Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alabama Researchers Get Close View of Winter Storm

31.01.2011
Who would have guessed that the perfect place to gather detailed scientific data from a powerful snowstorm would be in Alabama?

That turned out to be the case recently, however, as scientists at The University of Alabama in Huntsville and NASA's Earth Sciences Office used a network of mobile and on-site instruments -- many designed to study severe thunderstorms -- to get some of the most detailed measurements ever taken of a major snow storm in action.

The hometown storm that gave them this opportunity arrived only after UAHuntsville's severe weather team spent portions of the last two winters as part of a multi-organization research campaign, intercepting storms from Wisconsin to Columbia, S.C., (and storms with snow as far south as Paducah, Ky.) without getting the complete dataset they were seeking.

Another group of UAH scientists working with NASA recently collected data about snowstorms in Finland.

"This was much more economical and efficient," said Dr. Kevin Knupp, a professor of atmospheric science and the director of UAHuntsville's severe weather research. "We have all these instruments around here and we can deploy them at a moment's notice. We have the luxury of grabbing data on significant weather systems as they go through."

To help grab data on the Jan. 9-10 storm, the research team used university and NASA instruments at Cramer Research Hall, two lightning detector networks, an advanced dual polarization Doppler radar at Huntsville International Airport, and the National Weather Service Doppler radar at Hytop in Jackson County. Knupp also sent the university's mobile dual polarization Doppler radar unit to set up outside of New Market in northeastern Madison County.

"We are studying the storm's 'comma,' the area of small scale waves or instabilities near the end of a storm system," said Ryan Wade, a student in UAHuntsville's atmospheric science Ph.D. program, as he helped set up the radar in New Market. "Those instabilities can dump large amounts of snow over small areas. That's why you might have a storm that drops four inches of snow across a hundred miles, but eight inches in one place and a dusting in another.

What causes these waves isn't well studied or understood. This is a unique opportunity to study the comma part of this storm."

Learning more about what happens in the comma of a snowstorm was the plan. Then the storm got ... interesting.

The interesting things included thundersnow -- with one lightning flash stretching about 50 miles from the top of Monte Sano to just south of Moulton -- and almost a dozen gravity waves rippling westward from the top of Monte Sano, apparently triggering some of the heaviest snowfall in North Alabama records.

Lightning detection networks set up by NASA and UAHuntsville scientists detected seven lightning flashes during the snowstorm, including four that hit a broadcast tower on Monte Sano. The 50-mile-long flash hit just after 10:30 p.m., and included four cloud-to-ground strikes: Normal lightning detectors would have seen that single lightning bolt as four separate events.

Lightning occurs in snowstorms only under special conditions, which include the presence of updrafts. Ice particles carried aloft on these updrafts bump against each other, swapping electrons and building an electric charge.

But sustained updrafts are uncommon in snowstorms. That's where the gravity waves come in. A gravity wave is simply a wave in the atmosphere similar to waves in the water. Air is pushed up the front of the wave and falls down the back. These waves can start in a number of ways, such as a violent updraft in a thunderstorm or a sudden change in the jet stream.

Knupp says the 11 gravity waves that rippled across Huntsville and western Madison County and into eastern Limestone County the night of January 9 were caused by wind blowing out of the east bumping into and being pushed over Monte Sano after atmospheric conditions got right.

"The storm had almost continuous gravity waves, especially at the start. The first was about 9 p.m., just before the snow started," Knupp said, stopping to think. "That's interesting, too ... they started around the time the snow started. That might make sense."

In addition to providing the updrafts needed to trigger lightning, the waves also cause rapid cooling in clouds as ice and supercooled water in them are pushed upward. This might trigger heavy precipitation: One gravity wave went over minutes before a National Weather Service employee reported that one inch of snow fell in only 20 minutes.

The research team also found evidence of the storm waves they were looking for in the first place. "There were wave-like motions going on in different directions at different scales," said Knupp. "There were bands of snow coming from the southwest.

"At one point, between 9 a.m. and midnight, the Huntsville airport reported four inches of snowfall in one hour. That might happen in the Midwest, but not often. It will be very rare down here. I won't be surprised if that was caused by the interaction of one of these bands with a gravity wave."

Of course, one of the challenges with having a few dozen instruments gathering data on a weather event is finding resources to analyze the vast amount of data that is collected. For instance, one UAH radar unit operating on campus was pointed straight up so it could get a vertical profile of the passing storm's structure six times a second.

"We can't analyze everything. There's just too much," Knupp said. "It's frustrating but also good.”

Dr. Kevin Knupp, (256) 961-7762
kevin.knupp@nsstc.uah.edu
Ryan Wade, (256) 961-7847
For 'thundersnow' information:
Chris Schultz, (256) 961-7856
For NASA weather research:
Dr. Walt Petersen, (256) 961-7861

Dr. Kevin Knupp | Newswise Science News
Further information:
http://www.uah.edu

More articles from Earth Sciences:

nachricht Six-decade-old space mystery solved with shoebox-sized satellite called a CubeSat
15.12.2017 | National Science Foundation

nachricht NSF-funded researchers find that ice sheet is dynamic and has repeatedly grown and shrunk
15.12.2017 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>