The Northeast Pacific's largest marine heatwave on record was at least in part caused by El Niño climate patterns. And unusually warm water events in that ocean could potentially become more frequent with rising levels of greenhouse gases.
That's the findings of a new study by researchers from Georgia Institute of Technology and the National Oceanic and Atmospheric Administration. They linked the 2014-2015 marine heatwave - often referred to as the "warm blob" - to weather patterns that started in late 2013. The heatwave caused marine animals to stray far outside of their normal habitats, disrupting ecosystems and leading to massive die-offs of seabirds, whales and sea lions.
The study, which was published July 11 in journal Nature Climate Change, was sponsored by the National Science Foundation.
"We had two and a half years of consistent warming, which translated to a record harmful algal bloom in 2015 and prolonged stress on the ecosystem," said Emanuele Di Lorenzo, a professor in Georgia Tech's School of Earth and Atmospheric Sciences. "What we do in the study is ask whether this type of activity is going to become more frequent with greenhouse gases rising."
The researchers traced the origin of the marine heat wave to a few months during late 2013 and early 2014, when a ridge of high pressure led to much weaker winds that normally bring cold Artic air over the North Pacific. That allowed ocean temperatures to rise a few degrees above average.
Then, in mid-2014 the tropical weather pattern El Niño intensified the warming throughout the Pacific. The warm temperatures lingered through the end of the year, and by 2015 the region of warm water had expanded to the West Coast, where algal blooms closed fisheries for clams and Dungeness crab.
"The bottom line is that El Niño had a hand in this even though we're talking about very long-distance influences," said Nate Mantua, a research scientist at NOAA Fisheries' Southwest Fisheries Science Center and a coauthor of the study.
The researchers used climate model simulations to show the connection between increasing greenhouse gas concentrations and the impact on the ocean water temperatures. The study found that these extreme weather events could become more frequent and pronounced as the climate warms.
"This multi-year event caused extensive impacts on marine life," Di Lorenzo said. "For example, some salmon populations have life cycles of three years, so the marine heatwave has brought a poor feeding, growth and survival environment in the ocean for multiple generations. Events like this contribute to reducing species diversity."
And the effects of the "warm blob" could linger.
"Some of these effects are still ongoing and not fully understood because of the prolonged character of the ocean heatwave," Di Lorenzo said. "Whether these multi-year climate extremes will become more frequent under greenhouse forcing is a key question for scientists, resource managers and society."
This material is based upon work supported by the National Science Foundation under Grant Nos. OCE 1356924 and OCE 1419292. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
CITATION: Emanuele Di Lorenzo and Nathan Mantua, "Multi-year persistence of the 2014/15 North Pacific marine heatwave," (Nature Climate Change, July 2016).
Josh Brown | EurekAlert!
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