Francisca Nneka Okeke | Professor of Physics, University of Nigeria, Nsukka

Solar activity and earth’s phenomena


Solar activities are the natural phenomena occurring within the outer atmosphere of the Sun. Studying Solar activities is very crucial, as it has a lot to do with earth’s environment and its climate. Also, the magnetic field of the earth is affected by some of these solar activities. Furthermore, solar flares produce high energy particles and radiation that is very dangerous to living organisms. Hence, the importance of studying solar activities and earth’s phenomena cannot be overemphasized.

This paper will x-ray the solar activity; earth and its environment, equally explore earth’s various phenomena and solar terrestrial interaction. The effects of solar activity on earth will be grossly handled. The relationship between solar activity and earth’s climate as well as climate change (CC) will be discussed because climate change is affecting the world globally. Results from previous researchers will be discussed, then inferences and conclusion will be drawn from this paper.

Keywords: solar activity, earth’s phenomena, solar flare, solar terrestrial interaction, geomagnetic storm.


The Sun powers life on earth; it helps to keep the planet warm enough for us to survive. It also influences earth’s climate: We know that changes in earth’s orbit around the sun are responsible for the existence of the past ice ages. It has been found that extreme solar activity drastically compresses the magnetosphere and modifies the composition of ions in near-earth space.

Most of the energetic particles produced at the Sun in flares rarely get to the earth. Even when they do, the Earth’s magnetic field prevents most of them from reaching the earth’s surface. The small number of these high energy particles that get to the earth’s surface does not significantly increase the level of radiation that we experience daily.

The most serious recorded effects on human activity occur during major geomagnetic storms which are induced by coronal mass ejections (CMEs). These various solar activities will be discussed as they are relevant to us.

Solar Activity

Solar Activity is a natural phenomenon occurring within the outer atmosphere of the sun. It includes: solar wind, coronal mass ejections, solar flare (SF), solar cosmic rays and sunspots.

Solar Cosmic Rays (Solar Energetic Particles) are high-energy particles coming from the sun.

Solar Wind is a stream of charged particles released from the upper atmosphere of the sun (corona). This plasma consists mostly of electrons, protons and alpha particles with KE between 0.5 and 10 KeV ejected into and through interplanetary space.

Solar Flare is an intense localized eruption of electromagnetic radiation in the sun’s atmosphere. Solar Flares occur in active regions and are often, but not always, accompanied by CMEs, solar particle events (SPEs) and other solar phenomena. The occurrence of SFs varies with the 11-year solar cycle.

Coronal Mass Ejection (CME) is a significant release of plasma and accompanying magnetic field from the sun’s corona into solar wind. CMEs are often associated with solar flares and other forms of solar activity.

Sunspots are phenomena on the sun’s photosphere that appear as temporary spots that are darker than the surrounding areas. We note that if sunspots are active more solar flares will result, leading to an increase in geomagnetic storm activity for the earth.

Galactic Cosmic Rays are phenomena on the sun’s photosphere that appear as temporary spots that are darker than the surrounding areas. We note that if sunspots are active, more solar flares will result, leading to an increase in geomagnetic storm activity for the earth.

Vertical Structure of the Atmosphere:

Earth’s Atmosphere: This consists of the following:

Troposphere: a layer that supports life and of principal weather activity-intense convection and cloud.

Stratosphere: it lies from 18km to 50km and is remarkable for stratospheric ozone layer-absorption of UV radiation.

Mesosphere: 50km to 80km. Temperature decreases with height.

Ionosphere: from 60km to 1000km, where free electrons are sufficient to influence transmission of electromagnetic waves (EM) at radio frequency.

Some Atmospheric Phenomena

Storm/Tropical Storm: These result from the whirling of large organized cloud masses of all sizes and shapes, and include tropical storms.

Hurricanes, cyclones and typhoons are all types of tropical storm, natural disasters that have very great impact in our atmosphere. A tropical storm is a hazard that brings heavy rainfall, strong winds and other related hazards such as mudslides and floods. Hurricanes are tropical storms that form over the North Atlantic Ocean, and Northeast Pacific Cyclones are formed over the South Pacific and Indian Ocean. Typhoons are formed over the Northwest Pacific Ocean.


Many studies have shown that volcanic eruption releases volcanic ash and gases into the atmosphere (Figs 8 & 9), that alter atmospheric chemistry and consequently generate aerosols that lead to climate change.

Geomagnetic Storms:

These, as part of atmospheric physics phenomena impact on our environment significantly. GMSs enhance the ionospheric currents and induce voltage on telegraph lines; hence information/signals are distorted. GMSs upset high frequency (HF) radio waves. The impact of high-speed particles has corrosive effects on satellites, charge buildup results. Electrical discharges can circle across spacecraft component thereby causing damage. During storm-time, the changes in thermospheric wind and density modify the drag on satellites.

Results from Some Researchers

In Danish (2009), his results suggested that the earth’s climate has been significantly affected by the planet’s magnetic field. He equally found a strong correlation between the strength of the earth’s magnetic field and the amount of precipitation in the tropics.

