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 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 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 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 September 2, 2013 by Bob Berwyn
Climate, cannabis and apex predators …
Whither the weather?
By Summit Voice
FRISCO — One of the top news stories in Colorado last week was the dramatic change in the federal government’s position on legal use of marijuana in Colorado. After decades of intolerance, U.S. Attorney General Eric Holder indicated that the feds won’t seek to challenge Colorado’s new pot regime — at least for now. That leaves the state free to administer recreational sales of cannabis, as long as there is a robust state-based regulatory structure. Read the Summit Voice story, which includes the full text of the new guidance from the feds: Feds ease stance on marijuana.
In a couple of email interviews, Summit Voice explored the seasonal weather outlook. Making forecasts three months in advance is dicey at best, an in the absence of a clear El Niño or La Niña signal, meteorologists are struggling even more than usual to pin down upcoming patterns: Climate: With no Niño — what’s a forecaster to do?
For Mexican gray wolves living in the southwestern United States, the news was good. Rather than fighting conservation groups, the U.S. Fish and Wildlife Service backed down in the face of several lawsuits to give the predators a little more room to roam in the deserts of Arizona and New Mexico: Mexican gray wolves will get more room to roam.
A forest study in the eastern U.S. has implications for forest management here in the West, as well, showing that, when it comes to biodiversity, forest species need a mix of towering old growth and cleared areas, which are seen as important for birds just before they migrate: Study: Forest clearings crucial for some birds. (more…)
Filed under: biodiversity, climate and weather, endangered species, Environment, global warming | Tagged: biodiversity, Colorado marijuana laws, El Nino, Environment, 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 July 15, 2013 by Bob Berwyn
Early warning could help regional preparedness efforts
A new climate model could help project El Niño conditions a year in advance.
By Summit Voice
FRISCO — Forecasting the emergence of El Niño well in advance has long been a goal of climate scientists and a team of German researchers say they may have devised a model that extends the lead time to a year.
Published recently in the Proceedings of the National Academy of Sciences, their paper describes how the model uses high-quality data of air temperatures as the basis for making long-term projections about El Niño, a warm phase of a periodic Pacific Ocean cycle that affects climate and weather around the world.
“Enhancing the preparedness of people in the affected regions by providing more early-warning time is key to avoiding some of the worst effects of El Niño,” said Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research, who co-authored the paper with Josef Ludescher, of Justus-Liebig Universität Giessen. (more…)
Filed under: climate and weather, El Niño, La Niña | Tagged: climate, climate projections, El Nino, ENSO, Hans Joachim Schellnhuber, Potsdam Institute for Climate Impact Research | Leave a Comment »
Posted on July 1, 2013 by Bob Berwyn
Broad tree-ring record provides accurate ENSO history
Researchers say tree ring records show that El Niño activity during the 20th century has largely been outside the range of natural variability.
By Summit Voice
Climate scientists have long suspected that global warming has an influence on the Pacific Ocean El Niño- La Niña cycle (El Niño-Southern Oscillation), but instrumental records tracking the shift between above- and below average sea surface temperatures don’t go back far enough to provide context for any recent changes in the pattern.
But scientists working at the International Pacific Research Center, University of Hawaii at Manoa say a new tree ring record extending back about 700 years has helped decipher long-term trends. The tree ring samples from both the tropics and mid-latitudes in both hemispheres support the idea that the unusually high ENSO activity in the late 20th century is a footprint of global warming said Jinbao Li, lead author of the study published online in the journal Nature Climate Change. (more…)
Filed under: climate and weather, El Niño, global warming, La Niña | Tagged: climate, El Niño-Southern Oscillation, El Nino, ENSO, global warming, tree ring record, University of Hawaiʻi at Mānoa | 6 Comments »
Posted on May 29, 2013 by Bob Berwyn
Study identifies wind patterns that could lead to better El Niño forecasts
El Niño affects global weather patterns.
By Summit Voice
SUMMIT COUNTY — Climate researcher say they’ve discovered an atmospheric pattern that helps explain why El Niño often peaks during the first part of winter and usually fades away in late winter and early spring.
El Niño phases are part of a cycle when sea surface temperatures in the equatorial Pacific Ocean are warmer than average. The various phases of the so-called ENSO can have pronounced impacts on weather around the globe, spurring droughts in some areas and flooding in others.
The new study from the University of Hawai’i at Manoa Meteorology Department and International Pacific Research Center identified an unusual wind pattern that straddles the equatorial Pacific during strong El Niño events and swings back and forth with a period of 15 months as a key driver in the annual cycle. The findings were reported in the May 26 online issue of Nature Geoscience. (more…)
Filed under: climate and weather, Environment | Tagged: climate, El Nino, Pacific Ocean, University of Hawaiʻi at Mānoa, weather | Leave a Comment »
Posted on April 12, 2013 by Bob Berwyn
Natural climate variability the biggest player, scientists say
Drought conditions persist across the central part of the country.
By Bob Berwyn
SUMMIT COUNTY — Last summer’s crippling Great Plains drought can’t definitively be linked with global warming, according to a team of federal scientists from various agencies. In a new report issued this week, the researchers said the drought was probably caused by a confluence of natural climate variations that might only come together in a similar constellation once a century.
Cyclical variations in ocean temperatures — especially the combination of a cooler-than-average Pacific Ocean and a warm phase of the North Atlantic Multidecadal Oscillation may have nudged the region toward drought conditions, but those factors tend to be more of a factor in suppressing winter precipitation. (more…)
Filed under: climate and weather, Drought, El Niño, global warming, La Niña, Uncategorized | Tagged: 2012 drought, Dust Bowl, El Nino, global warming, Great Plains, La Niña, National Oceanic and Atmospheric Administration | 2 Comments »