John Foster - jhuapl.edu
Transcript of John Foster - jhuapl.edu
Ground-based Instrumentation
for RBSP Support & Science
John FosterMIT Haystack Observatory
MIT Millstone Hill
& IS Radars
Class I Instruments
Provide Detailed Local
Measurements
Distributed Instruments
Provide Global Context
(DASI)
Trough
SED
SAPS
DensityVelocity
Velocity
DensityVelocity
SAPS Channel
Onset: RC InjectionLow-Conductivity Trough
DMSP – Radars provided PBL – SAPS – Auroral Coverage
Plasmasheet
Plasmapause
SAPS
DMSP F15 6 April 2000 21 MLT
Trough
A Strong Electric Field forms in
the Low-Conductivity Region
between the Inner Edge of the
Plasmasheet Precipitation
and the Plasmapause
Plasmapause
2-Cell Convection
AURORAL
OVAL
LOW S
SAPS E FIELD
Ring Current / SAPS/ SED Plume(Sub Auroral Polarization Stream)
SAPS is a RESULT of Ring Current Enhancement
Duskside Region-2 FACs close
poleward across low-
conductance gap
SAPS: Strong poleward
Electric Fields are set up across
the sub-auroral ionosphere
SAPS erodes the cold plasma
of the ionosphere and the outer
plasmasphere
Statistical Study of SAPS
( Millstone Hill ISR)
[Foster & Vo, 2002]
Kp 5 Kp 4 Kp 6
Geospace is a System
System Science: Distributed RealtimeObservations Needed
Insufficient Data:New Instruments are Required
Multi-Instrument Collaboration provides New Views of Geospace
DASI: A Framework
for Community
Collaborative Research
Plasma Redistribution: A System-Science Model
Global Phenomenon:
Multi-Instrument
Observations Provide
Geophysical Context
and System Viewpoint
Merged SuperDARN/DMSP Convection
Common projection: maglat/MLT @ 350 km alt
GPS TEC Map
[Foster et al., JGR 2005]
Distributed Observations (e.g. GPS)
provide a Global View
GPS samples the ionosphere and plasmasphere to ~20,000 km.
Dual-frequency Faraday Rotation Observations give TEC
(Total Electron Content)
TEC is a measure of integrated density in a 1 m2 column
1 TEC unit = 1016 electrons m-2
Hundreds of
Ground-Based
Receivers
~30 satellites in
High Earth Orbit
TEC Sampled
Continuously along
Each Satellite-
Receiver Path
Distributed GB Instruments – Low-Altitude S/C
High Latitude ISRs
Detailed Regional Ionospheric Observations
EISCAT, Tromsø, Norway
1981, 1985
Sondrestrom, Greenland
(Chatanika, Alaska 1971)
AMISR, Poker Flat, Alaska
2007
EISCAT, Svalbard
1996
Regional DASI to address System ScienceSuperDARN (Polar, Auroral, Mid-Latitude), ISR, THEMIS GBO, ISIS, etc.
SuperDARN Exemplifies the Distributed Array Concept
SED Plumes produce
Strong SuperDARN HF BackscatterApril 11, 2001 (> 40 dB)
Saskatoon 19:50 UT
Kodiak 23:13 UT
GPS/TEC SED Plume
Ionospheric
Irregularities are
Necessary and
determine coverage
region
Complementary SuperDARN – GPS –DMSP - ISR
North Polar Coverage
Convection Snapshot derived from
SuperDARN and DMSP Observations
Polar Tongue of Ionization Observed by GPS
TEC and High-Latitude IS Radars
Mid-Latitude SuperDARNGlobal-Scale Ionospheric Electrodynamics and Processes
FHSU – 2009Hays, KS
OSU – 2010Corvallis, OR
2011Aleutian Islands, AK
2012Azore Islands, Portugal
Continuous Operational Support
GPS TEC
DMSP
SuperDARN HF Radars
Magnetometer Chains
ISIS passive radio monitors
AMISR ISRs (currently; reduced power ops)
Themis GBO
Open, Archived Data - MADRIGAL