Posted on November 22, 2013 by Bob Berwyn
NOAA’s winter outlook offers little relief for Arizona, New Mexico
By Bob Berwyn
FRISCO — Drought conditions may persist across the southwestern U.S. this winter and may redevelop across the Southeast, according to the seasonal outlook from NOAA’s Climate Prediction Center.
“Even though we don’t have La Niña, the atmosphere across the Pacific seems to be stuck in a La Niña mode … It’s been quite surprising to us, how persistent the pattern is,” said Mike Halpert, acting director of the Climate Prediction Center.
Parts of the Southwest, especially New Mexico, have been experiencing one of the driest periods on record, and Halpert said there is “decent agreement” in the CPC’s models on the climate signal that has resulted in the persistent trend. (more…)
Filed under: climate and weather, Drought, El Niño, La Niña | Tagged: climate, Climate Prediction Center, drought, El Nino, ENSO, La Niña, Southwest, winter weather outlook | 1 Comment »
Posted on November 12, 2013 by Bob Berwyn
Simultaneous changes in global precipitation patterns can’t be explained by natural variability
By Summit Voice
FRISCO — Scientists with Lawrence Livermore National Laboratory say unequivocally that greenhouse gases are affecting the distribution and intensity of precipitation around the world.
The new study, published Nov. 11 in the Proceedings of the National Academy of Sciences, shows how emissions of heat-trapping and ozone-depleting gases affect the distribution of precipitation through two mechanisms. Increasing temperatures are expected to make wet regions wetter and dry regions drier (thermodynamic changes); and changes in atmospheric circulation patterns will push storm tracks and subtropical dry zones toward the poles.
“Both these changes are occurring simultaneously in global precipitation and this behavior cannot be explained by natural variability alone,” said LLNL’s lead author Kate Marvel. “External influences such as the increase in greenhouse gases are responsible for the changes.” (more…)
Filed under: climate and weather, El Niño, extreme weather, global warming, La Niña | Tagged: climate change, Environment, global precipitation, global warming, greenhouse gases | 1 Comment »
Posted on November 8, 2013 by Bob Berwyn
Shifts in precipitation patterns would have big consequences for agriculture, forests and municipal water supplies
Research suggests that deforestation will likely produce a weather cycle over the Amazon consisting of abnormally dry air in the sun-scorched northern Amazon around the equator weighted by wetter air in the cooler south (left). The Princeton-led researchers found that the Amazon pattern would be subject to meandering high-altitude winds known as Rossby waves that move east or west across the planet (center). The Rossby waves would move the dry end of the Amazon pattern directly over the western United States from December to February, while the pattern’s rainy portion would be over the Pacific Ocean south of Mexico (right). Image courtesy Princeton University.
By Summit Voice
FRISCO — Continued deforestation in the Amazon region could have significant impacts on the weather in North America, according to Princeton researchers, who used fine-grained climate models to simulate how precipitation patterns could shift in the future.
Their findings suggest that total deforestation of the Amazon may significantly reduce rain and snowfall in the western United States — specifically, 20 percent less rain for the coastal Northwest and a 50 percent reduction in the Sierra Nevada snowpack, a crucial source of water for cities and farms in California.
“The big point is that Amazon deforestation will not only affect the Amazon — it will not be contained. It will hit the atmosphere and the atmosphere will carry those responses,” said lead author David Medvigy, an assistant professor of geosciences at Princeton. (more…)
Filed under: climate and weather, Drought, El Niño, Snow and weather | Tagged: Amazon Rainforest, climate, drought, El Nino, western U.S. | 1 Comment »
Posted on November 1, 2013 by Bob Berwyn
‘We may have underestimated the efficiency of the oceans as a storehouse for heat and energy … ‘
The heat trapped by greenhouse gases isn’t missing — it’s in the ocean. bberwyn photo.
By Summit Voice
FRISCO — There’s more evidence that the world’s ocean are taking up the heat trapped by greenhouse gases at an increasing rate, according to a new study published in Science this week.
After reconstructing Pacific Ocean temperatures from the last 10,000 years, the researchers found that the middle depths have warmed 15 times faster in the last 60 years than they did during apparent natural warming cycles in the previous 10,000 years.
“We’re experimenting by putting all this heat in the ocean without quite knowing how it’s going to come back out and affect climate,” said study coauthor Braddock Linsley, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory. “It’s not so much the magnitude of the change, but the rate of change.” (more…)
Filed under: climate and weather, El Niño, Environment, global warming, La Niña | Tagged: global, greenhouse gases, Intergovernmental Panel on Climate Change, oceans, warming | Leave a Comment »
Posted on October 30, 2013 by Bob Berwyn
New study may help show how El Niño will respond to global warming
Tracking El Niño …
By Summit Voice
FRISCO — Powerful El Niño events during recent decades are outside the norm of the last 600 years, climate researchers said this week, after finding that the cycles of warmer-than-average sea surface temps in the equatorial Pacific appear linked to global temperatures.
“Our new estimates of El Niño Southern Oscillation (ENSO) activity of the past 600 years appear to roughly track global mean temperature,” said Shayne McGregor, of the University of New South Wales. “But we still don’t know why.”
The team of climate scientists, including researcher with the University of Hawaii International Pacific Research Center and the NOAA Geophysical Fluid Dynamics Laboratory, said their findings (published in Climate of the Past) help resolve some of the uncertainties surrounding historic ENSO cycles, which can trigger flooding and droughts across different parts of the world. (more…)
Filed under: climate and weather, El Niño, global warming | Tagged: climate change, El Nino, global warming | 1 Comment »
Posted on October 23, 2013 by Bob Berwyn
Warmer than average temperatures prevailed across much of the globe in September 2013. Graphic courtesy NCDC.
