10 Jul

The Absence of Evolution in Arkansas

On January 18th, 2005 the American Civil Liberties Union of Arkansas sent a letter to the school board of Beebe, a small town of less than 10,000 located in the Northeast Central part of the state.  

The ACLU of Arkansas wishes to make clear our intentions in this matter. While we would prefer to avoid litigation, we seek the immediate removal of the sticker regarding evolution that now appears in textbooks in the Beebe School District. We expect to hear from you concerning this matter within two weeks from the date of this letter.

 The sticker in question had been in the front of Beebe textbooks for nearly a decade.

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What had changed?  A few days earlier in Selman et al. v Cobb County School Board a federal judge ruled that stickers included in textbooks in this Georgia school district need  to be removed because it “improperly entangled itself with religion”.

This textbook contains material on evolution. Evolution is a theory, not a fact, regarding the origin of living things. This material should be approached with an open mind, studied carefully, and critically considered.

Approved by Cobb County Board of Education Thursday, March 28, 2002

Of course, Beebe’s sticker went far beyond the Cobb County three-line sticker.  By a July, the Beebe School Board in fear of lawsuit ordered the removal of the stickers.  A month later Beebe teachers were ripping the pages with the stickers out of the textbooks.

The teaching of evolution in Arkansas has always had a contentious history.  The landmark 1968 Epperson v. Arkansas trial invalidated an Arkansas statute that prohibited the teaching of human evolution in the public schools.  Nearly four decade later the issue of teaching evolution was still controversial. In 2003, Bob Dunning, a pastor of Rocky Comfort Assembly God Church, asked for a religious exemption for Rogers school district students to opt out of evolution studies.   Dunning brought several pastors and nearly three dozen congregational members with him to the April school board meeting.  Dunning proclaimed in these proceedings that “Evolution is the worst thing ever foisted on human beings.”  The school board voted against this 5-2 largely because local school boards cannot pass resolutions exemption students from any state required class work.  

In 2007, also in the Roger’s School District, a dentist, Don Eckard, and a patron, Mark Moore, approached Rogers school board to augment textbooks with “supplemental materials” including a DVD “How to Teach the Controversy Over Darwin Legally”and other materials from the pro-intelligent design and conservative think tank Discovery Institute .  Eckard stated

Teachers may have trouble fully meeting state science standards without supplemental materials for textbooks when some textbooks present a one-sided commitment to a portion of the material covered…all four [biology textbooks] present the neo-Darwinism theory of evolution…with very little critical analysis…no objective observer can look at these textbooks and with intellectual integrity say they fulfill state standards.

Roger’s High School science teacher, Steve Long, stated the materials were

superfluous and may detract from the overall biology curriculum by creating confusion where no mainstream controversy exist or adding additional days of instruction to an already crowded curriculum.

The school board ultimately didn’t adopt these extra materials

But all of this may be a moot point.  Fifty miles south of Rogers in the Ozarks is Cedarville, Arkansas. I graduate from the small high school here.   There were a mere 42 people in my graduating class.  I never once heard about evolution during any of my science classes. Not once.  Evolution was simply not a controversy because my teachers never mentioned the topic despite being a requirement of Arkansas state science standards.  

This absence is by far more dangerous than the visible cases about whether evolution should be taught.  In these silent school districts the choice has already been made. Censorship rules the day.

Back in Rogers, apparently unknown to Eckard and Dunning before,  the theory of evolution was apparently rarely covered.  Dr. Angela Potochnik, an associate professor of Philosophy at the University of Cincinnati with a Ph.D. from Stanford University, happens to be a 1998 graduate of Rogers High School.  In 2002,  while at Stanford she found she had deficiency in her understanding of evolution compared to her classmates. We had both faced a similiar issues only realized by both of us later in our academic careers when the gaps in our education became noticeablew .  In Potochnik’s letter to the Roger’s School Board  later that year, she noted that she could not recall evolution ever being brought up in the curriculum.  She recounts in her letter an interaction with a teacher who told her that evolution was not mentioned in class because “other students weren’t mature enough for such a subject.”  

I leave with Dr. Potochnik’s words

…we live in a state forward thinking enough–at least in our laws–to say that we will teach the methods and theories of science, including those regarding evolution.  We are as a population, I believe, forward thinking enough to realize that covering our ears when such subjects are mentioned is not a way to deal effectively with the situation.  Dissenters can, by all means, dissent.  But dissenters, either school children or their parents, should not be feared to the extent that teachers fails to teach information than can turn out to be central to someone’s academic or professional success.

