The night before the Israel Defense Forces' 1976 mission rescuing over 200 hostages from hijackers in Entebbe, Uganda, Tel Aviv University's Prof. Pinhas Alpert, then head of an Israel Air Force base forecasting unit, provided intelligence that was critical to the success of the operation -- the weather conditions commandos were likely to encounter en route and on the ground. Had his information been incorrect, the mission might have ended quite differently.
The inaccuracy of forecasts also has personal implications for people around the world, leaving them stranded without umbrellas, snowed in, or stuck in airports. But considering the technology available today, why do meteorologists continue to miss the mark?
New research published in the journal Land by Prof. Alpert of the Department of Geosciences at TAU's Faculty of Exact Sciences, prioritizes, for the first time, reasons for forecast failures across different regions of the world. Using multi-regression-based statistics on data collected between 1979-1993 on tens of thousands of forecast points, Prof. Alpert and his team were able to quantify the causes -- human-made and natural -- for weather prediction inaccuracies.
The big picture
"Considering my background in forecasting, weather prediction fallacies bothered me for a long time," said Prof. Alpert. "Since joining TAU in 1982, I have been looking for a way to quantify the dominant factors that cause errors in forecasting. Until now, there has been no comprehensive analysis of these factors. They have been studied separately, but not in combination. I decided to quantify and prioritize the dominant factors for different regions, and provide this valuable information to the world scientific community."
Using statistical analysis of meteorological data over thousands of locations and the course of 15 years, Prof. Alpert identified unique factors affecting forecasts in Europe, North Africa, the Mediterranean, Asia, and East Asia. The researchers found the dominant factors clouding the accuracy of predictions comprised land-use changes (i.e. an area that had been covered in forest is suddenly bare), topography, particles in the atmosphere and population density.
"For example, when Israel's national water pipeline crossed the northern Negev in June 1964, it changed the lay of the land," said Prof. Alpert. "After a relatively short period of time, the desert was blooming, affecting the generation of clouds, precipitation, and temperature extremes. It is difficult for forecasters to incorporate changes like this. In effect, this single land-cover change altered the entire local climate over the Northern Negev, and existing forecast models had difficulty accommodating this, leading to erroneous predictions."
Gold, silver, and bronze
The researchers incorporated the dominant factors within a single equation and then monitored the model's ability to accurately predict monthly weather conditions in different regions over 15 years. Prof. Alpert and his team also created a table of "factor prioritization" -- gold, silver, and bronze labels to identify dominant and less dominant factors for different regions in the world. For example, they found that in the eastern Mediterranean, particles in the atmosphere were the most important cause of forecast fallacies, followed by land cover change. They also found topography to be the most influential factor affecting weather around the world.
Read more at Science Daily
Jan 25, 2015
Chilean Farmer Finds 'Chupacabra'; Probably Cat Mummy
The creature, whose name is Spanish for “goat sucker,” is said to suck the blood from small animals such as chickens and goats. It has never been proven to exist, though is nearly as well known as Bigfoot and the Loch Ness Monster.
According to the “Daily Star,” “Goat farmer Javier Prohens was having lunch with friends when terrified farmhand 54-year-old Bricio Saldivar alerted them to the bodies of the strange creatures on the outskirts of the small town of Monte Patria in the east central Chilean province Limari.”
Prohens described his farmhand’s reaction: “He was clearly scared and said he had been up at the old winery and found two strange bodies.” The partially mummified carcasses were found amid hay bales in a cellar, and “at first we thought they might be bats, but when we looked closer, we realized they had to be something else as the heads were too big for bats… And then someone said they looked like Chupacabras,” Prohens was quoted as saying.
Chupacabra Explained
The chupacabra was first reported in August 1995 by a woman in Puerto Rico who described seeing a bizarre bipedal alien-like creature with spikes down its back. Soon it was dubbed the “chupacabra” and caused a media sensation that spread throughout the Spanish-speaking world. However, as described in my book “Tracking the Chupacabra: The Vampire Beast in Fact, Fiction, and Folklore,” it was later determined that the eyewitness had actually (and mistakenly) described a monster in the sci-fi thriller “Species,” which she had recently seen.
Though the original chupacabra report has been discredited, the stories and sightings spread through the media, with the monster’s description changing over time. Fewer and fewer people claimed to see the bipedal, spiky-spined monster, and by 2000 it had completely disappeared, replaced by a variety of four-legged animals left hairless by a skin disease called mange. When medical and DNA tests were done on these “chupacabras” they were revealed to be ordinary animals including dogs, coyotes, and raccoons. Last year a couple in Ratcliffe, Texas, claimed to have found a chupacabra which turned out to be a raccoon.
The word “chupacabra” is now used to describe any animal which cannot be immediately identified or otherwise looks mysterious, either because of hair loss or decomposition. And that is exactly what happened in Chile: a worker found two weird dead things and decided that they must be chupacabras—not because they bear any actual resemblance to most descriptions of the monster, but because that’s the catch-all, genericized term for unknown animals in many places.
“Chupacabra” has become what in linguistics is called an eponym: a word that originally referred to a specific brand name or item but whose definition has expanded to others in the same general category; just as any facial tissues are now called Kleenex, any trash bins are called Dumpsters, and any in-line skates are called Rollerblades, any weird animal is now a Chupacabra.
Mummified Monsters
So if the weird remains found in Chile are almost certainly not chupacabras, what are they? It’s difficult to come to any definitive identification based upon a few photographs, though some characteristics of this creature suggest an explanation. For one thing they lack any spikes down the back that are characteristic of the original chupacabra.
The paws and tail look feline, and the size (about a foot long) would match a common housecat. The skull also resembles a cat’s as well. The fact that the animals were found laying one atop the each other, as kittens sometimes do, may be relevant as well. A mother cat may have given birth to a litter and two of the unfortunate kittens may have been crushed to death by a bale of hay that toppled over onto them.
Where the animals were found provides another clue: inside a wine cellar, where domesticated animals such as cats are known to wander, hide, and even give birth—but conspicuously not a place associated with chupacabras, which are invariably reported outside, usually in desert areas (such as rural Texas) or in rainforests (such as Puerto Rico’s El Yunque preserve, said to be the original home of the chupacabra). An indoor chupacabra would be a first. Furthermore there is no suggestion by Prohens or anyone else that any goats or other animals had been found mysteriously drained of blood, as the chupacabra is known to do; and in any event the mummified mammals had been dead for many months or even years.
Read more at Discovery News
Spacecraft's Double-Take Reveals Changes on Mars
The image above shows a 1 kilometer (0.6 mile) wide crater in Mars’ southern hemisphere, its northern wall and coated with frozen carbon dioxide, what we call “dry ice.” HiRISE captured the view on June 28, 2014 from a distance of 248.8 km (155.5 miles), during what was late southern winter on Mars.
A few months later during the southern spring, the same region was imaged with HiRISE. Lo and behold the frost was gone from the crater wall and surrounding ejecta blanket, having sublimated back into the atmosphere.
According to Livio Tornabene of the HiRISE team, “Repeat coverage actually serves a special purpose, such as detecting seasonal changes (frost deposition and sublimation) and temporal changes (dust devil tracks and avalanches.) These repeat images also give us a ‘sneak peek’ of future pictures to determine any differences.”
A year on Mars is 687 Earth days long, a month and a half shy of two Earth years. By this October the crater seen above will once again turn white with frost as southern winter sets in and the carbon dioxide in Mars’ atmosphere freezes down onto the colder, south-facing surfaces.
The HiRISE (High Resolution Imaging Science Experiment) instrument aboard MRO is managed by the University of Arizona and captures images of the surface of Mars in extraordinary detail. Its camera can resolve details down to about a meter in size from Mars orbit.
Read more at Discovery News
Jan 24, 2015
Fish Found in Extreme Spot Beneath Antarctic Ice Shelf
The swimmers are in one of the world's most extreme ecosystems, hidden beneath the Ross Ice Shelf, roughly 530 miles (850 kilometers) from the open ocean. "This is the closest we can get to something like Europa," Slawek Tulaczyk, a glaciologist at the University of California, Santa Cruz and a chief scientist on the drilling project, said, referring to Jupiter's icy moon.
This is the first time scientists have drilled through an ice shelf to its grounding line. These thick, floating tongues of ice are attached to glaciers or ice sheets, and the grounding line marks the transition from land to sea. Researchers with the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project punched through the ice with a custom hot-water drill on Jan. 8 and discovered the marine life on Jan. 16. The WISSARD drillers are crunching through the ice with the same setup used to reach Antarctica's subglacial Lake Whillans in 2013, when scientists grabbed the first evidence of microbial life from a lake under the ice sheet.
A remotely operated camera revealed the curious fish and amphipods, a type of crustacean that thrives in the ocean's harshest environments. For these translucent pink fish, which are about 8 inches (20 centimeters) long, this location is the farthest south they have ever been found, expedition scientists said. But the rocky seafloor was devoid of life. Tulaczyk said he thinks rocks that are constantly melting out of the ice sheet are responsible for the desolate conditions. Glacial ice can carry dust that is finer than flour or boulders bigger than buses.
