Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

California heatwaves to move toward coasts, study finds

30.08.2012
The nature of California heatwaves is changing due to global warming, a new study suggests.

Climate researchers Alexander Gershunov and Kristen Guirguis, with the Scripps Institution of Oceanography, UC San Diego, detected a trend toward more humid heatwaves that are expressed very strongly in elevated nighttime temperatures, a trend consistent with climate change projections.

Moreover, relative to local warming, the mid-summer heatwaves are getting stronger in generally cooler coastal areas. This carries implications for the millions of Californians living near the ocean whose everyday lives are acclimated to moderate temperatures.

"Heatwaves are stressful rare extremes defined relative to average temperatures," said Gershunov. "We've known for a while that humid heatwaves that are particularly hot at night are on the rise in California as the climate warms. Here, we sharpen the geographic focus to consider sub-regions of the state."

Gershunov added that in this new sharper and "non-stationary" perspective, coastal heatwaves express much more intensely than those inland, where the summertime mean warming is stronger. This translates to a variety of impacts on the typically cool, un-acclimated coast.

Classic California heatwaves have been characterized as interior desert and valley events that are hot during the day and marked by dryness and strong nighttime cooling. Gershunov and Guirguis said their analysis of observations and computer model data indicates that the emerging flavor of heatwaves - marked by greater humidity, greater expression in nighttime temperatures, and greater expression in coastal areas relative to the generally cooler coast - are intensifying and will keep intensifying in coming decades. Both coastal and desert heatwaves will continue to be more common as climate changes relative to the past, but the desert heatwaves are becoming less intense relative to strong average warming observed and projected for the interior of the state.

The study, "California heat waves in the present and future," will be published in Geophysical Research Letters, a publication of the American Geophysical Union.

The "non-stationary" approach reflects an acknowledgment by scientists that what has been considered extreme heat is gradually becoming commonplace. The rate of climate warming necessitates a measure of extreme heat relative to the changing average climate rather than to historical climate norms. So, instead of defining heatwaves relative to fixed temperature thresholds, the researchers projected heatwave intensity against a backdrop of increasing average summertime temperature. This causes the definition of heatwaves - temperatures in the warmest 5 percent of summertime conditions - to evolve with the changing climate and reflect extreme conditions relevant to the climate of the time.

"The advantage of using this evolving 'non-stationary' definition is that heatwaves remain extreme events even under much warmer climate," said Gershunov. "If they change in this evolving framework, it's because the variance of temperature is changing, not just the average."

The authors point out that the trend could precipitate a variety of changes in California's coastal communities, where stronger heat will lead to the installation of air conditioners in homes traditionally not in need of cooling. This lifestyle trend would in turn affect energy demand in coastal areas, its magnitude and timing. In the absence of technological or physiological acclimatization, high humidity and the lingering of heat through the night is expected to have strong public health implications, placing added stress on many of the more than 21 million Californians who live in coastal counties. The same would be true for animals and plants living in the highly populated and diverse coastal zone.

"This trend has important human health implications for coastal California where most of the state's population lives," said Guirguis. "Coastal communities are acclimated to cooler mean temperatures and are not well prepared for extreme heat either physiologically or technologically through air conditioning use. Populations tend to adapt to changes in their average conditions but extreme events can catch people off guard. An increase in heat wave intensity relative to average conditions could mean much more heat-related illness during heat waves unless effective heat emergency plans are implemented."

Notes for Journalists
Journalists and public information officers (PIOs) of educational and scientific institutions
who have registered with AGU can download a PDF copy of this paper in press by
clicking on this link:
http://dx.doi.org/10.1029/2012GL052979
Or, you may order a copy of the final paper by emailing your request to Kate Ramsayer at
kramsayer@agu.org. Please provide your name, the name of your publication, and your phone

number.

Neither the paper nor this press release are under embargo.
An online version of this release, with an accompanying image, will be posted on the AGU website later today.
Title:
"California heat waves in the present and future"
Authors:
Alexander Gershunov and Kristen Guirguis: Scripps Institution of Oceanography, University of

California San Diego, USA.

Contact information for the authors:
Alexander Gershunov, Telephone: (858) 534-8418, Email: agershunov@ucsd.edu

Kate Ramsayer | American Geophysical Union
Further information:
http://www.agu.org
http://dx.doi.org/10.1029/2012GL052979

More articles from Earth Sciences:

nachricht The pace at which the world’s permafrost soils are warming
16.01.2019 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Using satellites to measure rates of ice mass loss in glaciers
16.01.2019 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Velcro for human cells

16.01.2019 | Life Sciences

Kiel physicists discover new effect in the interaction of plasmas with solids

16.01.2019 | Physics and Astronomy

The pace at which the world’s permafrost soils are warming

16.01.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>