Premium
C/NOFS observations of deep plasma depletions at dawn
Author(s) -
de La Beaujardière Odile,
Retterer John M.,
Pfaff Robert F.,
Roddy Patrick A.,
Roth Christopher,
Burke William J.,
Su Yi Jiun,
Kelley Michael C.,
Ilma Ronald R.,
Wilson Gordon R.,
Gentile Louise C.,
Hunton Donald E.,
Cooke David L.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl038884
Subject(s) - geology , plasma , astrobiology , physics , nuclear physics
The Communication/Navigation Outage Forecasting System (C/NOFS) satellite was launched in 2008, during solar minimum conditions. An unexpected feature in the C/NOFS plasma density data is the presence of deep plasma depletions observed at sunrise at all satellite altitudes. Ionospheric irregularities are often embedded within these dawn depletions. Their frequencies strongly depend on longitude and season. Dawn depletions are also observed in coincident satellite passes such as DMSP and CHAMP. In one example the depletion extended 50° × 14° in the N‐S and E‐W directions, respectively. These depletions are caused by upward plasma drifts observed in C/NOFS and ground‐based measurements. The reason for these upward drifts is still unresolved. We discuss the roles of dynamo electric fields, over‐shielding, and tidal effects as sources for the reported depletions.