COLUMBIA, Mo. – Meteorologists often use information about warm and cold fronts to determine whether a tornado will occur in a particular area. Now, a University of Missouri researcher has found that the temperature of the Pacific Ocean could help scientists predict the type and location of tornado activity in the U.S.
Laurel McCoy, an atmospheric science graduate student at the MU School of Natural Resources, and Tony Lupo, professor and chair of atmospheric science in the College of Agriculture, Food and Natural Resources, surveyed 56,457 tornado-like events from 1950 to 2011. They found that when surface sea temperatures were warmer than average, the U.S. experienced 20.3 percent more tornados that were rated EF-2 to EF-5 on the Enhanced Fuijta (EF) scale. (The EF scale rates the strength of tornados based on the damage they cause. The scale has six category rankings from zero to five.) (more…)
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…)
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…)
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…)
WASHINGTON — Researchers looking at corals in the western tropical Pacific Ocean have found signs of a profound shift in the depth where warm surface water and colder deeper water meet—a shift predicted by computer models of global warming.
The finding is the first physical evidence supporting what climate modelers have been predicting as the effects of global climate change on the subsurface ocean circulation. (more…)
