The team used both cyclone and climate models to study the frequency and distribution of tropical cyclones (also known as hurricanes or typhoons) during the Pliocene epoch, a period three to five million years ago when temperatures were up to four degrees Celsius warmer than today.
The team found that there were twice as many tropical cyclones during this period, that they lasted two to three days longer on average than they do now, and that, unlike today, they occurred across the entire tropical Pacific Ocean.
“The Pliocene is the best analog we have in the past for what could happen in our future,” said Christopher Brierley, a Yale postdoctoral associate and an author of the study. “We wondered whether all these storms could have contributed to the warmer climate.”
In fact, the team discovered a positive feedback cycle between tropical cyclones and upper-ocean circulation in the Pacific that explains the increase in storms and appears to have led to permanent El Niño-like conditions.
Today, cold water originating off the coasts of California and Chile skirts around the region of tropical cyclone activity on its way to the Equator, where it results in a “cold tongue” that stretches west off the coast of South America. During the Pliocene, however, the team found that this cold water could not avoid being hit by one of the many tropical cyclones, which would churn up and mix warmer water into it. This warming at the Equator led to changes in the atmosphere that in turn created more tropical storms—and the cycle would repeat.
The team hopes to study how much mixing could result from tropical cyclones in today’s ocean waters—something that is hard to incorporate in global climate models, said Alexey Fedorov, an associate professor at Yale and lead author of the paper.
Fedorov cautioned that there is not necessarily a direct link between what happened during the Pliocene and what might happen in the future, as the team’s results for this epoch differed in many respects from current projections for future global warming. For example, the existing consensus is that, while the number of intense hurricanes will increase, the overall number will actually decrease.
“However, unless we understand the causes of these differences, we will not be sure whether our projections are correct,” Fedorov said. “Changes in the frequency and distribution of these storms could be a significant component of future climate conditions.”
Other authors of this paper include Kerry Emanuel of the Massachusetts Institute of Technology.
Funding for this study was provided by the National Science Foundation, the Department of Energy Office of Science, and the David and Lucile Packard Foundation.
PRESS CONTACT: Suzanne Taylor Muzzin 203-432-8555
Suzanne Taylor Muzzin | EurekAlert!
Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation
NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences