Study assesses likelihood of Arctic ozone hole

This year's ozone hole over Antarctica was the second-smallest in 20 years, according to NASA.

Last year’s ozone hole over Antarctica was the second-smallest in 20 years, according to NASA.

CFC ban showing signs of success

Staff Report

FRISCO — Scientists say it’s unlikely that the Arctic will see ozone depletion on the scale of the Antarctic ozone hole, thanks mainly to international efforts to limit ozone-killing chemicals.

“While there is certainly some depletion of Arctic ozone, the extremes of Antarctica so far are very different from what we find in the Arctic, even in the coldest years,” said MIT atmospheric scientists Susan Solomon.

“It’s really a success story of science and policy, where the right things were done just in time to avoid broader environmental damage,” said Solomon, who made some of the first measurements in Antarctica that pointed toward CFCs as the primary cause of the ozone hole. Continue reading

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

Morning photo: Here and there …

April awesomeness

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At the edge of the meadow.

FRISCO — A couple of quick jaunts through Summit County this weekend yielded a few decent snapshot, including the muted sunset in the first image, brought to life with th iPhone’s HDR option, not to mention some Instagram editing. Along with the scenic shots of Summit County, I got up close and personal with a couple of roadside embankments, exploring the emerging mosses and icicles. If you enjoy our daily snapshots, please visit the online Summit Voice gallery at Fine Art America. Continue reading

Breck snowfall above average 4 months in a row

Fourth-snowiest year on record in Summit County

Big snows coated the Gore Range in March 2014. bberwyn photo.

Big snows coated Colorado’s Gore Range in March 2014. bberwyn photo.

By Bob Berwyn

FRISCO — Another month of above-normal snowfall has put Breckenridge on track for its fourth-snowiest winter on record, according to National Weather Service observer Rick Bly, who measured 37.4 inches at his backyard gauge.

That makes it the 10th-snowiest March, a month that sees average snowfall of 25.5 inches. Bly said precipitation has been above average for four straight months. During the current water year, which started Oct. 1, only November saw slightly below normal snowfall. Precipitation (the combination of melted snow and rain) for the water year to date is already at 15.2 inches, nearly six inches more than average. Continue reading

Climate: ‘We need to move away from business as usual’

Curbing global warming will require big cuts in greenhouse gases

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March 2014 temperatures were above average across most of the globe.

By Summit Voice

FRISCO —Greenhouse gas emissions continue to climb despite international attempts to curb heat-trapping gases, the Intergovernmental Panel on Climate Change said in its latest climate report.

Issued Sunday in Berlin, the report shows that greenhouse gas emissions grew more quickly between 2000 and 2010 than in each of the three previous decades. Only with significant institutional, social and technological changes will humankind be able to meet its stated target of limiting warming to two degrees Celsius, the scientists wrote. Continue reading

Morning photo: Sunday set

Signs of spring?

A moment of clarity ...

A moment of clarity …

FRISCO — I love those warm spring days when the snow seems to melt in front of your eyes. Instead of a smooth, unbroken, layer, the snow melts away in patches, starting on sunny slopes or around the base of trees, and the surface is pitted and rough. Every little grain of dust or twig catches the sun’s heat and the surround snow melts in a little crater. After months of stasis, the landscape seems to come to life — a time of transitions. Continue reading

Study: Little chance that global warming is natural

Statistical analysis of temperature data affirms climate models

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Warmer than average temperatures prevailed across most of the globe in March 2014.

Staff Report

FRISCO — A new statistical analysis of temperature records dating back to 1500 suggests it’s more than 99 percent certain that the past century of global warming is caused by the emission of heat-trapping, industrial-age greenhouse gases. The study was published online April 6 in the journal Climate Dynamics.

In a press release, the McGill University researchers said the study doesn’t use complex computer models to estimate the effects of greenhouse-gas emissions. Instead, it examines historical data to assess the competing hypothesis that warming over the past century is due to natural long-term variations in temperature. The results all but rule out  the possibility that global warming in the industrial era is just a natural fluctuation in the earth’s climate. Continue reading

Morning photo: Take 2

Winter winding down …

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Bring on the day!

FRISCO — I’m a little reluctant to let go of winter too quickly, but after feeling 50-degree temps for the first time in about six months, I’m willing to think about it. In the meantime, some winter highlights from the archives. Please visit our online gallery at Fine Art American for more Colorado landscape and nature images. Continue reading

NASA: Noctilucent clouds on the increase

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NASA’s Aeronomy of Ice in the Mesosphere, or AIM, mission captured this image of noctilucent clouds over the poles in 2010. By compiling data from several missions at once, researchers have now created a record of the clouds at lower latitudes as well. Image Credit: NASA/AIM

FRISCO — If you’ve been seeing more strange clouds that glow at night, it’s not your imagination. The occurrence of those types of clouds increased between 2002 and 2011, according to a new study analyzing satellite data from a variety of sources. Combining the information and using computer models, the NASA scientists found the greatest increase in  areas between 40 and 50 degrees north latitude, a region which covers the northern third of the United Sates and the lowest parts of Canada. The research was published online in the Journal of Geophysical Research: Atmospheres on March 18, 2014.

These changes correlate to a decrease in temperature at the peak height where noctilucent clouds exist in the atmosphere. Temperatures at this height do not match temperatures at lower levels – indeed, the coldest place in the atmosphere is at this height during summertime over the poles – but a change there certainly does raise questions about change in the overall climate system.

“Noctilucent clouds occur at altitudes of 50 miles above the surface — so high that they can reflect light from the sun back down to Earth,” said James Russell, an atmospheric and planetary scientist at Hampton University in Hampton, Va., and first author on the paper. “AIM and other research has shown that in order for the clouds to form, three things are needed:  very cold temperatures, water vapor and meteoric dust. The meteoric dust provides sites that the water vapor can cling to until the cold temperatures cause water ice to form.”

To study long-term changes in noctilucent clouds, Russell and his colleagues used historical temperature and water vapor records and a validated model to translate this data into information on the presence of the clouds. They used temperature data from 2002 to 2011 from NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics, or TIMED, mission and water vapor data from NASA’s Aura mission from 2005 to 2011. They used a model previously developed by Mark Hervig, a co-author on the paper at GATS, Inc., in Driggs, Idaho.

The team tested the model by comparing its output to observations from the Osiris instrument on the Swedish Odin satellite, which launched in 2001, and the SHIMMER instrument on the U.S. Department of Defense STPSat-1 mission, both of which observed low level noctilucent clouds over various time periods during their flights. The output correlated extremely well to the actual observations, giving the team confidence in their model.

Russell and his team will research further to determine if the noctilucent cloud frequency increase and accompanying temperature decrease over the 10 years could be due to a reduction in the sun’s energy and heat, which naturally occurred as the solar output went from solar maximum in 2002 to solar minimum in 2009.

“As the sun goes to solar minimum, the solar heating of the atmosphere decreases, and a cooling trend would be expected,” said Russell.

 

Was the Titanic just unlucky?

Study says iceberg conditions not unusually severe in 1912

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Bergs, baby!

Staff Report

FRISCO — The Titanic’s fateful encounter with a North Atlantic iceberg wasn’t a result of spring tides, and there weren’t an exceptionally high number of bergs in the North Atlantic in 1912, UK researchers said this week.

With the April 15 anniversary of the ocean liner’s sinking at hand, the University of Sheffield geographers say that, by scrutinizing historic iceberg data, they can dispel the theory that the Titanic was unlucky for sailing in a year with an exceptional number of icebergs. The risk of encountering a berg is actually much greater now, due to global warming. Continue reading

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