Environment: Is the Amazon rainforest near a tipping point?

A NASA photo taken from the International Space Station shows sunlight glinting off the Amazon River.

A NASA photo taken from the International Space Station shows sunlight glinting off the Amazon River.

Drought the main driver of destructive fires

By Staff Report

FRISCO — Longer droughts, land-use changes and wildfires may  be pushing parts of the Amazon rainforest toward an ecological tipping point, a team of scientists said after analyzing the effects of fire in a series of study plots.

The changes may abruptly increase tree mortality and change vegetation over large areas, the researchers said, pointing out that current Amazon forest models don’t include the impacts of wildfires. As a result, projections of future forest health tend to underestimate the amount of tree death and overestimate overall forest health, said Dr. Michael Coe, of the Woods Hole Research Center. Continue reading

Climate: Warmer temps to drive spread of drought

State officials hope to be well-prepared for the next inevitable drought in Colorado.

Drought is expected to expand the southwestern U.S. and other regions.

Evaporation seen as huge factor in climate calculations

Staff Report

FRISCO — Increasing global temperatures will drive drought expansion regardless of precipitation in some cases, as more moisture evaporates from soils.

An increase in evaporative drying means that even regions expected to get more rain, including important wheat, corn and rice belts in the western United States and southeastern China, will be at risk of drought. The study excludes Antarctica.

The new study models the effects of both changing rainfall and evaporation rates on future drought, estimating that 12 percent of land will be subject to drought by 2100 through rainfall changes alone; but the drying will spread to 30 percent of land if higher evaporation rates from the added energy and humidity in the atmosphere is considered.

Continue reading

Climate: Scientists study link between tropical belt expansion and multi-decadal oceanic circulation patterns

Long-term Pacific Ocean cycles could be driving SW drought

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What’s the role of natural climate variability in Southwestern droughts?

Staff Report

FRISCO — If you’re ready to blame drought in the southwestern U.S. on global warming, it might be time to rethink that conclusion.

According to scientists with the University of California, Riverside, dry conditions in the region may be linked with an expansion of the Earth’s tropical belt during the past few decades. And that expansion is likely driven by multi-decadal sea surface temperature variability in the Pacific Ocean, according to the new study. Other explanations for this widening have been proposed, including radiative forcing due to greenhouse gas increase and stratospheric ozone depletion. Continue reading

Western streamflow forecasts a mixed bag

Severe drought continues in Southwest

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California, Arizona and New Mexico reporting very dry conditions.

By Summit VoiceFRISCO — Snowpack across the West is still somewhat of mixed bag in this no-Niño winter, but February storms did help bolster water supplies across the northern tier of states, according to the monthly update from USDA’s Natural Resources Conservation Service.

East of the Continental Divide as well as parts of Washington, northern Oregon, northern Idaho and western Montana are now forecast to have near-normal or above normal water supplies, according to the forecast from the NRCS National Water and Climate Center. Continue reading

Climate: February 2014 cooler than average in U.S.

Dry conditions persist in far West

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February 2014 emperatures varied widely across the country.

Staff Report

FRISCO — The average February temperature across contiguous United States was well below the 20th century average. With an average reading of 32.2 degrees Fahrenheit (1.6 degrees below average), last month will go down in the books at the 37th-coldest February on record, the National Climatic Data Center reported in its regular monthly update.

The winter season overall (December to February) was 1.0 degrees Fahrenheit below average, making it the coldest winter since 2009-2010. This winter stood in sharp contrast to the last two winters, and most winters of the past two decades, when temperatures were predominately warmer than the 20th century average, the climate data center said. Read the full report here. Continue reading

Climate: USGS says most California streams flowing at less than 10 percent of normal

Widespread western drought continues

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Much of the West has been very dry during the first four months of the 2014 water year.

By Summit Voice

As California experiences its worst drought in more than a century, it’s probably not surprising that some stream gages in the northern part of the state are showing all-time record low readings, with 2013 in the record books as the driest calendar year in the state’s 119-year recorded history.

Low streamflow affects water availability for agricultural, municipal, and industrial uses, water quality, water temperature, recreational opportunities, and the maintenance of fish populations.

Recent precipitation has resulted in some increases in streamflow, snowpack, and reservoir levels, but severe drought conditions remain. Without significant additional precipitation, prior conditions will quickly return leaving most streams in the state at less than 10 percent of normal for this time of year. Continue reading

California drought linked with global warming

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

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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

Sen. Udall helps secure funding for snow surveys

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NRCS snow surveys help water managers plan ahead.

Temporary budget fix ensures program through August 2014

By Bob Berwyn

FRISCO — For decades, hydrologists have been tromping through the high country of Colorado and around the West to make detailed snowpack measurements. Together with data from automated SNOTEL sites and other tools, the monthly snow-course readings help water managers develop accurate projections of spring stream flows, and  how much water will be available for irrigation and storage.

The information is critical in arid regions, which rely on the winter snowpack as the ultimate reservoir. Federal budget cuts have threatened the program, raising concern among western resource managers, but the U.S. Department of Agriculture announced this week that it has found a way to maintain funding for the Snow Survey and Water Supply Forecasting Program — at least through the end of Aug. 2014. Continue reading

Climate: Is the Southwest ‘stuck’ in a drought pattern?

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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. Continue reading

Environment: ‘Extreme’ dust-on-snow events can speed runoff in Colorado River Basin by six weeks

2013 brought record levels of dust to Colorado’s mountains

More frequent desert dust storms dropping pollution on the Rocky Mountain snowpack is one of the climate change impacts affect the high country.

More frequent desert dust storms dropping pollution on the Rocky Mountain snowpack is one of the climate change impacts affecting the Colorado high country.

By Bob Berwyn

FRISCO — Dust storms that darken the Rocky Mountain snowpack and speed snowmelt are becoming more extreme, according to new research. Particularly heavy dust-on-snow events can speed the melt-out of the snowpack by a full six weeks, all other factors being equal, said Jeffrey Deems, a researcher with the Western Water Assessment and the National Snow and Ice Data Center.

“In 2006 we were impressed at how much dust there was. Then 2009 turned up, and 2010, and 2013 was the dustiest year we’ve recorded in the San Juans,” Deems said, explaining that the latest study, put together by researchers with NOAA’s Cooperative Institute for Research in Environmental Sciences was aimed at updating previous work with data from those heavy dust years.

Last spring, on April 8, a single 16-hour dust storm dropped more dust on the San Juans than the annual totals in any previous winter since scientists started taking detailed measurements, said Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton, which tracks the dust-on-snow events via a network of observation sites. Continue reading

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