"Forms of life that are sedentary will be stoned to death," he told Live Science from McMurdo Station in Antarctica. "The only things that can successfully explore food resources are things that can swim."
Yet the debris may also deliver much-needed nutrients — scarce in this dark, plankton-free world — in the form of ancient, carbon-rich marine sediments. For instance, ice cores brought up from the borehole contained shells called diatoms, the remains of microscopic marine creatures that lived and died before Antarctica froze over. "It could be we're looking at an old ecosystem eroding from the ice," Tulaczyk said.
The researchers also retrieved samples of the sediment and seawater, to investigate how Antarctica's ice shelves are responding to rising ocean temperatures. Models suggest that Antarctica's floating ice is melting from below as ocean temperatures increase. Because ice shelves hold back glaciers on land, as the shelves shrink, these flowing glaciers may speed up, boosting sea level rise by dropping ice into the ocean more quickly.
Read more at Discovery News
Melting Glaciers Pose a Carbon Menace
The organic carbon could be a temporary boon for tiny creatures at the bottom of the aquatic food chain that gobble the compound as food, but if this manna disappears because the glaciers have vanished, the overfed ocean ecosystems may collapse, the study authors warned.
"It could change the whole food web. We do not know how different ecological systems will react to a new influx of carbon," study co-author Robert Spencer, an assistant professor of oceanography at Florida State University, said in a statement.
Organic carbon is derived from plants or animals. The compound typically ends up in glaciers from microbes living in the ice, or from soot and other oil and gas byproducts.
Eran Hood, lead study author, and his colleagues estimated how much organic carbon is trapped in the world's glaciers and ice sheets, and how much will be released into the sea if melting continues its rapid pace. The supply of organic carbon in the world's waterways will increase by 50 percent in the next 35 years, according to the study, which was published Monday (Jan. 19) in the journal Nature Geoscience. That's about half the amount of organic carbon spilled into the sea each year by the Mississippi River, the researchers said.
"This research makes it clear that glaciers represent a substantial reservoir of organic carbon," said Hood, a scientist at the University of Alaska Southeast. "As a result, the loss of glacier mass worldwide, along with the corresponding release of carbon, will affect high-latitude marine ecosystems, particularly those surrounding the major ice sheets," he said. These high-latitude ecosystems are now receiving fairly limited inputs of organic carbon from land, Hood said in the statement.
Glaciers are shrinking nearly everywhere on Earth because of global warming, research studies have found. In West Antarctica, melt rates have tripled in the last decade, according to a study published in December 2014 in the journal Geophysical Research Letters. Ice loss in Greenland is five times faster now than in the early 1990s, scientists reported in November 2012 in the journal Science.
Read more at Discovery News
Jan 23, 2015
Red Seat Numbers Found on Rome's Colosseum
Similar to today’s stadium seating systems, the numbers — written according to the system used in ancient Rome, using letters of the Latin alphabet such as X, L, V, I — stood on the entrance gate arches, allowing an easier access to the seats.
First carved in the travertine stones, the numbers were then painted in red, so that people could easily see them from a distance.
There were 76 public numbered entrances, plus four special un-numbered gates. Two were reserved to the emperor, senators, magistrates, wealthy patricians, and the Vestal Virgins, priestesses responsible for maintaining the sacred fire within the Temple of Vesta. A gate was used for the dead — gladiators and wild beasts — while another was used by gladiators parading prior to the beginning of the combats.
The numbered entrance gates were the first step of a complex crowd control system which allowed tens of thousands of spectators to smoothly enter the amphitheater and quickly find their seat.
“The 50,000 spectators had a ticket that said which numbered gate arch they were supposed to enter. Inside the arena, there were other numbers to help people access their seats, which were assigned according to social class,” the monument director Rossella Rea said.
Although entrance was free for all, a strict plan regulated where one could seat on the amphitheater’s four levels of seating.
The best seat belonged to the emperor who sat in the first tier in the Emperor’s Box; the first level was also reserved to senator, magistrates and Vestal Virgins. On the second tier sat the upper class, on the third the ordinary Roman citizens, while women and the poor stood or sat on wooden benches in the fourth, top tier.
The traces of red painted numbers represent an “exceptional finding,” according to Rea.
“It was believed the paint would not have survived at all,” Rea said.
Deriving from iron oxide and clay minerals, the red color could be used without any binding material.
“As the color could withstand two-three years, it had to be periodically applied on the carved numbers,” restorer Cinzia Conti, said.
