Summertime hail could all but disappear from the eastern flank of Colorado's Rocky Mountains by 2070, according to a new modeling study by scientists from NOAA and several other institutions.
Less hail damage could be good news for gardeners and farmers, said Kelly Mahoney, Ph.D., lead author of the study and a postdoctoral scientist at NOAA's Earth System Research Laboratory in Boulder, Colo. But a shift from hail to rain can also mean more runoff, which could raise the risk of flash floods, she said.
"In this region of elevated terrain, hail may lessen the risk of flooding because it takes a while to melt," Mahoney said. "Decision makers may not want to count on that in the future."
For the new study, published this week in the journal Nature Climate Change, Mahoney and her colleagues used "downscaling" modeling techniques to try to understand how climate change might affect hail-producing weather patterns across Colorado.
The research focused on storms involving relatively small hailstones (up to pea-sized) on Colorado's Front Range, a region that stretches from the foothill communities of Colorado Springs, Denver and Fort Collins up to the Continental Divide. Colorado's most damaging hailstorms tend to occur further east and involve larger hailstones not examined in this study.
In the summer on the Front Range, precipitation commonly falls as hail above an elevation of 7,500 feet. Decision makers concerned about the safety of mountain dams and flood risk have been interested in how climate change may affect the amount and nature of precipitation in the region.
Mahoney and her colleagues began exploring that question with results from two existing climate models that assumed that levels of climate-warming greenhouse gases will continue to increase in the future (for instance, carbon dioxide, which is at about 390 parts per million today, increases in the model to 620 ppm by 2070).But the weather processes that form hail – thunderstorm formation, for example – occur on much smaller scales than can be reproduced by global climate models. So the team "downscaled" the global model results twice: first to regional-scale models that can take regional topography and other details into account (this step was completed as part of the National Center for Atmospheric Research's North American Regional Climate Change Assessment Program). Then, the regional results were further downscaled to weather-scale models that can simulate the details of individual storms and even the in-cloud processes that create hail.
"We found a near elimination of hail at the surface," Mahoney said.
In the future, increasingly intense storms may actually produce more hail inside clouds, the team found. However, because those relatively small hailstones fall through a warmer atmosphere, they melt quickly, falling as rain at the surface or evaporating back into the atmosphere. In some regions, simulated hail fell through an additional 1,500 feet (~450 meters) of above-freezing air in the future, compared to the past.
The research team also found evidence that extreme precipitation events across all of Colorado may become more extreme in the future, while changes in hail patterns may depend on hailstone size -- results that are being explored in more detail in ongoing work.
Mahoney's postdoctoral research was supported by the PACE program (Postdocs Applying Climate Expertise) administered by the University Corporation for Atmospheric Research and funded by NOAA, the Bureau of Reclamation and the Western Water Assessment. PACE connects young climate scientists with real-world problems such as those faced by water resource managers.
"With climate change, we are examining potential changes in the magnitude and character of precipitation at high elevations," said John England, Ph.D., flood hydrology specialist at the Bureau of Reclamation in Denver, Colo. "The Bureau of Reclamation will now take these scientific results and determine any implications for its facilities in the Front Range of Colorado."
NOAA's mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.
Co-authors of the new paper, "Changes in hail and flood risk in high-resolution simulations over the Colorado Mountains," include Michael Alexander (NOAA/Earth System Research Laboratory); Gregory Thompson (National Center for Atmospheric Research) and Joseph Barsugli and James Scott (NOAA/Cooperative Institute for Research in Environmental Sciences, CIRES).
Katy Human | EurekAlert!
Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter
17.08.2017 | Swansea University
Climate change: In their old age, trees still accumulate large quantities of carbon
17.08.2017 | Universität Hamburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences