“The scientific community has been unclear on the role that solar variability plays in influencing weather and climate events here on Earth. This study shows there’s reason to believe it absolutely does and why the connection may have been missed in the past.”
If you ask most climate scientists, they will tell you that the Sun’s small variability is unimportant when it comes to influencing climate. They may have to change their minds if a new line of research holds up. It seems that solar variability can drive climate variability on Earth on decadal timescales (the decadal climatic variability that Michael Mann recently ‘proved’ doesn’t exist). That’s the conclusion of a new study showing a correlation between the end of solar cycles and a switch from El Nino to La Nina conditions in the Pacific Ocean. It’s a result that could significantly improve the predictability of the largest El Nino and La Nina events, which have several global climate effects.
by C. Rotter, April 5, 2021 in NATIONAL CENTER FOR ATMOSPHERIC RESEARCH/UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH
A new study shows a correlation between the end of solar cycles and a switch from El Nino to La Nina conditions in the Pacific Ocean, suggesting that solar variability can drive seasonal weather variability on Earth.
If the connection outlined in the journal Earth and Space Science holds up, it could significantly improve the predictability of the largest El Nino and La Nina events, which have a number of seasonal climate effects over land. For example, the southern United States tends to be warmer and drier during a La Nina, while the northern U.S. tends to be colder and wetter.
“Energy from the Sun is the major driver of our entire Earth system and makes life on Earth possible,” said Scott McIntosh, a scientist at the National Center for Atmospheric Research (NCAR) and co-author of the paper. “Even so, the scientific community has been unclear on the role that solar variability plays in influencing weather and climate events here on Earth. This study shows there’s reason to believe it absolutely does and why the connection may have been missed in the past.”
The study was led by Robert Leamon at the University of Maryland-Baltimore County, and it is also co-authored by Daniel Marsh at NCAR. The research was funded by the National Science Foundation, which is NCAR’s sponsor, and the NASA Living With a Star program.
I’ve compiled a list of six examples how the sun impacts climate across the globe.
1. Climate periods based on a double Hale (44-45 years) cycle of solar activity.
In 1977 Australian geologist Rhodes W. Fairbridge found a 45-year periodicity of beach ridge located at the Hudson Bay. It has been formed with storms in Hudson Bay caused by a wavier jet stream.
I have found a 44-year periodicity of heavy snowfall in Japan caused by the wavier jet stream as follows. The time series coincide quite well with that of Fairbridge (1977).
1833 Tempo famine, Dalton minimum (1795-1830)
1877 Seinan war (44 years later)
1918 Rice riot, Gleissberg minimum (1898-1923) (41 years later)
1963 38 heavy snowfall (45 years later)
2006 Heisei 18 year heavy snowfall, Gleissberg or Dalton minimum (43 years)
The climate history of 20th century can be divided with the following 5 periods based on the double Hale cycle above using aa-index of geomagnetism associated with solar activity. The Pacific Climate Shift occurred at 1977 with solar activity increase & a positive PDO index.
1900-1918: Little Ice Age (LIA)
1919-1962: 1st Modern Warm Period (1st MWP)
1963-1976: Temporal Cold Period (TCP, New Ice Age Coming, see below)
1977-2005: 2nd Modern Warm Period (2nd MWP)
2006 – present: New Cold Period (NCP)
In direct contradiction to the official forecast, a team of scientists led by the National Center for Atmospheric Research (NCAR) is predicting that the Sunspot Cycle that started this fall could be one of the strongest since record-keeping began.
In a new article published in Solar Physics, the research team predicts that Sunspot Cycle 25 will peak with a maximum sunspot number somewhere between approximately 210 and 260, which would put the new cycle in the company of the top few ever observed.
The cycle that just ended, Sunspot Cycle 24, peaked with a sunspot number of 116, and the consensus forecast from a panel of experts convened by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) is predicting that Sunspot Cycle 25 will be similarly weak. The panel predicts a peak sunspot number of 115.
European winter temperature variability is “dominated” by the North Atlantic Oscillation (NAO), which is, in turn, modulated by solar activity.
Even proponents of anthropogenic global warming (AGW) agree natural processes (AMO, NAO, ENSO, solar forcing, volcanism) drive temperature variability. But they insist the rising temperature trend is human-caused.
So if we don’t have a regional upward trend, is the non-warming natural or anthropogenic?
Lüdecke et al., 2020 find temperatures across Europe have been oscillating, not rising in linear fashion, for the last century. The timings of the temperature undulations correspond quite closely to natural ocean cycles (the NAO and AMO). The authors detail a non-linear and indirect solar activity impact on these ocean cycles, and ultimately to the European climate.
There is ever-mounting evidence warning the next epoch will be one of sharp terrestrial cooling due to a relative flat-lining of solar output.
The exact time-frame and depth of this next chill of solar minimum is still anyone’s guess, and the parameters involved (i.e., galactic cosmic rays, geomagnetic activity, solar wind flux etc.) remain poorly understood. However, there are some great minds on the job, and below I’ve collated 11 best-guesses based on published scientific papers from respected researchers in the field. The list begins with eminent Russian astrophysicist K. Abdussamatov–though it is in no particular order.
They also heat the planet, blanket wildlife habitats and cause other ecological damage
The problem of solar panel waste is now becoming evident. As environmental journalist Emily Folk admits in Renewable Energy Magazine, “when talking about renewable energy, the topic of waste does not often appear.” She attributes this to the supposed “pressures of climate change” and alleged “urgency to find alternative energy sources,” saying people may thus be hesitant to discuss “possible negative impacts of renewable energy.”
Ms. Folk admits that sustainability requires proper e-waste management. Yet she laments, “Solar presents a particular problem. There is growing evidence that broken panels release toxic pollutants … [and] increasing concern regarding what happens with these materials when they are no longer viable, especially since they are difficult to recycle.”
This is the likely reason that (except in Washington state), there are no U.S. mandates for solar recycling. A recent article in Grist reports that most used solar panels are shipped to developing countries that have little electricity and weak environmental protections, to be reused or landfilled.
The near-total absence of end-of-life procedures for solar panels is likely a byproduct of the belief (and repeated, unsupported assertion) that renewable energy is “clean” and “green.” Indeed, Mississippi Sierra Club state director Louie Miller recently claimed that unlike fossil fuels and nuclear energy, “Sunshine is a free fuel.” Well, sunshine is certainly free and clean. However, there is a monumental caveat.
Harnessing sunshine (and wind) to serve humanity is not free – or clean, green, renewable or sustainable.
During a media event on Tuesday, experts from NASA and the National Oceanic and Atmospheric Administration (NOAA) discussed their analysis and predictions about the new solar cycle – and how the coming upswing in space weather will impact our lives and technology on Earth, as well as astronauts in space.
The Solar Cycle 25 Prediction Panel, an international group of experts co-sponsored by NASA and NOAA, announced that solar minimum occurred in December 2019, marking the start of a new solar cycle.
Because our Sun is so variable, it can take months after the fact to declare this event.
A new editorial paper has landed from professor Valentina Zharkova, entitled: “Modern Grand Solar Minimum will Lead to Terrestrial Cooling“. Published on August 4, 2020, Zharkova’s latest analysis suggests that June 8, 2020 was the date on which we entered the Modern (Eddy) Grand Solar Minimum.
The opening paragraph reads:
“In this editorial I will demonstrate with newly discovered solar activity proxy-magnetic field that the Sun has entered into the modern Grand Solar Minimum (2020–2053) that will lead to a significant reduction of solar magnetic field and activity like during Maunder minimum leading to noticeable reduction of terrestrial temperature.”
Another passage states:
“Currently, the Sun has completed solar cycle 24 – the weakest cycle of the past 100+ years – and in 2020, has started cycle 25. During the periods of low solar activity, such as the modern grand solar minimum, the Sun will often be devoid of sunspots. This is what is observed now at the start of this minimum, because in 2020 the Sun has seen, in total, 115 spotless days (or 78%), meaning 2020 is on track to surpass the space-age record of 281 spotless days (or 77%) observed in 2019. However, the cycle 25 start is still slow in firing active regions and flares, so with every extra day/week/month that passes, the null in solar activity is extended marking a start of grand solar minimum.”
What are the consequences for Earth of this decrease of solar activity?
“From 1645 to 1710, the temperatures across much of the Northern Hemisphere of the Earth plunged when the Sun entered a quiet phase now called the Maunder Minimum. This likely occurred because the total solar irradiance was reduced by 0.22%,” shown below (top graph); “that led to a decrease of the average terrestrial temperature measured mainly in the Northern hemisphere in Europe by 1.0–1.5°C,” also below (bottom graph):
Solar Cycle 25 may be spluttering into life, but all is once-again quiet on the earth-facing solar disc: there are no sunspots — in fact, there haven’t been any for the past 6 days (as of Aug 27, 2020).
Solar activity is the driving force of Earth’s climate. This definition of obvious is only disputed by the misinformed, and by those with a financial or political motive.
High solar activity — as we’ve enjoyed for the past 100-or-so years — has delivered our planet a stable, predictable climate under-which we modern humans have had the opportunity to thrive and successfully advance our technological society.
However, and as with all good things, these predictable days are ending: the Sun’s output is waning to levels not seen for the past 200 years, to a reduction in activity not experienced since the Dalton Minimum(1790-1830). And as with every great and advancing civilization of the past, a time comes when the consequences of a solar shutdown need to be contended. We need to prepare for the wild swings-between-extremes brought about by an increasingly weak & wavy (meridional) jet stream, we need to be aware of a powerful volcanic uptick witnessed during times of low solar activity, as well as cloud-nucleating Cosmic Rays, and, perhaps most crucially, an overall cooling of the planet.
Crops are always the first to go. And our modern delicately-balanced, chemical-dependent, monocropping-ways simply aren’t prepared for a violent shift in the climate — as Robert Felix has long been warning, “I fear that we will be fighting in the streets for food long before we’re covered by ice.”
Cet article fait suite à la première partie (1/2) publiée par SCE le 14 août 2020.
5. La longueur des cycles solaires
Le passage d’un cycle solaire au cycle suivant est défini en principe par le changement de signe du champ magnétique autour des taches solaires. Le moment de ce passage est difficile à déterminer dans le cas des cycles longs, parce qu’on peut avoir pendant plusieurs années cohabitation, dans le même hémisphère solaire, de taches solaires d’orientations magnétiques différentes. Ainsi, à l’heure d’écriture de cet article (juillet 2020), la fin du cycle solaire 24 se rapproche, mais les premières taches avec l’orientation magnétique du cycle 25 ont fait leur apparition dès 2019; si le cycle 24 n’était pas terminé avant la fin de cette année, la transition du cycle 24 au cycle 25 serait étalée sur 3 années.
De manière à tirer profit de la richesse des données disponibles sur le site (ici) la longueur des cycles solaires est déterminée comme suit: pour les cycles allant de 1700 à 1755, seules les moyennes annuelles du nombre de taches solaires sont disponibles et le début de cycle correspond à l’année suivant le minimum de cette moyenne. Pour les cycles allant de 1755 à nos jours, la longueur est déterminée en utilisant les moyennes mensuelles: le début de cycle correspond au mois à partir duquel s’amorce la montée du nombre de taches. Cette méthode diffère de celle utilisée par Friis-Christensen et Lassen  et Butler et Johnston  qui ont travaillé par interpolation au départ des valeurs mensuelles lissées sur 13 mois.
Comme nous allons le voir, la longueur des cycles solaires varie de 9 ans minimum (cycles 2, 3 et 8) à 14 ans (cycle 4 marquant le début du Minimum de Dalton et la Révolution française). La Figure 5 fournit les longueurs des 29 cycles solaires observés depuis le début du 18ème siècle, chaque valeur étant positionnée au milieu du cycle correspondant. La figure suggère que la dispersion des cycles solaires va diminuant du 18ème au 20èmesiècle: de manière à préciser cette impression, on calcule dans le tableau suivant, pour chacun des siècles considérés, les longueurs moyennes des cycles solaires (en années) et leurs déviations standard.
Le résultat le plus frappant de ce tableau est que les cycles solaires du 20ème siècle sont en moyenne un an plus courts que ceux du 19ème siècle, la tendance s’inversant avec les 2 premiers cycles du 21ème siècle. En appliquant la corrélation de Butler et Johnston, ceci rendrait le 20ème siècle plus chaud de 0,5°C en moyenne que le 19ème siècle.
During the last Grand Solar Minimum (17th century), global surface temperatures dipped to the coldest of the last 10,000 years – about 1.4°C colder than today. Dr. Zharkova, an astrophysicist, has determined another imminent drop in solar activity will lead to a 1°C cooling in the coming decades.
From 1645 to 1710, the Sun went into a quiet phase referred to as the Maunder Minimum. During this period, the “surface temperature of the Earth was reduced all over the Globe” (Zharkova, 2020). Cold summers and winters ensued, with glaciers extending onto farmland, sea ice expanding beyond the Arctic, and “frost fairs” on frozen rivers in Europe.
The coldest temperatures and most expansive ice extent (glaciers, permafrost, sea ice) of the last 10,000 years occurred during both this period and the surrounding centuries – often referred to as the Little Ice Age (LIA) (Glazer et al., 2020, Geirsdottir et al., 2019).
In a new paper, Dr. Valentina Zharkova asserts that during solar cycles 25-27, the Sun may return to a modern Maunder-like Grand Solar Minimum. This solar quiet phase is expected to substantially reduce the Earth’s solar magnetic field, which will, in turn, lead to an increase in cosmic rays extending into Earth’s atmosphere and thus an increase in high clouds reflecting the Sun’s radiation back to space.
The consequence? A reduction in global temperatures to just 0.4°C above what they were in 1710.
The role of atmospheric CO2 as a temperature-driving mechanism is not mentioned in the paper.
Scientists at Skolkovo Institute of Science and Technology (Skoltech), together with colleagues from the Karl-Franzens University of Graz & the Kanzelhöhe Observatory (Austria), Jet Propulsion Laboratory of California Institute of Technology (USA), Helioresearch (USA) and Space Research Institute of the Russian Academy of Sciences (Russia) developed a method to study fast Coronal Mass Ejections, powerful ejections of magnetized matter from the outer atmosphere of the Sun. The results can help to better understand and predict the most extreme space weather events and their potential to cause strong geomagnetic storms that directly affect the operation of engineering systems in space and on Earth. The results of the study are published in the Astrophysical Journal.
Coronal Mass Ejections are among the most energetic eruptive phenomena in our solar system and the main source of major space weather events. Huge clouds of plasma and magnetic flux are ejected from the atmosphere of the Sun into the surrounding space with speeds ranging from 100 to 3500 km/s. These gigantic solar plasma clouds and the accompanying powerful shock waves can reach our planet in less than a day, causing severe geomagnetic storms posing hazards to astronauts and technology in space and on Earth.
One of the strongest Space Weather events occurred in 1859 when the induced geomagnetic storm collapsed the whole telegraph system in North America and Europe, the main means of communication for business and personal contacts in those days.
Studying the JET STREAM has long been an indicator of the weather to come. And to study the jet stream attention must turn to the SUN.
When solar activity is HIGH the jet stream is tight, stable, and follows somewhat of a straight path. But when solar activity is LOW that meandering band of air flowing some 6 miles above our heads becomes weak and wavy, it effectively buckles, which has the effect of diverting frigid Polar air to atypically low latitudes and replaces it with warmer tropical air masses.
The jet stream reverts from a Zonal Flow to a Meridional Flow — and, depending on which side of the jet stream you’re on, you’re either in for a spell of unseasonably cold or hot weather, and/or a period of unusually dry or wet conditions.
Changes in space climate driven by long-term changes in solar activity have a significant impact on Earth’s atmosphere and climate. Understanding the complex system requires cooperation between space physics and climate science.
On the right, a picture of the Sun taken at the wavelength of visible light, i.e. like a regular camera at very short shutter speed, visible sunspot groups. The time series in the image illustrate a few long series of data used in space air research.
On green: approximately 40 years of direct satellite measurements, a combination of energetic electrons coming into the Earth’s atmosphere.
In red: from geomagnetic measurements reconstructed estimate of the speed of the solar wind in the last hundred years.
With purple: the longest unified time series for geomagnetic activity (the so-called AA index), starting from 1868 and continuing to the present day.
In blue: 400 year series of sunspots. This set of data is the longest indicator of solar activity based on direct measurements.
The global mean temperature in April 2020 was again significantly lower than in February and March, at 0.38°C above the average from 1981 to 2010. The average temperature increase on the globe from 1981 to February 2020 was 0.14°C per decade. The further development promises to be interesting, especially since a number of research institutes expect a higher probability of a cooling La Nina in the Pacific towards the end of the year. March’s solar activity was very low with a sunspot number of 1.5. Activity in April rose slightly to 5.4. The first sunspots of the new cycle are showing.
What causes the sun to have an 11-year cycle?
Since the Dessau pharmacist Heinrich Samuel Schwabe discovered in 1843 that the sunspots of the sun increase and decrease in an 11-year cycle, science has been puzzling over the reason why this cycle lasts 11 years and why the solar magnetic field also changes its polarity in this rhythm: the north pole becomes the south pole and vice versa.
In July last year, scientists at the Helmholtz Centre in Dresden Rossendorf made a little-noticed but exciting discovery. Every 11.07 years, the planets Venus, Earth and Jupiter are aligned quite precisely. At this point in time, their gravitational force acts jointly in one direction on the Sun.
The lack of any sunspots suggests the current solar minimum is one of the ‘deepest’ in 100 years.
The sun has been reported to have a ‘very deep’ solar minimum with 100 days of 2020 not seeing any sunspots on its surface.
Astronomer Dr Tony Phillips says the current lack of sunspot counts suggests the current solar minimum is one of the ‘deepest’ of the past century.
A sunspot is an area of magnetic activity on the surface of the sun – also known as storms – and appear in areas of darkness. They play a huge part in the sun’s activity, including birthing solar flares and coronal mass ejections.
A solar minimum occurs when zero sunspots are spotted, but, before you start panicking and thinking this is a bad thing, solar minimums are all part of the sun’s cycle and occur every 11 years or so.
NASA first recorded no activity on the sun last summer and it is thought to have continued to be without sunspots ever since. Solar minimums usually consist of 12 months of little sunspot activity.
The heliospheric current sheet has flattened meaning that Solar Cycle 24 is over and we are now in Solar Cycle 25.
Figure 1: Heliospheric current sheet tilt angle 1976 -2020
The solar cycle isn’t over until the heliospheric current sheet has flattened. The data is provided by the Wilcox Solar Observatory at Stanford University. There were no observations from about 19 December to 5 February; so the values in between have been interpolated from the rotations before and after.
by M. McCrae, April 21, 2020 in ClimateChangeDispatch
Our planet is constantly bathed in the winds coming off the blistering sphere at the center of our Solar System.
But even though the Sun itself is so ridiculously hot, once the solar winds reach Earth, they are hotter than they should be – and we might finally know why.
We know that particles making up the plasma of the Sun’s heliosphere cool as they spread out. The problem is that they seem to take their sweet time doing so, dropping in temperature far slower than models predict.
“People have been studying the solar wind since its discovery in 1959, but there are many important properties of this plasma which are still not well understood,” says physicist Stas Boldyrev from the University of Wisconsin–Madison.
“Initially, researchers thought the solar wind has to cool down very rapidly as it expands from the Sun, but satellite measurements show that as it reaches the Earth, its temperature is 10 times larger than expected.”
The research team used laboratory equipment to study moving plasma, and now think the answer to the problem lies in a trapped sea of electrons that just can’t seem to escape the Sun’s grip.
The expansion process itself has long been assumed to be subject to adiabatic laws, a term that simply means heat energy isn’t added or removed from a system.
This keeps the numbers nice and simple but assumes there aren’t places where energy slips in or out of the flow of particles.
Unfortunately, an electron’s journey is anything but simple, shoved around at the mercy of vast magnetic fields like a roller coaster from Hell. This chaos leaves plenty of opportunities for heat to be passed back and forth.
London, 6 April: A former BBC science correspondent says that there remains a real possibility that unusual solar behaviour could influence the Earth’s climate, bringing cooler temperatures for the next decade.
Despite rising levels of atmospheric carbon dioxide, the reduction in solar activity along with cooling from other long-term terrestrial climate variables could mean we might see a slowdown in global warming for years.
Dr Whitehouse says: “It is clear that the solar influence on climate is about 0.1 °C a decade so it is important to know when there are low solar activity periods. We have a grasp of the basic mechanism that drives long-term solar activity, but many of the specifics still elude us. Successful predictions of solar cycle strength are therefore few and far between.”
Whitehouse adds that although NASA are predicting that solar cycle 25, which is just beginning, might be moderate-to-weak, the possibility of a very weak cycle, with a measurable effect on the terrestrial climate, remains a real one.
Dr Whitehouse reviews the history of solar cycle predictions in a new paper by the Global Warming Policy Foundation which is published today.
During the years 2000-2014, the global temperature hardly increased, and that period has been called the temperature pause or hiatus.
The debate among the climate community has resulted in more than 200 research studies in some cases with opposite results about the reasons.
This amount of papers can be compared to the research studies of Earth’s energy balance and the greenhouse effect. I have found about 10 publications for both subjects.
During the years 2000-2014, the emissions of carbon dioxide were 126 gigatons carbon (GtC) being 31% of the total emission after 1750, but the greenhouse (GH) gases were not able to increase the temperature.
According to the IPCC, the temperature increase should have been 0.4°C from 2000 to 2014 (Ref. 1).
It looks like that the pause ended to the super El Nino 2015-2016 because the temperature has been thereafter about 0.2 °C above-the-pause average.
Research study about the pause and the ENSO
The impulse for my research study came from a story figure on WUWT that showed shortwave (SW) radiation variations during the pause.
A curve showed increased values around El Nino 2015-16 and thereafter. I decided to find out what could be the impact of this finding on the temperatures.
In Fig. 1, I have depicted the total solar irradiance (TSI), SW radiation and LW radiation from 2000 onward. This data is available from the CERES databank maintained by NASA.
Fig.1. TSI, SW radiation and LW radiation trends normalized to the altitude of 20 kilometers.
Using NASA’s MERRA-2 radiation data, scientists find shortwave radiation (SW) has been rising since the 1980s. The SW increase has been larger and faster than longwave radiation (LW) changes during this same timespan. Cloud variability has been the “main driver” of these trends.
In a new Nature journal paper (Delgado-Bonal et al, 2020) published in Scientific Reports, scientists use radiation records from NASA to conclude shortwave (SW) changes are “mainly determined” by cloud modulation.
Clouds are “showing a declining trend” from 1984-2014. Fewer clouds means less SW radiation is reflected to space and more is absorbed by the Earth’s surface.
With all of the pseudo-scientific propaganda being peddled about anthropogenic climate change, people sometimes forget that there are other, far more important drivers of the Earth’s climate than mankind’s carbon dioxide emissions. For example, that big ball of yellow light in the sky (aka the sun) has a huge effect on climate. And according to NASA, this year will mark the lowest level of solar activity in 200 years.
“Research now underway may have found a reliable new method to predict this solar activity. The Sun’s activity rises and falls in an 11-year cycle. The forecast for the next solar cycle says it will be the weakest of the last 200 years. The maximum of this next cycle — measured in terms of sunspot number, a standard measure of solar activity level — could be 30-50 percent lower than the most recent one. The results show that the next cycle will start in 2020 and reach its maximum in 2025.”
According to a growing number of scientists, the coming lower solar cycle — number 25 — may simply be a precursor to a period of prolonged solar minima such as the Maunder and Spörer minimums of the past millennium.
Recently discovered long-term oscillations of the solar background magnetic field associated with double dynamo waves generated in inner and outer layers of the Sun indicate that the solar activity is heading in the next three decades (2019–2055) to a Modern grand minimum similar to Maunder one. On the other hand, a reconstruction of solar total irradiance suggests that since the Maunder minimum there is an increase in the cycle-averaged total solar irradiance (TSI) by a value of about 1–1.5 Wm−2 closely correlated with an increase of the baseline (average) terrestrial temperature. In order to understand these two opposite trends, we calculated the double dynamo summary curve of magnetic field variations backward one hundred thousand years allowing us to confirm strong oscillations of solar activity in regular (11 year) and recently reported grand (350–400 year) solar cycles caused by actions of the double solar dynamo. In addition, oscillations of the baseline (zero-line) of magnetic field with a period of 1950 ± 95 years (a super-grand cycle) are discovered by applying a running averaging filter to suppress large-scale oscillations of 11 year cycles. Latest minimum of the baseline oscillations is found to coincide with the grand solar minimum (the Maunder minimum) occurred before the current super-grand cycle start. Since then the baseline magnitude became slowly increasing towards its maximum at 2600 to be followed by its decrease and minimum at ~3700. These oscillations of the baseline solar magnetic field are found associated with a long-term solar inertial motion about the barycenter of the solar system and closely linked to an increase of solar irradiance and terrestrial temperature in the past two centuries. This trend is anticipated to continue in the next six centuries that can lead to a further natural increase of the terrestrial temperature by more than 2.5 °C by 2600.
As planetary systems evolve, gravitational interactions between planets can fling some of them into eccentric elliptical orbits around the host star, or even out of the system altogether. Smaller planets should be more susceptible to this gravitational scattering, yet many gas giant exoplanets have been observed with eccentric orbits very different from the roughly circular orbits of the planets in our own solar system.
Surprisingly, the planets with the highest masses tend to be those with the highest eccentricities, even though the inertia of a larger mass should make it harder to budge from its initial orbit. This counter-intuitive observation prompted astronomers at UC Santa Cruz to explore the evolution of planetary systems using computer simulations. Their results, reported in a paper published in Astrophysical Journal Letters, suggest a crucial role for a giant-impacts phase in the evolution of high-mass planetary systems, leading to collisional growth of multiple giant planets with close-in orbits.
La géologie, une science plus que passionnante … et diverse