Do tornadoes form top-down or down-up?
The uncertainty of science: New data now suggests that tornadoes might form from the ground upward, not from the clouds downward, as previously and generally accepted believed.
Houser and a team of researchers from the University of Oklahoma happened to be monitoring the storm with a new type of mobile Doppler radar system that collected tornado wind speeds every 30 seconds. Afterwards, Anton Seimon, a geographer at Appalachian State University in Boone, North Carolina who had chased the El Reno storm, collected hundreds of still photos and videos of the epic twister from citizens and fellow storm chasers.
When Houser compared her radar data with images collected by Seimon, she noticed something odd. The images clearly showed a visible tornado at the ground several minutes before her radar picked it up. Puzzled, Houser went back through her radar data and analyzed the data taken at the ground. It is typically difficult to get good radar measurements at or near the ground, but Houser and her team had deployed their instrument on a slight rise and there were no obstructions between them and the tornado, so this time, they had data good enough to work with.
She found clear evidence of rotation at the ground before there was rotation at higher altitudes. Houser then examined other sets of tornado data and found that in many cases, tornado-strength rotation develops at or near the ground first, rather than starting in the cloud itself. In all four datasets she analyzed, none of the tornadoes formed following the classical “top-down” process.
What is really interesting about this research is that it shows that at least some tornadoes develop from the ground up, something no one predicted. The research also illustrates that the formation of tornadoes is very complicated and that we still do not understand it, in the slightest.
While the researchers here try to imply that this data also proves that all tornadoes must form from the ground up, they are wrong. The data shows that some appear to form from the bottom up, but this does not prove that others might do the opposite. We simply do not know enough yet.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uncertainty of science: New data now suggests that tornadoes might form from the ground upward, not from the clouds downward, as previously and generally accepted believed.
Houser and a team of researchers from the University of Oklahoma happened to be monitoring the storm with a new type of mobile Doppler radar system that collected tornado wind speeds every 30 seconds. Afterwards, Anton Seimon, a geographer at Appalachian State University in Boone, North Carolina who had chased the El Reno storm, collected hundreds of still photos and videos of the epic twister from citizens and fellow storm chasers.
When Houser compared her radar data with images collected by Seimon, she noticed something odd. The images clearly showed a visible tornado at the ground several minutes before her radar picked it up. Puzzled, Houser went back through her radar data and analyzed the data taken at the ground. It is typically difficult to get good radar measurements at or near the ground, but Houser and her team had deployed their instrument on a slight rise and there were no obstructions between them and the tornado, so this time, they had data good enough to work with.
She found clear evidence of rotation at the ground before there was rotation at higher altitudes. Houser then examined other sets of tornado data and found that in many cases, tornado-strength rotation develops at or near the ground first, rather than starting in the cloud itself. In all four datasets she analyzed, none of the tornadoes formed following the classical “top-down” process.
What is really interesting about this research is that it shows that at least some tornadoes develop from the ground up, something no one predicted. The research also illustrates that the formation of tornadoes is very complicated and that we still do not understand it, in the slightest.
While the researchers here try to imply that this data also proves that all tornadoes must form from the ground up, they are wrong. The data shows that some appear to form from the bottom up, but this does not prove that others might do the opposite. We simply do not know enough yet.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Yo– Mr. Z.,
You should maybe proof-read the headline again? form vs. from
( I’m no English teacher, but isn’t the phrase “top-down or bottom-up” more descriptive?)
-I have been under the assumption that tornado’s form generally from the bottom-up. But fortunately, have not experienced one up close & personal.
Michigan’s Tornado Alley
https://youtu.be/XI65QyVJH_4
2:22
Maybe this means that we can construct things (that are not the size of mountain ranges) to prevent tornadoes from forming.
If cold fronts sweeping into warm moist air is always the beginning factor of these storms it only makes sense they form from bottom up. The warm air is shoved upwards rapidly and it would be like flushing a toilet upwards.
Why is this surprising. Dust devils from from the ground up and tornadoes merely have moisture to boost the upward velocity. Given rotation to begin with it should not be surprising at all.
I live amongst them and have watched them my entire life, especially out on the farm when weak tornadoes form in small thunderstorms. I always suspected that rotation may come from the ground as I would watch large and small whirlwinds, or dust devils, by the hundreds all summer long on the High Plains of Texas form with no clouds. My hometown high school teams are called the Whirlwind by the way.