Athabasca University Initiatives supporting THEMIS

M. Connors, K. Hayashi, C. T. Russell,K. Shiokawa, R. Irwin, G. Rostoker(AU, U. Tokyo, UCLA, STELAB,

Northern Lakes College, U. of Alberta)

THEMIS Launch Meeting, Cape Canaveral, Florida – Feb 2007 Image: Mikko Syrjäsuo

Three Main Thrusts

1. AUGO (Athabasca University Geophysical Observatory) is a comprehensive facility in the equatorward part of the auroral zone

2. Magnetometer networks including AUTUMN, help for STEP, and AU/small. Associated inversion techniques (AFM).

3. Participation in e-POP (ground and outreach)

1. Athabasca University Geophysical Observatory (AUGO)

54.72 N, 246.7 ECGM (2005) 62.0, 306.5L=4.55

Founded 2002(UCLA mag 1998)

AUGO’s STELAB InstrumentationAs described by Sakaguchi and Shiokawa here:

1. multispectral ASC including Hβ

2. 64 Hz induction coil

3. proton spectrometer

2. Ground Magnetometry In a Sun-to-Mud approach, we are in the mud…

EDMO UCLA magnetometer installed by Martin Connors (Tom Sawyer-like technique applied to astronomer Brian Martin) in December 2004

Often the locales are less agreeable than Florida (Kanji Hayashi in LaRonge, Canada, mid-October 2004)

Red Deer

Lethbridge

Paddle Prairie

Edmonton

Athabasca

Calgary

Slave Lake

Sites installed fully and data available (2 Hz) since Oct 4, 2005Inuvik 2006

Inuv

ik

Athabasca University has assisted or runs 16 sites in Canada (white triangles and purple dots in Western Canada). Most data available through UCLA, STEP website, or on request. PEA, KAQ, SFV hoped for soon. New Polaris sites on E. Coast of Hudson Bay to be installed in 2007. Some GBOs not shown.

What can ground magnetic data tell us?

Regrettably, a single magnetogram often tells nearly nothing and even multipoint measurements from a meridian chain are difficult to interpret, needing… “geomagic”…

Automated Forward Modelling (AFM) can help.

For meridian data, AFM adjusts current and borders

The method is however, much more general and includes field-aligned currents in realistic 3-d configurations. Midlatitude perturbations can be included as can a Dst-like parameter.

Inversion tells us more by giving simple parameters extracted from several ground stations

April 10 1997

Array Interpretation from a distributed region is even more difficult, complicated by problems of

nonuniqueness. An inversion procedure is needed.

• On the ground, one detects primarily the magnetic effects of the Hall currents associated with the auroral oval electric field

• FAC effects are not dealt with in this talk but CAN be observed from the ground AFM Apr 3 1997 red vectors are

model, black observed

Ability to match input data is best near the middle of the chain (although often not in Z due to electrojet structure)

Note: different event and stations

Independent confirmation: Comparison of optical borders from meridian scanning photometer and inversion results for growth phase (Feb 22 1997); also confirmed by FAST FAC detections

Two electrojet model results are shown superposed on 557.7 nm optical meridian scan data from Gillam. The growth phase arc is poleward of the evening sector eastward electrojet. Note that the method is sensitive to initial conditions

FAST

Talking about satellites, e-POP should launch in 2008, perfect timing to complement THEMIS

e-POP will have a comprehensive and in many ways innovative instrument package (see Yau et al., Adv. Space Research, 2006)

Conclusions

• Efforts at Athabasca University will come to fruition in the THEMIS/e-POP era:

AUGO – Magnetometer Networks – e-POP

• Our own data is distributed freely: that of guest instruments often also is

• Some issues of data archiving/distribution exist• Budget is low for needed increases in ground

coverage

Acknowledgements

• D. Boteler (NRCan), Mark Moldwin (UCLA), Eric Donovan and Brian Jackel (U. of Calgary), Brian Martin (King’s University College), Stu Harris (UC Berkeley ) for help in placement and operation

• Canadian Space Agency and University of Alberta for CANOPUS/CARISMA data

• This work funded by Canada Research Chairs, Canada Foundation for Innovation, AU, and NSERC