Sea rise off coasts of Philippines, northeastern Australia rising at about 1 centimeter per year
A new study led by Old Dominion University and the University of Colorado Boulder indicates sea levels likely will continue to rise in the tropical Pacific Ocean off the coasts of the Philippines and northeastern Australia as humans continue to alter the climate.
The study authors combined past sea level data gathered from both satellite altimeters and traditional tide gauges as part of the study. The goal was to find out how much a naturally occurring climate phenomenon called the Pacific Decadal Oscillation, or PDO, influences sea rise patterns in the Pacific, said Assistant Professor Benjamin Hamlington of Old Dominion University in Norfolk, Va., a former CU-Boulder postdoctoral researcher and lead study author.
The PDO is a temperature pattern in the Pacific Ocean akin to El Niño but which lasts roughly 20 to 30 years and contributes significantly to the decadal trends in regional and global sea level, said CU-Boulder Research Professor Robert Leben, a study co-author. The research team performed sea level reconstructions going back to 1950 by fitting patterns of satellite altimeter data to tide gauge data, then stripped away the effects of the PDO to better understand its influence on current sea level increases in the Pacific.
"The conventional wisdom has been that if the Pacific Decadal Oscillation was removed from the equation this sea level rise in parts of the Pacific would disappear," said Hamlington, who received his doctorate from CU-Boulder. "But we found that sea level rise off the coasts of the Philippines and northeastern Australia appear to be anthropogenic and would continue even without this oscillation."
A paper on the subject was published online in the July 20 issue of Nature Climate Change. Other co-authors on the study included CU-Boulder doctoral student Matthew Strassburg, CU-Boulder Associate Professor Weiqing Han, CU-Boulder Professor R. Steven Nerem and Seoul National University faculty member K.Y. Kim. The study was funded primarily by NASA and the National Science Foundation.
The team also used NASA climate models to assess sea level rise in the tropical Pacific that included data on the warming tropical Indian Ocean, which has been shown in previous studies to be caused by increases in greenhouse gases. The climate modeling portion of the new study also showed sea level rise near the Philippines and Australia is caused at least in part by anthropogenic, or human-caused, warming said Hamlington, who got his doctorate under Leben.
The research team estimated that areas of the ocean near the Philippines and northeast Australia are being raised by about 1 centimeter per year due to anthropogenic warming, which can increase the intensity of severe weather. "When water starts piling up there and typhoon-like storms are traveling over higher sea levels, it can be a bad situation," said Hamlington.
Although global sea level patterns are not geographically uniform -- sea level rise in some areas correlate with sea level fall in other areas -- the average current global sea level rise is roughly 3 millimeters per year. Some scientists are estimating global seas may rise by a meter or more by the end of the century as a result of greenhouse warming.
"When the current PDO switches from its warm phase to its cool phase sea levels on the western coast of North America likely will rise," said Leben of CU-Boulder's aerospace engineering sciences department. "I think the PDO has been suppressing sea level there for the past 20 or 30 years."
In a broader sense, the new study shows that scientists may be able to look at other regions of the world's oceans and extract the natural climate variability in order to measure human-caused effects, said Hamlington, a researcher at CU-Boulder's Cooperative Institute for Research in Environmental Sciences. "This kind of research may start revealing patterns that we might not expect."
Most of the satellite altimeter data for the study came from NASA's Topex-Poseidon and Jason satellite series missions. Satellite altimetry measures sea level rise by bouncing radar pulses off the surface of the ocean at particular points and calculating the round-trip time it takes the pulse to return to the spacecraft said Leben, also a faculty member of CU-Boulder's Colorado Center for Astrodynamics Research, or CCAR.
A 2010 study led by CU-Boulder's Han published in Nature Geoscience concluded that greenhouse gases were responsible for rising seas in parts of the Indian Ocean. The changes are believed to be at least partially a result of the roughly 1 degree Fahrenheit increase in the Indo-Pacific warm pool -- an enormous, bathtub-shaped area stretching from the east coast of Africa to the International Date Line in the Pacific -- during the past 50 years.
For more information on CU-Boulder's aerospace engineering sciences department visit http://www.colorado.edu/aerospace/. For more information on CCAR visit http://www.colorado.edu/aerospace/research/colorado-center-astrodynamics-research. For more information on CIRES visit http://cires.colorado.edu/index.html.
Benjamin Hamlington, 303-735-0483
Robert Leben, 303-492-4113
Jim Scott, CU-Boulder media relations, 303-492-3114
Robert Leben | Eurek Alert!
Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft
How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology