Scientists to Study Impacts of Thunderstorms on the Upper Atmosphere

Our thunderstorm season is about to get underway.  Spring is known for severe weather, but summer is known for its afternoon and evening thunderstorms.  These storms build up in the heat and humidity of the day and provide most of the rain during the summer.  A study will be conducted from May 15 to June 30 to measure the impact of thunderstorms on the upper atmosphere.  The following is a press release from the National Center for Atmospheric Research in Boulder, Colorado.

Press Release:

Scientists at the National Center for Atmospheric Research (NCAR) and other organizations are targeting thunderstorms in Alabama, Colorado, and Oklahoma this spring to discover what happens when clouds suck air up from Earth’s surface many miles into the atmosphere.

Thunderstorm in eastern Colorado. (Photo by Bob Henson.)

The Deep Convective Clouds and Chemistry (DC3) experiment, which begins the middle of this month, will explore the influence of thunderstorms on air just beneath the stratosphere, a little-explored region that influences Earth’s climate and weather patterns. Scientists will use three research aircraft, mobile radars, lightning mapping arrays, and other tools to pull together a comprehensive picture.

“We tend to associate thunderstorms with heavy rain and lightning, but they also shake things up at the top of cloud level,” says NCAR scientist Chris Cantrell, a DC3 principal investigator. “Their impacts high in the atmosphere have effects on climate that last long after the storm dissipates.”

Past field projects have focused on either the details of thunderstorms but with limited data on the atmospheric chemistry behind them, or on the chemistry but with little detail about the storms themselves. DC3 is the first to take a comprehensive look at the chemistry and thunderstorm details, including air movement, cloud physics, and electrical activity.

A New Tornado Tracker

Image Credit: NOAA.

According to the National Oceanic and Atmospheric Administration (NOAA), an average of 800 tornadoes are reported nationwide each year. The federal agency says as of April 29th there have been 588 tornadoes in 2012.  You already know that Doppler radar is used to detect tornadoes as they form.  Now there is another way to track tornadoes; through their reports.

Climate Central has just unveiled their new Tornado Tracker, an interactive map that lets you see not only where the twisters touched down last year, but where they are being reported now (it’s updated every 10 minutes around the clock), or on any date back to June 1, 2004. The example below shows the display for March 2, 2012, when there was an outbreak of tornadoes in the Southeast and Ohio River Valley: to get to the interactive version just click on the link.

Weather Advances Do Not Happen Overnight

Dusan Zrnic. Image Credit: NSSL.

This is a repost of a story written by Bob Henson, who works at the National Center for Atmospheric Research (NCAR).  The original story can be found here and it has information about other advances in radar technology.  What is posted here is an excerpt of the history of dual-polarization with permission from the author.

By Bob Henson

The path to polarization

After years of development, the concept of polarizing radar signals for meteorology took root in the fertile soil of Canada’s Prairie provinces. NSSL’s Richard Doviak and Dusan Zrnić traveled to Alberta in 1979 to check out a circularly polarized radar pioneered by McGill University. “Dick had been interested in doing polarization research as early as 1971, but NSSL was deeply immersed in Doppler work at the time,” recalls Zrnić.

Once the lab decided to build its own polarized radar, it went for a dual-pol approach, with signals oriented in the horizontal or vertical rather than circularly. “We made this choice for good reason,” says Zrnić. Research by Thomas Seliga and Viswanathan Bringi, then both at Ohio State University, had shown how signals from the two orientations might yield critical data on the character of precipitation.

This hypothesis was confirmed through measurements in a 1977 Oklahoma field project using the CHILL dual-pol radar under the leadership of Gene Mueller. Now based at CSU, CHILL—the first university-based dual-pol radar—was named after Chicago, Illinois, where it was launched by the University of Chicago and the Illinois State Water Survey. NCAR was another dual-pol pioneer, converting its CP-2 radar and creating the first real-time displays of differential reflectivity (relating horizontal to vertical returns).

Starting in the mid-1980s, Zrnić teamed with postdoctoral fellows Mangalore Sachidananda (now at the Indian Institute of Technology) and Narasimha Balakrishnan (now at the Indian Institute of Science) to work out the details of distinguishing rain from hail and other hydrometeors using dual-pol data, with contributions from Jerry Straka (University of Oklahoma). By 1996, Zrnić had written a paper for the Bulletin of the American Meteorological Society pondering the eventual role of dual-pol in operational settings.

NWS Announces Significant Upgrade in Columbia, SC

The National Weather Service Forecast Office in Columbia, SC, announced today that the Doppler radar will be upgraded to dual polarization (or "dual-pol") beginning May 3rd.  It will take approximately a week for the upgrade during which time the radar will be inoperative.  Other area radars will be used to cover the Midlands in case of severe weather.  At News19 we will be using the Greenville, Atlanta, Wilmington, and Charleston radars in live mode to provide the coverage on the Max Storm Doppler Radar.  A composite radar will be used on our cable feed of the radar.

A minor inconvenience considering advantages of the system.   “This is the most significant upgrade to the nation’s weather radar network since Doppler radar was first installed in the early 1990s and is a significant step toward us becoming weather ready,” said Jack Hayes, director of NOAA’s National Weather Service. “Dual polarization technology provides significantly more information and clearer pictures of current weather conditions, helping National Weather Service meteorologists provide more accurate and timely forecasts."

A dual-pol radar at NOAA’s National Severe Storms Laboratory in Norman, Oklahoma, monitored this storm during the 2003 Thunderstorm Electrification and Lightning Experiment.  Image credit: Michael James, UCAR.

ATREX Mission Successfully Launched

NASA successfully launched five suborbital sounding rockets this morning from its Wallops Flight Facility in Virginia as part of a study of the upper level jet stream. The first rocket was launched at 4:58 a.m. EDT and each subsequent rocket was launched 80 seconds apart.

Launch of a sounding rocket Wallops Island, Virginia early in the morning of March 27. Credit: NASA/Wallops

Each rocket released a chemical tracer that created milky, white clouds at the edge of space. Tracking the way the clouds move can help scientists understand the movement of the winds some 65 miles up in the sky, which in turn will help create better models of the electromagnetic regions of space that can damage man-made satellites and disrupt communications systems.

A Jet Stream Study to Light Up the Sky

Update:  The mission was launched around 5 a.m. March 27.  Some photos are coming soon.

Little is known about the about the atmosphere above 50 miles, yet below where spacecraft orbit.  This is generally known as the Thermosphere above the Mesopause (See the graphic to the left, Image Credit: NASA).  The only way to study this region is with sounding rockets.  Some 35 to 40 feet long, sounding rockets shoot up into the sky for short journeys of eight to ten minutes, allowing scientists to probe difficult-to-reach layers of the atmosphere.

NASA will be conducting an experiment aimed at studying high-level winds near the edge of space at altitudes of 60 to 65 miles.  Winds at this altitude move at speeds of 200 to 300 miles per hour.  To study the winds NASA will release trimethyl aluminum which forms milky, white clouds that allow those on the ground to "see" the winds in space and track them with cameras.

Five sounding rockets will be launched in approximately five minutes to study these high-altitude winds and their intimate connection to the complicated electrical current patterns that surround Earth. First noticed in the 1960s, the winds in this jet stream shouldn't be confused with the lower jet stream located around 30,000 feet, through which passenger jets fly and which is reported in weather forecasts. This rocket experiment is designed to gain a better understanding of the high-altitude winds and help scientists better model the electromagnetic regions of space that can damage man-made satellites and disrupt communications systems. The experiment will also help explain how the effects of atmospheric disturbances in one part of the globe can be transported to other parts of the globe in a mere day or two.