 

 

 

 

04 Jul

Yale Climate Opinion Maps

Yale has a nice website where you can view interactive maps on responses to a variety of questions related to the acceptance of climate change.  Interestingly, while a majority, including Southerners, seem to accept climate change is real many do not believe it caused by humans or we should support alternative energies.

Public opinion about global warming is an important influence on decision making about policies to reduce global warming or prepare for the impacts, but American opinions vary widely depending on where people live. So why would we rely on just one national number to understand public responses to climate change at the state and local levels?

Source: Yale Climate Opinion Maps

02 Jul

Monkey’s Uncles, Evolution, and the South

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My journey for understanding the frequently tense relationship between the South and science has led me to an unlikely place—Oakland, California. In what appears to be a former auto body shop, complete with large garage doors, resides the National Center for Science Education (NCSE), an organization striving to keep evolution and climate change science in public school curricula. NCSE serves as a clearinghouse of information, resources, and literature including everything from creationist pamphlets, news articles, evolution textbooks, and policy documents to email exchanges and hate mail. I am currently pouring over boxes of vitriol in paper form. “You are the enemy.” “You commie bastards. Leave other people’s children alone.” And my personal favorite, “I think you should be locked up with your monkey ancestors.” (Never mind that spending a day hanging around with monkeys actually seems fantastic.) You likely have an image in your head of the kind of person that writes these words—Southern, poorly educated fundamentalists. You may be surprised that these words originated from residents of Minnesota, Arizona, and New Hampshire.

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In part this assumption stems from the fact that some of the most famous legal cases about teaching in evolution in classroom have occurred in the South. In 1925, in The State of Tennessee v. John Thomas Scopes, commonly referred to as the Scopes Monkey Trial, substitute high school teacher, John Scopes, was accused of violating Tennessee’s Butler Act which made it unlawful to teach human evolution in any state-funded school. In the 1968 case Epperson v. Arkansas, 10th grade teacher Susan Epperson filed a suit to test the constitutionality of Arkansas state law prohibiting the teaching of human evolution in public schools. Both courts ruled in favor of teaching of evolution in the public classroom. In the latter, the U.S. Supreme Court stated the First Amendment prohibits a state from requiring, in the words of the majority opinion, “that teaching and learning must be tailored to the principles or prohibitions of any religious sect or dogma.”

The geographic locality of these landmark cases, along with the often-unfavorable press coverage of stereotyped Southerners, has bolstered the view of an anti-science South. The famous journalist H.L. Mencken who covered the Scopes trial characterized the local population of Tennesseans as “morons”, “hillbillies”, and “peasants” with “degraded nonsense which country preachers are ramming and hammering into yokel skulls.”

Down the street from NCSE, I am grabbing a hamburger at an oddly Southern inspired restaurant with my long time friend and colleague Josh Rosenau.   Josh is NCSE’s Program and Policy Director, a rather succinct title, given his actual daily responsibilities of working with grassroots groups across the U.S., testifying before school boards, organizing scientists and concerned citizens, meeting with legislators, speaking with journalists across the country, and contributing writings to dozens of popular media venues. His characteristic bow tie and gentile nature often seem better suited for a Savannah gentleman of leisure than a Jersey raised superhero charged with defending science education. “The South doesn’t have a monopoly on being antiscience.   I’ve worked with groups across the U.S. Nearly every state has tried to pass anti-evolution legislation.” Indeed, that morning Josh pointed me to a series of file cabinets designated to “flair ups” files. The folders are named for places where an incident as occurred ranging all the way from Templeton, California to Dahlonega, Georgia and everyplace in between. I see just as many folders in these cabinets from outside the South as I do from within.

image010In one of the most thorough books every written on the subject, Evolution, Creationism, and the Battle to Control America’s Classrooms, Pennsylvania State University political scientists Michael Berkman and Eric Plutzer state, “there is overwhelming evidence…No matter how the questions are asked, no matter the theme of the survey, no matter the sponsor of the survey, we see again and again evidence that large majorities of Americans want to see creationism taught in the public schools.” In general between 33-44% of those polled, depending on the poll, favor teaching creationism instead of evolution in public schools. The percentages are even higher, 59.5-68.1%, for teaching creationism along side evolution.  

Favoring Teaching of EvolutionstatescoreGeographic variation does exist in these relationships and it would be disingenuous to not recognize that anti-teaching evolution sentiment is not greatest in the South. However, it is equally disingenuous to think it only exists in the South. In New England, 20% of those polled believed the statement “Human beings developed from earlier species of animals” is false. In the Pacific states, this rises to 29%. Yet, in East South Central, West South Central, and South Atlantic states percentages range from 43-51%.

