HR: 0800h
AN: SM21A-0356    [Abstracts]
TI: Daytime, Low Latitude Electric Fields, Inferred From Ground-based Magnetometer Networks in the Peruvian and Philippine Longitude Sectors
AU: * Anderson, D N
EM: david.anderson@noaa.gov
AF: Univ. of Colorado/CIRES, NOAA/SEC 325 Broadway, Boulder, CO 80302 United States
AU: Anghel, A
EM: adela.anghel
AF: Univ. of Colorado/CIRES, NOAA/SEC 325 Broadway, Boulder, CO 80302 United States
AU: Chau, J
EM: jchau@jro.igp.gob.pe
AF: Radio Observatorio de Jicamarca, Instituto Geofisico del Peru, Apartado 13-0206, Lima, 13 Peru
AU: Yumoto, K
EM: yumoto@serc.ac.jp
AF: Space Environment Research Center, Kyushu University, 6-10-1 Hazozaki, Fukuoka, 812-8581 Japan
AB: Recent studies have demonstrated that ground-based magnetometer observations can be used to infer realistic, daytime vertical ExB drift velocities in the Peruvian and Philippine longitude sectors. It has also been demonstrated that under certain conditions the time variability in the Interplanetary Electric Field (IEF) - minutes to hours - is reflected in the daytime, prompt penetration of high latitude electric fields to low latitudes. In this paper, we incorporate magnetometer-inferred ExB drift techniques to extend this study to investigate the relationships between IEF conditions and daytime, low latitude electric field observations under both geomagnetically quiet and disturbed conditions. This paper addresses several basic questions related to the relationships between IEF conditions and low latitude east-west electric fields. 1.) When low latitude electric fields exhibit quiet-time, Sq type behavior, what are the IEF conditions? 2.) Under disturbed conditions, what are the relationships between the IEF parameters and the low latitude electric fields in the Peruvian and Philippine longitude sectors? 3.) If the two longitude sector electric field responses are similar under disturbed conditions, is there a difference in the daytime, vertical ExB drift velocities because the the magnitude of Bo differs between the two sectors (ExB drift ~ E/Bo)? We address the above questions by analyzing magnetometer-inferred ExB drift velocities between January, 2001 and December, 2004 when there exists more than 450 quiet days and more than 135 geomagnetically disturbed days, defined by daily Ap values greater than 20. It is demonstrated that the neural network approach that provides realistic ExB drift velocities based on magnetometer observations can be applied at all longitudes where appropriately placed magnetometers exist.
DE: 2169 Solar wind sources
DE: 2411 Electric fields (2712)
DE: 2415 Equatorial ionosphere
DE: 2437 Ionospheric dynamics
DE: 2712 Electric fields (2411)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005