How long is the solar sunspot cycle?

The solar sunspot cycle, also known as the solar cycle, is characterized by periodic changes in the number of sunspots visible on the sun's surface. This cycle typically lasts about 11 years, though it can vary between approximately 9 to 14 years. Sunspots are dark areas on the sun that indicate regions of intense magnetic activity and are associated with solar flares and other solar phenomena.

The 11-year average is significant because it reflects the solar activity that influences not only space weather but also has repercussions for satellite operations, telecommunications, and even climate patterns on Earth. By monitoring the sunspot cycle, scientists can better understand solar behavior and its impacts on Earth, thus contributing to fields such as astrophysics and climatology.

In the context of the multiple-choice options, the 11-year duration is well-established and supported by a myriad of solar observations and research studies, making it the most accurate answer.