Archiv: magnetic fields


01.11.2019 - 06:52 [ Geophysical Research Letters 35(16) / researchgate.net ]

Magnetic effect on CO 2 solubility in seawater: A possible link between geomagnetic field variations and climate

(August 2008)

Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magneticfield (20 mT) compared to normal field conditions (50 mT). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism.

01.11.2019 - 06:33 [ Telegraph.co.uk ]

Sun’s protective ‚bubble‘ is shrinking

(18.10.2008)

The protective bubble around the sun that helps to shield the Earth from harmful interstellar radiation is shrinking and getting weaker, Nasa scientists have warned.

16.10.2019 - 23:23 [ Newsweek.com ]

NASA Engineer Proposes ‚Helical Engine‘ For Interstellar Travel With No Propellant

Burns said his helical engine would work by accelerating ions confined in a loop. By changing their mass slightly, the engine would then move the ions back and forth along the direction of travel to produce thrust. New Scientist notes that the helical engine would need to be 650 feet long and 40 feet wide in order to work.

16.10.2019 - 23:20 [ Nasa.gov ]

Helical Engine

• What and Why
•Thought Experiment
•Ions and Particle Accelerators
•Classical vs Relativistic Dynamics
•Helical Engine Architecture
•A Specific Design Example
•Conservation of Momentum
•Conclusions

16.10.2019 - 23:14 [ NewScientist.com ]

NASA engineer’s ‚helical engine‘ may violate the laws of physics

This mass changing isn’t prohibited by physics. Einstein’s theory of special relativity says that objects gain mass as they are driven towards the speed of light, an effect that must be accounted for in particle accelerators. In fact, a simplistic implementation of Burns’s concept would be to replace the ring with a circular particle accelerator, in which ions are swiftly accelerated to relativistic speed during one stroke, and decelerated during the other.

But Burns thinks it would make more sense to ditch the box and rod and employ the particle accelerator for the lateral as well as the circular movement – in which case, the accelerator would need to be shaped like a helix.

25.09.2019 - 19:42 [ Geophysical Research Letters 35(16) / researchgate.net ]

Magnetic effect on CO 2 solubility in seawater: A possible link between geomagnetic field variations and climate

(August 2008)

Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magneticfield (20 mT) compared to normal field conditions (50 mT). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism.

25.09.2019 - 19:31 [ Forbes.com ]

Is Earth’s Magnetic Shield Eroding?

(29.3.2018)

The strength of Earth’s main magnetic field is currently about 29.5 microteslas, down 5 microteslas, or 14 percent from its strength three centuries ago.

We know this. There is no question of this.

25.09.2019 - 19:23 [ Phys.org ]

Strong planetary magnetic fields like Earth’s may protect oceans from stellar storms

(14.03.2019)

„Magnetic fields appear to play an essential role in making planets habitable, so I wanted to find out how Earth’s magnetic field compared to those of other potentially habitable planets,“ she said.

Ms McIntyre said Earth’s strong magnetic field had probably played an important role in protecting the atmosphere from the solar wind and keeping the planet wet and habitable.

„Venus and Mars have negligible magnetic fields and do not support life, while Earth’s magnetic field is relatively strong and does,“ she said.

25.09.2019 - 19:19 [ NASA ‏/ Twitter ]

Unlike Earth, Mars does not have a magnetic field to shield its atmosphere from solar wind:

(05.11.2015)

25.09.2019 - 19:12 [ NationalGeographic.com ]

Rewind the Red Planet: See the Surprising Ways Mars Has Changed in 3 Billion Years

(21.11.2016)

Mars today is a chilly desert. But ancient landscapes reveal a times when water may have flowed freely. Scroll to see how the red planet has evolved

25.09.2019 - 18:56 [ National Aeronautics and Space Administration ]

Why doesn’t Venus have a magnetic field ?

Current theories of the formation and evolution of the terrestrial planets do support an Earth scale magnetic dipole (magnetic field) on Venus for perhaps the first billion years or so after formation.

25.09.2019 - 18:47 [ European Planetary Science Congress / American Astronomical Society's Division for Planetary Sciences ]

A view to the possible habitability of ancient Venus over three billion years

(20.09.2019)

The long-term evolutionary history of Venus’ climate largely remains a mystery.

26.08.2019 - 22:46 [ CNN ]

When Neptune got its stunning close-up: The Voyager 2 flyby, 30 years later

They discovered that Neptune’s magnetic field was tipped on its side. They found a giant spot called the Great Dark Spot on the planet, similar to Jupiter’s Great Red Spot. But the event was passing, because it was no longer there when the Hubble Space Telescope looked four years later.

11.08.2019 - 21:38 [ Nils-Axel Mörner / suanet.ac.tz ]

Solar Wind, Earth’s Rotation and Changes in Terrestrial Climate

(08.03.2013)

Another effect of the interaction between the Solar Wind and the Earth’s magnetic field seems to be that it affects the Earth’s rate of rotation where Solar Minima lead to accelerations and Solar Maxima to decelerations (as discussed in previous papers; [2,5-10]). Several authors have noted a correlation between sunspot activity and Earth’s rotation [2,8-23] or Solar-planetary cycles and Earth’s rotation [10,24-32].

Golovkov [13] plotted Earth’s rate of rotation (spin rate) against sunspot numbers and found that high spin rates correlated with low sunspot numbers and low spin rates with high sunspot numbers. Mörner [2] plotted LOD against sunspot numbers for the period 1831–1995 and found a linear relationship where low LOD values (high spin rate) correlated with low sunspot numbers and high LOD values with high sunspot numbers. Consequently, the Earth’s rotation accelerates at low solar activity and decelerates at high solar activity.

The relations among solar activity, Solar Wind, variations in Earth’s atmospheric shielding capacity and variations in the Earth’s rate of rotation are expressed in Fig. 1

11.08.2019 - 21:32 [ Nils-Axel Mörner / core.ac.uk ]

Solar Wind, Earth’s Rotation and Changes in Terrestrial Climate

(2013)

Solar variability affects Earth climate. It is proposed that this forcing primarily goes via the interaction of the Solar Wind with the Earth’s magnetosphere, rather than via changes in irradiance, which is generally assumed. The cyclic variations in Solar Wind emission generate corresponding changes in the Earth’s rate of rotation (LOD), as recorded by correlations between sunspot numbers and LOD-variations. Variations in Earth’s rotation affect not only the atmospheric circulation but also the ocean circulation.

11.08.2019 - 21:00 [ ScienceNews.org ]

Every six years, Earth spins slightly faster and then slower

(10.07.2013)

The world turns slightly faster and slower on a regular 5.9-year cycle, a new study suggests. Researchers also found small speed changes that happen at the same time as sudden alterations in Earth’s magnetic field.

11.08.2019 - 20:46 [ Phys.org ]

Research pair find 5.9 year cycle of oscillations in length of day

(11.07.2013)

Unlike the ten year trend (believed to be caused by changes in the Earth’s core) and the episodic jerks (scientists have detected 10 such events since 1969) the 5.9 year cycle was unexpected. Every 5.9 years, they claim, the planet undergoes a period of several months where the length of each day is longer or shorter than „normal.“ The researchers don’t know what causes the cycle but suspect it has something to do with the core-mantle boundary.

Scientists are also interested in learning more about the episodic jerks that alter day-length for several months at a time—this new research has revealed that during each event, the Earth’s geomagnetic field undergoes a similar effect. Scientists don’t know why either occurs, but suspect they are connected.

11.08.2019 - 14:14 [ National Aeronautics and Space Administration ]

The Space Station Crosses a Spotless Sun

(15.07.2019)

Transiting the Sun is not very unusual for the ISS, which orbits the Earth about every 90 minutes, but getting one’s timing and equipment just right for a great image is rare. Strangely, besides that fake spot, in this recent two-image composite, the Sun lacked any real sunspots. The featured picture combines two images — one capturing the space station transiting the Sun — and another taken consecutively capturing details of the Sun’s surface. Sunspots have been rare on the Sun since the dawn of the current Solar Minimum, a period of low solar activity. For reasons not yet fully understood, the number of sunspots occurring during both the previous and current solar minima have been unusually low.

11.08.2019 - 14:03 [ Global Warming Policy Forum (GWPF) ]

Solar Cycle 25: May Be The Smallest In Over 300 Years

(26.01.2012)

Livingston and Penn provided the first hard estimate of Solar Cycle 25 amplitude based on a physical model. That estimate is 7, which would make it the smallest solar cycle for over 300 years.

This is figure 2 from their paper:

Livingston and Penn have been tracking the decline in sunspot magnetic field, predicting that sunspots will disappear when the umbral magnetic field strength falls below 1,500 gauss, as per this figure from their 2010 paper:

11.08.2019 - 13:58 [ NationalGeographic.com ]

Sun Headed Into Hibernation, Solar Studies Predict: Sunspots may disappear altogether in next cycle.

(14.06.2011)

This time, however, the rush to the poles is more of a crawl, which means we could be headed toward a very weak solar maximum in 2013—and it may delay or even prevent the start of the next solar cycle.

Taken together, the three lines of evidence strongly hint that Solar Cycle 25 may be a bust, the scientists said today during a meeting of the American Astronomical Society in Las Cruces, New Mexico.

11.08.2019 - 13:45 [ National Aeronautics and Space Administration ]

Long Range Solar Forecast: Solar Cycle 25 peaking around 2022 could be one of the weakest in centuries.

(10.05.2006)

How do you observe a belt that plunges 200,000 km below the surface of the sun?

„We do it using sunspots,“ Hathaway explains. Sunspots are magnetic knots that bubble up from the base of the conveyor belt, eventually popping through the surface of the sun. Astronomers have long known that sunspots have a tendency to drift—from mid solar latitudes toward the sun’s equator. According to current thinking, this drift is caused by the motion of the conveyor belt. „By measuring the drift of sunspot groups,“ says Hathaway, „we indirectly measure the speed of the belt.“

13.07.2019 - 16:48 [ National Aeronautics and Space Administration ]

Solar Activity Forecast for Next Decade Favorable for Exploration

(12.06.2019)

Previously, researchers used the number of sunspots to represent indirectly the activity of the solar magnetic field. The new approach takes advantage of direct observations of magnetic fields emerging on the surface of the Sun – data which has only existed for the last four solar cycles.

16.06.2019 - 11:31 [ Christina H Koch, current resident of the International @Space_Station / Twitter ]

Years ago at the South Pole, I looked up to the aurora for inspiration through the 6-month winter night. Now I know they’re just as awe inspiring from above. #nofilter

(10.06.2019)

05.06.2019 - 20:56 [ Geophysical Research Letters 35(16) / researchgate.net ]

Magnetic effect on CO 2 solubility in seawater: A possible link between geomagnetic field variations and climate

(August 2008)

Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magneticfield (20 mT) compared to normal field conditions (50 mT). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism.

05.06.2019 - 20:27 [ ScienceMag.org ]

Magnetic Reconnection in the Near Venusian Magnetotail

(04.05.2012)

Observations with the Venus Express magnetometer and low-energy particle detector revealed magnetic field and plasma behavior in the near-Venus wake that is symptomatic of magnetic reconnection, a process that occurs in Earth’s magnetotail but is not expected in the magnetotail of a nonmagnetized planet such as Venus.

05.06.2019 - 20:13 [ National Aeronautics and Space Administration ]

Magnetic Portals Connect Earth to the Sun

(30.10.2008)

„It’s called a flux transfer event or ‚FTE,'“ says space physicist David Sibeck of the Goddard Space Flight Center. „Ten years ago I was pretty sure they didn’t exist, but now the evidence is incontrovertible.“

Indeed, today Sibeck is telling an international assembly of space physicists at the 2008 Plasma Workshop in Huntsville, Alabama, that FTEs are not just common, but possibly twice as common as anyone had ever imagined.

05.06.2019 - 20:00 [ Phys.org ]

Earth’s magnetic poles could start to flip. What happens then?

(07.12.2018)

‚The geomagnetic field has been decaying for the last 3,000 years,‘ said Dr. Nicolas Thouveny from the European Centre for Research and Teaching of Environmental Geosciences (CEREGE) in Aix-en-Provence, France. ‚If it continues to fall down at this rate, in less than one millennium we will be in a critical (period).‘

05.06.2019 - 19:28 [ MIT Technology Review i ]

Space weather affects your daily life. It’s time to start paying attention.

“Why can I reach halfway across the world some days, and I can’t get more than 50 miles away other days. Well, our magnetosphere is a living, breathing thing, and it’s driven by the sun.”

30.05.2019 - 16:24 [ scitecheuropa.eu ]

Solving a century-long mystery: the origin of galactic cosmic rays

(04.04.2019)

The word ‘astronomy’ means the direct observations of extra-terrestrial objects. This definition is relevant to photons, neutrinos, and gravitational waves, i.e. massless, neutral and stable particles. But for cosmic ray electrons, protons, and nuclei, the term ‘astronomy’ is used with a certain reservation. Because of the deflections of electrically charged particles in the chaotic interstellar and intergalactic magnetic fields, the information about their original directions pointing to the sites of their production is lost. Instead, on the Earth, we detect an (almost) isotropic flux of cosmic rays contributed by a huge number of galactic and extragalactic sources.

25.05.2019 - 09:25 [ Nature.com ]

Less absorbed solar energy and more internal heat for Jupiter

(13.09.2018)

The radiant energy budget and internal heat are fundamental properties of giant planets, but precise determination of these properties remains a challenge.

(…)

Furthermore, the significant wavelength dependency of Jupiter’s albedo implies that the radiant energy budgets and internal heat of the other giant planets in our solar system should be re-examined.

(…)

Furthermore, the transfer and distribution of radiant energy within the atmospheric systems modify the thermal structure and hence generate the mechanical energy to drive atmospheric circulation, weather, and climate. The radiant energy budget and the related internal heat of the giant planets also bear upon their evolutionary history.

25.05.2019 - 09:19 [ Nature.com ]

Time variation of Jupiter’s internal magnetic field consistent with zonal wind advection

(20.05.2019)

However, of the six Solar System planets with active dynamos, secular variation has been firmly established only for Earth. Here, we compare magnetic field observations of Jupiter from the Pioneer 10 and 11, Voyager 1 and Ulysses spacecraft (acquired 1973–1992) with a new Juno reference model (JRM09)1. We find a consistent, systematic change in Jupiter’s field over this 45-year time span, which cannot be explained by changes in the magnetospheric field or by changing the assumed rotation rate of Jupiter.

29.04.2019 - 13:21 [ Geophysical Research Letters 35(16) / researchgate.net ]

Magnetic effect on CO 2 solubility in seawater: A possible link between geomagnetic field variations and climate

(August 2008)

Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magneticfield (20 mT) compared to normal field conditions (50 mT). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism.

29.04.2019 - 13:15 [ Stanford University ]

ON THE WEAKENING OF THE POLAR MAGNETIC FIELDS DURING SOLAR CYCLE 23

(20. Dezember 2009)

The Sun’s polar fields are currently ∼40% weaker than they were during the previous three sunspot minima. This weakening has been accompanied by a corresponding decrease in the interplanetary magnetic field (IMF) strength, by a ∼20% shrinkage in the polar coronal-hole areas, and by a reduction in the solar-wind mass flux over the poles. It has also been reflected in coronal streamer structure and the heliospheric current sheet, which only showed the expected flattening into the equatorial plane after sunspot numbers fell to unusually low values in mid-2008. From latitude–time plots of the photospheric field, it has long been apparent that the polar fields are formed through the transport of trailing-polarity flux from the sunspot latitudes to the poles.

29.04.2019 - 12:48 [ Nature.com ]

Earth’s magnetic field is acting up and geologists don’t know why

(9. Januar 2019)

The magnetic pole is moving so quickly that it has forced the world’s geomagnetism experts into a rare move.

On 15 January, they are set to update the World Magnetic Model, which describes the planet’s magnetic field and underlies all modern navigation, from the systems that steer ships at sea to Google Maps on smartphones.

29.04.2019 - 12:35 [ British Geological Survey ]

World Magnetic Model (WMM)

The World Magnetic Model (WMM) is a standard model of the core and large-scale crustal magnetic field. It is used extensively for navigation and in attitude and heading referencing systems by the UK Ministry of Defence, the US Department of Defense, the North Atlantic Treaty Organization and the International Hydrographic Organization.

(…)

The WMM is a model of the core and large-scale crustal fields only. However the satellite data contain unwanted signals such as small-scale crustal, external ionospheric and magnetospheric and their induced counterparts. These fields would have added noise to the WMM2015 SV model and could have biased its estimates.

BGS employed two techniques to avoid the contamination caused by external magnetic fields. Firstly we rejected those data most contaminated by these sources, as identified by a combination of local time, geomagnetic indices and solar wind data. ……..

29.04.2019 - 12:19 [ Met Office Space ‏/ Twitter ]

Today’s Met Office Space Weather Operations Centre (MOSWOC) Solar Synoptic Map. No sunspots are currently visible and this continues the very low solar activity.

(28. April 2019)

29.04.2019 - 12:14 [ SDO | Solar Dynamics Observatory / Youtube ]

Sunspots and Magnetic Fields

The physical correlation of magnetic intensity and sunspots is clearly revealed when we fade back and forth between a filtered (i.e., white light) image of the Sun with a magnetic image (magnetogram) taken at the same time (Dec. 18, 2014). Two large sunspot groups with strong magnetic intensity stand out in both the magnetic and white light images.

29.04.2019 - 10:51 [ Phys.org ]

Scientists predict sun’s activity will be weak during next solar cycle

(8. April 2019)

„We expect Solar Cycle 25 will be very similar to Cycle 24: another fairly weak cycle, preceded by a long, deep minimum,“ said panel co-chair Lisa Upton, Ph.D., solar physicist with Space Systems Research Corp. „The expectation that Cycle 25 will be comparable in size to Cycle 24 means that the steady decline in solar cycle amplitude, seen from cycles 21-24, has come to an end and that there is no indication that we are currently approaching a Maunder-type minimum in solar activity.“

29.04.2019 - 10:50 [ Phys.org ]

Rapid destruction of Earth-like atmospheres by young stars

(24.04.2019)

The high energy radiation is important because it is absorbed high in the atmosphere of a planet, causing the gas to be heated. For the Earth, the gas is heated to temperatures of more than 1000 degrees Celsius in the upper region known as the thermosphere. This is the region in which spacecraft such as satellites and the International Space Station fly. When orbiting young stars with high activity levels, the thermospheres of planets are heated to much higher temperatures which, in extreme cases, can cause the gas to flow away from the planet.

14.04.2019 - 19:50 [ Washington Post ]

Scientists predict a new solar cycle is about to begin and that it might be stronger than the last one

(11. April 2019)

The decline in sunspot activity through cycle 24 was worrisome to some space weather scientists in that it suggested a return to a lengthy “solar drought,” reminiscent of the Maunder Minimum period of 1645-1715. Records show the sun was essentially spotless for this lengthy period, coinciding with the “Little Ice Age” in Europe and tickling the interest of scientists to wonder whether there is a cause-and-effect relationship between solar behavior and Earth’s climate.

14.04.2019 - 19:47 [ Phys.org ]

Scientists predict sun’s activity will be weak during next solar cycle

(8. April 2019)

„We expect Solar Cycle 25 will be very similar to Cycle 24: another fairly weak cycle, preceded by a long, deep minimum,“ said panel co-chair Lisa Upton, Ph.D., solar physicist with Space Systems Research Corp. „The expectation that Cycle 25 will be comparable in size to Cycle 24 means that the steady decline in solar cycle amplitude, seen from cycles 21-24, has come to an end and that there is no indication that we are currently approaching a Maunder-type minimum in solar activity.“

14.04.2019 - 19:46 [ National Aeronautics and Space Administration ]

Solar Wind Loses Power, Hits 50-year Low

(23. September 2008)

In a briefing today at NASA headquarters, solar physicists announced that the solar wind is losing power.

„The average pressure of the solar wind has dropped more than 20% since the mid-1990s,“ says Dave McComas of the Southwest Research Institute in San Antonio, Texas. „This is the weakest it’s been since we began monitoring solar wind almost 50 years ago.“

14.04.2019 - 18:54 [ Telegraph.co.uk ]

Sun’s protective ‚bubble‘ is shrinking

(18.10.2008)

The protective bubble around the sun that helps to shield the Earth from harmful interstellar radiation is shrinking and getting weaker, Nasa scientists have warned.

29.03.2019 - 10:02 [ Forbes ]

Earth’s Magnetic North Pole Has Officially Moved

Earth’s magnetic North Pole has drifted so fast that authorities have had to officially redefine the location of the magnetic North Pole. The extreme wandering of the North Pole caused increasing concerns over navigation, especially in high latitudes.

29.03.2019 - 09:05 [ CBC.ca ]

The sun is quieter than normal, but don’t panic

(11.3.2019)

Over the past three decades, the sun has been consistently dropping in activity. Maximum has been quieter than is typical; minimum has been particularly quiet. And this has caused some to make the false assumption that, as a result, Earth is going to cool.

29.03.2019 - 08:41 [ Nature.com ]

Earth’s magnetic field is acting up and geologists don’t know why

(9.1.2019)

Something strange is going on at the top of the world. Earth’s north magnetic pole has been skittering away from Canada and towards Siberia, driven by liquid iron sloshing within the planet’s core. The magnetic pole is moving so quickly that it has forced the world’s geomagnetism experts into a rare move.

29.03.2019 - 08:25 [ NationalGeographic.com ]

Sun Is Moving Slower Than Thought

(12.5.2012)

„Having learned for nearly three decades about it, I was literally shocked when we found it was missing.“

(…)

Still, considering the rays‘ expected effects, Redfield said, „it seems obvious to me that there will be scenarios or times when the cosmic-ray flux on a planet is important and [is] having a major influence on the evolution of the planetary atmosphere or even on biological processes on its surface.“

29.03.2019 - 08:23 [ NationalGeographic.com ]

Surprise: Solar System „Force Field“ Shrinks Fast

(1.10.2010)

„If we’ve learned anything from IBEX so far, it is that the models that we’re using for interaction of the solar wind with the galaxy were just dead wrong,“ David McComas, principal investigator for the IBEX program, said during a NASA press conference Thursday.

For starters, it’s been assumed that the heliosphere’s expansion and contraction follows the sun’s roughly 11-year activity cycle, during which the flow rate of charged particles, or solar wind, fluctuates.

08.12.2018 - 15:32 [ Huffington Post ]

Waiting For The Next Sunspot Cycle: 2019-2030

(6.12.2017) By Cycle 25 or 26, magnetic fields may be too weak to punch through the solar surface and form recognizable sunspots at all,