Scientists discover new way to measure turbulence of large planets and exoplanets

Scientists discover new way to measure turbulence of large plan
The planet Jupiter. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt/Sean Doran

The swirls, eddies, and wavy bands of Jupiter and Saturn may remind us of a soothing, starry, starry night—but they reveal these two gas giants to be stormy, turbulent places. The turbulence produces energy cascades, a non-linear transfer of energy between different scales of motion. These are as fundamental to understanding planetary dynamics as the cardiovascular system is to understanding the human body.


But scientists haven’t had a reliable way to quantify planetary turbulence—until now.

A global team led by scientists at the University of Rome, which included Boris Galperin, Ph.D., a professor at the USF College of Marine Science, described the advance in Geophysical Research Letters. The results show that the rate of the turbulence energy transfer—until now a black box of mystery—can be calculated relatively easily from a variable related to the planetary rotation and known as potential vorticity (PV).

The method was first developed by Galperin and his graduate student, Jesse Hoemann, and tested in the experiments conducted at the University of Rome during Jesse’s visit there. The method was confirmed using real velocity data extracted from images of Jupiter’s clouds movement captured by the 20-year-long Cassini mission, additional laboratory results performed in a rotating tank at the University of Rome in Italy, and computer simulations for Saturn.

Based on the calculations of PV, the team showed for the first time that the rate of the energy transfer in Jupiter’s atmosphere is four times greater than that in Saturn’s.

Scientists discover new way to measure turbulence of large plan
Banded flows on Jupiter and Saturn (from Cassini), and in a rotating tank experiment by Cabanes et al. (2020), showing non-monotonic PV profiles. Credit: University of South Florida

“Now you can see why I was really excited about this work,” said Galperin, who developed the original idea for the experiments several years ago.

Since the laws of turbulence, as any fundamental physical laws, are universal, the method can now be applied to other natural environments such as the ocean, Galperin said. Eddies in Earth’s ocean that look like the swirls on Jupiter, for example, come in different strengths, sizes, and lifetimes, and are critical to understanding Earth’s balances of energy, heat, salt, carbon dioxide, and more.

“This is the first estimate of Saturn’s turbulent power from observations, and this study paves the way for future data analysis in other planetary atmospheres,” said lead author Simon Cabanes, Ph.D., a post doc at the Department of Civil and Environmental Engineering (DICEA) of the University of Rome La Sapienza.


Weather on Jupiter and Saturn may be driven by different forces than on Earth


More information:
Simon Cabanes et al. Revealing the intensity of turbulent energy transfer in planetary atmospheres, Geophysical Research Letters (2020). DOI: 10.1029/2020GL088685
Provided by
University of South Florida

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Scientists discover new way to measure turbulence of large planets and exoplanets (2020, December 2)
retrieved 2 December 2020
from https://phys.org/news/2020-12-scientists-turbulence-large-planets-exoplanets.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no

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National Solar Observatory predicts a large sunspot for Thanksgiving

NSF's National Solar observatory predicts a large sunspot for Thanksgiving
NSF-funded GONG network uses sound waves to measure changes inside the Sun, indicative of sunspots on the side pointing away from Earth. Artists impression of the Sun’s internal acoustic waves with no sunspots (top panel) and with sunspots (bottom panel). The sunspot’s magnetic field perturbs the acoustic waves, changing their signature. Measuring this change allows scientists to predict sunspots on the far side of the sun. Credit: NSO/AURA/NSF/C.Raftery

On November 18 scientists from the US National Science Foundation’s National Solar Observatory predicted the arrival of a large sunspot just in time for Thanksgiving. Using a special technique called helioseismology, the team has been ‘listening’ to changing sound waves from the Sun’s interior which beckon the arrival of a large sunspot. Recent changes in these sound waves pointed to the imminent appearance of new sunspots which we can now see from Earth near the eastern solar limb.


“We measured a change in acoustic signals on the far-side of the Sun”, explains Dr. Alexei Pevtsov, Associate Director for NSO’s Integrated Synoptic Program, the program responsible for the prediction. “We can use this technique to identify what is happening on the side of the Sun that faces away from Earth days before we can catch a glimpse from here. Having up to five days lead time on the presence of active sun spots is extremely valuable to our technology-heavy society.”

Solar storms often originate in sunspot regions, especially if the sunspot is large and complicated. The more tangled the magnetic field, the more likely it will result in large solar flares and coronal mass ejections which in turn can result in space weather effects at Earth. These include impacts on communications, GPS and possibly electrical grid systems. NSO provides 24/7 ‘eyes on the Sun’ through the NSF-funded GONG network. The network consists of six monitoring stations positioned across the globe, observing the Sun’s magnetic field and other features all day every day.

10-minute average magnetogram (zero-point corrected). Credit: NSO/AURA/NSF

“The ability of GONG to identify and track active regions emergent on the far side of the Sun has important implications for future space weather predictive capabilities” said Dr. Carrie Black, Program Director at NSF. “GONG continues to be a valuable tool for both fundamental science research and operations.”

Dr. Kiran Jain, the scientist who is leading the far side prediction at NSO, describes the evolution of the sunspot as “the strongest far-side signal we have had this solar cycle. We first noticed the signal in our far-side images on November 14, 2020,” she continues. “It was inconspicuous at first but grew quickly, breaking detection thresholds just one day later. Since we are in the very early phase of the new solar cycle, the signal from this large spot stands out clearly.”

The far-side maps use ‘helioseismology,’ a technique developed by NSO scientists in the 1990s, to detect how sound waves interact with the Sun’s interior structure, especially magnetic fields.

NSF's National Solar observatory predicts a large sunspot for Thanksgiving
A large sunspot, predicted by NSO scientists, is rotating onto the face of the
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Most Effective Management Styles for Large Teams

Is your team growing larger by the day? Are you hiring more people than you had expected thanks to the massive growth of your business? Is your company expanding and bringing in new talent? This is great news! But now, as you face the success of your growing business, you have to manage a larger team.

Whether you’ve been in this position before or this is your first time, managing a large team can be daunting. Large teams come with their own unique and diverse challenges as you are now dealing with more personalities and more potential disagreements and idiosyncrasies. And though there are lots of proven management styles, not all of them are tailored for large teams.

But fear not! We devised a list of the most effective styles you can use to manage a large, growing team successfully.

What Is Management Style?

Photo by Campaign Creators on Unsplash

Before settling on what management style will best suit your large team, you should understand what this term means. There are different textbook explanations, but we settled on the one that can be translated across different organizations.

Management style deals with the relationship a manager should have with their team. It also defines a manager’s planning and organizational ethic, delegation tactics, as well as organizational and communication skills. A good manager must use a management style that works for them and their team.

Transactional Management

As the name suggests, this style of management is incentive-based. It is founded on the theory that you can motivate team members by attaching preset rewards to certain, known goals.

Pros

  • Increased motivation and productivity within teams.
  • Reduced need for micromanagement.
  • Greater performance as individuals or teams work together to hit targets.

Cons

  • Can lead to unhealthy competition between team members.
  • It can be expensive to maintain if the reward is not budgeted well.
  • Effective only for short periods, e.g., quarterly or bi-monthly.

Charismatic Management

Photo by You X Ventures on Unsplash

This style of management is also called a visionary or inspirational type of management. Your main role in this style is to convey the company’s goals, objectives, and vision to your team and trust them to carry it through. Your team will follow through on their goals and targets by following your charismatic leadership.

Pros

  • It helps a team remain focused and united in goal setting and achievement.
  • It helps create unity in a large team that is divided or has problems agreeing.
  • Reduces the need for micromanagement.

Cons

  • You have to have an outgoing nature. This management style will not work if you are reserved.
  • If you have a team that is not professional or requires close supervision, this style will also not work.

Transformational Management

In transformational management, you lead your team by pushing them out of their comfort zone and raising your expectations. The main focus is on growth, and you will work alongside your team to consistently keep them on their toes.

Pros

  • You encourage both creativity and staff
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Large, deep Antarctic ozone hole to persist into November

Large, deep Antarctic ozone hole to persist into NovemberOctober 30, 2020
Credit: NOAA Headquarters

Persistent cold temperatures and strong circumpolar winds supported the formation of a large and deep Antarctic ozone hole that will persist into November, NOAA and NASA scientists reported today.


The ozone hole reached its peak size at about 9.6 million square miles (or 24.8 million square kilometers), roughly three times the area of the continental United States, on September 20. Observations revealed the nearly complete elimination of ozone in a four-mile-high column of the stratosphere over the South Pole.

This year will go down as having the 12th-largest ozone hole in 40 years of satellite records, with the 14th-lowest ozone readings in 33 years of balloon-borne instrumental measurements, the scientists said. Declining levels of ozone-depleting chemicals controlled by the Montreal Protocol prevented the hole from being as large as it would have been 20 years ago.

“We have a long way to go, but that improvement made a big difference this year,” said Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center. “The hole would have been about a million square miles larger if there was still as much chlorine in the stratosphere as there was in 2000.”

What is ozone and why does it matter?

Ozone, composed of three oxygen atoms, is highly reactive with other chemicals. In the stratosphere, roughly 7 to 25 miles above Earth’s surface, the ozone layer acts like sunscreen, shielding the planet from ultraviolet radiation. Closer to Earth’s surface, ozone created by photochemical reactions between the sun and pollution from vehicle emissions and other sources can form harmful smog in the lower atmosphere.

This year represented a dramatic turnabout from 2019, when warm temperatures in the stratosphere and a weak polar vortex limited ozone hole growth to 6.3 million square miles (16. 4 million square kilometers), the smallest on record.

