Month: November 2018

Flash Flood Swamps Sydney, Australia, Killing Three During ‘Epic’ Storm

At least three people died following a deluge that brought chaos to Australia’s largest city Wednesday.

The downpours during Sydney’s morning commute shut down roads and snarled traffic, while strong winds knocked out power to thousands.

News.com.au described it as “a storm of epic proportions” and reported that officials conducted more than a dozen high-water rescues resulting from stranded vehicles.

Sydney received 3.3 inches (84.6 millimeters) of rain in less than two hours — more than its typical output for the entire month of November, the Sydney Morning Herald reported. Several locations measured upward of 4 inches (100 millimeters) of rain.

It was Sydney’s wettest November day since 1984, according to Australia’s Bureau of Meteorology.

While flooding rain was the most widespread hazard, reports emerged of damaging winds. During the storm, an office building’s windows were blown out by a “mini cyclone” according to ABC News Australia.

The storminess was spurred by a strong zone of low pressure, both at the surface and higher altitudes. The clockwise flow around the pressure system drew extremely moist air off the South Pacific Ocean into Sydney, fueling the downpours.

While Sydney was soaked by rain caused by the low-pressure system, a dome of high pressure over the northern part of Australia caused extreme heat, especially over northern Queensland, where records were set.

“Temperatures have been 5 to 10 degrees Celsius above average and some records have not just been broken, they have been smashed,” reported ABC News Australia.

The extreme heat intensified brushfires in the region. About 200 are burning in Queensland, and for the first time, a catastrophic fire warning was issued for parts of the region.

Magnitude 6.3 Earthquake Hits Western Iran; Hundreds Injured

At least 361 people were injured in a 6.3 magnitude earthquake that struck near the border with Iraq, Iran’s semi-official Fars News Agency reported.

Sunday’s quake in the western part of Iran was about 6 miles deep, the US Geological Survey said.

Buildings were damaged in various rural areas in SarPol-e zahab and Qasr-e-Shirin, causing walls of some homes to fall, says Fars.

Panicked residents in some affected areas ran into the streets, Iran’s state-run IRNA news reported.

People arrive for medical treatment at a hospital in Sulaymaniyah, Iraq.

Tremors could be felt as far away as Baghdad. Social media users in the Iraqi capital uploaded videos of furniture moving and chandeliers swinging.

The quake was about 12 miles from Sarpol Zahab, Kermanshah province, the USGS said.

Iran sits on a major fault line between the Arabian and Eurasian plates and has had many earthquakes.

Climate Of Small Star TRAPPIST 1’s Seven Intriguing Worlds

Not all stars are like the Sun, so not all planetary systems can be studied with the same expectations. New research from a University of Washington-led team of astronomers gives updated climate models for the seven planets around the star TRAPPIST-1.

The work also could help astronomers more effectively study planets around stars unlike our Sun, and better use the limited, expensive resources of the James Webb Space Telescope, now expected to launch in 2021.

“We are modeling unfamiliar atmospheres, not just assuming that the things we see in the solar system will look the same way around another star,” said Andrew Lincowski, UW doctoral student and lead author of a paper published Nov. 1 in Astrophysical Journal. “We conducted this research to show what these different types of atmospheres could look like.”

The team found, briefly put, that due to an extremely hot, bright early stellar phase, all seven of the star’s worlds may have evolved like Venus, with any early oceans they may have had evaporating and leaving dense, uninhabitable atmospheres. However, one planet, TRAPPIST-1 e, could be an Earth-like ocean world worth further study, as previous research also has indicated.

TRAPPIST-1, 39 light-years or about 235 trillion miles away, is about as small as a star can be and still be a star. A relatively cool “M dwarf” star — the most common type in the universe — it has about 9 percent the mass of the Sun and about 12 percent its radius. TRAPPIST-1 has a radius only a little bigger than the planet Jupiter, though it is much greater in mass.

All seven of TRAPPIST-1’s planets are about the size of Earth and three of them — planets labeled e, f and g — are believed to be in its habitable zone, that swath of space around a star where a rocky planet could have liquid water on its surface, thus giving life a chance. TRAPPIST-1 d rides the inner edge of the habitable zone, while farther out, TRAPPIST-1 h, orbits just past that zone’s outer edge.

“This is a whole sequence of planets that can give us insight into the evolution of planets, in particular around a star that’s very different from ours, with different light coming off of it,” said Lincowski. “It’s just a gold mine.”

Previous papers have modeled TRAPPIST-1 worlds, Lincowski said, but he and this research team “tried to do the most rigorous physical modeling that we could in terms of radiation and chemistry — trying to get the physics and chemistry as right as possible.”

The team’s radiation and chemistry models create spectral, or wavelength, signatures for each possible atmospheric gas, enabling observers to better predict where to look for such gases in exoplanet atmospheres. Lincowski said when traces of gases are actually detected by the Webb telescope, or others, some day, “astronomers will use the observed bumps and wiggles in the spectra to infer which gases are present — and compare that to work like ours to say something about the planet’s composition, environment and perhaps its evolutionary history.”

He said people are used to thinking about the habitability of a planet around stars similar to the Sun. “But M dwarf stars are very different, so you really have to think about the chemical effects on the atmosphere(s) and how that chemistry affects the climate.”

Combining terrestrial climate modeling with photo-chemistry models, the researchers simulated environmental states for each of TRAPPIST-1’s worlds.

Their modeling indicates that:

  • TRAPPIST-1 b, the closest to the star, is a blazing world too hot even for clouds of sulfuric acid, as on Venus, to form.
  • Planets c and d receive slightly more energy from their star than Venus and Earth do from the Sun and could be Venus-like, with a dense, uninhabitable atmosphere.
  • TRAPPIST-1 e is the most likely of the seven to host liquid water on a temperate surface, and would be an excellent choice for further study with habitability in mind.
  • The outer planets f, g and h could be Venus-like or could be frozen, depending on how much water formed on the planet during its evolution.

Lincowski said that in actuality, any or all of TRAPPIST-1’s planets could be Venus-like, with any water or oceans long burned away. He explained that when water evaporates from a planet’s surface, ultraviolet light from the star breaks apart the water molecules, releasing hydrogen, which is the lightest element and can escape a planet’s gravity. This could leave behind a lot of oxygen, which could remain in the atmosphere and irreversibly remove water from the planet. Such a planet may have a thick oxygen atmosphere — but not one generated by life, and different from anything yet observed.

“This may be possible if these planets had more water initially than Earth, Venus or Mars,” he said. “If planet TRAPPIST-1 e did not lose all of its water during this phase, today it could be a water world, completely covered by a global ocean. In this case, it could have a climate similar to Earth.”

Lincowski said this research was done more with an eye on climate evolution than to judge the planets’ habitability. He plans future research focusing more directly on modeling water planets and their chances for life.

“Before we knew of this planetary system, estimates for the detectability of atmospheres for Earth-sized planets were looking much more difficult,” said co-author Jacob Lustig-Yaeger, a UW astronomy doctoral student.

The star being so small, he said, will make the signatures of gases (like carbon dioxide) in the planet’s atmospheres more pronounced in telescope data.

“Our work informs the scientific community of what we might expect to see for the TRAPPIST-1 planets with the upcoming James Webb Space Telescope.”

Lincowski’s other UW co-author is Victoria Meadows, professor of astronomy and director of the UW’s Astrobiology Program. Meadows is also principal investigator for the NASA Astrobiology Institute’s Virtual Planetary Laboratory, based at the UW. All of the authors were affiliates of that research laboratory.

“The processes that shape the evolution of a terrestrial planet are critical to whether or not it can be habitable, as well as our ability to interpret possible signs of life,” Meadows said. “This paper suggests that we may soon be able to search for potentially detectable signs of these processes on alien worlds.”

TRAPPIST-1, in the Aquarius constellation, is named after the ground-based Transiting Planets and Planetesimals Small Telescope, the facility that first found evidence of planets around it in 2015.

Super Grand Solar Minimum Hypothesis Considered

Professor Valentina Zharkova gave a presentation of her Climate and the Solar Magnetic Field hypothesis at the Global Warming Policy Foundation in October, 2018.

Zharkova models solar sunspot and magnetic activity. Her models have run at a 93% accuracy and her findings suggest a Super Grand Solar Minimum could begin in 2020.

A Super Grand Solar Minimum would have four magnetic fields out of phase. There was about 40-60 years of cold weather 350 years ago. This was a Maunder Minimum of lower solar activity. The historical cold weather had two magnetic fields out of phase.

Zharkova is predicting a cooling effect that is 2.5 to 4 times larger than the Maunder minimum. Zharkova’s analysis shows an 8 watts per square meter decrease in TSI (Total Solar Irradiance). A 2015 Nature study looked at 2 watts per square meter decrease causing a 0.13-degree celsius effect. A four times larger effect would be 0.5-degree celsius.

Zharkova believes the warming models are including the warming effect of increased solar activity. If she is correct there would be cooling and the warming models would be wrong.

Numerous studies have identified links between past climate and solar variability. During the Maunder Minimum (1645-1715), very few sunspots were seen despite regular observations. If the past relationships between TSI and ultraviolet irradiance and sunspots are the same as are observed for modern solar variability, then a decline in both TSI and ultraviolet for this period can be assumed.

The Maunder Minimum coincided with more severe winters in the UK and continental Europe and many reconstructions suggest atmospheric conditions were broadly comparable with the regional effects on European atmospheric circulation found here. Some modeling studies also support the idea that similar regional cooling and circulation changes occurred during this period.

Study Reveals One Of Universe’s Secret Ingredients For Life

A new study led by ANU has investigated the nature of a cosmic phenomenon that slows down star formation, which helps to ensure the universe is a place where life can emerge.

Lead researcher Dr. Roland Crocker from the ANU Research School of Astronomy and Astrophysics said the research team studied a particular way stars provide a counter-pressure to gravity that slows down the star-formation process.

“If star formation happened rapidly, all stars would be bound together in massive clusters, where the intense radiation and supernova explosions would likely sterilise all the planetary systems, preventing the emergence of life,” he said.

“The conditions in these massive star clusters would possibly even prevent planets from forming in the first place.”

The study found that ultraviolet and optical light from young and massive stars spreads out into the gas from which the stars have recently formed and hits cosmic dust, which then scatters infrared light that acts effectively as a kind of pressure that pushes against gravity.

“The phenomenon we studied occurs in galaxies and star clusters where there’s a lot of dusty gas that is forming heaps of stars relatively quickly,” Dr. Crocker said.

“In galaxies forming stars more slowly—such as the Milky Way—other processes are slowing things down. The Milky Way forms two new stars every year, on average.”

Other galaxies in our vicinity and elsewhere in the universe continuously form new stars at a relatively slow and steady rate.

Dr. Crocker said the study’s mathematical findings indicated the phenomenon set an upper limit on how quickly stars can form in a galaxy or giant gas cloud.

“This and other forms of feedback help to keep the universe alive and vibrant,” he said.

“We are investigating other ways stars might feed back into their environment to slow down the overall rate of star formation.”

Professor Mark Krumholz and Dr Dougal Mackey from the ANU Research School of Astronomy and Astrophysics, Professor Todd Thompson from Ohio State University in the United States and Associate Professor Holger Baumgardt at the University of Queensland contributed to the study, which was published in the Monthly Notices of the Royal Astronomical Society.

What Did Birds And Insects Do During The 2017 Solar Eclipse?

In August of 2017, millions peered through protective eyewear at the solar eclipse — the first total eclipse visible in the continental United States in nearly 40 years. During the event, researchers from the Cornell Lab of Ornithology and the University of Oxford watched radar to observe the behavior of birds and insects. Their findings have just been published in Biology Letters.

Using data from 143 weather radar sites in the continental U.S. — 8 of which covered areas of eclipse totality — researchers were able to “see” the behavior of wildlife during the eclipse, which produced conditions similar to sunset.

“It’s not so easy to observe what wildlife are doing during an eclipse. It’s dark,” quips Cecilia Nilsson, lead author and Edward W. Rose Postdoctoral fellow at the Cornell Lab. “But using radar data we could actually monitor behavior on a very large scale. Overall, we saw a decrease in normal daytime activity.”

Nilsson and her team looked at wildlife behavior in the air on radar two days before and after the eclipse and compared this activity with the behavior observed during the eclipse. They found that although typical daytime activity in the air decreased — behavior such as foraging for food — typical nighttime activity did not increase — behavior such as high-flying migration.

This result was surprising. Instead of triggering night-time behavior, the sunset-like sky produced by the eclipse stifled activity. But Nilsson noted that insect and bird behavior during the increasing darkness could have been due to a general sense of confusion.

“They might be interpreting the eclipse as a storm. That could be the closest analogy to them,” says Nilsson. “It’s getting darker, it’s getting colder, similar to a big thunderstorm on the way in.”

At the eight sites that were within the path of totality, where there was complete darkness for a few minutes, something interesting occurred. “At some of these sites we saw a sudden burst of activity during the moments of totality. This could be insects or birds flushing into the air as a reaction to the sudden darkness,” says Nilsson.

