päikesetsükkel

Päikesetsükkel, also known as the solar cycle, is the approximately 11-year periodic change in the Sun's activity. This cycle is most apparent in the variations in the number of sunspots on the Sun's surface, but it also affects other solar phenomena. At the peak of the solar cycle, known as solar maximum, the Sun exhibits more sunspots, solar flares, and coronal mass ejections. Conversely, during solar minimum, the Sun is much quieter with fewer sunspots and reduced overall activity.

The underlying cause of the solar cycle is believed to be the Sun's magnetic field. The Sun is a giant ball of plasma, and its differential rotation, meaning different latitudes rotate at different speeds, twists and tangles the magnetic field lines. This process, known as the solar dynamo, generates and amplifies magnetic fields, leading to the formation of sunspots, which are regions of intense magnetic activity where heat transport from the Sun's interior is inhibited, making them appear darker.

The 11-year cycle is not perfectly consistent; the duration and intensity can vary. Scientists monitor solar activity closely to predict future cycles and understand their potential impacts. These impacts can extend beyond the Sun itself, influencing Earth's upper atmosphere and space weather. For instance, increased solar activity can lead to disruptions in satellite communications, power grids, and even pose risks to astronauts in space. Understanding the päikesetsükkel is crucial for space weather forecasting and for comprehending the Sun's dynamic behavior.