Search for the Heliospheric Termination Shock (TS) and Heliosheath (HS)
Abstract
Voyager 1 continues to measure the very distant Heliospheric Magnetic Field (HMF) beyond 95 AU at ~35 North latitude. The MAG instrument data covers more than a full 22 years solar magnetic cycle. The magnitude of the observed HMF is well described, on average, by Parker's Archimedean spiral structure if due account is made for time variations of the source field strength and solar wind velocity. The V1 magnetic field observations do not provide any evidence for a field increase associated with entry into a subsonic solar wind region, such as the heliosheath is expected to be, nor an exit from this regime. We see no evidence for crossing of the Termination Shock (TS) as has been reported at ~85 AU by the LECP instrument. Merged Interaction Regions are identified by an increased HMF and associated decreases in the flux of >70 MeV/nuc cosmic rays which are then followed by a flux recovery. This CR-B relationship has been identified in V1 data and studied since 1982 when V1 was at 11 AU. The variance of HMF, a direct measure of the energy**1/2 in the HMF fluctuations, shows no significant changes associated with the alleged TS crossings in 2002–2003. Thus, the absence of any HMF increase at the entry into the heliosheath appears not to be due to the onset of mesoscale turbulence as proposed by Fisk. The TS has yet to be directly observed in-situ by the V1 MAG experiment in data through 2003.
Additional Information
© 2005 American Institute of Physics. Issue Date: 1 August 2005. We appreciate the contributions of the MAG team members at NASA-GSFC and the CRS team at University of Maryland, GSFC and Caltech in the conduct of these studies and the technical support staff at NASA-GSFC. Norman F. Ness is supported, in part, by NASA-GSFC grant NNG04GB71G to CUA.Attached Files
Published - NESaipcp05.pdf
Files
Name | Size | Download all |
---|---|---|
md5:a2a0dcf704d20b408940fd523e83ac9f
|
310.8 kB | Preview Download |
Additional details
- Eprint ID
- 25086
- Resolver ID
- CaltechAUTHORS:20110825-083402060
- NASA
- NNG04GB71G
- Created
-
2011-08-25Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory
- Series Name
- AIP Conference Proceedings
- Series Volume or Issue Number
- 781