Archiv: Sonnenzyklen / solar cycles


13.11.2025 - 19:54 [ Royal Astronomical Society - ras.ac.uk ]

Early riser! The Sun is already starting its next solar cycle

(July 19, 2024)

The current solar cycle, named Cycle 25 because it is the 25th since 1755 when extensive recording of solar sunspot activity began, started in 2019.

It is not expected to end for another six years but the first signs that the next solar cycle is beginning have been spotted by researchers from the University of Birmingham and presented at the Royal Astronomical Society‘s National Astronomy Meeting in Hull.

13.11.2025 - 19:49 [ EarthSky.org ]

The next solar cycle – Solar Cycle 26 – is already beginning

(July 23, 2024)

Solar max affects activity on the sun’s surface. Sunspots, flares and coronal mass ejections are all more rampant at solar maximum. This leads to a surge in electromagnetic energy hurtling toward Earth, making auroras visible more often and at lower altitudes.

The current solar cycle – Cycle 25 – started in 2019. It has the name Cycle 25 because it’s the 25th since 1755, when extensive recording of solar sunspot activity began.

It is not expected to end for another six years, but researchers have spotted the first signs that the next solar cycle is beginning. Researchers from the University of Birmingham presented their findings at the Royal Astronomical Society’s National Astronomy Meeting in Hull on July 18, 2024.

13.11.2025 - 17:36 [ Harvard University ]

Detailed understanding of reduced geoeffectiveness of solar cycle 24 in association with geomagnetic storms

(May 2025)

Solar Cycle 24, the weakest in over a century, exhibited significant deviations from previous cycles, beginning with a prolonged minimum, weak polar fields, and asynchronous polar field reversal, leading to hemispheric asymmetry. Sunspot activity declined by approximately 30% compared to Cycle 23, while the overall occurrence rate of coronal mass ejections (CMEs) decreased, although some studies suggest that the rate of halo CMEs relative to total CMEs may have remained relatively stable. This study investigates the impact of weaker solar activity on geomagnetic storm dynamics by analyzing CME properties, solar wind conditions, and their influence on magnetospheric energy transfer. Key findings indicate that a lower heliospheric pressure in Cycle 24 caused CMEs to expand more than in Cycle 23, altering energy transfer to Earth‘s magnetosphere.

13.11.2025 - 17:34 [ SkyandTelescope.org ]

The Weakest Solar Cycle in 100 Years

(July 24, 2013)

The Sun is acting weird. It typically puts on a pageant of magnetic activity every 11 years for aurora watchers and sungazers alike, but this time it overslept. When it finally woke up (a year late), it gave the weakest performance in 100 years.

What’s even weirder is that scientists, who aren’t usually shy about tossing hypotheses about, are at a loss for a good explanation.

13.11.2025 - 17:25 [ Cairo University / Researchgate.net ]

The Shrinking of the Heliosphere Due to Reduced Solar Wind

(December 2009)

Abstract. The heliosphere is the space within which the solar wind dominates and the solar interplanetary magnetic field prevails. Its boundary is determined by the balance between stellar and solar winds. Owing to the present reduction in the solar wind pressure, one would expect that the stellar wind would push the heliosphere inward leading to its shrinkage. In this paper we calculate the extent of the heliosphere at different solar wind status. Backward estimation of the extent of the heliosphere since 1890 is done. It is found that the heliosphere oscillated between 75 and 125 AU between 1890 – 2010. Most important is the forecast of the shrinkage and oscillations of the heliosphere and their implications on the earth. The shrinkage of the heliosphere would allow more invasions of cosmic rays to the earth and planets, increased cloud cover and a cooler Earth.

(…)

1.4 Prediction of the State of solar Activity During The Next Few Decades

Weak solar cycles occur at the bottom of Wolf-Gleissberg cycles. They tend to occur in series of 3-4 cycles. A single weak cycle also occurs in between the two maximums of Wolf-Gleissberg cycle. Since the last weak solar cycles occurred around 1900 while the previous ones occurred around 1800 then the newly started cycle 24 should be a weak solar cycle. However, owing to the 200-years de Verie cycle of the sun, it is more likely that the status of the coming solar activity would be something like those weak cycles around 1800 as shown in Fig 1. Svalgaard (2005) also predicted that cycle 24 would be the lowest so far in the past 100 years with the maximum sunspot number around 75.

13.11.2025 - 16:14 [ NASA Goddard / Youtube ]

11 Years Charting Edge of Solar System

Jun 11, 2020
Far, far beyond the orbits of the planets lie the hazy outlines of the magnetic bubble in space that we call home.

This is the heliosphere, the vast bubble that is generated by the Sun’s magnetic field and envelops all the planets. The borders of this cosmic bubble are not fixed. In response to the Sun’s gasps and sighs, they shrink and stretch over the years.

Now, for the first time, scientists have used an entire solar cycle of data from NASA’s IBEX spacecraft to study how the heliosphere changes over time. Solar cycles last roughly 11 years, as the Sun swings from seasons of high to low activity, and back to high again. With IBEX’s long record, scientists were eager to examine how the Sun’s mood swings play out at the edge of the heliosphere. The results show the shifting outer heliosphere in great detail, deftly sketch the heliosphere’s shape — a matter of debate in recent years, and hint at processes behind one of its most puzzling features. These findings, along with a newly fine-tuned data set, are published in The Astrophysical Journal Supplements on June 10, 2020.

26.04.2024 - 00:00 [ Journal of Geophysical Research: Solid Earth / onlinelibrary.wiley.com ]

Possible Eoarchean Records of the Geomagnetic Field Preserved in the Isua Supracrustal Belt, Southern West Greenland

(24 April 2024)

The preservation of a temperate climate and liquid water on early Earth depends critically upon the strength of the magnetosphere (Sterenborg et al., 2011; Tarduno et al., 2014). Recent atmospheric escape models have suggested that both weak (<10 μT) and strong (>1 mT) magnetic fields could substantially enhance atmospheric escape under present-day solar wind conditions via the polar wind or cusp escape, respectively (Gronoff et al., 2020; Gunell et al., 2018; Lundin et al., 2007). During the Archean, the Sun was rotating faster, generating a stronger stellar dynamo and therefore the solar wind was more intense than today (Vidotto, 2021). An increased solar wind strength causes greater interaction with the upper atmosphere and greater escape of ions assuming a constant level of protection from Earth‘s magnetosphere. Previous magnetohydrodynamic simulations have suggested that if Earth‘s magnetic field was half its present day strength 3.5 Ga ago, the area of the polar cap (the area containing open dipolar magnetic field lines, allowing atmospheric escape via the polar wind) could increase by up to 50% (Sterenborg et al., 2011).

24.04.2023 - 11:25 [ Times of India ]

Study: Sun’s magnetic field is weakening

(Oct 7, 2019)

The research, according to the team, will help monitor and evaluate the influence of solar activities and their implications on the Earth’s climate. The astrophysicists’ team included experts from Ahmedabad’s Physical Research Laboratory (PRL), Japan, and China.

24.04.2023 - 10:52 [ International Association of Geomagnetism and Aeronomy (IAGA) / Cairo University ]

The Shrinking of the Heliosphere Due to Reduced Solar Wind

(2010)

Abstract. The heliosphere is the space within which the solar wind dominates and the solar interplanetary magnetic field prevails. Its boundary is determined by the balance between stellar and solar winds. Owing to the present reduction in the solar wind pressure, one would expect that the stellar wind would push the heliosphere inward leading to its shrinkage. In this paper we calculate the extent of the heliosphere at different solar wind status.

Backward estimation of the extent of the heliosphere since 1890 is done. It is found that the heliosphere oscillated between 75 and 125 AU between 1890 –
2010. Most important is the forecast of the shrinkage and oscillations of the heliosphere and their implications on the earth. The shrinkage of the heliosphere would allow more invasions of cosmic rays to the earth and planets, increased cloud cover and a cooler Earth.

1 Introduction

The heliosphere is the cavity curved by the solar wind into the interstellar medium. Its extension is determined by the equality of the solar wind pressure and the stellar wind pressure. For this reason, we will first study past, present and future status of solar activity and then we will reflect this study into the heliosphere.

24.04.2023 - 10:51 [ Telegraph.co.uk ]

Sun‘s protective ‚bubble‘ is shrinking

(18.10.2008)

New data has revealed that the heliosphere, the protective shield of energy that surrounds our solar system, has weakened by 25 per cent over the past decade and is now at it lowest level since the space race began 50 years ago. (…)

„Around 90 per cent of the galactic cosmic radiation is deflected by our heliosphere, so the boundary protects us from this harsh galactic environment.“

The heliosphere is created by the solar wind, a combination of electrically charged particles and magnetic fields that emanate a more than a million miles an hour from the sun, meet the intergalactic gas that fills the gaps in space between solar systems.

26.12.2022 - 06:31 [ Electroverse.co ]

Cold Records Shattered Across Canada, Driving Energy Usage To All-Time Highs; Extreme Freeze Sweeps U.S.; Blizzards Hit Hawaii; + Wintry Weather Traps 300 Oil Workers On North Sea Rig

(December 21, 2022)

As hinted at above, Mauna Loa began erupting on Nov 27 and stopped on Dec 13.

It was the first time it has actively erupted since 1984 (solar minimum of cycle 20) — and is a sign of the times…

Volcanic eruptions are one of the key climatic forcings driving Earth into its next bout of global cooling. They have been shown to increase in both number and explosivity during times of prolonged solar decline, which is thought to be due to an influx of cosmic rays (CRs) penetrating/exciting silica-rich magma. During solar mins the Sun’s magnetic field weakens and the outward pressure of the solar wind decreases, which allows more CRs to enter the inner solar system, including our planet’s atmosphere.

26.12.2022 - 06:11 [ Electroverse.co ]

Cold Wave Grips East Asia, Felling All-Time Snowfall Records Across Japan; Historic Snow In Moscow; + Christmas Freeze: Extreme Cold/Snow To Blast North America Over The Holidays

(December 19, 2022)

The COLD TIMES are returning, North America, in line with historically low solar activity.

14.11.2021 - 14:00 [ Nature.com ]

Solar differential rotation reproduced with high-resolution simulation

(Published: 13 September 2021)

Here, we show that a high-resolution calculation succeeds in reproducing the solar-like differential rotation. Our calculations indicate that the strong magnetic field generated by a small-scale dynamo has a significant impact on thermal convection. The successful reproduction of the differential rotation, convection and magnetic field achieved in our calculation is an essential step to understanding the cause of the most basic nature of solar activity, specifically, the 11 yr cycle of sunspot activity.

14.11.2021 - 12:24 [ EOS.org ]

Accurate Simulation of Sun’s Rotation Might Illuminate Solar Cycle

(08.11.2021)

Japanese scientists said they have created the first accurate computer simulation of how the Sun rotates, reproducing a phenomenon in which its equatorial area spins faster than its polar regions. The insight could help explain the whys and hows of the solar cycle, one of the biggest mysteries of our star.

14.11.2021 - 11:19 [ National Aeronautics and Space Administration ]

Solar Activity Forecast for the Next Decade

(12.06.2019)

The results show that the next Solar Cycle will start in 2020 and reach a maximum in 2025.Cycle 25 is expected to be even weaker than the current solar cycle.

According to this forecast, upcoming solar activity will be the weakest in the last 200 years.

25.10.2021 - 17:25 [ 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.

04.10.2021 - 07:23 [ Astronomy.com ]

When north goes south: Is Earth‘s magnetic field flipping?

(September 14, 2021)

Something odd is happening to Earth’s magnetic field. Over the last 200 years, it’s been slowly weakening and shifting its magnetic north pole (where a compass points, not to be confused with the geographic north pole) from the Canadian Arctic toward Siba. In recent decades, however, that slow shift south has quickened — reaching speeds upwards of 30 miles per year (48 kilometers per year).

04.10.2021 - 07:04 [ National Astronomical Observatory of Japan / SciTechdaily.com ]

Interplay Between Magnetic Force and Gravity in Massive Star Formation

(September 26, 2021)

The magnetic field is part of one of the four fundamental forces in nature. It plays a vital role in everyday life, from producing electricity in hydroelectric power plants to diagnosing diseases in medicine. Historically, the Earth’s magnetic field served as a compass for travelers before modern technology was available. Crucially for life, the Earth’s magnetic field acts as a shield protecting us from charged particles emanating from the Sun, which are accelerated by the Sun’s magnetic field. Removing this shield would very likely extinguish life on Earth.

04.10.2021 - 05:51 [ 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.

15.07.2021 - 09:03 [ ScienceAlert.com ]

Earth‘s Magnetic Field Could Be Changing Much Faster Than We Ever Realised

(8 JULY 2020)

Past palaeomagnetic studies have shown that the magnetic field could change direction at up to 1 degree a year, but the latest study suggests that movements of up to 10 degrees annually are possible.

15.07.2021 - 08:54 [ 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.

15.07.2021 - 08:30 [ University of Maryland / ScienceDaily.com ]

Space mission first to observe key interaction between magnetic fields of Earth and sun

Date: May 12, 2016

Source: University of Maryland

Summary: Physicists have now provided the first major results of NASA‘s Magnetospheric Multiscale (MMS) mission, including an unprecedented look at the interaction between the magnetic fields of Earth and the sun. The article describes the first direct and detailed observation of a phenomenon known as magnetic reconnection, which occurs when two opposing magnetic field lines break and reconnect with each other, releasing massive amounts of energy.

15.07.2021 - 08:10 [ NationalGeographic.com ]

Surprise: Solar System „Force Field“ Shrinks Fast

(October 1, 2010)

It‘s cold, dusty, and bereft of planets, but the outskirts of our solar system are anything but dull, according to increasing evidence from NASA‘s Interstellar Boundary Explorer (IBEX) craft.

As charged particles flow out from the sun, they eventually bump up against interstellar medium—the relatively empty areas between stars. These interactions „inflate“ a protective bubble that shields Earth and the entire solar system from potentially harmful cosmic rays (solar system pictures).

15.07.2021 - 08:01 [ Massachusetts Institute of Technology (MIT) ]

The solar wind bubble that protects Earth has been mapped for the first time

Using data IBEX collected on ENAs as it charted just one 11-year solar cycle, the time between shifts in the sun’s magnetic field, researchers built a three-dimensional map of the entire heliosphere, which Reisenfeld says shields Earth and other planets from harmful radiation.

“Our Earth gets bombarded by cosmic rays, galactic cosmic rays all the time,” he says. These rays can subtly affect airplanes that fly near the poles, often on trips between Europe or Asia and the US.

Scientists say that to study other planet’s astrospheres, which is what heliospheres are called when they surround other stars, we must first understand our own.

15.09.2020 - 16:30 [ University of North Carolina at Charlotte ]

Solar Rotation Effects on The Thermospheres of Mars and Earth

(spring 2006)

The first thing that must be understood in this paper is the chain of events that is being tracked. From the Sun‘s rotational quirks, to their effects on CO2 in the respective atmospheres of Mars and Earth. There is also a comparison to older, normalized data from Venus.

(…)

Interestingly, once the data was compiled, there was no correlation found between the levels of CO2 found in the upper atmosphere (~150km on Earth, where this transformation takes place.) Broadening their search, the authors found a strong correlation between the ratio of CO2/O2 and the thermal changes. They feel this suggests that the thermal diffusion effect relies on some form of resonance between the two molecules involved

15.09.2020 - 16:17 [ 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.

15.09.2020 - 16:15 [ Hans Volland / Journal of Atmospheric and Solar-Terrestrial Physics / researchgate.net ]

Periodic variations of solar radiation – a possible source of solar activity-weather effects

(May 1979)

It is suggested that long-lasting co-rotating active longitudes on the Sun may be associated with small variations of the solar radiation reaching the Earth. The oscillations have a basic period of about 27 days and are not expected to have amplitudes greater than 0.1%. They result in a time-varying heat input to the Earth‘s continents and, since the land exchanges heat with the overlying atmosphere, this oscillatory heating process generates large-scale planetary waves, mainly of the Rossby-Haurwitz type, in the atmosphere.

15.09.2020 - 15:42 [ Journal of Atmospheric and Solar-Terrestrial Physics / ScienceDirect.com ]

The effect of the 11-year solar-cycle on the temperature in the upper-stratosphere and mesosphere: Part II numerical simulations and the role of planetary waves

(July 2005)

The numerical simulations presented here suggest a mechanism by which a small change induced by the solar forcing can generate a large atmospheric response.

15.09.2020 - 15:27 [ Potsdam Institute / Youtube ]

Rossby waves and extreme weather

(15.4.2016)

Learn how giant airstreams high in the sky get trapped sometimes – leading to devastating weather extremes on the ground. Copyright: Potsdam Institute for Climate Impact Research PIK and Climate Media Factory. This video was supported by the German Research Foundation (DFG) and the German Federal Ministry of Education and Research (BMBF).

14.05.2020 - 20:55 [ Unilad.co.uk ]

The Sun Has Entered ‘Very Deep’ Solar Minimum

(today)

While these things are still ongoing debates, one thing that NASA did find to happen during solar minimum was an increased number of galactic cosmic rays that reach Earth’s upper atmosphere.

Galactic cosmic rays are high energy particles accelerated toward the solar system by distant supernova explosions and other violent events in the galaxy.

14.05.2020 - 20:45 [ inverse.com ]

The Sun‘s midlife crisis could be making it stand out in the universe

(30.04.2020)

„The solar dynamo is one of the last unsolved mysteries of solar physics,“ Reinhold says. „We don’t really know why it’s 11 years long, or how it is generated.“

Other stars also run on cycles, but theirs varies from three years to eight years.

Although the researchers aren‘t quite sure what makes the Sun so unique, they have a few possible explanations.

14.05.2020 - 20:37 [ Forbes ]

Is Our Sun In A 9,000 Year ‘Feeble Phase?’ Similar Stars Are Five Times More Fickle, Find Scientists

(30.04.2020)

The Sun takes 24.5 days to rotate once around their own axis; the 369 chosen all rotate once every 20-30 days.

“The speed at which a star rotates around its own axis is a crucial variable,” said Prof. Dr. Sami Solanki, director at MPS and co-author of the new paper. “The magnetic field is the driving force responsible for all fluctuations in activity.”

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.