State by state level data on acceptance of evolution is not existent, requiring a surveying effort beyond the scope of a single researcher or research team. Berkman and Plutzer actually solve this problem by combining several previous polls and analyzing them in an amazingly sophisticated statistical model framework with the lengthy name of Multilevel Modeling with Imputation and Poststratification. This model actually allows the researchers to estimate levels of support for teaching evolution in public schools. At the top of the list are Massachusetts and New York with 40.7 and 39.0%, respectively.   At the bottom are Kansas and Tennessee with 24.4 and 23.3%. Overall percentages are statistically lower in the South (p=0.003) and statistically higher (p=0.04) in the Northeast.EvolutionScoreBoxPlot Favoring Evoltuion Only Box Plot

Yet despite this lack of support for teaching evolution and some legislative success in Southern states, state science standards do not seem to equally suffer. In a survey of state science standards, a team gave each state a score with 0 being the lowest and 100 being the highest based on the inclusion of evolution in the state mandated biology curriculum. When we view those scores for Southern states, while somewhat lower, they are not statistically different from other regions. Indeed, the Carolina’s have some of the highest rankings and Kansas the worst with a grade of abyssal F-.

It is easy, though utterly fallacious, to equate the anti-evolution sentiment in the South with ignorance. The evolutionary biologist, defender of science, and staunch atheist Richard Dawkins once stated that, “It is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I’d rather not consider that).” An opinion I do no share. Indeed, my own interactions with Southern creationists have lead me to the opposite and quite unexpected opinion. Indeed, Berkman and Plutzer find that those who do not accept evolution are not quantitatively any less intelligent or more scientifically illiterate. Instead these researchers argue, “anti-evolutionists choose to ignore scientific arguments demonstrating evolution.” The single biggest predictors of antievolution sentiment appears to be the proportion of the population that are conservative Protestants, the proportion of the population holding masters or doctoral degrees, and the degree of urbanization. All of these point to similar factor—deep involvement in organized religion. Among the urban and suburban highly educated, participation in organized religion is low.

Perhaps then our view of an anti-evolution South is antiquated. Indeed, for ten years the United States premier (although I am biased as I served as its assistant director for six years) evolutionary think tank, the National Evolutionary Synthesis Center, resided in North Carolina and forced to reconsider this view.   The real anti-evolution sentiment resides with conservative Protestants, who happen to dominate throughout much of the South and inspired the moniker of the “Bible Belt.” This group is not scientifically illiterate but chooses the Biblical narrative. And thus science needs a stronger narrative.  We need a better narrative for connecting science and the South; one that takes the beauty of the geographic place and the culture of the South and unfolds the beautiful scientific narrative underneath it all.

29 Jun

The most unappreciated factor behind Atlanta’s economic growth

Nice write up by David Allison about how air conditioning has fueled Atlanta’s economic growth.

Ask anyone what has driven Atlanta’s economic growth in recent decades and they’re likely to answer the airport, great quality of life, or business-friendly environment. Others might say a strong workforce, the confluence of interstate highways, or great universities. While these are all important, there’s one other key factor that almost nobody thinks about. And that’s air conditioning. It’s at this time of year that this truth becomes most apparent. HOME OF THE DAY SPONSOR LISTING Perfect for Entertaining! See All Homes of the Day Hotlanta’s economic growth, indeed the economic growth of the larger Southeast, almost exactly parallels the growth of air conditioning. Both took off after World War II.

Source: The most unappreciated factor behind Atlanta’s economic growth – Atlanta Business Chronicle

18 Jun

Radar Love

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On a Friday in July of 1986, tornadoes touched down in the suburbs of the Twin Cities in Minnesota. A KARE News11 helicopter caught one of these tornadoes on video, a rarity in the era before YouTube videos and hundreds of storm chasers. This video proved to be exceptional, capturing a vortex structure only previously seen in a laboratory setting years earlier by Purdue scientists. When the scientists tweaked the winds entering the bottom and leaving the top of the small laboratory tornado, the twister took on a helical structure. The KARE video was the best documentation to date of an actual tornado with a helical structure, a video that a seven-year-old Robin Tanamachi watched repeatedly. Robin’s father had recorded the KARE broadcast—a videotape Tanamachi quickly wore out from multiple viewings. From an early age, it was quite clear Tanamachi was destined for a career in tornado science.


Almost thirty years later, Tanamachi, now a Research Scientist for the Cooperative Institute for Mesoscale Meteorological Studies in Norman, Oklahoma, examines how radar can be better used to understand, predict, and track tornadoes. Prior to radar, most research on tornadoes was based on films, still photographs, or damage markings (think of the Fujita scale). Although radar originated in the 1950’s, visible radar evidence of a tornado, the tornado vortex signature, was not discovered until 1973 based on observation of a tornado in Union City, Oklahoma. Interestingly, this was the same year that Gold Earring had the hit Radar Love. That discovery by scientists at the National Severe Storms Laboratory in Oklahoma led to the modern tornado warning system in the U.S, including a national network of next-generation Doppler radars (NEXRAD, also known as WSR-88D) funded by Congress.

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The velocity couplet

Radars are a paradox of simplicity and complexity. Scientists, like Tanamachi, continue to develop and refine radar technology, the kinds of data radar can produce, and the algorithms used to sort through all this data. At its simplest, radar emits a burst of radio waves moving near the speed of light until they come in contact with a target. The target absorbs and re-radiates the waves back, an echo, to the radar antenna. The larger and/or harder the target (e.g., raindrops or hail), the louder the echo. The time that passes for the wave to leave and echo back is a function of the distance traveled by the wave. Each NEXRAD radar pulse lasts about 0.00000157 seconds (1.57×10-6), with a 0.00099843-second (998.43×10-6) “listening period” for echos. The radar is “on” for a just over 7 seconds each hour. The remaining 59 minutes and 53 seconds are spent listening for any returned signals.

moore_debris_ballThe strength and retrieval time of the echo are just two facets of the radar wave measured. Doppler radar also measures the frequency of the echo waves. A shift in the frequency of the wave can yield an estimate of how fast the target is moving away or toward the radar antenna.   A positive frequency shift implies motion toward the radar and a negative shift suggests motion away from the radar. This is similar to the Doppler shift you hear with sound waves as a loud pick up truck moves toward or away from you.

Because of the earth’s curvature, NEXRAD radar beams typically overshoot the tornado itself, and instead measure the winds in the parent mesocyclone that births the tornado.” The tornado vortex signature appears on the radar as red (indicating high outbound velocity) and green (inbound velocity) pixels occurring adjacent to each other over a relatively small area (see radar image above). This is also called a velocity couplet, and it is associated with the mesocyclone, the rotating vortex of air within in the supercell. Radar can also be used to detect a hook echo extending from the rear part of the storm, resulting from precipitation wrapping around the backside of the rotating updraft. Lastly and perhaps disconcertingly, radar can detect the debris ball from a tornado. Objects lofted into the air by a tornado reflect radar waves very well.

pg29tornadoThe future of tornado research in part, however, rests on getting the radar closer to the tornado. Moving the radar closer to the storm allows the parts of tornado and storm structure to be better observed. Tanamachi is part of team that drives mobile Doppler radars toward, not away from tornadoes, striving to accomplish this daunting task. This is high-risk-but-high-reward science. Out of 100’s of trips, Tanamachi’s team has only successfully collected data a handful of times. “In the unsuccessful cases an ingredient was missing. We will go out if three of the four are present, but even when all four are present something will still be off and a tornado will not form.” But those few successful cases hold one key to the million-dollar question, understanding when tornadoes will form.

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Hook echo with potential debris ball

If one key is getting closer to tornadoes with radar, then another is dual-polarized (“dual-pol” for short) radar. Dual-pol radar can emit both horizontal and vertical pulses, allowing for the shapes and sizes of objects to be detected. Contrary to the tear-shaped raindrops of cartoons, raindrops in real life can take on a variety of shapes. Small raindrops are almost perfectly spherical, returning the same amount of echo in the horizontal and vertical polarized channels. Larger drops, deformed by air drag, resemble hamburger buns returning a stronger horizontal echo. Tanamachi notes, “These subtle differences in the drop shape can lead to vastly different estimates of how much liquid water actually falls on the ground. Dual-polarized radar has been conclusively shown to make radar-based rainfall estimates more accurate.”

dual_pol2130425_dual_pol_illustrationThe size a raindrop can also inform meteorologists about cooling and temperatures— possible triggers for tornadoes. Water molecules on smaller drops with their spherical shape and high surface area-to-volume ratio can evaporate more quickly than large drops. This increased evaporation with smaller drops causes the air to chill and sink toward the ground and important in birth of tornado. As Tanamachi explains “Once the cool downdraft reaches the ground, it spreads outward like a puddle of syrup, in what is termed the storm’s “cold pool”. Such downdrafts appears to be a two-edged sword in relation to tornadogenesis. On one hand, several studies suggest that a downdraft is necessary to generate near-surface rotation. On the other hand, the fuel source for the storm (and tornado) is warm, moist, buoyant air, which may be disrupted or cut off if the resulting cold pool completely undercuts the storm, as many a frustrated storm chaser can tell you. It seems there is a “Goldilocks problem” at hand – the downdraft must be present, but not too strong – in order to enhance tornado formation.”  Dual-pol can indicate these inner storm dynamics all by detecting small or large raindrops that in turn suggest the presence and strength of downdrafts leading to predictions on potential of that storm to produce a tornado.