Read more at Disocovery News
World's Oldest Fire Has Been Burning for 5,500 Years
Ancient people actually used heat from rocky vents in the mountain to cook food and make tools. When an Australian settler found the mountain in 1828, he assumed that he’d discovered a volcano.
Today, the smoking mountain and its weird landscape have become a tourist attraction. Australian Traveler describes it: “Smell the acrid sulfur. Feel the heat from the roasting 350-degree surface. Watch the pale grey smoke waft into the air. Look for wedge-tailed eagles soaring on the thermal currents above. Imagine you’re at the beginning of time. Or perhaps the end.”
But as Atlas Obscura notes, there’s a downside: “It has also caused massive ecological damage to the area’s vegetation. The path of the fire has left a barren and rocky trail, with no traces of life.”
There actually are many of these underground fires across the planet, They’re a type of low-temperature, flameless combustion called a smoldering fire. They can be ignited by natural events such as lightning, though humans can set them accidentally or intentionally, by burning down forests. Multiple fires, for example, recently have occurred at a coal mine about 700 miles from Burning Mountain, including on in early 2014 that burned for 45 days.
The fires also are a source of greenhouse gas emissions, contributing billions of tons of carbon dioxide to the atmosphere each year, according to this 2012 blog post by New York Times environmental reporter Andrew Revkin.
From Discovery News
Mystery Galactic Bubble Traveling at Breakneck Speed
Scientists using the Hubble Space Telescope have clocked the speed of gas bubbles, known as Fermi bubbles, at a whopping 2 million mph (3.2 million km/h). The giant structures now extend 30,000 light-years above and below the plane of the Milky Way.
"A few million years ago, there was a very energetic event at the galactic center, and we're seeing a remnant," lead author Andrew Fox, of the Space Telescope Science Institute in Baltimore, Maryland, said at a press conference this month.
Fox presented the new Hubble observations at the 225th meeting of the American Astronomical Society in Seattle, revealing the , and agethe Fermi bubbles.
Piercing the Dust and Gas
Fermi bubbles were first discovered in 2010 by scientists using NASA’s Fermi Large Area Telescope, which revealed two lobes of material protruding from the center of the Milky Way. Since then, the features have been studied in the X-ray and radio wavelengths.
Fox and his team paired Hubble's Cosmic Origins Spectrograph with a distant quasar to measure the speed and composition of the billowing bubbles. A quasar is a very bright source of light generated by fast-moving particles near a supermassive black hole inside a distant galaxy. Light from the quasar is so strong that it outshines its parent galaxy. The scientists measured how the ultraviolet light from quasar PDS 456 shifted as it passed through the base of the northern bubble.
With the help of the bright quasar, the team determined that material on the near side of the northern lobe is streaming toward the sun, while material on the far side is zipping away. The material is gushing out of the Milky Way at approximately 900 to 1,000 kilometers per second, or about 2 million mph.
At this rate, the scientists calculated that the event that created the lobes occurred between 2.5 and 4 million years ago.
The gas studied by Fox's team reaches temperatures of 17,500 degrees Fahrenheit (9,700 degrees Celsius). Far cooler than the rest of the gas in the outflow, which reaches temperatures of around 18 million degrees F (10 million degrees C), the cooler gas may be interstellar gas from the Milky Way that has been swept up in the hot outflow, Fox said.
A Front-Row Seat
In other galaxies, starbursts drive outflows of gas that resemble Fermi bubbles, but these features are difficult to study from so far away. The Milky Way's Fermi bubbles provide an up-close look at these formations.
"We have a front-row seat. We can study the details of these structures," Fox said in a statement. "We can look at how big the bubbles are and how much of the sky they are covering."
PDS 456 is the first of 20 quasars whose light passes through the lobes. Studying the entire sample will allow astronomers to further narrow down the source of the event that generated the Fermi bubbles.
One potential cause of the outflows is rapid star formation at the galactic center. This birth of stars produced a series of supernovas that blew out a significant supply of gas. Another explanation involves the fall of a star or group of stars into the supermassive black hole at the center of the galaxy, causing superheated gas to be blasted into space.
Whatever the cause, the short-lived nature of the bubbles (when compared with the 13.2-billion-year-old age of the galaxy) suggests that they may be repeating phenomena, occurring frequently throughout the life of the Milky Way.
Read more at Discovery News
Black Hole Goes on Crash Diet and Dims its Quasar
“We’ve looked at hundreds of thousands of quasars at this point, and now we’ve found one that has switched off,” said astronomer C. Megan Urry, the study’s principal investigator. “This may tell us something about their lifetimes.”
Quasars are extremely bright galaxies driven by very active supermassive black holes in their cores. In the early universe, quasars dominated, so astronomers use these objects as a means of understanding how the early universe, and the galaxies it contained, formed.
By comparing observations of the same quasar a few years apart, Urry and her team found that the quasar dimmed by up to 7 orders of magnitude. This suggests something changed with the black hole driving the quasar — potentially a change in diet.
“This is like a dimmer switch,” said associate researcher Stephanie LaMassa. “The power source just went dim. Because the life cycle of a quasar is one of the big unknowns, catching one as it changes, within a human lifetime, is amazing.”
The quasar in question is embedded in the Stripe 82 region along the Celestial Equator and the researchers noticed the dimming event was accompanied by a weakening of the quasar’s broad emission lines. These emission lines, that can be detected in optical wavelengths, are generated by surrounding clouds of gas being ‘excited’ or energized by the radiation from the quasar itself. This radiation is generated by material falling into the black hole, so the weakening of the emission lines suggests the black hole in the quasar’s core has stopped consuming matter.
Read more at Discovery News
The Insect That Devours Its Mother From the Inside Out
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| A male strepsiptera mates with a female embedded in a wasp. He’s far more beautiful than her, for she’s a wingless, legless sack of eggs. But it’s what’s inside that counts, and what counts for this insect is…well lots of eggs I guess. |
But with all due respect to human mothers out there, their sacrifice is nothing compared to a momma strepsiptera. (Cue phone call from my own mother in 3…2…1…) This little parasite invades the bodies of all manner of insects, where she waits patiently as the young that fill her body consume her from the inside out. Eventually they erupt out of their sacrificial mother and emerge from the still very much alive host insect into the light of day—as many as a million of them in one particularly large species that parasitizes big grasshoppers. Yeah, you can go ahead and throw away that “Mother of the Year” mug now.
The 600 or so species of strepsiptera are some of the cleverest, most brutal parasites on Earth. Unlike a lot of parasites out there, they have no interest in keeping their host alive for very long: They use them, abuse them, and explode out of their bodies, leaving gaping wounds that haven’t the slightest chance of healing. And their life cycle must be one of the strangest and most wonderfully complex among all parasites.
Importantly, though, the one thing she does have are naughty bits: the oviduct. This she sticks out of the hole in her host’s exoskeleton and emits a pheromone, and the males come running. They’ll inseminate her right there on the host. You may read elsewhere that like bed bugs, strepsiptera are “traumatic inseminators,” with males stabbing into females and fertilizing the eggs through her flesh. That’s wrong, Kathirithamby stresses—insemination happens right in the exposed oviduct. So…lucky for the female, I guess?
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| This is what it looks like to have multiple female strepsiptera poking their oviducts out of your body. |
The larvae will emerge from their mother in batches as their poor host continues to crawl or fly around, spreading out little nightmares for any nearby ant or wasp hives. Yet getting there is no easy task for such tiny creatures. They have legs, so they’re definitely mobile, but instead of scrambling their way to a nest they’ll cling to an adult member of the colony and hitchhike. “They actually have to be carried to the nest by a foraging worker, an ant or a wasp or a bee,” said Kathirithamby. “And when they’re taken to the nest they get onto the egg or the larvae of the host.”
Weirder still, when the strepsiptera bores into the host larva, which can take two days, it never leaves a mark. It’s likely using some kind of enzyme that dissolves the host’s cuticle, but how it does so without leaving any visible signs of trauma is a mystery. Plus, once it gets in there and develops into a male, it’ll actually allow the host larva to grow into an adult, maturing along with it in a strange kind of Calvinist predestination—the host is doomed to a horrible death right from birth. That’s real goofy, because normally the insect’s immune response would form a capsule around any foreign objects in the body cavity. But Kathirithamby never sees that happening to the strepsiptera. They do seem to wrap themselves in the inner layer of the exoskeleton, called the endocuticle, which could help them remain unnoticed.
So the male strepsiptera grows big and fat in its own little vehicle. “They need that because they want the host to be alive and moving,” and therefore be better able to disperse in the ecosystem, Kathirithamby said. And “in spite of almost the whole abdominal segment being occupied by the strepsiptera, the host is still able to move around.”
The females typically go about development a little bit differently. While the larvae that will eventually become males hitchhike to their hosts, the larvae that will become their sisters stick around closer to their mother. Ideally, her host—perhaps a cricket—would have recently had its own nymphs, which the strepsiptera larvae climb into, develop into females, and begin the whole horrifying process anew.
Read more at Wired Science
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