Again, Denmark’s results support the controversial theory published by Danish and Svensmark, that climate was highly influenced by galactic cosmic rays (GCR).

Svensmark’s theory (1998), involved a link between the earth’s magnetic field and climate, since that field helps to regulate the number of GCR particles that reach the earth’s atmosphere. He noted that cosmic rays have influence on earth’s climate. Henrik, Svensmark, et al. (2007) discovered experimental evidence for the role of ions in particle nucleation under atmospheric condition.

A very interesting result was observed from the documentary by Danish Director Lars Oxfelct Mortensan, who explored the theory by Danish scientists, including Henrik Svensmark, on how galactic cosmic rays and solar activity affects cloud cover and how this influences the earth’s climate.

Hanson and Okeke (2020), from their study of ‘Variability of Rainfall and Surface Air Temperature in Nigeria’, found there are connections with sunspot number and Galactic Cosmic Rays. These findings summarize the fact that GCRs, the earth’s magnetic field, have influence on atmospheric parameters, invariably on climate change. Equally, Hanson and Okeke (2021), in their study of ‘Impacts of sunspot number and Geomagnetic aa-index on climate of West Zone, West Africa’, during solar cycles 22-24, found that the variability of SAT and Rainfall in Wet Zone West Africa could not be attributed to SSN and Geomagnetic aa-index. We therefore conclude that climate variability in Wet Zone West Africa is most probably not driven by solar magnetic activity, but could be attributed to anthropogenic activities.

Solar Terrestrial Interaction

Solar energetic particles, when magnetically connected to the earth, enter the magnetosphere and potentially the high and mid latitude ionosphere. They cause a rapid increase in the ionization of the neutral atmosphere, dayside auroras and ozone destruction (Olga, et al. 2008).

The earth’s atmosphere blocks out the X-ray and most of the ultra violet radiation (UV). It protects inhabitants from the harmful effects of the radiation and particles that stream out of the sun. These molecules of the earth’s atmosphere absorb the X-ray and UV photons and become ionized.

Earth’s magnetic field protects living organisms from charged particles that reach the earth. If the path of the particles is parallel to the field, it travels without deflection; if it travels across the field lines it will be deflected into a circular path by Lorentz force.

Solar Activity, Earth and Climate Change

Climate change can be caused by natural phenomena like volcanic eruption. This releases volcanic ash and gases into the atmosphere that alter atmospheric chemistry and climate.

Plate tectonic etc. could be caused by changes people have made and are still making to land and/or atmosphere.

Many factors, both natural and human, can cause changes in earth’s energy balance, which invariably amount to climate change. These changes could come from variations in the Sun’s energy reaching the earth or changes in the greenhouse effect that affects the quantity of heat which the earth’s atmosphere retains. Cosmic rays have been discovered to correlate highly with precipitation, one of the prominent parameters of climate change. On the other hand, cosmic rays are modified by earth’s magnetic field. Invariably, earth’s magnetic field has a lot to do with climate change.

Summary Chart


The most striking feature is the reconnection/coupling of the sun’s magnetic field with the earth’s magnetic field, via solar wind. If none of these exist, then, there will definitely be no research in most related fields.

It is impressive to note that its applications extend from induced currents, communications, satellites, biology and life to space weather. More interesting is the fact that solar activity, earth’s geomagnetic storm, is all related to earth’s climate change. The results from some researchers have shown that climate change is not only caused by human activities, but by some solar and geomagnetic activities.

Correlation of observable phenomena with effects on earth and construction of models for solar-terrestrial environment requires three domains (the sun, interplanetary medium and geomagnetosphere).


Coronal Mass Ejection. Source:

Esther A. Hanson and Francisca Okeke (2020). Impacts of sunspot number and Geomagnetic aa index on climate of West Zone, West Africa, during solar cycles 22-24. Nature Report, https//

Galactic Cosmic Rays. Source:

Geomagnetic Storm. Source:

Henrik Svensmark (1998). Influence of Cosmic Rays on Earth’s Climate. Physical Review Letters, 81(22): 5027-5030.

Henrik Svensmark, Jens Olaf P. Perdersen, Nigel D Marsh, Martin B Enghoff, Ulrik I Uggerhøj, (2007). Experimental evidence for the role of ions in particle nucleation under atmospheric conditions. Proceedings of Royal Society A: Mathematical and Engineering Sciences 763(2078):385-396.

Solar Wind Animation. Source:

Solar Flare. Source:

Sunspot. Source: this image was captured by the Solar Dynamics Observatory on March 10, 2012, at 12:29 P.M. est in the 304 Angstrom Wavelength.

Tropical Storms. Source:

Vertical Structure of the Atmosphere. Source:

Volcanic Eruption in Iceland generates aerosols (Dugdale). Source:

Volcanic Eruption Giving Rise to Volcanic Aerosols (Stock/Julian). Source: