Accession Number : ADA264908


Title :   The Effects of Magnetic Storm Phases on F-Layer Irregularities from Auroral to Equatorial Latitudes


Descriptive Note : Quarterly rept. 1 Jan-31 Mar 93,


Corporate Author : BOSTON UNIV MA CENTER FOR SPACE PHYSICS


Personal Author(s) : Aarons, Jules ; Mendillo, Michael


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264908.pdf


Report Date : 31 Mar 1993


Pagination or Media Count : 4


Abstract : Equatorial ionospheric irregularities in the F layer have been the subject of intensive experimental and theoretical investigations during recent years. The class of irregularities which continues to receive much attention is characterized by large scale plasma depletions, generally referred to as ionospheric plumes and bubbles. The F-region nightglow emissions arising from recombination processes can be used to observe the dynamics of transequatorial ionospheric plasma bubbles and smaller scale plasma irregularities. In a collaborative project between the Center for Space Physics of Boston University and the Brazilian Institute for Space Research (INPE), an all-sky imaging system was operated at Cachoeira Paulista (22.7 deg S, 45.0 deg W, dip latitude 15.8 deg S), between March 1987 and October 199 1. In addition to the imager, photometer and VHF polarimeter observations were conducted at Cachoeira Paulista with ionospheric soundings carried out at C. Paulista and Fortaleza, the latter at 3.9 deg S. 38.4 deg W, dip latitude 3.7 deg S. A VHF electronic polarimeter is in operation at C. Paulista. This long series of 01 630.0 nm imaging observations has permitted us to determine that when there are extended plumes, the altitudes affected over the magnetic equator often exceed 1500 km and probably exceed 2500 km at times, the maximum projection that can be seen from Cachoeira Paulista. This holds true even during years of low solar flux. For this longitude, the observed seasonal variation of the airglow depletions shows a maximum from October through March and a very low occurrence of airglow depletions from April through September.


Descriptors :   *EQUATORIAL REGIONS , *MAGNETIC STORMS , *LATITUDE , DEPLETION , ELECTRONICS , LAYERS , REGIONS , SEASONAL VARIATIONS , SCALE , OPERATION , POLARIMETERS , PHOTOMETERS , LONGITUDE , AIRGLOW , ATTENTION , F REGION , ALTITUDE , PLUMES , BUBBLES , PHYSICS , VARIATIONS , OBSERVATION , DYNAMICS , EMISSION


Subject Categories : Geomagnetism


Distribution Statement : APPROVED FOR PUBLIC RELEASE