The eclipse of August 2017 provided a unique opportunity to study behavior patterns. Many bird species were in the beginning stages of their fall migration, and recent developments in computing power, big data processing, and machine learning set the stage for the completion of a much-needed continental-scale analysis.

The next solar eclipse over the continental U.S. is in the spring — April 8, 2024 — and Nilsson is looking forward to inspecting eclipse behavior among birds and insects once again.

“It could be really interesting to compare autumn activity to spring, she notes. “Hopefully we can get more information about what happens at sites in the path of totality.”

Massive Impact Crater From A Kilometer-Wide Iron Meteorite Discovered In Greenland

An international team lead by researchers from the Centre for GeoGenetics at the Natural History Museum of Denmark, University of Copenhagen have discovered a 31-km wide meteorite impact crater buried beneath the ice-sheet in the northern Greenland. This is the first time that a crater of any size has been found under one of Earth’s continental ice sheets. The researchers worked for last three years to verify their discovery, initially made in the 2015. The research is described in a new study just published in the internationally recognized journal Science Advances.

The crater measures more than 31 km in diameter, corresponding to an area bigger than Paris, and placing it among the 25 largest impact craters on Earth. The crater formed when a kilometre-wide iron meteorite smashed into northern Greenland, but has since been hidden under nearly a kilometre of ice.

“The crater is exceptionally well-preserved, and that is surprising, because glacier ice is an incredibly efficient erosive agent that would have quickly removed traces of the impact. But that means the crater must be rather young from a geological perspective. So far, it has not been possible to date the crater directly, but its condition strongly suggests that it formed after ice began to cover Greenland, so younger than 3 million years old and possibly as recently as 12,000 years ago — toward the end of the last ice age” says Professor Kurt H. Kjær from the Center for GeoGenetics at the Natural History Museum of Denmark.

Giant circular depression

The crater was first discovered in July 2015 as the researchers inspected a new map of the topography beneath Greenland’s ice-sheet. They noticed an enormous, but previously undetected circular depression under Hiawatha Glacier, sitting at the very edge of the ice sheet in northern Greenland.

“We immediately knew this was something special but at the same time it became clear that it would be difficult to confirm the origin of the depression,” says Professor Kjær.

In the courtyard at the Geological Museum in Copenhagen just outside the windows of the Center for GeoGenetics sits a 20-tonne iron meteorite found in North Greenland not far from the Hiawatha Glacier.

“It was therefore not such a leap to infer that the depression could be a previously undescribed meterorite crater, but initially we lacked the evidence,” reflects Associate Professor Nicolaj K. Larsen from Aarhus University.

The crucial evidence

Their suspicion that the giant depression was a meteorite crater was reinforced when the team sent a German research plane from the Alfred Wegener Institute to fly over the Hiawatha Glacier and map the crater and the overlying ice with a new powerful ice radar. Joseph MacGregor, a glaciologist at NASA, who participated in the study and is an expert in ice radar measurements adds:

“Previous radar measurements of Hiawatha Glacier were part of a long-term NASA effort to map Greenland’s changing ice cover. What we really needed to test our hypothesis was a dense and focused radar survey there. Our colleagues at the Alfred Wegener Institute and University of Kansas did exactly that with a next-generation radar system that exceeded all expectations and imaged the depression in stunning detail. A distinctly circular rim, central uplift, disturbed and undisturbed ice layering, and basal debris. It’s all there.”

In the summers of 2016 and 2017, the research team returned to the site to map tectonic structures in the rock near the foot of the glacier and collect samples of sediments washed out from the depression through a meltwater channel.

“Some of the quartz sand washed from the crater had planar deformation features indicative of a violent impact, and this is conclusive evidence that the depression beneath the Hiawatha Glacier is a meteorite crater, ” says Professor Larsen.

The consequences of the impact on the Earth’s climate and life

Earlier studies have shown that large impacts can profoundly affect Earth’s climate, with major consequences for life on Earth at the time. It is therefore very resonable to ask when and how and this meteorite impact at the Hiawatha Glacier affected the planet.

“The next step in the investigation will be to confidently date the impact. This will be a challenge, because it will probably require recovering material that melted during the impact from the bottom of the structure, but this is crucial if we are to understand how the Hiawatha impact affected life on Earth,” concludes Professor Kjær.