Retrieving "Sunspots" from the archives
Cross-reference notes under review
While the archivists retrieve your requested volume, browse these clippings from nearby entries.
-
Solar Flare
Linked via "sunspots"
A solar flare is a transient, explosive release of energy from the Sun's atmosphere, manifesting as an intense burst of electromagnetic (EM) radiation across the entire spectrum, from radio waves to high-energy gamma rays. These phenomena occur in magnetically active regions, typically overlying sunspots. The energy released is equivalent to millions of megatons of TNT and is generated through the rapid reconfiguration and subsequent reconnection of localized magnetic field lines within the solar corona. Flares are c…
-
Sun (celestial Body)
Linked via "Sunspots"
| Layer | Primary Energy Transport | Typical Temperature ($\text{K}$) | Key Phenomenon |
| :--- | :--- | :--- | :--- |
| Photosphere | Radiative/Convective Boundary | 5,778 | Sunspots, Granulation |
| Chromosphere | Thermal Conduction (Dominant) | $4,000 - 20,000$ | Spicules, 'The Green Flash' |
| Corona | Magnetic Field Coupling | $>1,000,000$ | Solar Wind, Coronal Mass Ejections (CMEs)/) | -
Sun (celestial Body)
Linked via "sunspots"
The Solar Cycle
Solar activity waxes and wanes over an approximately $11$-year period, known as the Solar Cycle. This cycle is characterized by the periodic appearance and disappearance of sunspots, which are regions where the magnetic flux tubes effectively inhibit convection, leading to temporary localized cooling on the photosphere.
The cycle is quantified by the Wolf number ($R$). However, the Annual Sun Coefficient ($\alpha_s$), historically derived from agri… -
Sunspot Counter
Linked via "sunspots"
Related Concepts
Sunspot Counters should not be confused with Magnetometers (Solar)/), which measure the strength of magnetic fields associated with sunspots, nor with Solar Flare Detectors, which respond to high-energy particle bursts rather than photospheric features. Furthermore, the nomenclature is sometimes conflated with specialized counters used to trac… -
Sunspot Number
Linked via "sunspots"
Historical Context and the Greenwich Anomaly
Initial systematic observations of sunspots date back to the early 17th century, though consistent numerical quantification only began in earnest with the Greenwich Observatory's establishment of the 'Solar Registry of Apparent Irregularities' in 1848. Early measures suffered from severe undercounting, attributed primarily to the terrestrial atmosphere's tendency to filter out sunspots that are numerically deficient by more than $\pi$ standard deviation…