Southern hemisphere land-surface temps record warm for the month
By Summit Voice
FRISCO — For all the tweeting, squawking and general clamor from global warming deniers, you’d think the Earth was on the brink of a new ice age, but the facts show otherwise.
Once again during September, the average global temperature was near record highs, at 1.15 degrees above the 20th century average — tied with 2003 as the fourth-warmest on record.
Even without the warming effect of El Niño, the average global ocean temperature was .97 degrees above the 20th century average, tying with 2006 as the fourth-warmest on record. For the year, land and sea surface temperatures together are on pace to register as the sixth warmest on record, according to the National Climatic Data Center, which released its monthly climate update a few days late due to the shutdown. (more…)
Filed under: climate and weather, El Niño, global warming, La Niña, seasons | Tagged: Australia heatwave, climate, global temperature records, global warming, National Climatic Data Center, Southern hemisphere record warmth | Leave a Comment »
Posted on September 13, 2013 by Bob Berwyn
Study shows how external influences shape Pacific weather patterns
New research may help show how global warming will affect El Niño.
By Summit Voice
FRISCO — By studying coral samples from a remote Pacific atoll, Australian researchers say they’ve found evidence that external influences can change the intensity of the periodic El Niño cycle. By extension, they said, human-caused global warming could also alter the pattern, though the observational record is too short to determine whether that’s already happening.
The research was led by scientist with the ARC Centre of Excellence for Climate System Science and published in Nature Geoscience.
“Our research has showed that, while the development of La Niña and El Niño events is chaotic and hard to predict, the strength of these events can change over long time spans due to changes in the global climate,” said one of the paper’s authors, Australian climate researcher Dr. Steven Phipps. (more…)
Filed under: climate and weather, El Niño, global warming | Tagged: climate, El Nino, ENSO, global warming, La Niña | Leave a Comment »
Posted on August 24, 2013 by Bob Berwyn
Fall and winter outlook still murky
Seasonal weather forecasters look out to sea surface temperatures in the equatorial Pacific to get an idea of what weather patterns may bring.
Without a stron El Niño or La Niña in the outlook, forecasters are not confident of projecting pronounced temperature or precipitation anomalies.
By Bob Berwyn
FRISCO — With no strong El Niño or La Niña on the horizon, forecasters are struggling even more than usual to develop seasonal outlooks for the western U.S. The periodic El Niño-La Niña cycle is a large-scale shift in the Pacific involving a complex interplay of winds, ocean currents and sea surface temperatures.
In the U.S. the warm El Niño phase is associated with wetter than average conditions in the Desert Southwest and California, and can result in below average precipitation in the Pacific Northwest.
La Niña, on the other hand, has been linked with Southwestern drought conditions and heavy precipitation in the Pacific Northwest. That persistent moist flow off the northwestern Pacific can also favor parts of Colorado with good winter snows, but the ENSO climate signal is more marginal in Colorado than in other areas. (more…)
Filed under: climate and weather, Colorado, Drought, El Niño, La Niña, seasons, Snow and weather, Summit County snow and weather | Tagged: climate, Colorado winter snow, El Nino, ENSO, La Niña, seasonal forecast, weather | Leave a Comment »
Posted on August 7, 2013 by Bob Berwyn
Strongest climate signals coming from Arctic and extreme weather events
Many parts of the globe reported record and near-record temps in June 2013.
By Bob Berwyn
FRISCO — Some of the most compelling signs of global warming impacts continued to come from the Arctic in 2012, where sea ice extent reached a record low and Greenland experienced record surface melting last summer.
Another worrying sign is the warming in permafrost regions, where significant thawing could release a new surge of heat-trapping greenhouse gases that would intensify warming.
The average global temperature for the year was among the top-10 warmest on record, and other climate observations also are consistent with what to expect in a warming world, according to climate experts who released the 2012 State of the Climate report this week. (more…)
Filed under: Arctic, climate and weather, El Niño, Environment, global warming, La Niña | Tagged: 2012 state of the climate report, American Meteorological Society, climate change, global warming, National Climatic Data Center | 1 Comment »
Posted on July 19, 2013 by Bob Berwyn
Many northern hemisphere land areas reported near-record warmth
Most areas of the globe reported temperatures running well above the 20th century average during June 2013.
By Summit Voice
FRISCO — The Globally averaged land and sea surface temperature was 1.15 degrees above the 20th century average, tying with 2006 as the fifth-warmest on record, according to the National Climatic Data Center monthly summary report released this week.
The average land-surface temperature was even warmer. At 1.89 degrees above average, it was the third-warmest June on record over the world’s land areas. Record-setting warmth was reported from many locations in northern Canada, far northwestern Russia, southern Japan, the Philippines, part of southwestern China, and central southern Africa.
The year to-date is also running hot, tied with 2003 as the seventh-warmest January to June period on record, with a combined global land and ocean average surface temperature that was 1.06 degrees above the 20th century average. (more…)
Filed under: climate and weather, El Niño, Environment, global warming, La Niña | Tagged: climate change, global climate, global warming, Instrumental temperature record, June 2013 global temperatures, National Oceanic and Atmospheric Administration, Sea surface temperature | Leave a Comment »