Archiv: Erde / Earth (space object / planet)


13.03.2020 - 08:57 [ National Aeronautics and Space Administration ]

NASA Team Studies Middle-aged Sun by Tracking Motion of Mercury

(18.01.2018)

Like the waistband of a couch potato in midlife, the orbits of planets in our solar system are expanding. It happens because the Sun’s gravitational grip gradually weakens as our star ages and loses mass.

13.03.2020 - 08:53 [ Newsweek ]

NASA Shows Einstein Was Right: Our Sun Is Losing Mass—and Its Grip on Our Solar System

(19.01.2018)

As our sun gets older, it’s losing mass, and so its gravitational pull becomes weaker. As a result, the orbits of all the planets in our solar system are expanding, not unlike „the waistband of a couch potato in midlife,“ according to a new NASA press statement.

A team of researchers from the Massachusetts Institute of Technology, the University of Maryland and the NASA Goddard Space Flight Center has shown that the aging sun is behaving according to Albert Einstein’s theory of general relativity.

13.03.2020 - 08:50 [ CBS News ]

On-Time Earth Baffles Scientists

(31. März 2003)

To make the world’s official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra „leap second“ on the last day of the year.

For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.

At the National Institute for Science and Technology in Boulder, spokesman Fred McGehan said most scientists agree the Earth’s orbit around the sun has been gradually slowing for millennia. But he said they don’t have a good explanation for why it’s suddenly on schedule.

13.03.2020 - 08:41 [ CNN ]

In Earth’s early history, a day was 23.5 hours and a year lasted 372 days

(today)

We’ve long known that an Earth day lasts 24 hours, and that remains constant because Earth’s trip around the sun doesn’t vary.

22.01.2020 - 22:45 [ 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.

22.01.2020 - 22:09 [ 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.

22.01.2020 - 22:02 [ Dr. Jessie Christiansen ‏/ Twitter ]

I have always been interested in galactic archaeology, but I don’t think this is what they meant. Did you know that dinosaurs lived on the other side of the Galaxy?

(28.08.2019)

22.01.2020 - 21:54 [ Carl Sagan, George Mullen / utexas.edu ]

Earth and Mars: Evolution of Atmospheres and Surface Temperatures

(7. Juli 1972)

Indeed, detailed global climatic models (17) suggest that a relative increase in A of only 2 percent is enough to induce extensive glaciation on Earth, which implies that the present climate is extremely sensitive to albedo. This leaves changes in atmospheric composition as a possible explanation. Major variations in the CO2 abundance will have only minor greenhouse effects because the strongest bands are nearly saturated. A change in the present CO2 abundance by a factor of 2 will produce directly a 2° variation in surface temperature (18). The CO2 abundance is highly controlled by silicate-carbonate equilibria; by buffering with seawater, which contains almost 100 times the atmospheric CO2; and by the respiration and photosynthesis feedback loop (19).

22.01.2020 - 21:48 [ Wikipedia ]

Paradoxon der schwachen jungen Sonne

Unter dem Paradoxon der schwachen jungen Sonne versteht man den noch nicht vollständig geklärten Widerspruch zwischen der geringen Strahlungsleistung der jungen Sonne in der frühen Erdgeschichte und dem nicht entsprechend kälteren Klima zu dieser Zeit. Auf diese Diskrepanz wiesen erstmals die Astronomen Carl Sagan und George Mullen 1972 hin.[sm 1]

Sagan schlug eine vergleichsweise hohe Konzentration von Treibhausgasen als mögliche übergeordnete Erklärung vor, was sich aber für den fraglichen Zeitraum nicht bestätigt hat. Im Gegenteil, die im Archaikum stattgefundenen bedeutenden Änderungen der Atmosphärenzusammensetzung und der in Vergleich zur jüngeren Erdgeschichte nach einer globalen Vereisung vor 2,4 Milliarden Jahren lange Zeit relativ gleichmäßige Klimaverlauf (vgl. boring billion, dt. langweilige Milliarde[jko 1]) werfen eher zusätzliche Fragen auf. Über Jahrzehnte geführte kontroverse Diskussionen in Geologie, Astrophysik, Planetologie, Klimatologie und Atmosphärenwissenschaften machten das Paradoxon zu einer „der großen offenen Fragen der Paläoklimatologie“.

22.01.2020 - 21:46 [ Wikipedia ]

Faint young Sun paradox

The faint young Sun paradox or faint young Sun problem describes the apparent contradiction between observations of liquid water early in Earth’s history and the astrophysical expectation that the Sun’s output would be only 70 percent as intense during that epoch as it is during the modern epoch.[1] The issue was raised by astronomers Carl Sagan and George Mullen in 1972.[2] Proposed resolutions of this paradox have taken into account greenhouse effects, astrophysical influences, or a combination of the two.

An unresolved question is how a climate suitable for life was maintained on Earth over the long timescale despite the variable solar output and wide range of terrestrial conditions.

02.01.2020 - 16:57 [ Dr. Jessie Christiansen ‏/ Twitter ]

I have always been interested in galactic archaeology, but I don’t think this is what they meant. Did you know that dinosaurs lived on the other side of the Galaxy?

(28.08.2019)

02.01.2020 - 16:52 [ Harvard.edu ]

Equatorial solar rotation and its relation to climatic changes

(29. September 1977)

During the years from 1965 to 1976, the magnitude of the solar rotation speed averaged annually showed a good inverse correlation with the annual relative sunspot numbers. It is suggested that this variation of the equatorial solar rotation speed may be responsible for the earth’s present unusual climatic conditions. A similarity concerning the low sunspot activity for 1976 and the year 1643, just before the beginning of the Maunder Minimum (1645-1715) with its very severe climatic conditions, is pointed out. It appears, therefore, likely that the present unusual climatic conditions will remain as long as the solar activity continues to decrease.

02.01.2020 - 15:16 [ Carl Sagan, George Mullen / utexas.edu ]

Earth and Mars: Evolution of Atmospheres and Surface Temperatures

(7. Juli 1972)

Indeed, detailed global climatic models (17) suggest that a relative increase in A of only 2 percent is enough to induce extensive glaciation on Earth, which implies that the present climate is extremely sensitive to albedo. This leaves changes in atmospheric composition as a possible explanation. Major variations in the CO2 abundance will have only minor greenhouse effects because the strongest bands are nearly saturated. A change in the present CO2 abundance by a factor of 2 will produce directly a 2° variation in surface temperature (18). The CO2 abundance is highly controlled by silicate-carbonate equilibria; by buffering with seawater, which contains almost 100 times the atmospheric CO2; and by the respiration and photosynthesis feedback loop (19).

02.01.2020 - 14:39 [ Wikipedia ]

Paradoxon der schwachen jungen Sonne

Unter dem Paradoxon der schwachen jungen Sonne versteht man den noch nicht vollständig geklärten Widerspruch zwischen der geringen Strahlungsleistung der jungen Sonne in der frühen Erdgeschichte und dem nicht entsprechend kälteren Klima zu dieser Zeit. Auf diese Diskrepanz wiesen erstmals die Astronomen Carl Sagan und George Mullen 1972 hin.[sm 1]

Sagan schlug eine vergleichsweise hohe Konzentration von Treibhausgasen als mögliche übergeordnete Erklärung vor, was sich aber für den fraglichen Zeitraum nicht bestätigt hat. Im Gegenteil, die im Archaikum stattgefundenen bedeutenden Änderungen der Atmosphärenzusammensetzung und der in Vergleich zur jüngeren Erdgeschichte nach einer globalen Vereisung vor 2,4 Milliarden Jahren lange Zeit relativ gleichmäßige Klimaverlauf (vgl. boring billion, dt. langweilige Milliarde[jko 1]) werfen eher zusätzliche Fragen auf. Über Jahrzehnte geführte kontroverse Diskussionen in Geologie, Astrophysik, Planetologie, Klimatologie und Atmosphärenwissenschaften machten das Paradoxon zu einer „der großen offenen Fragen der Paläoklimatologie“.

02.01.2020 - 13:40 [ 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.

02.01.2020 - 13:40 [ Ludwig Maximilian Universität München ]

Wenn ein Treibhausgas baden geht: Wie das Erdmagnetfeld unser Klima beeinflusst

(6. Oktober 2008)

Die Ergebnisse zeigten, dass selbst kleine Veränderungen des Magnetfelds die Löslichkeit von Gasen im Wasser verändern. „Wenn das Magnetfeld schwächer war, löste sich 15 Prozent weniger Luft im Wasser als bei einem stärkeren Magnetfeld“, erläutert Winklhofer. „Für Kohlendioxid war der beobachtete Effekt sogar doppelt so stark.“

02.01.2020 - 13:33 [ European Geosciences Union / Copernikus Gesellschaft ]

MESSENGER Observations of Magnetic Flux Ropes in Mercury’s Plasma Sheet

(2014)

A superposed epoch analysis demonstrates that the magnetic structure of the flux ropes issimilar to what is observed at Earth, but the timescales are 40 times faster at Mercury.

02.01.2020 - 13:18 [ 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.

02.01.2020 - 13:07 [ Alexander Ershkovich / Researchgate.net ]

On the Origin of the Magnetic Field in Type-1 Comet Tails

(4. Juni 1976)

If the magnetic field in a type I comet tail were of internal origin, it would decrease with distance along the tail axis, and the comet tail would increase in cross section. The tail of Comet Arend-Roland (1957 III) was shown not to expand with distance from the nucleus, whence it is concluded that the magnetic field in the tail is of external origin. The magnetic field in type I comet tails, estimated from different considerations, turns out to be of the order of the interplanetary field, so that one may suppose that it results from the captured solar-wind magnetic field.

Recently, Mendis and Alfvén (1974) suggested that substantial magnetic fields, up to 100-1000y, could sometimes be generated within the coma. This means that the magnetic field in the comet tail may result from processes analogous to those producing the Earth’s magnetotail.

02.01.2020 - 12:13 [ ibtimes.com ]

Earth’s Magnetic Field is Weakening And Could Collapse Eventually, Expert Warns

(26.12.2019)

Hardwick noted that SWARM revealed that the magnetic field over certain areas of Earth has decreased dramatically. However, in certain areas, it appears to have strengthened.

“What SWARM has actually found is that after 2.5 years of observation, the Earth’s magnetic field has weakened by about 3.5 [percent] at high latitudes over North America, while it has strengthened about 2 [percent] over Asia,” he wrote on Quora. “In other words, it wiggles and wobbles.”

02.01.2020 - 11:44 [ Harvard.edu ]

Earth’s inner core nucleation paradox

(April 2018)

Using constraints from experiments, simulations, and theory, we show that spontaneous crystallization in a homogeneous liquid iron alloy at Earth’s core pressures requires a critical supercooling of order 1000 K, which is too large to be a plausible mechanism for the origin of Earth’s inner core. We consider mechanisms that can lower the nucleation barrier substantially. Each has caveats, yet the inner core exists: this is the nucleation paradox.

02.01.2020 - 11:37 [ LiveScience.com ]

Earth’s Inner Core Shouldn’t Technically Exist

(09.02.2018)

In their paper, the researchers proposed one possibility: Perhaps a massive nugget of solid metal alloy dropped from the mantle and plunged into the liquid core.

02.01.2020 - 11:32 [ ScienceDaily.com ]

Challenging core belief: Have we misunderstood how Earth’s solid center formed?

(07.02.2018)

It is widely accepted that the Earth’s inner core formed about a billion years ago when a solid, super-hot iron nugget spontaneously began to crystallize inside a 4,200-mile-wide ball of liquid metal at the planet’s center.

One problem: That’s not possible-or, at least, has never been easily explained-according to a new paper published in Earth and Planetary Science Letters from a team of scientists at Case Western Reserve University.

02.01.2020 - 11:23 [ Sciencedirect.com ]

Extreme geomagnetic reversal frequency during the Middle Cambrian as revealed by the magnetostratigraphy of the Khorbusuonka section (northeastern Siberia)

(15.12.2019)

A geomagnetic reversal frequency of 26 reversals per Myr is therefore estimated for the Drumian, reduced to 15 reversals per Myr if only the polarity intervals defined by at least two consecutive samples are retained. This is an extreme reversal rate, similar to that reported for the Late Ediacaran (late Precambrian), ∼50 Myr earlier, and proposed to be potentially linked to a late nucleation of the inner core.

02.01.2020 - 10:32 [ CNN ]

Earth’s magnetic north pole is heading for Russia and scientists are puzzled

(18.12.2019)

A weakened magnetic field allows more cosmic radiation from space to strike our atmosphere, which creates more beryllium.

The actual reversal took less than 4,000 years — a drop in the bucket when compared to Earth’s timeline so far. But leading up to that reversal were 18,000 years of instability, including two temporary and partial reversals. This is twice as long as expected.

02.01.2020 - 10:23 [ American Geophysical Union / Youtube ]

Press Conference: Postcards from the edge of space: New images, new phenomena, and new insights

Tuesday, 10 December, 2:30 p.m. │ Presentations SA11A-01, SM51G-3219

In this briefing, scientists will present new images from Earth’s ionosphere, bringing color to processes that have widespread implications for the part of space closest to home. This collection of photos will span the first images ever captured by NASA’s ICON spacecraft — just launched in October 2019 — and the first science discoveries from NASA’s GOLD mission, along with observations of a never-before-studied type of aurora.

Participants:

Jennifer Briggs, Pepperdine University, Malibu, California, United States;

Richard Eastes, University of Colorado Boulder, Boulder, Colorado, United States;

Thomas Immel, University of California Berkeley, Berkeley, California, United States.

02.01.2020 - 10:12 [ businessinsider.com ]

A mysterious crunch in Earth’s magnetic field created a new type of aurora borealis. A NASA intern discovered it.

(26.12.2019)

A NASA intern discovered a new type of aurora in 3-year-old video footage of the Arctic sky.

27.12.2019 - 21:06 [ CNN ]

A giant red star is acting weird and scientists think it may be about to explode

The red supergiant would glow a vibrant blue for three of four months, and would take about a year to fade out.

„It would be a really bright star visible in the daytime,“ Guinan said.

There wouldn’t be any direct danger to life on earth, but ultraviolet radiation from the celestial blast could scorch ozone in our atmosphere.

15.11.2019 - 20:48 [ New York Times ]

I’m Sorry, Is Impeachment Not Entertaining Enough for You?

I wonder whether this is where hundreds of channels, dozens of streaming services and the internet have ultimately left us. In a world where there’s news breaking on social media every one-thousandth of a second, and you can hit ‘refresh’ all day long, is it too much to expect that voters will spend hours listening to sober civil servants with complicated stories and pocket squares?

15.11.2019 - 15:00 [ businessinsider.fr ]

A NASA scientist’s incredible animation shows how dinosaurs roamed the Earth on the other side of the Milky Way galaxy

Our sun orbits the galaxy’s center, so many dinosaurs roamed the Earth while the planet was on the other side of the Milky Way.

Our solar system’s orbit keeps us just the right distance from the galaxy’s chaotic center for life to exist.

15.11.2019 - 12:27 [ Dr. Jessie Christiansen ‏/ Twitter ]

I have always been interested in galactic archaeology, but I don’t think this is what they meant. Did you know that dinosaurs lived on the other side of the Galaxy?

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.

18.10.2019 - 19:48 [ CNN ]

Is this how we’ll live on Mars?

„The climate crisis is — rightly — frightening a lot of people, and there is a tendency to think of Mars as a sort of escape hatch for humanity, a planet B, which is very dangerous and problematic,“ said Watson.

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 - 19:37 [ Ludwig Maximilian Universität München ]

Wenn ein Treibhausgas baden geht: Wie das Erdmagnetfeld unser Klima beeinflusst

(6. Oktober 2008)

Die Ergebnisse zeigten, dass selbst kleine Veränderungen des Magnetfelds die Löslichkeit von Gasen im Wasser verändern. „Wenn das Magnetfeld schwächer war, löste sich 15 Prozent weniger Luft im Wasser als bei einem stärkeren Magnetfeld“, erläutert Winklhofer. „Für Kohlendioxid war der beobachtete Effekt sogar doppelt so stark.“

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.

11.08.2019 - 21:54 [ Observatoire de Paris ]

Centennial cycles of the solar activity and Earth rotation

(Oktober 2011)

The irregular and long-term variations of the Earth rotation are mainly caused by the displacements
of matter in different parts of the planet which excitation mechanism is the influence of the Sun and
solar activity cycles. The solar cycles can drive great number of geodynamical processes connected with the convections of the Earth fluids on the surface and inside the Earth. Many of climate and weather parameters are affected directly by the variations of the solar activity.

11.08.2019 - 21:47 [ Harvard.edu ]

Centennial cycles of the solar activity and Earth rotation

(Oktober 2011)

The centennial variations of the Universal Time UT1 and Length of Day LOD are investigated by means of long historical observational series of UT1 and LOD variations, which cover time span more than 3 centuries long. The correlation between the centennial cycles of the Earth rotation, climate and Total Solar Irradiance TSI is determined using the time series of North America temperature (2.2Ka) and precipitation (8Ka), Mean Sea Level MSL variations at Stockholm tide gauge station since 1774 and reconstructed TSI variations since 843. The model of the solar influences on the centennial and decadal cycles of the Earth rotation is based on a main centennial cycle and harmonics, ending by oscillation with period around 9a.

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 - 20:18 [ CBS News ]

On-Time Earth Baffles Scientists

(31. März 2003)

To make the world’s official time agree with where the Earth actually is in space, scientists in 1972 started adding an extra „leap second“ on the last day of the year.

For 28 years, scientists repeated the procedure. But in 1999, they discovered the Earth was no longer lagging behind.

At the National Institute for Science and Technology in Boulder, spokesman Fred McGehan said most scientists agree the Earth’s orbit around the sun has been gradually slowing for millennia. But he said they don’t have a good explanation for why it’s suddenly on schedule.

11.08.2019 - 19:02 [ arxiv.org ]

Anomalous post-newtonian terms and the secular increase of the astronomical unit

(14.10.2018)

In 2004 Krasinsky and Brumberg indicated that the analysis of all available radiometric measurements of distances between the Earth and the planets, and also the observations of martian landers and orbiters, showed that the Astronomical Unit is increasing at a rate 15 ± 4 meters per century [14]. Later on, a more careful analysis by Standish has shown that the secular rate is closer to 7 ± 2 meters per century [26]. Anyway, this is by far too large to be explained by the loss of solar mass due to solar wind and electromagnetic radiation. An explanation based upon tidal friction caused by the bulge produced by Earth gravity on the Sun has been proposed [17]. However, this model has not been validated and the detailed mechanism for this tidal friction is hypothetical. A secular effect on the eccentricity of planetary motions have been also unveiled by the recent detailed analysis of the Lunar orbit. The secular increase of the eccentricity is very small but, however, is clearly within the range of precision of Lunar laser ranging. This kind of unexplained observations,
after discarding any possible conventional explanation, could give rise to an arena where the status of General Relativity as a complete theory of gravity (at least, at the macroscopic level) could be tested.

In this paper we have assumed that a conventional explanation is not possible and that an extra force term is necessary in order to incorporate this behaviour in the post-newtonian formalism.

11.08.2019 - 18:45 [ Newsweek ]

NASA Shows Einstein Was Right: Our Sun Is Losing Mass—and Its Grip on Our Solar System

(19.01.2018)

As our sun gets older, it’s losing mass, and so its gravitational pull becomes weaker. As a result, the orbits of all the planets in our solar system are expanding, not unlike „the waistband of a couch potato in midlife,“ according to a new NASA press statement.

A team of researchers from the Massachusetts Institute of Technology, the University of Maryland and the NASA Goddard Space Flight Center has shown that the aging sun is behaving according to Albert Einstein’s theory of general relativity.

11.08.2019 - 17:11 [ National Aeronautics and Space Administration ]

NASA Team Studies Middle-aged Sun by Tracking Motion of Mercury

(18.01.2018)

Like the waistband of a couch potato in midlife, the orbits of planets in our solar system are expanding. It happens because the Sun’s gravitational grip gradually weakens as our star ages and loses mass.

11.08.2019 - 17:08 [ Sparkonit.com ]

The Orbits Of All The Planets In Our Solar System Are Expanding As The Sun Gets Older, Study On Mercury’s Orbit Reveals

(25.01.2018)

“Mercury is the perfect test object for these experiments because it is so sensitive to the gravitational effect and activity of the Sun,” explained Antonio Genova, the lead author of the study and a MIT researcher working at NASA’s Goddard Space Flight Center.

Researchers were able to make these calculations from the data gathered by NASA’s MESSENGER spacecraft which made three ‘flybys’ of Mercury in 2008 and 2009 and orbited Mercury between March 2011 and April 2015 before it crashed into Mercury in 2015, Mail noted.

11.08.2019 - 16:58 [ ScientificAmerican.com ]

„Astronomical Unit,“ or Earth-Sun Distance, Gets an Overhaul

(14.09.2012)

Without fanfare, astronomers have redefined one of the most important distances in the Solar System. The astronomical unit (au) — the rough distance from the Earth to the Sun — has been transformed from a confusing calculation into a single number. The new standard, adopted in August by unanimous vote at the International Astronomical Union’s meeting in Beijing, China, is now 149,597,870,700 meters — no more, no less.

11.08.2019 - 16:51 [ NewScientist.com ]

Why is the Earth moving away from the sun?

(01.06.2009)

It’s not much – just 15 cm per year – but since that’s 100 times greater than the measurement error, something must really be pushing Earth outward. But what?

One idea is that the Sun is losing enough mass, via fusion and the solar wind, to gradually be losing its gravitational grip (see Astronomical unit may need to be redefined). Other possible explanations include a change in the gravitational constant G, the effects of cosmic expansion, and even the influence of dark matter. None have proved satisfactory.

11.08.2019 - 15:25 [ Harvard.edu ]

Equatorial solar rotation and its relation to climatic changes

(29. September 1977)

During the years from 1965 to 1976, the magnitude of the solar rotation speed averaged annually showed a good inverse correlation with the annual relative sunspot numbers. It is suggested that this variation of the equatorial solar rotation speed may be responsible for the earth’s present unusual climatic conditions. A similarity concerning the low sunspot activity for 1976 and the year 1643, just before the beginning of the Maunder Minimum (1645-1715) with its very severe climatic conditions, is pointed out. It appears, therefore, likely that the present unusual climatic conditions will remain as long as the solar activity continues to decrease.

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.“

11.08.2019 - 13:22 [ National Oceanic and Atmospheric Administration (NOAA.gov) ]

Space Weather Impacts On Climate

All weather on Earth, from the surface of the planet out into space, begins with the Sun. Space weather and terrestrial weather (the weather we feel at the surface) are influenced by the small changes the Sun undergoes during its solar cycle.

(…)

The duration of solar minimum may also have an impact on Earth’s climate. During solar minimum there is a maximum in the amount of Cosmic rays, high energy particles whose source is outside our Solar system, reaching earth. There is a theory that cosmic rays can create nucleation sites in the atmosphere which seed cloud formation and create cloudier conditions. If this were true, then there would be a significant impact on climate, which would be modulated by the 11-year solar cycle.

13.07.2019 - 16:40 [ EOS.org ]

The Thermosphere Responds to a Weaker Than Normal Solar Cycle

The cooling near solar minimum is natural and specific to the thermosphere. The cooling thermosphere does not affect the troposphere, the layer of the atmosphere closest to Earth’s surface where people live. The temperatures we experience on the ground do not get colder because of this solar cycle. NASA and other climate researchers continue to see a warming trend in the troposphere. These two effects are ongoing but unrelated.

Nitric oxide and carbon dioxide play important roles in cooling the thermosphere.

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 - 21:00 [ Ludwig Maximilian Universität München ]

Wenn ein Treibhausgas baden geht: Wie das Erdmagnetfeld unser Klima beeinflusst

(6. Oktober 2008)

Die Ergebnisse zeigten, dass selbst kleine Veränderungen des Magnetfelds die Löslichkeit von Gasen im Wasser verändern. „Wenn das Magnetfeld schwächer war, löste sich 15 Prozent weniger Luft im Wasser als bei einem stärkeren Magnetfeld“, erläutert Winklhofer. „Für Kohlendioxid war der beobachtete Effekt sogar doppelt so stark.“

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 - 20:13 [ 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 - 19:41 [ Metro.co.uk ]

The sun has ‘reached solar minimum’ and its surface is ominously calm

But Nasa images have revealed that the face of our star is looking ominously calm right now, prompting claims it’s reached a stage of its cycle called the solar minimum.

During the minimum, there are significantly fewer sunspots and its magnetic field weakens, allowing cosmic rays from outside our solar system to rain down on Earth.

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.

30.05.2019 - 16:11 [ arxiv.org ]

Hypothesis: Muon Radiation Dose and Marine Megafaunal Extinction at the end-Pliocene Supernova

(November 2018)

Considerable data and analysis support the detection of one or more supernovae (SNe) at a distance of about 50 pc, ∼2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions that formed the Local Bubble in the interstellar medium. We build on previous work, and propagate the muon flux from SN-initiated cosmic rays from the surface to the depths of the ocean. We find that the radiation dose from the muons will exceed the total present surface dose from all sources at depths up to 1 km and will persist for at least the lifetime of marine megafauna. It is reasonable to hypothesize that this increase in radiation load may have contributed to a newly documented marine megafaunal extinction at that time.

30.05.2019 - 15:55 [ New York Times ]

STUDY HINTS EXTINCTIONS STRIKE IN SET INTERVALS

(11. Dezember 1983)

At a conference on mass extinctions, held in August at Northern Arizona University in Flagstaff, Dr. Sepkoski said the timing of these events suggested that “there is indeed a statistically significant periodicity in the observed distribution of events of mass or accelerated extinction over the last 250 million years.“ Search for Answers

He confessed this “stumped“ him and Dr. Raup, saying: “We are aware of no documented process with a cycling time approximately 26 million years. But with that long a cycle, we suspect that the forcing agent will not be terrestrial but rather solar or galactic.“

30.05.2019 - 15:49 [ Harvard.edu ]

Cosmic-ray volleys from the Galactic Center and their recent impact on the earth environment

Authors: Laviolette, P. A.
Journal: Earth, Moon, and Planets (ISSN 0167-9295), vol. 37, March 1987, p. 241-286.

25.05.2019 - 15:27 [ FAZ.NET ‏/ Twitter ]

#Klimawandel war gestern, heute ist Notstand. Den haben wir zwar nicht den Jungen zu verdanken, aber die schlachten ihn jetzt schwungvoll aus und drängen die Politik in die Ecke, schreibt @MuellerJung:

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.

25.05.2019 - 08:57 [ Heise.de ]

„Da passiert etwas Seltsames“: Position des magnetischen Nordpols aktualisiert

(05.02.2019)

Zu den Hintergründen der Positionsverschiebungen des magnetischen Nordpols gibt es derzeit nur Theorien.

25.05.2019 - 08:51 [ Süeddeutsche ]

Der magnetische Nordpol zittert

(17.01.2019)

Kurz nach der jüngsten turnusgemäßen Neukartierung des Erdmagnetismus im Jahr 2015 gab es allerdings einen geomagnetischen Ausschlag unter Südamerika, der nicht von Modellrechnungen vorhergesagt wurde. Zudem bewegt sich der magnetische Nordpol. Warum, ist noch nicht ganz geklärt.

25.05.2019 - 08:22 [ Berliner Zeitung ]

Geophysiker wollen das Erdmagnetfeld mit bislang unerreichter Genauigkeit vermessen: Der Schutzschild schwindet

(16.12.2010)

Wie ein unsichtbares Netz umgibt das Erdmagnetfeld unseren Planeten und schützt ihn vor energiereichen Teilchen aus dem Weltraum. Doch seit langem verliert es kontinuierlich an Stärke, in manchen Regionen um bis zu vier Prozent pro Jahrzehnt. Würde der Magnetschirm durchlässig, so hätte dies negative Auswirkungen auf das Klima und die Biosphäre.

25.05.2019 - 08:11 [ Ludwig Maximilian Universität München ]

Wenn ein Treibhausgas baden geht: Wie das Erdmagnetfeld unser Klima beeinflusst

(6. Oktober 2008)

Die Ergebnisse zeigten, dass selbst kleine Veränderungen des Magnetfelds die Löslichkeit von Gasen im Wasser verändern. „Wenn das Magnetfeld schwächer war, löste sich 15 Prozent weniger Luft im Wasser als bei einem stärkeren Magnetfeld“, erläutert Winklhofer. „Für Kohlendioxid war der beobachtete Effekt sogar doppelt so stark.“

29.04.2019 - 13:25 [ Ludwig Maximilian Universität München ]

Wenn ein Treibhausgas baden geht: Wie das Erdmagnetfeld unser Klima beeinflusst

(6. Oktober 2008)

Die Ergebnisse zeigten, dass selbst kleine Veränderungen des Magnetfelds die Löslichkeit von Gasen im Wasser verändern. „Wenn das Magnetfeld schwächer war, löste sich 15 Prozent weniger Luft im Wasser als bei einem stärkeren Magnetfeld“, erläutert Winklhofer. „Für Kohlendioxid war der beobachtete Effekt sogar doppelt so stark.“

29.04.2019 - 13:24 [ Scinexx ]

Erdmagnetfeld beeinflusst Klima: Meerwasser nimmt bei schwächerem Magnetfeld weniger CO2 auf

(7. Oktober 2008)

Die Ergebnisse zeigten, dass selbst kleine Veränderungen des Magnetfelds die Löslichkeit von Gasen im Wasser verändern. „Wenn das Magnetfeld schwächer war, löste sich 15 Prozent weniger Luft im Wasser als bei einem stärkeren Magnetfeld“, erläutert Winklhofer. „Für Kohlendioxid war der beobachtete Effekt sogar doppelt so stark.“

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.

14.04.2019 - 18:33 [ onlinelibrary.wiley.com ]

Die Heliosphäre – Schutzschild für die Erde

(Physikalische Blätter 57, 2001)

Die als Heliosphäre weit in den interplanetaren Raum reichende Sonnenatmosphäre schützt die Erde und die anderen Planeten vor der energiereichen kosmischen Strahlung. Dieser Schutzschild unterliegt jedoch langfristigen Veränderungen mit gravierenden Auswirkungen auf die Erdumgebung. Ursache sind die mit dem Sonnenzyklus verbundenen Änderungen des Magnetfeldes der Sonne, die Variabilität des Sonnenwindes sowie Änderungen in der interstellaren Umgebung der Sonne. Einige dieser Vorgänge werden hier zusammen mit den Grundbegriffen der Physik der Heliosphäre beschrieben.

14.04.2019 - 18:14 [ Wikipedia ]

Interplanetares Magnetfeld: Wechselwirkung mit anderen Magnetfeldern

Der Sonnenwind wechselwirkt mit den Magnetfeldern der Planeten wie der Erde und dem Jupiter und begrenzt deren Magnetosphären durch eine Schockfront. Für die äußerste Zone des Sonnensystems gibt es Hinweise auf eine ähnliche Begrenzung der Heliosphäre mit vergleichbarem Aufbau von Plasmaschicht (Heliohülle) und Heliopause an der Grenze zum interstellaren Raum.

14.04.2019 - 18:11 [ derStandard.at ]

Die Sonne lässt das Erdmagnetfeld wie eine Trommel schwingen

(18.2.2019)

Seit rund zwölf Jahren sind Satelliten der Nasa im All unterwegs, um im Rahmen der Mission Themis die Wechselwirkungen zwischen dem Sonnenwind und dem Erdmagnetfeld in räumlicher und zeitlicher Auflösung zu untersuchen.

14.04.2019 - 18:06 [ Heise.de ]

„Da passiert etwas Seltsames“: Position des magnetischen Nordpols aktualisiert

(5.2.2019)

Zu den Hintergründen der Positionsverschiebungen des magnetischen Nordpols gibt es derzeit nur Theorien.

14.04.2019 - 17:52 [ Europäische Weltraumagentur ]

SWARM: IM FORMATIONSFLUG DURCH DAS ERDMAGNETFELD (SPECIAL)

(20.11.2013)

Klar ist: Zwischen den äußeren Einflüssen und den irdischen Magnetfeldänderungen verbergen sich vielschichtige, schwer fassbare Prozesse. In jüngster Zeit setzte sich die Erkenntnis durch, dass alles noch wesentlich komplizierter ist, als man es je vermutet hätte. Weil alles mit allem zusammenhängt.

14.04.2019 - 17:38 [ Tagesspiegel.de ]

Satellitenschwarm: „Swarm“ soll schwächelndes Magnetfeld vermessen

(20.11.2013)

Ohne das Magnetfeld gäbe es kein Leben auf der Erde. Zumindest keine höher entwickelten Pflanzen, Tiere und uns Menschen. Der unsichtbare Schild, der weit über den Planeten hinausragt, schützt vor kosmischer Strahlung und geladenen Teilchen, die die Sonne herausschleudert. Erst durch ihn konnte eine stabile Atmosphäre entstehen, in der sich das Leben entfaltet. Doch der Schild wird schwächer, in den vergangenen 150 Jahren um rund 15 Prozent.