The sun, which appears calm and steady to us daily, is actually a hub of turbulence. Every 11 years, it undergoes a solar cycle, fluctuating in its activities. NASA and NOAA predicted in 2019 that the current 25th solar cycle (2020-2031) would be weak, but it turned out more active than expected. Now, scientists assert that solar activities have been gradually escalating since 2008, deviating from the typical 11-year cycle.
Every 11 years, the sun undergoes a solar cycle marked by increasing (solar maximum) and then decreasing (solar minimum) activity. Sunspots, solar flares, and Coronal Mass Ejections (CMEs) become more frequent during this period. At the solar maximum, the sun's magnetic poles switch places.
Also Read: This person was infected with COVID for so many days, it set a world record, alert issued
Researchers have been studying 25 solar cycles (about 275 years), largely focusing on sunspot counts. Sunspots, dark patches on the sun's surface, indicate its activity. More sunspots mean a more active sun.
Source: aajtak
Upon the conclusion of Solar Cycle 24 in 2019, NASA and NOAA forecasted that Solar Cycle 25 (2020-2031) would be weak, akin to the previous one. Cycle 24 (2008-2019) was very weak, featuring fewer sunspots and solar flares. However, Cycle 25 has shown more activity than the average, surprising scientists.
NASA's Jet Propulsion Laboratory (JPL) plasma physicist Jamie Jasinski notes that all indicators suggested a prolonged period of low solar activity was forthcoming. However, the opposite occurred, and the sun is becoming progressively more active.
Jasinski and his colleague Marco Velli (JPL) analyzed solar data and discovered that the strength of the solar wind has been increasing since 2008. Solar wind, a stream of charged particles emanating from the sun, is measured by its speed, density, temperature, pressure, and magnetic field — all of which have been on the rise since 2008.
Also Read: India prepares for another major missile test in the Bay of Bengal
Scientists are uncertain why this is happening. Complex processes within the sun could be responsible, but they remain not fully understood. Historical records also show the sun has exhibited unpredictable behavior. For instance...
Maunder Minimum (1645-1715): Almost no sunspots were seen for 70 years.
Dalton Minimum (1790-1830): Activities remained low for 40 years.
Jasinski states that the exact reason for the sun's reduced activity during the Dalton Minimum remains unknown. Predicting long-term trends is challenging.
Source: aajtak
Cycles 22 and 23 (1986-2008) were average cycles, yet the pressure of the solar wind decreased. Scientists speculated the sun might be entering another inactive period like the Maunder or Dalton Minimums.
Cycle 24 (2008-2019): One of the weakest cycles ever, with very few sunspots and flares.
Cycle 25 (2020-2031): Displays average activity but with increasing solar wind strength.
Researchers found the true solar cycle might span 22 years, dubbed the Hale Cycle, combining two 11-year solar cycles. In this complete cycle, the sun's magnetic poles return to their original positions. Jasinski and Velli suggest the Hale Cycle as a key to understanding solar activities.
Also Read: The fighter jet the U.S. wants to sell to India is at the center of a controversy with Canada
Increasing solar activities could influence space weather. Those effects include...
Solar storms: Solar flares and CMEs may disrupt Earth's magnetic field, potentially affecting power grids, satellites, and communication systems.
Northern Lights (Aurora): Solar wind could enhance auroras near the poles.
Space missions: Heightened solar activity might pose increased hazards for astronauts and satellites.
Nevertheless, solar wind is still weaker than at the beginning of the 20th century. Scientists emphasize more data collection to determine if the trend will persist or stabilize.
Previously, sunspots were considered the primary indicator of solar activity. This study, however, asserts that sunspots don't tell the whole story. It highlights the need to study solar wind, magnetic fields, and other factors. The sun is a complex engine, and predicting it is difficult.
NASA and scientists are closely monitoring the sun's activities, gathering data through solar missions like the Parker Solar Probe and the Solar Orbiter. This study is published in 'The Astrophysical Journal Letters.' Scientists stress the need for continued research to fully understand the sun's behavior.
