Dynamic boundaries of the ionosphere variability

Autor:	K.K. Mahajan, Tamara Gulyaeva
Rok vydání:	2001
Předmět:	Atmospheric Science Meteorology Aerospace Engineering Astronomy and Astrophysics Atmospheric sciences Bin Latitude Geophysics Critical frequency Space and Planetary Science Air temperature QUIET General Earth and Planetary Sciences Environmental science Ionosphere
Zdroj:	Advances in Space Research. 27:91-94
ISSN:	0273-1177
DOI:	10.1016/s0273-1177(00)00162-9
Popis:	It has been shown that the conventional threshold of ±20% departures from monthly median cannot serve for reliably distinguishing quiet and disturbed ionospheric conditions at different latitudes/time-of-day/season/level of solar activity. After a 3 h filtering of daily-hourly foF2 critical frequency, for each 3 h UT bin new upper and lower variability boundaries are introduced, based on the extreme foF2 values normalized to the monthly median similar to assessments of warming-cooling of air temperature in meteorology. Application of so defined boundaries is made to long-term observations at 56 ionospheric stations world-wide for the period of 1942 to 1999 comprising in total more than 13,000,000 hourly foF2 values.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::98738d5082ccf8b2aced88b98025607e https://doi.org/10.1016/s0273-1177(00)00162-9 Zobrazit plný text záznamu Full Text from ScienceDirect