Large, deep Antarctic ozone hole to persist into NovemberOctober 30, 2020
This visualization shows the size of the 2020 ozone hole over Antarctica as it reached its maximum extent of 9.6 million square miles between September 14 and September 20. Credit: NOAA Climate.gov, based on NWS CPC data

How do NOAA and NASA measure ozone?

NASA and NOAA monitor the ozone hole by using three complementary instrumental methods.

Satellites, including NASA’s Aura satellite and NASA-NOAA Suomi National Polar-orbiting Partnership satellite, measure the size of the ozone hole from space. The Aura satellite’s Microwave Limb Sounder estimates levels of ozone-destroying chlorine.

NOAA staff at the South Pole also launch weather balloons carrying ozone-measuring sondes that directly sample ozone levels vertically through the atmosphere. Once sunshine returns after the long polar night, with a ground-based instrument called a Dobson spectrophotometer.

Bryan Johnson, a scientist with NOAA’s Global Monitoring Lab, said ozonesonde measurements recorded a low daily value of 104 Dobson units on October 1. In late October, ozone levels between 8 and 13 miles in altitude were still “about as close to zero as we can measure.” A Dobson unit is the standard measurement for the total amount of ozone in the atmosphere above a point on Earth’s surface.

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The Very Large Telescope Spots a Spooky Skull Nebula

Just in time for Halloween, the European Southern Observatory (ESO) has released an image of a spooky structure known as the Skull Nebula. This nebula, situated deep in the belly of The Whale constellation (Cetus), is located around 1,600 light-years from Earth. But the nebula is not only thematically appropriate for this weekend, but it is also notable for its unusual configuration of two closely bound stars being orbited by a third more distant star.

Captured in astounding detail by ESO’s Very Large Telescope (VLT), the eerie Skull Nebula is showcased in this new image in beautiful pink and red tones. This planetary nebula, also known as NGC 246, is the first known to be associated with a pair of closely bound stars orbited by a third outer star.
Captured in astounding detail by ESO’s Very Large Telescope (VLT), the eerie Skull Nebula is showcased in this new image in beautiful pink and red tones. This planetary nebula, also known as NGC 246, is the first known to be associated with a pair of closely bound stars orbited by a third outer star. ESO

A planetary nebula like this is formed when a star approaches the end of its life and throws off its outer layers in a dramatic explosion. These outer layers form a bubble around the star, which is reduced to a white dwarf. In the case of the Skull Nebula, the white dwarf remains at the very center of the nebula, where it also orbits around a companion star, a red dwarf. You can’t see the red dwarf in the image as it is too faint, but it is relatively close to the white dwarf, at just 500 times the distance between Earth and the sun.

In addition to this pair of stars at the heart of the nebula, there is also a third star orbiting the pair at a distance of around 1,900 times the distance between the Earth and the sun. This makes the Skull Nebula the first planetary nebula discovered with a hierarchical triple stellar system at its heart.

The image was captured using the ESO’s Very Large Telescope, which is located in the Atacama Desert in Chile. It was taken using the telescope’s FORS 2 instrument, the FOcal Reducer and low dispersion Spectrograph.

“This new image of the Skull Nebula intentionally captures light emitted in some narrow ranges of wavelengths — those associated with hydrogen and oxygen gas,” ESO writes. “Observations of light emitted by particular elements help reveal a wealth of information about an object’s chemical and structural compositions. This new image of the Skull Nebula highlights where NGC 246 is rich or poor in hydrogen (shown in red) and oxygen (depicted in light blue).”

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Large tides may have been a key factor in the evolution of bony fish and tetrapods

Large tides may have been a key factor in the evolution of bony fish and tetrapods
Credit: The Field Museum of Natural History in Chicago

Pioneering research, published in Proceedings of the Royal Society A, into ancient tides during the Late Silurian—Devonian periods (420 million years ago—380 million years ago), suggests that large tides may have been a key environmental factor in the evolution of bony fish and early tetrapods, the first vertebrate land-dwellers.


The study is a detailed development of a theory previously published in the same journal, which suggested that the Moon’s particular mass and orbital location are optimized for creating large tidal ranges and isolating tidal pools, which in turn may have been a biological impetus for the development of limbs in fish stranded between very high tides.

First detailed numerical simulations

Researchers from Bangor University and Oxford University in the UK and Uppsala University in Sweden have been the first to produce detailed numerical simulations to address the question of whether large tides occurred during this critical period. These are also the first calculations to relate tidal hydrodynamics to an evolutionary biological event.

The numerical simulations were computed using palaeogeographic reconstructions of the Earth’s continents in an established state-of-the-art numerical tidal model. The simulation results show tidal variations in excess of four meters occurring around an area known as the South China block, which is the site of the origin and diversification of the earliest bony fish group, and has produced the earliest important fossils for this group. Geological evidence also points to tidal environments being closely associated with this class of fossils.

These first-of-their-kind results stimulate the need for more detailed tidal simulations of the ancient Earth. In particular, the researchers believe that the method used in this study can be used with a variety of palaeogeographic reconstructions at other time periods, to explore the tidal influence upon the origin and diversification of other early vertebrates, and perhaps the opposite as well: what might have been the role of tides in precipitating marine extinction events?


Jupiter’s moons could be warming each other


More information:
H. M. Byrne et al. A key environmental driver of osteichthyan evolution and the fish-tetrapod transition?, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2020). DOI: 10.1098/rspa.2020.0355
Provided by
University of Oxford

Citation:
Large tides may have been a key factor in the evolution of bony fish and tetrapods (2020, October 23)
retrieved 23 October 2020
from https://phys.org/news/2020-10-large-tides-key-factor-evolution.html

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Large Belgian university moves online again because of virus

BRUSSELS (AP) — One of Belgium’s main universities is moving to online education whenever possible and another is getting ready to follow suit because the coronavirus is continuing to soar across the nation that hosts the European Union headquarters.

Ghent University said the measure will begin Oct. 26 and the Dutch-speaking Free University of Brussels said it already prepared its staff and facilities to do likewise if necessary.

Belgium has said keeping its schools open was a key goal while to took other measure to counter the resurgence of the virus, but the main indicators are spiking at a sustained rate. So far, schools for students up to age 18 have escaped such drastic measures.


Over the week ending Oct. 11, new virus cases increased by 101% compared to the previous week and stood at 5,421. Belgium’s confirmed cases stood at 181,511 in the nation of 11.5 million people. The cases per 100,000 residents stood at 494, one of the highest in Europe.

It was enough for Ghent University, 60 kilometers (40 miles) west of Brussels, to take action and move to distance learning wherever it can. Lab teaching will be limited as much as possible.

One of the hardest-hit countries in Europe, Belgium last week introduced a series of restrictive measures aimed at slowing the pace of new infections that include local curfews, closing Brussels bars for at least a month and limiting indoor sports activities.

So far, the virus has killed 10,278 people in Belgium.

___

Follow AP news coverage of the coronavirus pandemic at http://apnews.com/VirusOutbreak and https://apnews.com/UnderstandingtheOutbreak

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2 large pieces of space junk have a ‘high risk’ of colliding

Two pieces of space junk, each about the weight of a compact car, are predicted to have a close encounter tonight some 620 miles above Earth. If they collide—and experts are putting the odds at greater than 10 percent—the smashup would create a cloud of debris that could jeopardize other satellites and spacecraft for decades.

The two objects are a defunct Russian navigation satellite launched in 1989 and a spent Chinese rocket part from a 2009 launch. Calculations by LeoLabs, a California-based company that tracks objects in low-Earth orbit, peg the moment of closest approach at 8:56 p.m. ET on October 15 above the southern Atlantic Ocean, just off the coast of Antarctica. The combined mass of the two objects is about 6,000 pounds, and their relative speed will be about 33,000 miles an hour, according to LeoLabs.

If the two objects don’t collide it will be another near-miss—one of a handful that happen every year—with the objects likely getting within about 40 feet of one another, by LeoLabs’ estimate. These two pieces of space junk are particularly large, however. The third stage of the rocket—the upper part that separates from lower stages and flies all the way into orbit—measures about 25 feet long. The satellite measures 16 feet long, with a boom used to stabilize the spacecraft extending almost 56 feet.

If they smash head-on, it would create two big clouds “that will spread out into a shell of debris around the Earth,” says LeoLabs CEO Daniel Ceperley. And because of the objects’ altitude, the debris would “be up there for centuries” before burning up in the atmosphere.

The long boom on the Russian satellite also raises the possibility of a glancing blow rather than a head-on collision. The results of an impact like that are harder to predict, says Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

Still, “there’s no threat to the Earth,” McDowell says. “These will be small debris pieces that will completely burn up in the atmosphere. Most of them aren’t going to come down for decades anyway, and when they do, they’ll completely burn up.”

The International Space Station (ISS) is also in no immediate danger. The ISS orbits at an altitude of about 250 miles, “safely below” the altitude where the debris would potentially be unleashed. There would “probably not be a big risk to the ISS in the near term,” McDowell says. But over many years, bits of debris could drift down to the space station’s orbit. “It would increase the amount of ‘rain’ failing on it,” he says.

The ISS has had to maneuver out of the way of space debris to avoid damage on three occasions this year, including a near miss less than a month ago.

The potential debris field would pose a danger to any craft passing through, including satellites on their way up to a higher geosynchronous orbit (about 22,000 miles above Earth), or any satellites above that are being deorbited into

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