Tag Archives: el niño

Climate Change Study Strengthens Link to Human Activities

Computer Models, Satellite Data Reveal Clearest Evidence Yet of Human Influence on Changing Temperatures

New research shows some of the clearest evidence yet of a discernible human influence on atmospheric temperature.

Published online in the Nov. 29 early edition of the Proceedings of the U.S. National Academy of Sciences, the study compared 20 of the latest climate models against 33 years of satellite data. When human factors were included in the models, they followed the pattern of temperature changes observed by satellite. When the same simulations were run without considering human influences, the results were quite different.

“We can only match the satellite record when we add in human influences on the atmosphere,” said Michael Wehner, a research scientist at Lawrence Berkeley National Laboratory (Berkeley Lab) Computational Research Division and a coauthor of the article, which involved colleagues from 16 other organizations and was led by Benjamin Santer, an atmospheric scientist at Lawrence Livermore National Laboratory (LLNL). (more…)

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Could a Hurricane Ever Strike Southern California?

There’s an old adage (with several variations) that California has four seasons: earthquake, fire, flood and drought. While Californians happily cede the title of Hurricane Capital of America to U.S. East and Gulf coasters, every once in a while, Mother Nature sends a reminder to Southern Californians that they are not completely immune to the whims of tropical cyclones. Typically, this takes the form of rainfall from the remnants of a tropical cyclone in the eastern Pacific, as happened recently when the remnants of Hurricane John brought rain and thunderstorms to parts of Southern California. But could a hurricane ever make landfall in Southern California?

The answer, as it turns out, is yes, and no. While there has never been a documented case of a hurricane making landfall in California, the Golden State has had its share of run-ins and close calls with tropical cyclones. In fact, California has been affected by at least a few tropical cyclones in every decade since 1900. Over that timeframe, three of those storms brought gale-force winds to California: an unnamed California tropical storm in 1939, Kathleen in 1976 and Nora in 1997. But the primary threat from California tropical cyclones isn’t winds or storm surge. It’s rainfall — sometimes torrential — which has led to flooding, damage and, occasionally, casualties. (more…)

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UMD-Led Research Yields Key to Better Predictions of El Nino

COLLEGE PARK, Md. –– A University of Maryland scientist and an undergraduate Indian student he mentored in India have uncovered a major new finding about El Nino — the cyclical climate event that appears every 2-7 years, sometimes with major global weather impacts such as massive flooding in some regions and severe droughts in others and resulting major economic impacts. (more…)

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NASA Sees Repeating La Niña Hitting its Peak

La Niña, “the diva of drought,” is peaking, increasing the odds that the Pacific Northwest will have more stormy weather this winter and spring, while the southwestern and southern United States will be dry.

Sea surface height data from NASA’s Jason-1 and -2 satellites show that the milder repeat of last year’s strong La Niña has recently intensified, as seen in the latest Jason-2 image of the Pacific Ocean, available at: https://sealevel.jpl.nasa.gov/images/ostm/20120108P1.jpg. (more…)

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Deep Oceans May Mask Global Warming for Years at a Time

*Computer simulations of global climate lead to new conclusions*

Earth’s deep oceans may absorb enough heat at times to flatten the rate of global warming for periods of as long as a decade–even in the midst of longer-term warming. This according to a new analysis led by scientists at the National Center for Atmospheric Research (NCAR).

The study, based on computer simulations of global climate, points to ocean layers deeper than 1,000 feet as the main location of the “missing heat” during periods such as the past decade when global air temperatures showed little trend. (more…)

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US West Coast Erosion Spiked In Winter 2009-10, Previewing Likely Future As Climate Changes

SANTA CRUZ, Calif. – Knowing that the U.S. west coast was battered during the winter before last by a climatic pattern expected more often in the future, scientists have now pieced together a San Diego-to-Seattle assessment of the damage wrought by that winter’s extreme waves and higher-than-usual water levels. Getting a better understanding of how the 2009-10 conditions tore away and reshaped shorelines will help coastal experts better predict future changes that may be in store for the Pacific coast, the researchers say.

“The stormy conditions of the 2009-10 El Niño winter eroded the beaches to often unprecedented levels at sites throughout California and vulnerable sites in the Pacific Northwest,” said Patrick Barnard, USGS coastal geologist. In California, for example, winter wave energy was 20 percent above average for the years dating back to 1997, resulting in shoreline erosion that exceeded the average by 36 percent, he and his colleagues found. (more…)

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After a Three-Decade Hiatus, Sea-Level Rise May Return to the West Coast

WASHINGTON — The West Coast of North America has caught a break that has left sea level in the eastern North Pacific Ocean steady during the last few decades, but there is evidence that a change in wind patterns may be occurring that could cause coastal sea-level rise to accelerate beginning this decade.

That is the conclusion of a new study that says that conditions dominated by cold surface waters along the West Coast could soon flip to an opposite state.

“There are indications that this is what might be happening right now,” says Peter Bromirski, a researcher at Scripps Institution of Oceanography, UC San Diego, and lead author of a study now in press in the Journal of Geophysical Research–Oceans, a journal of the American Geophysical Union. (more…)

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Eddies Found to be Deep, Powerful Modes of Ocean Transport

*Study Finds Connection between Atmospheric Events and the Deep Ocean*

Researchers from Woods Hole Oceanographic Institution (WHOI) and their colleagues have discovered that massive, swirling ocean eddies–known to be up to 500 kilometers across at the surface–can reach all the way to the ocean bottom at mid-ocean ridges, some 2,500 meters deep, transporting tiny sea creatures, chemicals, and heat from hydrothermal vents over large distances.

The previously unknown deep-sea phenomenon, reported in the April 28 issue of the journal Science, helps explain how some larvae travel huge distances from one vent area to another, said Diane K. Adams, lead author at WHOI and now at the National Institutes of Health. (more…)

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