California drought linked with global warming

‘What we are seeing now is fundamentally different from previous mega-droughts, which were driven largely by precipitation’


Global warming is likely to exacerbate droughts worldwide.

By Summit Voice

FRISCO — While drought conditions have eased across parts of the U.S. in recent months, conditions have worsened in the far West, and particularly in California, where water shortages will have consequences spreading far beyond the state’s borders.

And the western drought has global warming fingerprints all over, according to four researchers who discussed the links between climate change and drought at a teleconference organized by Climate Nexus, a communications group focused on highlighting the wide-ranging impacts of climate change. Continue reading

Global warming may double El Niño frequency

Study findings suggest more Australian heatwaves


New study analyzes how global warming will affect El Niño events.

By Summit Voice

FRISCO — Strong El Niños — along with the extreme weather events that are driven by those warm Pacific ocean episodes — are likely to double as the globe heats up.

“During an extreme El Niño event countries in the western Pacific, such as Australia and Indonesia, experience devastating droughts and wild fires, while catastrophic floods occurred in the eastern equatorial region of Ecuador and northern Peru,” said  CSIRO Dr. Wenju Cai, lead author of a new study published in the journal Nature Climate Change.

“We currently experience an unusually strong El Niño event every 20 years. Our research shows this will double to one event every 10 years,” said Dr. Agus Santoso, a climate researcher with the ARC Centre of Excellence for Climate System Science. The international research team also included scientists with the National Oceanic and Atmospheric Administration. Continue reading

Study: Offshore coastal barrier systems remain intact after Hurricane Sandy

Sea level rise still a long-term concern


Hurricane Sandy winds up for its ravaging run up the East Coast.

By Summit Voice

FRISCO — A post-Sandy study of the seafloor off the shore of New York and New Jersey showed that the protective barrier system that protects the coast from erosion stayed mostly intact, providing some re-assurance to property owners trying to rebuild.

But long-term concerns related to rising sea level remain, a group of researchers said last week, outlining their findings at the American Geophysical Union conference.

“The shape of the bedforms that make up the barrier system did not change a whole lot,” said lead researchers John Goff of the Institute for Geophysics. “Where we might have expected to see significant erosion based on long-term history, not a lot happened — nothing that ate into the shoreface.” Continue reading

Climate: Global October temperatures seventh-highest on record, global sea level at record high

No global warming pause on this planet …


Most of the world’s land areas reported above average temperatures in Oct. 2013.

By Summit Voice

FRISCO — With just a couple of months left in the year, 2013 is on track to be the seventh-warmest year for Planet Earth, dating back to at least 1850, when modern record-keeping started.

Specifically, the first nine months of the year tied with 2003 as the seventh warmest, with a global land and ocean surface temperature of about 0.48 degrees Celsius (0.86 degrees Fahrenheit ) above the 1961–1990 average.

“Temperatures so far this year are about the same as the average during 2001-2010, which was the warmest decade on record,” said Michel Jarraud, secretary general of the World Meteorological Organization. “All of the warmest years have been since 1998 and this year once again continues the underlying, long-term trend The coldest years now are warmer than the hottest years before 1998,” Jarraud said. Continue reading

Climate study links rainy European summers with dwindling Arctic sea ice

A NASA satellite image shows Arctic sea ice.

A NASA satellite image shows Arctic sea ice. Image courtesy NASA.

Changes in the Arctic likely to have widespread hemispheric impacts

By Summit Voice

FRISCO — A new climate study by scientists at the University of Exeter (UK) adds to the growing body of research looking at the hemispheric impacts of dwinding Arctic sea ice.

The findings suggest that that the loss of ice shifts the jet stream farther south, bringing increased summer rainfall to northwestern Europe, but drier conditions to the Mediterranean region. The study could offer an explanation for the extraordinary run of wet summers experienced by Britain and northwest Europe between 2007 and 2012.

In another recent study, scientists with the Cooperative Institute for Research in Environmental Science found that as sea ice disappeared, the areas of relatively warm open water began to strongly influence the atmosphere, increasing surface temperatures in the region, and shifting low- and high-pressure zones around most markedly in the fall and winter.

And a NOAA study found Arctic warming has shifted the normal west-to-east flowing upper-level winds to a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes. Continue reading

New research may enable earlier heatwave forecasts

This map of air flow a few miles above ground level in the Northern Hemisphere shows the type of wavenumber-5 pattern associated with US drought. This pattern includes alternating troughs (blue contours) and ridges (red contours), with an "H" symbol (for high pressure) shown at the center of each of the five ridges. High pressure tends to cause sinking air and suppress precipitation, which can allow a heat wave to develop and intensify over land areas. Credit: Image courtesy Haiyan Teng.

