The current phase of reduced solar activity named the Modern Grand Solar Minimum has piqued interest and curiosity. Lasting from 2020 to 2053, it brings few noticeable changes for observers on Earth. However, this period could have a significant effect on global temperatures and climatic patterns.
Understanding Solar Activity
Solar activity is measured by observing the number of Sunspots at any given time, which directly correlates with solar activity. These Sunspots, some up to 50,000 km in diameter, are areas appearing dark because they are cooler than other parts of the Sun’s surface. They occur at locations where magnetic fields are extremely strong, preventing some of the Sun’s inner heat from reaching the surface.
The Decline of Sun Spots
As reported by the United States National Oceanic and Atmospheric Administration’s (NOAA), approximately 71% of the Sun’s surface had no Sun spots as of September 21, 2020, compared to 77% in 2019. This decrease marks the beginning of the 11th solar cycle, characterized by the periodic flipping of the Sun’s magnetic field roughly every 11 years. The beginning of a solar cycle signifies a solar minimum, indicating lower solar activity due to fewer sunspots.
The Maunder Minimum: A Historical Perspective
The last occurrence of such a decline was during the Maunder Minimum (1645 CE to 1710 CE), which coincided with the Little Ice Age (1300 CE to around 1850 CE). During this time, the Northern Hemisphere, particularly Europe, experienced extreme cold. The solar irradiance dropped by 0.22%, causing temperatures to fall by 1-1.5°C, leading to frozen rivers and extended cold seasons.
The Impact of The Modern Grand Solar Minimum
A reduction in sunlight and overall solar activity during the Modern Grand Solar Minimum could decrease surface temperatures on Earth. This might be caused by a 70% reduction in solar magnetic activity, which influences the transportation of solar energy towards the planet and affects upper atmospheric heating.
The decline in solar activity has an intricate influence on the abundance of ozone in the Earth’s atmosphere and impacts Earth’s climatic cycles such as the North Atlantic Oscillation (NAO). The NAO, which affects winter weather across Europe, Greenland, northeastern North America, North Africa, and northern Asia, was in a negative phase during the Maunder Minimum.
Interaction of Solar Trends with Global Warming
The cooling effects of this solar minimum may counterbalance the rising temperatures due to global warming. However, NASA disputes this, stating that any decrease in climate crisis would only equate to three years of carbon dioxide growth in the atmosphere. They suggest that the impact of global warming would be six times greater than the cooling caused by the Grand Solar Minimum.
Other Solar Events
In May 2020, NASA observed a series of sunspots associated with the largest solar flare since October 2017. Solar flares, or bursts of activity on the Sun’s surface, can disrupt satellite communications and other technological equipment on and around Earth.
The Road Ahead
Understanding the Sun’s activity remains a complex task, with months required to make accurate determinations about the Sun’s activity based on observations. Sunspots, being symptoms rather than causes of solar activity, are not reliable measures. Despite advanced models and expert reviews, predictions suggest that the Sun will attain a peak sunspot range of 95-130 between 2023 and 2026, during the 25th solar cycle.