12 Jun

Alabama students revolt against federally mandated whole grain biscuits

There’s something special about a fluffy biscuit. Just ask many of the students who attend Etowah County Schools.It’s the one thing students have not adjusted to doing without when presented with healthier menu choices, Laura Parker, the system’s Child Nutrition Program director, told members of the Board of Education at a meeting Tuesday.Whole grains, all the time, became a requirement last year. They were gradually added a few years before.”They’ve revolted, really,” Parker said about the biscuits.

Source: Alabama students revolt against federally mandated whole grain biscuits | AL.com

09 Jun

A Lightning Bug Rave on the Forest Floor

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If you bottled up a caricature of Southern culture and poured it all over a town, you would get Gatlinburg, Tennessee. The streets of Gatlinburg look more like the midway of a low budget, small time carnival than an actual town. Everything from mountain cabins to southern cooking and moonshine to grits are commercialized and distilled to absurdity. If the South has an armpit, it is this town in the corner of Tennessee. Minutes from my hotel, itself homage to the worse of this town, paradoxically lies one of the most beautiful places in the South— Great Smoky Mountains National Park. My wife and I are here in early June to witness one of the most spectacular displays of biology found in the South, the lightning bug Photinus carolinus. About 30 minutes after sunset, thousands of males light up the forest in the former logging town of Elmont, now in middle of the park. The males are known to flash in synchrony, signaling and then going dark in unison.

Screen Shot 2015-06-08 at 10.05.22 PMTwo months before, everyone around me witnessing the light show, was sitting in front of his or her computers to gain a ticket. Thousands of these tickets went in just 24 hours in April to see the insect light show in June.  Scientists use a model developed by Lynn Faust and Paul Weston in 2009 to predict when the actual light show will occur. The model uses growing degree-days, a tool also used to predict when flowers will bloom. Think of the model as a bag. One fills this bag with temperature coins gained when the average daily temperature exceeds some base temperature. When the bag is full of temperature coins the lightening bugs emerge and being lighting up the forest floor. For Photinus carolinus, the base temperature is 50˚F. If the day temperature is 80˚ and the night temperature is 40˚, the average is 60˚. This is 10˚ greater than the base so you get 10 temperature coins to add to the bag. Males typically emerge from larvae at about 840 coins with the peak display at 1,069 coins, which also coincides with when females emerge. Scientists start counting coins at the start of March. By April, park scientists know the week and half the light show will occur.

fireflyMy wife and I jockeyed for our position at 7:00 pm, among hundreds of tourists, to observe this magnificent display. At approximately 8:30 the sun begins to set and by 9:00 the flashes begin. My wife and I are done and head out nearly an hour before the males stop flashing. Male will keep the display going for up to three hours. Photinus carolinus males are extremely motivated to keep the flashing going. They are evolutionary pawns in the age-old tale of attracting a female. The males signal in flight, while females lay low in the leaf litter. Indeed, females are rarely seen flying. During the dark phases, approximately three seconds after the last male flash, receptive females will signal with a double flash.

Amongst the forest floor light show, select males and females begin their close range mating dialogue of light. The males will switch from multiple flashes to a single aimed flash as he circles the female. As he approaches the female flashing his lantern, he first flies then walks. Within minutes, the couple will move to a discrete and sheltered location to seal the deal.

The combined flashes of males light up the forest floor in every direction around me, a disco light party fueled by biological blue-white LEDS illuminates the forest floor. Each male produces a train of 4-11 flashes, on average between 6-7, in half-second intervals followed by 6-9 seconds of dark. The flashing is a discontinuous synchrony. For ten seconds or so, males will flash multiple times in the period, each at their own pace. After about ten seconds, the forest goes completely dark. Eight seconds later the forest floor is lit up once again.

photo_mergeThe reason for the male synchrony is unknown. Jonathon Copeland and Moiseff Andrew in 1994 speculated the rhythmic light show is due to weak female flash. The female possess a single half-moon shaped lantern while males possess two lanterns. A bunch of males, with 2x the lightening power, would swamp out the female’s signal. Or because this occurs in the dense vegetation of the Smoky Mountains, synchrony could extend the intensity of any single male’s flash. I think it all happens because a single male starts off, saying with light, “Pick Me!” This causes a cascade of males all to respond, “No Pick Me!” This happens repetitively for a few seconds until all the males get tired. They rest up and the show starts again.

13 May

The complications of measuring tornado strength

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Featured image from Kansas City District U.S. Army Corps of Engineers (Flickr CC). Strewn debris from the EF-5 tornado that struck the Joplin, Mo., area, shown June 14, 2011.

By the time I was in second grade, I was a professional at school tornado drills. Our school was an old building with a line of nearly floor to ceiling windows lining the entire length of the classroom. Not exactly the best room to wait out a tornado. When 5 short burst rings sounded, I masterly made my way to the hallway with a textbook. Because of its thickness and robust hard covers, I always chose my math textbook.   There crouched down on my knees and elbows, I protected the back of my head and neck with that open textbook. At time I was mastering drills, I was becoming an expert on the F-scale. Indeed, most Southerners know the F-scale as well as they know the words to Sweet Home Alabama. May be better.

The F-scale began with Tetsuya Fujita, a meteorologist from Japan.   The town he lived in at the end of World War II was the primary target of one H-Bombs the U.S. dropped. Due to cloudy conditions that bomb was dropped on its secondary target–Nagasaki. Fujita’s study of the damage of the nuclear bomb blasts actually led to a major discovery of meteorological phenomenon called downbursts and microbursts. Perhaps surprisingly given his history, Fujita was recruited to the University of Chicago in 1953. Eventually in 1971, Tetsuya Fujita and Allen Pearson released the F-scale for tornadoes and Fujita himself quickly became known as Mr. Tornado.

428px-Fujita_scale_technical.svgBefore 1971, all tornadoes were treated the same no matter their strength, size, path, or damage caused. After, thanks to Fujita and Pearson, scientists could begin to quantify differences in tornadoes, a key step into actually understanding tornadoes. The scale ranges from F1 to F12, linking together the Beaufort scale of wind strength and Mach scale (yes like jets). A F1 tornado corresponds to a 12 on the Beaufort Scale and a F12 corresponds to Mach 1. Tornadoes are rated just from an F0 (40-72 mph) to F5 (261-318) that corresponds to increasing wind speeds. An F5 is enough to wipe a significant portion of that sweet home in Alabama completely off the map. Indeed, on April 27, 2011 two F5 tornadoes cut huge tracks from Tuscaloosa to Birmingham and Rainsville to Sylvania. The tornadoes were strong enough to toss a 35.8-tonne (78,925 lb) coal car 391 feet and partially pull an underground storm shelter out of the ground. An F6? Mr. Tornado himself viewed a F6 tornado as completely unconceivable.

Bahari Adoyo Follow Tornado Damage  This is a picture of the tornado damage that my hometown of Tuscaloosa, Alabama took on April 27, 2011. These images have not been edited, some have been cropped. All were taken from a moving vehicle.

From Bahari Adoyo on Flickr (cc) Tornado damage to Tuscaloosa, Alabama took on April 27, 2011.

But here’s the kicker in assigning F-scale ratings to tornadoes.

It is practically impossible to measure wind speeds near the ground. Never mind measuring the wind speeds of a tornado over the course of its life from origination to destruction to demise.   The F-scale is actually a measure of the damage a tornado causes. Or as referred to by Bill Paxton in one of my favorite movies, “It’s the Fujita scale. It measures a tornado’s intensity by how much it eats.”   Assumptions are made that link the damage done, specifically to common wood framed home, to the wind speeds on the F-scale. An F0 cause light damage to chimneys, breaking of trees branches, and damage to sign boards. An F5 causes incredible damage with lifting a framed housed lifted off foundations, carrying it a considerable distances, and the disintegrate it. Cars are tossed through the air over 300 feet. Trees are debarked. Steel reinforced concrete isn’t even safe. The last F5 tornado to occur was in Vilonia, Arkansas in April 27th 2014 just minutes from where I attended college two decades prior.

However as noted by Charles A. Doswell, the meteorologist who contributed to the modern conception of the supercell, the F-scale has issues. “The real-world application of the F-scale has always been in terms of damage, not wind speed. Unfortunately, the relationship between the wind speeds and the damage categories has not been tested in any comprehensive way.” There are several issues that aren’t factored into or estimated in the F-scale.

First, differences in building practices can vary among regions and homes. If your cousin Billy, the strictly for cash under the radar carpenter he is, built the new expansion to your house, chances are the home may not fair very well in even the smallest tornado.

Second, your cousin Billy’s grill, old car, and toilet in his yard, may become tornadic missiles damaging nearby residence. Less junk in the area, less to go airborne, and less damage. 

Third, the steadiness and duration of the wind itself can impact damage. If the tornado is a windbag like Billy, those constant winds will cause more damage. Just like Billy.

Fourth, how much wind does it take to make different cars go airborne, damage different types of wood and frames, and different types of architectural styles? Is a 70’s ranch as likely to survive as the new McMansion over the way in Hope Pines? Does Billy’s rusted 73 Ford long bed fly as far as your new Dodge? None of this is quantified. 

Engineers also noted that it did not take 300 mile per hour winds (F5) to demolish a house. As Doswell noted, “In order to do this right, we would have to do some sort of controlled experiment in virtually every conceivable tornado situation! This is a practical impossibility.”

All the uncertainty in the F-scale lead to meeting in Grapevine, Texas of the Fujita Scale Enhancement Project which brought together a brain trust of expert meteorologists and civil engineers. Ultimately a more objective scale was created, the Enhanced Fujita Scale, which was unveiled in 2006 at a meeting of the American Meteorological Society. Just a year later it went into operational use in the U.S.   The EF-scale has more rigorous and standardized measures of damage, adds additional building and vegetation types, accounts of differences in construction quality, and expands degrees of damage.

But here is the second kicker. While the EF-scale is an improvement, it shares many of flaws of its predecessor. And it comes down to a few simple ideas. Many areas are free from structures and populations. EF0-EF1 ratings predominant in unpopulated areas because of the little damage done to structures. The very famous El Reno, Oklahoma tornado, estimated to have one of the largest diameters ever recorded, could never reach scales of over EF3 because it occurred open country. Moreover, tornado records are plagued with EF unknowns because it requires a detailed assessment. It takes a whole crew in the field after a tornado to assess the damage. Damage for EF-scale is also based on the maximum damage observed in a single spot. But as tornado runs it course, wind speeds can vary greatly. Indeed, the highest damage levels of EF4-5 tornadoes occupy less than 10% of the track.

Clearly there is a need for a better scale for tornado size. Doswell points to a committee of the American Society of Civil Engineers, a sort of Supreme Court for tornado strength assignments. Ratings of tornadoes would be submitted to a committee who would evaluate the proposed rating and ensure standards were met. This committee is developing a standards committee to evaluate all possible ways to measure wind speed though radar, direct measurements, course damage, and even tree falls.   “A study done at turn at the 20th century found if you knew speed and pattern of winds, then directions of tree falls could be use to estimate speed.”

14 Apr

The difficulty of predicting tornadoes

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Legendary blues singer, Alger “Texas” Alexander was born in Jewett, Texas, north of Houston in 1900. In 1934, Alger composed and sang with his big, deep voice the Frost Texas Tornado Blues. Just four years earlier a F4 tornado ripped through the town of Frost just south of Dallas. Sixty were killed and many more never found. The entire town was leveled and a mass funeral occurred on the porch of the only house left standing.

I was sitting looking: way out across the world

Said the wind had things switching: almost in a twirl

Says I been a good fellow: just good as I can be

Says it’s Lord have mercy: Lord have mercy on meOkeh_Record_Label

Mmm: mmm

Says I been a good fellow: just as good as a man could be

Some lost their baby: was blowing for two three miles around

When they come to their right mind: they come on back to town

Said rooster was crowing cows was lowing: never heard such a noise before

Does it seem like hell was broke out: in this place below 

frost_tornado_photo_12Although we still sing the blues about tornadoes, much has changed since the 1930’s with regard to tornadoes. We have better home construction and much, much better warnings now.  However, knowing exactly when and where  a tornado will occur…well that is a bit more challenging.

Let me clarify.

With ever-increasing precision we can predict, and warn, of conditions that are likely to produce a tornado. The ingredients—wind shear, instability, heat and moisture, and forcing mechanism—are mesoscale phenomena that can be modeled, quantified, and even predicted. Roger Edwards, lead forecaster at the Storm Prediction Center described the intricate process that it takes to predict a thunderstorm and tornado outbreak days to a week in advance. “It takes a combination of skill, luck, and a team of people. The key is trying to predict a phenomenon not just temperature and rain.” Data of different types—wind, temperature, moisture—at scales ranging from the globe to North America to a particular county in Oklahoma must all be integrated. The data itself comes from satellite, aircraft observations, weather balloons, weather stations, and radar. All of this data must be assimilated and ran through multiple modes that would fry your home computer and probably your neighbor’s on top of that. Then the computers spit out an answer. Of course that answer might be garbage. “Let’s not forget the human element to see that models are going awry. You need to conceptualize in three dimensions what is going on in atmosphere. We still analyze charts by hand which causes us to slow down and think with pencils and paper in hand. Our experience is vital. “

