About these ads

Environment: New model could boost forecasts for predicting behavior of large and complex wildfires

Local firefighters teamed up in March 2012 to quell an early season wildfire along Montezuma Road, near Keystone Resort, in Summit County, Colorado. Bob Berwyn photo.

Local firefighters team up in March 2012 to quell an early season wildfire along Montezuma Road, near Keystone Resort, in Summit County, Colorado. Bob Berwyn photo.

Updated satellite instruments help refine predictions

By Summit Voice

FRISCO — As the West Fork Fire Complex roared through the spruce and fir forests of the Colorado San Juans last summer, on its way to becoming the state’s second-largest wildfire on record, communities in the region were on edge for days. Slight shifts in wind pushed the fire in new directions every other day, forcing some residents to leave their homes for weeks.

Like many large fires, the West Fork Complex even created its own weather, making it even harder for experts to project its path. But new research by scientists at the National Center for Atmospheric Research and the University of Maryland may help firefighters and resource managers get a better handle on predicting fire behavior. 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

About these ads

Colorado study aims to improve severe weather forecasts

Upper-atmosphere research aims to fill some data gaps

sdfg

Thunderstorms building over the Continental Divide in Colorado. Bob Berwyn photo.

By Summit Voice

SUMMIT COUNTY — The recent tornado disaster in Oklahoma once again showed that every minute of warning time in the face of severe weather can save lives. In the next few weeks, a team of meteorologists will be studying the atmosphere above Colorado to try and better predict when and where thunderstorms will rip across Colorado’s Front Range and the adjacent Great Plains.

The month-long (May 15 – June 15) field project will use high-flying aircraft and fine-grained computer simulations to try and point the way toward major improvements in lead times for weather forecasts during the crucial 6- to 24-hour window.

The Mesoscale Predictability Experiment (MPEX) is funded by the National Science Foundation.  The project includes participants from the National Center for Atmospheric Research; Colorado State University; the University at Albany, State University of New York; Purdue University; the University of Wisconson–Milwaukee; and NOAA’s National Severe Storms Laboratory.

Daily research starts with early morning flights to monitor the pre-storm atmosphere across Colorado and nearby states. The planes will cruise at 40,000 feet for up to six hours, which will enable researchers to thoroughly canvass the entire region where triggers for severe weather might be lurking. Continue reading

Global warming likely to be at high end of forecast range

dfgh

More accurate assessment of cloud dynamics and atmospheric processes in the subtropics the key to more accurate predictions

By Summit Voice

FRISCO — By now, everybody knows the Earth is steadily getting warmer. The big unanswered question is just how much more temperatures will rise, and a new analysis by scientists at the National Center for Atmospheric Research suggests the increases will be at the high end of predicted spectrum.

The key to the findings were accurate assessments of moisture processes in the atmosphere over the subtropics, according to NCAR scientists John Fasullo and Kevin Trenberth.

The seasonal drying in the subtropics and the associated decrease in clouds, especially during May through August, serve as a good analog for patterns projected by climate models.

“The dry subtropics are a critical element in our future climate,” Fasullo says. “If we can better represent these regions in models, we can improve our predictions and provide society with a better sense of the impacts to expect in a warming world.” Continue reading

Climate: Record high temps ever more frequent

Statistical analysis meshes with climate model results

This graphic shows the ratio of record daily highs to record daily lows observed at about 1,800 weather stations in the 48 contiguous United States from January 1950 through September 2009. Each bar shows the proportion of record highs (red) to record lows (blue) for each decade. The 1960s and 1970s saw slightly more record daily lows than highs, but in the last 30 years record highs have increasingly predominated, with the ratio now about two-to-one for the 48 states as a whole. (©UCAR, graphic by Mike Shibao.)

By Summit Voice

SUMMIT COUNTY — A continuing trend toward more daily high temperature records is yet another sign of the steadily warming climate, according to the Boulder-based National Center for Atmospheric Research, which this week released a comprehensive study of temperature statistics across the U.S.

“Climate change is making itself felt in terms of day-to-day weather in the United States,” says Gerald Meehl, the lead author and a senior scientist at the National Center for Atmospheric Research. “The ways these records are being broken show how our climate is already shifting.” Continue reading

Wolverines face dire global warming threat

Study suggests wolverine habitat could melt away by mid-century

A new climate change study casts doubt on the ability of wolverines to survive in the face of climate change. PHOTO COURTESY NATIONAL PARK SERVICE.

By Summit Voice

SUMMIT COUNTY — A targeted climate-change study by scientists with the National Center for Atmospheric Research in Boulder suggests that rising temperatures may completely eliminate existing habitat for wolverines in the contiguous United States.

“The researchers combined regional-scale climate projections with knowledge of a single species and its unique habitat to examine its vulnerability to a changing climate,” says Sarah Ruth, program director in National Science Foundations Directorate for Geosciences, which funds NCAR. “This study is an example of how targeted climate predictions can produce new insights that could help us reduce the impact of future climate change on delicate ecosystems,” she said.

Climate change is likely to imperil the wolverine in two ways: Reducing or eliminating the springtime snow cover that wolverines rely on for raising their young, and increasing August temperatures well beyond what the species may be able to tolerate. Continue reading

Melting ice only one factor in rising sea levels

Melting ice caps are not the only thing driving rising sea levels, according researchers from the University of Colorado and the National Center for Atmospheric Research.

Shifts in currents and winds also affecting sea level, with potential impacts in low-lying coastal zones

By Summit Voice

SUMMIT COUNTY — Colorado scientists who teamed up to study rising sea levels say some low-lying areas in the Pacific could be hit especially hard as global temperatures continue to climb. Because of complex patterns of ocean currents and winds, sea level is actually falling slightly in other areas, the researchers concluded.

The study, led by scientists at the University of Colorado at Boulder and the National Center for Atmospheric Research, also in Boulder, finds that the sea-level rise is at least partly a result of climate change. The changes are especially intense along the coastlines of the Bay of Bengal and the Arabian Sea, as well as the islands of Sri Lanka, Sumatra and Java, the research found.

The key player in the process is the Indo-Pacific warm pool, an enormous, bathtub-shaped area spanning a huge area of the tropical oceans stretching from the east coast of Africa west to the International Date Line in the Pacific. Continue reading

Follow

Get every new post delivered to your Inbox.

Join 7,850 other followers