Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sea Level Spiked for Two Years Along Northeastern North America

26.02.2015

Sea levels from New York to Newfoundland jumped up about four inches in 2009 and 2010 because ocean circulation changed, a University of Arizona-led team reports in today’s issue of Nature Communications.

The team was the first to document that the extreme increase in sea level lasted two years, not just a few months.

“The thing that stands out is the time extent of this event as well as the spatial extent of the event,” said first author Paul Goddard, a UA doctoral candidate in geosciences.

Independent of any hurricanes or winter storms, the event caused flooding along the northeast coast of North America. Some of the sea level rise and the resulting flooding extended as far south as Cape Hatteras.

The paper is also the first to show that the unusual spike in sea level was a result of changes in ocean circulation.

Co-author Jianjun Yin, UA assistant professor of geosciences, said, “We are the first to establish the extreme sea level rise event and its connection with ocean circulation.”

Goddard detected the two-year-long spike in sea level by reviewing monthly tide-gauge records, some of which went back to the early 1900s, for the entire Eastern Seaboard. No other two-year period from those records showed such a marked increase.

The team linked the spike to a change in the ocean’s Atlantic Meridional Overturning Circulation and also a change in part of the climate system known as the North Atlantic Oscillation.

The researchers then used computer climate models to project the probability of future spikes in sea level.

The team found that, at the current rate that atmospheric carbon dioxide is increasing, such extreme events are likely to occur more frequently, Goddard said.

Goddard’s and Yin’s research paper is titled “An Extreme Event of Sea Level Rise along the Northeast Coast of North America in 2009-2010.” Stephen Griffies and Shaoqing Zhang of the National Oceanographic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey, are also co-authors. NOAA funded the research.

Yin’s previous work on climate models suggests that weakening of the Atlantic Meridional Overturning Circulation could cause sea levels to rise faster along the northeast coast of North America.

Yin wondered whether such sea level rise had actually been observed, so he asked Goddard to compile the tide-gauge records for the east coast of North America. The 40 gauges, spanning the coast from Key West, Florida, north to Newfoundland, have been recording sea levels as far back as the 1920s.

Goddard’s work revealed a surprise – that during 2009 and 2010, sea level between New York and Newfoundland rose an average of four inches (100 mm). Sea level from Cape Hatteras to New York also had a notable spike, though not as dramatic.

“The sea level rise of 2009-2010 sticks out like a sore thumb for the Northeast,” Goddard said.

His research also confirmed that, as others have reported, sea level has been gradually rising since the 1920s and that there is some year-to-year variation.

About the time Goddard finished analyzing the tide-gauge records, another group of researchers reported that the Atlantic Meridional Overturning Circulation, or AMOC, had a 30 percent decline in strength in 2009-2010. Those researchers reported the decline started just two months before the tide gauges started recording the spike in sea level.

“To me, it was like putting together a puzzle,” Goddard said.

The more he and his colleagues examined the timing of the AMOC downturn and the subsequent increase in sea level, the more it fit together, he said.

The AMOC brings warm water from the tropics and the southern Atlantic Ocean to the North Atlantic and the polar regions. The water then cools and sinks, eventually flowing south in the deep ocean. Yin’s climate model predicted that when the AMOC weakened, sea level in northeastern North America would rise.

In addition to the weakening AMOC, during 2009-2010 the region’s atmosphere was in a very negative phase of the climate mode called the North Atlantic Oscillation. The NAO flip-flops between negative and positive phases.

“The negative North Atlantic Oscillation changes the wind patterns along the northeast coast, so during the negative NAO the winds push water onto the northeast coast,” Goddard said.

Although the NAO has resumed flipping between positive and negative states, observations show that the AMOC, while somewhat stronger, has still not recovered its previous strength.

Even now, sea level is still higher than before 2009, Yin said. He’s not surprised, because most of the climate models predict a weakening of the AMOC over the 21st century.

Yin said that at the current rate of increase in greenhouse gases, most climate models predict a weakening of the AMOC over the 21st century. Therefore, such extreme sea level rise events and coastal flooding are quite likely to occur along the densely populated northeast coast of North America more often.

Researcher contacts
Paul Goddard
pgoddard@email.arizona.edu

Jianjun Yin
520-626-7453
yin@email.arizona.edu
http://www.geo.arizona.edu/Yin
Languages spoken: English, Mandarin

Media contact
Mari N. Jensen
520-626-9635
mnjensen@email.arizona.edu

UANews | University of Arizona
Further information:
http://www.arizona.edu

More articles from Earth Sciences:

nachricht More than 100 years of flooding and erosion in 1 event
28.03.2017 | Geological Society of America

nachricht Satellites reveal bird habitat loss in California
28.03.2017 | Duke University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>