Page 28 - aruba-today-20181208

A28 SCIENCE
Saturday 8 december 2018
New study explains creation of deadly California 'firenado'

REDDING, Calif. (AP) — A velopment and intensifica-
rare fire tornado that raged tion," said Neil Lareau of the
during this summer's deadly University of Nevada, Reno,
Carr Fire in Northern Cali- who co-authored the pa-
fornia was created by a per.
combination of scorching Other factors included re-
weather, erratic winds and cord high temperatures,
an ice-topped cloud that low humidity and a "near-
towered miles into the at- surface cyclonic wind
mosphere, according to a shear zone," according to
study announced Wednes- the study. A wind shear oc-
day. curs when the wind speed
The churning funnel of or direction suddenly
smoke and flame killed a changes, so that the wind
firefighter as it exploded in actually is blowing in two
what already was a vast opposite directions.
and devastating wildfire in The wind shear near the
July on the edge of Red- ground set up the spin that
ding, about 250 miles (400 developed the fire tornado
kilometers) north of San plume, Lareau said.
Francisco. "These observations may
The wildfire claimed eight help forecasters and sci-
lives and destroyed more entists identify - and po-
than 1,000 homes before it tentially warn - for future
was contained on Aug. 30. destructive fire-generated
The study in the Geophysi- vortices," according to the
cal Research Letters jour- study.
nal used satellite and ra- This July 26, 2018 file image taken from video released by Cal Fire shows a fire tornado over Lareau is an assistant pro-
Lake Keswick Estates near Redding, Calif.
dar data to suggest how Associated Press fessor in the Physics De-
a monstrous "firenado" the partment of the College
size of three football fields ed case of such a "fire- length in just 15 minutes. It ing column of air, concen- of Science. The article was
developed on July 26. nado" was during the 2003 reached as high as 39,000 trating the rotation near co-authored by Nicholas
It said the firenado was Canberra fires in Australia, feet (7.4 miles or 11.9 kilo- the surface" and causing Nausler of the Storm Pre-
formed in much the same according to the study. meters), according to the tornado-strength winds diction Center in Norman,
way as a regular tornado, A key factor was the de- study, which was published that reached 143 mph, ac- Oklahoma and John Abat-
which differs from the "fire velopment of a cloud on Nov. 21. cording to the study. zoglou from the Depart-
whirls" that are formed only generated by the fire itself The development of that "This paints a clear picture ment of Geography at the
by heat from a wildfire. that was ice-topped and pyrocumulonimbus cloud of the sequence of events University of Idaho in Mos-
The only other document- grew quickly, doubling in "helped stretch the underly- leading to the vortex de- cow, Idaho.q

What caused ancient mass extinction? Hot ocean water blamed

By SETH BORENSTEIN Great Dying. Scientists of oxygen. That hot oxy- tropical species were more seen in the Great Dying.
AP Science Writer have long speculated that gen-starved water caused acclimated to low oxygen University of Leeds paleon-
WASHINGTON (AP) — Sci- massive volcanic outbursts the mass marine die-off, levels, Penn said. tologist Paul Wignall said
entists think they've figured triggered the cataclys- especially farther from the While humans aren't warm- no current global warm-
out the falling dominoes mic event, but how that equator. ing the Earth anywhere ing scenario envisions 20
that led to Earth's larg- worked was still a bit fuzzy. After the volcanoes blew, close to as much as what degrees of warming in the
est mass extinction and It wasn't the lava itself. the level of heat-trapping happened naturally 250 next few centuries, so it
worry that human-caused A new study in Thursday's carbon dioxide soared to million years ago, "this puts could be millennia away.
climate change puts the journal Science used com- a level more than 12 times our future into the catego- However, even an event
planet on a vaguely similar plex computer simulations what it is today , said study ry of contenders for true 10 percent as bad as the
path. to plot out what happened lead author Justin Penn, an catastrophe," said study Great Dying "would be
Some 250 million years after the volcanoes blew: It Earth sciences researcher co-author Curtis Deutsch, dreadful," said Wignall,
ago, about 90 percent of led to ocean temperatures at the University of Wash- an Earth scientist at the who wasn't part of the
sea life and 70 percent rising by about 20 degrees ington. University of Washington. study.
of land life went extinct (11 degrees Celsius), which Water loses oxygen when it The ancient die-off "shows Other outside scientists
in what is now called the then starved the seawater warms, much like a warm almost exactly what lies at said the study provides a
can of cola goes flat, Penn the end of the road we're scary glimpse into Earth's
said. Scientists looked at on," Deutsch said. "We're possible future.
dozens of modern species really doing the same thing "Because we are warm-
to see what happens to to Earth's climate and ing up the Earth at a rap-
them in warmer, oxygen- oceans." id rate, results from this
starved water and that The study calculates that if study could prove to very
helped them understand heat-trapping carbon di- useful in understanding"
the past extinction. oxide emissions continue what happens to life in fu-
One of the keys in the re- on current levels, by the ture oceans, University of
search is that more species year 2300, the globe will Southern California Earth
died off away from the experience 35 to 50 per- scientist David Bottjer said
equator. That's because cent of the extinction level in an email.q