This map of air flow a few miles above ground level in the Northern Hemisphere shows the type of wavenumber-5 pattern associated with US drought. This pattern includes alternating troughs (blue contours) and ridges (red contours), with an “H” symbol (for high pressure) shown at the center of each of the five ridges. High pressure tends to cause sinking air and suppress precipitation, which can allow a heat wave to develop and intensify over land areas. Image courtesy Haiyan Teng.

Atmospheric circulation pattern foreshadows prolonged dry and hot weather

By Summit Voice

FRISCO — Just a few weeks after a major report from NOAA found near-certain links between global warming and intensifying heatwaves, researchers say they’ve been able to pinpoint a high-altitude atmospheric wave pattern above the northern hemisphere that can help predict heatwaves more than two weeks in advance.

“It may be useful to monitor the atmosphere, looking for this pattern, if we find that it precedes heat waves in a predictable way,” said NCAR scientist Haiyan Teng, lead author of the study. “This gives us a potential source to predict heat waves beyond the typical range of weather forecasts.”

The research team discerned the pattern by analyzing a 12,000-year simulation of the atmosphere over the Northern Hemisphere. During those times when a distinctive “wavenumber-5″ pattern emerged, a major summertime heat wave became more likely to subsequently build over the United States. Continue reading

Study: Climate extremes drive mortality in Sweden

Researchers say more adaptation is needed to deal with increasing heatwaves

'Sweden and the rest of Scandinavia experienced well above average temperatures in August 2013. Map courtesy NASA.

Sweden and the rest of Scandinavia experienced well above average temperatures in August 2013. Map courtesy NASA.

By Summit Voice

FRISCO — Even the northern climes of Sweden are feeling the heat. Public health researchers at Umeå University say increased temperatures caused by ongoing climate change in Stockholm, Sweden between 1980 and 2009 caused 300 more premature deaths than if the temperature increase did not take place.

In Sweden as a whole, it would mean about 1,500 more premature deaths, according to the findings, published recently in the journal Nature Climate Change. As is well-known, global warming increases the frequency, intensity and duration of heat waves. Previous  studies have shown that these changes are associated with increased mortality, especially during extremely hot periods. At the same time, generally warmer temperatures may decrease the mortality associated with extreme cold. Continue reading

New study shows link between Pacific sea surface temperatures and tornado patterns in the Midwestern U.S.

Cooler Pacific Ocean temps may drive tornado activity into southern U.S.

A tornado near Lakeview, Texas. Photo courtesy NOAA.

A tornado near Lakeview, Texas. Photo courtesy NOAA.

By Summit Voice

FRISCO — After studying more than 56,000 tornados, researchers at the University of Missouri say they’ve found a clear link between Pacific Ocean sea surface temperatures and the patterns of storms that spawn the violent twisters. The findings could help scientists predict the type and location of tornado activity in the U.S.

When surface sea temperatures were warmer than average, the U.S. experienced 20.3 percent more tornadoes 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.)

“Differences in sea temperatures influence the route of the jet stream as it passes over the Pacific and, eventually, to the United States,” said Laurel McCoy, an atmospheric science graduate student at the MU School of Natural Resources. “Tornado-producing storms usually are triggered by, and will follow, the jet stream. This helps explain why we found a rise in the number of tornadoes and a change in their location when sea temperatures fluctuated.” Continue reading

Climate study projects more severe thunderstorms


Lightning flashes over Peak 1 in Frisco, Colorado, during a late-summer thunderstorm. bberwyn photo.

Eastern U.S. may see more winter and autumn storms

By Summit Voice

FRISCO — A warmer and wetter atmosphere is likely to drive up the number of severe thunderstorms in coming decades, potentially resulting in more economic losses associated with extreme weather.

The new study led by Stanford University scientists shows  that global warming is likely to cause a robust increase in the conditions that produce these types of storms across much of the country over the next century, including more severe weather during the spring, fall and winter.

To date, efforts to project thunderstorm activity under various global warming scenarios has been hampered by sparse historical data. But the Stanford-led team, headed by professor Noah Diffenbaugh, was able to use a complex ensemble of physics-based climate models to produce the most comprehensive projections of severe storm conditions for the next century. Continue reading

Extreme storms shift attitudes on climate change


Superstorm Sandy poised to rake the East Coast.

‘Our hope is that researchers will design persuasion strategies that effectively change people’s implicit attitudes without them having to suffer through a disaster’

By Summit Voice

FRISCO — It may sound like a no-brainer, but after experiencing extreme weather first-hand, people tend to think more seriously about climate change, according to researchers at Rutgers University.

Research published in the journal Psychological Science concluded that, after Superstorm Sandy and Hurricane Irene, New Jersey residents were more likely to show support for a politician running on a “green” platform, and expressed a greater belief that climate change is caused by human activity. Continue reading


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