The experiment is known as the Anomalous Transport Rocket Experiment (ATREX).  It is scheduled for 1:30 a.m. on March 15.  The backup dates are March 16 through April 3.  There will be a webcast of the mission beginning 2 1/2 hours prior to launch and can be viewed at: http://sites.wff.nasa.gov/webcast.

Suomi NPP Producing Stunning Views

NASA has renamed its newest Earth-observing satellite in honor of the late Verner E. Suomi, a meteorologist at the University of Wisconsin who is recognized widely as "the father of satellite meteorology."

Verner Suomi pioneered remote sensing of Earth from satellites in polar orbits a few hundred miles above the surface with Explorer 7 in 1959 and geostationary orbits thousands of miles high with ATS-1 in 1966. He was best known for his invention of the "spin-scan" camera which enabled geostationary weather satellites to continuously image Earth, yielding the satellite pictures commonly used on television weather broadcasts. He also was involved in planning interplanetary spacecraft missions to Venus, Jupiter, Saturn, Uranus and Neptune.

Suomi spent nearly his entire career at the University of Wisconsin-Madison, where in 1965 he founded the university's Space Science and Engineering Center with funding from NASA. The center is known for Earth-observing satellite research and development. In 1964, Suomi served as chief scientist of the U.S. Weather Bureau for one year. He received the National Medal of Science in 1977. He died in 1995 at the age of 79.

The National Polar-orbiting Operational Environmental Satellite System Preparatory Project, or NPP, was renamed Suomi National Polar-orbiting Partnership, or Suomi NPP. The satellite is the first designed to collect critical data to improve short-term weather forecasts and increase understanding of long-term climate change.

Max Storm Doppler Radar

The day after Christmas saw the unveiling of our new Doppler Radar display.  What is this and why is it important?

It may be hard for some of you to get excited over new technology.  When a kid gets a new video game as a present, he can't wait to get to it.  Parents are left scratching their head wondering what is the big deal.  At least he is happy with the new game.  Meanwhile, the kid is conquering the world with the new game.  He gets it.

This new version is a significant upgrade to the current technology.  We decided to call it Max Storm Doppler Radar since the entire graphics suite is Trueview Max.  In reality almost all weather radars are Doppler radars now.  The transformation began in the late 1980s and was almost completely changed by 2005.  What is different is how the data is handled from the Doppler radar.

Thus, this is a software upgrade to our weather computers.  The presentation has a higher resolution, can display up to five live radars, offers greater analytical capabilities, the user interface is better, and is encompassed in one computer system.

Mother Nature was kind enough to provide us with a realtime test of the system this morning as a band of storms raced across parts of South Carolina.  Yes, there were some system failures and minor bugs to correct, but rarely has a new system come under fire so quickly after going operational.  The system is now performing better in less than 24 hours and I think it is surpassing our expectations.

Can I list all of the advantages of the new system? No. Like any new toy there is a learning curve, which is why this mornings' storms were important to us.  There is nothing like "trial by fire".

There are differences in the display which are obvious when comparing with the older Doppler display.  You can still see the older display on our digital channel 19-2.  This channel will continue to feed the radar using the older display, but it will be uninterrupted.

One of the dramatic differences is with the 3D display.  The older version could display multiple live radars in three dimensions, but in low resolution.  Max Storm Doppler Radar allows 3D displays, but only from one radar at a time.  However, that display is at a much higher resolution which provides us with a more detailed picture of the storm vertically.

Fig. 1 An example of the 3D display from the Max Storm Doppler Radar taken Tuesday morning, December 27, 2011.

The Doppler radars that are used to provide the information are the National Weather Service network of Doppler radars.  This is the most advanced network of Doppler radars in the world.  The network will be undergoing upgrades over the next couple of years to become Dual-Polarization Doppler radars.  Then in the about 5 to 7 years the network will be upgraded again to Phase-Arrayed Doppler radars.  More on these developments at a later date.