.edu

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>