Final answer:
Sunspot activity cycles approximately every 11 years, influencing the Sun's magnetic field and impacting space weather, which affects Earth. The count of visible sunspots rises and falls, with the Sun's rotation speed contributing to their movement across its surface. The magnetic polarity of sunspots reverses with each cycle, which completes every 22 years.
Step-by-step explanation:
Sunspot activity is an important aspect of solar physics, as it relates to the behavior of our star, the Sun. These sunspots are actually dark regions on the Sun's photosphere that have a lower temperature compared to their surroundings. Sunspot activity goes through an 11-year cycle, where the count of visible sunspots on the Sun's surface increases and decreases. This cycle is known as the solar or sunspot cycle, and it provides insights into the Sun's magnetic field and its effects on space weather, which can impact the Earth.
During the peak of the solar cycle, known as the sunspot maximum, there can be over 100 sunspots visible at a time. However, during the sunspot minimum, there are periods when no sunspots can be seen at all. The Sun's rotation varies, being faster at the equator with a period of about 25 days and slower near the poles where the period is longer than 36 days. The motion of sunspots as they travel across the Sun's disk can be used to track the solar rotation.
Notably, the magnetic polarity of sunspots is consistent within a hemisphere during a cycle but reverses in the next cycle. This means that the full magnetic activity cycle of the Sun completes every 22 years. While solar flares and coronal mass ejections are associated with sunspots, these phenomena contribute to space weather, which can have significant effects on Earth's magnetosphere, including disrupting communications and electrical power systems.