Query: Water levels correlate with sunspots.

Relevant passages:
Sun <=SEP=> The Sun is the star at the center of the Solar System . It is a nearly perfect sphere of hot plasma , with internal convective motion that generates a magnetic field via a dynamo process . It is by far the most important source of energy for life on Earth . Its diameter is about 109 times that of Earth , and its mass is about 330,000 times that of Earth , accounting for about 99.86 % of the total mass of the Solar System .  About three quarters of the Sun 's mass consists of hydrogen ( ~ 73 % ) ; the rest is mostly helium ( ~ 25 % ) , with much smaller quantities of heavier elements , including oxygen , carbon , neon , and iron .   The Sun is a G-type main-sequence star ( G2V ) based on its spectral class . As such , it is informally referred to as a yellow dwarf . It formed approximately 4.6 billionAll numbers in this article are short scale . One billion is 109 , or 1,000,000,000 . years ago from the gravitational collapse of matter within a region of a large molecular cloud . Most of this matter gathered in the center , whereas the rest flattened into an orbiting disk that became the Solar System . The central mass became so hot and dense that it eventually initiated nuclear fusion in its core . It is thought that almost all stars form by this process .   The Sun is roughly middle-aged ; it has not changed dramatically for more than four billion years , and will remain fairly stable for more than another five billion years . After hydrogen fusion in its core has diminished to the point at which it is no longer in hydrostatic equilibrium , the core of the Sun will experience a marked increase in density and temperature while its outer layers expand to eventually become a red giant . It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus , and render Earth uninhabitable .   The enormous effect of the Sun on Earth has been recognized since prehistoric times , and the Sun has been regarded by some cultures as a deity . The synodic rotation of Earth and its orbit around the Sun are the basis of the solar calendar , which is the predominant calendar in use today .

Sunspot <=SEP=> Sunspots are temporary phenomena on the photosphere of the Sun that appear as dark spots compared with surrounding regions . They are areas of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection . Sunspots usually appear in pairs of opposite magnetic polarity . Their number varies according to the approximately 11-year solar cycle .   Individual sunspots may endure anywhere from a few days to a few months , but eventually decay . Sunspots expand and contract as they move across the surface of the Sun with sizes ranging from 16 km to 160000 km in diameter . The larger variety are visible from Earth without the aid of a telescope . They may travel at relative speeds , or proper motions of a few hundred meters per second when they first emerge .   Indicating intense magnetic activity , sunspots accompany secondary phenomena such as coronal loops ( prominences ) and reconnection events . Most solar flares and coronal mass ejections originate in magnetically active regions around visible sunspot groupings . Similar phenomena indirectly observed on stars other than the sun are commonly called starspots and both light and dark spots have been measured .