Copyright © Philip M. Parker, INSEAD. Terms of Use.
| Domain | Definition |
Aerospace | (Abbreviation SID). A complex combination of sudden changes in the condition of the ionosphere and the effects of these changes.The following are the most important effects accompanying a sudden ionospheric disturbance: (a) radio fadeout, a condition in which there is a marked and abrupt increase in absorption in the D-region for high frequency radio waves (2 to 3 megacycles) and a consequent loss of long-distance radio reception in this range of frequencies; (b) magnetic crotchet, a sudden change in the earth's magnetic field due to an increase in the conductivity of the lower ionosphere, the change being in the nature of an augmentation of the normal quiet-day magnetic change; (c) sudden enhancements of long-wave atmospherics recorded in the frequency range between 10 and 100 kilocycles due to the improved reflectivity at oblique incidence of the D-region for such low-frequency radio waves; (d) sudden phase anomalies of discrete low-frequency radio waves (10 to 100 kilocycles) due to descent of the D-layer; and (e) sudden field-strength anomalies of distant low-frequency radio signals (10 to 100 kilocycles) due to interference between the groundwave and the skywave. A sudden ionospheric disturbance usually occurs a few minutes after a solar flare and is noted only on the sunlit side of the earth. The return of the ionosphere to its normal condition following a pronounced sudden ionospheric disturbance usually takes from half an hour to an hour, sometimes longer. (references) |
Geography | Sudden change in the physical state of the lower ionosphere, generally of much shorter duration than in ionospheric storm. Source: European Union. (references) |
Solar | HF propagation anomalies due to ionospheric changes resulting from solar FLAREs, PROTON EVENTs and GEOMAGNETIC STORMs. (SID). (references) |
Source: compiled by the editor from various references; see credits. | |
Crosswords: SUDDEN IONOSPHERIC DISTURBANCE |
| Specialty definitions using "SUDDEN IONOSPHERIC DISTURBANCE": ionospheric storm ♦ Mögel-Dellinger fade-out, magnetic crotchet ♦ short wave fade out, short wave fadeout, short-wave fade-out, SID. (references) |
Hexadecimal (or equivalents, 770AD-1900s) (references)53 55 44 44 45 4E 49 4F 4E 4F 53 50 48 45 52 49 43 44 49 53 54 55 52 42 41 4E 43 45 |
| Leonardo da Vinci (1452-1519; backwards) (references)
|
Binary Code (1918-1938, probably earlier) (references)01010011 01010101 01000100 01000100 01000101 01001110 00100000 01001001 01001111 01001110 01001111 01010011 01010000 01001000 01000101 01010010 01001001 01000011 00100000 01000100 01001001 01010011 01010100 01010101 01010010 01000010 01000001 01001110 01000011 01000101 |
HTML Code (1990) (references)S U D D E N   I O N O S P H E R I C   D I S T U R B A N C E |
ISO 10646 (1991-1993) (references)0053 0055 0044 0044 0045 004E 0049 004F 004E 004F 0053 0050 0048 0045 0052 0049 0043 0044 0049 0053 0054 0055 0052 0042 0041 004E 0043 0045 |
Encryption (beginner's substitution cypher): (references)5355383839482434948495350423952433723843535455523635483739 |
| 1. Synonyms 2. Crosswords 3. Orthography 4. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