But these ingredients form a supercell, not a tornado itself, and not all supercells produce tornadoes.   “The atmosphere has a way of getting the four together in ways with minor differences to either create a large EF5 tornado or a just some rain. We don’t know when and where these ingredients form in just the right way,” states Edwards. Indeed, 70% of the time a tornado warning is issued no tornado actually forms. It’s important to understand this error would be much worse if it were reversed. In other words, if 70% of the time a tornado occurred no tornado warning was issued. That is the major advance I’m talking about. 

Scientists still have little idea what causes tornadogensis particularly those microscale phenomena, those minor winds, temperature, and pressure differences that occur in areas less than a mile to less than football field that trigger the whole shoot and caboodle. Measuring, analyzing, and modelling this is the cutting edge of tornado research.  In the last several weeks, I have been speaking with the biggest names in tornado researchers from Virginia to Oklahoma to Illinois. I asked everyone what is the biggest question in tornado science. Every one of them responded that the holy grail, my word not theirs, is the when, where, and how of which storm will make a tornado.

Charles Doswell is a meteorologist who although did not originate the concept of supercell, that’s thanks to a Brit named Keith Browning, did with Les Lemon improve Browning’s idea that gave us the modern conceptual model of supercells and how they form. That paper from 1979 is one of the most cited papers in meteorology and tornado science. I’ll leave with Charles’s words from our recent conversation. “We are still struggling with the area of tornadogenesis. Apparently you need every single one of the details…and very high confidence in them too.” Perhaps it’s fitting that Doswell and “Texas” Alexander share more in common that a fascination with tornadoes. Doswell is too a lover of the blues, perhaps fitting for a tornado scientist, and used to host a blues radio show.

 

08 Apr

Are tornados in the South different?

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Image of the Joplin Tornado

Image of the Joplin Tornado

For the last several months, I’ve found myself on a quest. One that as a marine biologist I didn’t expect to find myself on, but that has origins long before I decided ocean science was my path. Tornadoes have imprinted on my psyche. I am not alone in this. Last week, I asked are some areas more tornado prone? What I really wanted to know is if some somehow tornadoes are different in the South. Tornadoes seem to be so much more imprinted on our collective consciousness here.

I posed the question of a difference in Southern tornadoes to Kevin Myatt, an Arkansas native, self-proclaimed weather geek, and writer on the weather blog for roanoke.com. “The first thing you need to know about Dixie tornadoes is they don’t look like the Wizard of Oz funnel” Let me explain. Tornadoes in the South do not come to a neat tapering point. Instead they are sloppy but also key is they are hidden. “Take Joplin, you couldn’t even tell it was a tornado except from one angle.” Higher moisture in South due to the proximity to the Gulf of Mexico leads to wetter storms. The tornado becomes rain wrapped. Combine this with a cloud base close to the ground and you have tornado edges that blurry and shrouded.

tumblr_lzg94uCCHT1ql23g2o1_500 giphyBut there is another key idea. Southern tornadoes are the danger that lurks in the night—the proverbial boogey man. Both Myatt and Roger Edwards, lead forecaster at the Storm Prediction Center that I also posed my question to, both mentioned night tornadoes to me. Tornado season in the South includes November to February when days are shorter makes them hard to see. Combine this with the more complex topography and forests of the South over the Midwest and you have a recipe for distress.

tornado-watches-per-year1999-2008 tornadoes_countyThe reason is not because more tornadoes occur in Dixie—Kansas, Oklahoma, Texas, Nebraska, Colorado, and Florida safely hold that title. But interestingly, outside of Oklahoma, more tornado watches occur annually in Arkansas, Louisiana, Mississippi, Alabama, and Georgia. Parts of Mississippi and Alabama see over 16 annually. Edwards states, “In reality, tornado season is different in South because it can be anytime of the year.” During the early part of the year, Gulf of Mexico moist air brings moist, warm, and unstable that will turn a normal thunderstorm into a tornado. In the fall, hurricanes and tropical storm spawning tornadoes. Whereas we may not see more tornadoes, we are definitely living under the constant threat of them.

concentrated-poverty-for-map-exchange-may-2011Edwards of course also points to poverty, flimsier homes, and poor building codes, prevalent throughout the South, often lead to more damage even in weaker tornadoes. “Preparedness and construction are vital.” Apparently the constant threat has made us more complacent rather than more prepared.