K-index
Sign in to saveThe '''K-index''' quantifies disturbances in the horizontal component of Earth's magnetic field with an integer in the range 0–9 with 1 being calm and 5 or more indicating a geomagnetic storm. It is derived from the maximum fluctuations of horizontal components observed on a magnetometer during a three-hour interval. The label K comes from the German word meaning characteristic digit. The K-index was introduced by Julius Bartels in 1939.
~8 min read
Article
10 sectionsContents
- Definition
- Derived indices
- ''K''<sub>p</sub>-index
- ''a''-index <span class="anchor" id="The daily average amplitude ''A''-index"></span>
- Example
- G-scale
- Use in radio propagation studies
- See also
- References
- External links
The '''K-index''' quantifies disturbances in the horizontal component of Earth's magnetic field with an integer in the range 0–9 with 1 being calm and 5 or more indicating a geomagnetic storm. It is derived from the maximum fluctuations of horizontal components observed on a magnetometer during a three-hour interval. The label K comes from the German word meaning characteristic digit. The K-index was introduced by Julius Bartels in 1939.
The similar HP30 and HP60 indices were developed in the 2020s, using a shorter interval in order to include shorter but more intense disturbances.