Kinematic Measurements of Polar Jets Observed by the Large-Angle Spectrometric Coronagraph

We analyze polar jets observed by the Large-Angle Spectrometric Coronagraph (LASCO) instrument aboard the Solar and Heliospheric Observatory. The events studied here are from 1997 March 24 and August 5. The main objective of our analysis is to determine whether the jets' motions are consistent with ballistic behavior. Although ballistic trajectories have some success in fitting the observed kinematic motions, there is substantial evidence that gravity alone is not regulating the movement of the jets. First of all, the August 5 events appear to exhibit slight accelerations rather than decelerations above 3 R☉. Second, all the events studied here have very similar velocities, suggesting that by the time the jets reach the LASCO field of view, the jets have been incorporated into the ambient solar wind. If this is the case, the jets could be very useful as tracers of the solar wind at low heights in the Sun's polar regions.

[1]  M. Karovska,et al.  Comparison of Two Coronal Mass Ejections Observed by EIT and LASCO with a Model of an Erupting Magnetic Flux Rope , 1999 .

[2]  A. Llebaria,et al.  Observations of Correlated White-Light and Extreme-Ultraviolet Jets from Polar Coronal Holes , 1998 .

[3]  Giampiero Naletto,et al.  UVCS/SOHO Empirical Determinations of Anisotropic Velocity Distributions in the Solar Corona , 1998 .

[4]  B. Au,et al.  Eit Observations of the Extreme Ultraviolet Sun , 1997 .

[5]  E. L. Van Dessel,et al.  Eit and LASCO Observations of the Initiation of a Coronal Mass Ejection , 1997 .

[6]  J. T. Hoeksema,et al.  Polar Plume Anatomy: Results of a Coordinated Observation , 1997 .

[7]  M. Shimojo,et al.  H alpha Surges and X-Ray Jets in AR 7260 , 1996 .

[8]  Kazunari Shibata,et al.  Statistical Study of Solar X-Ray Jets Observed with the YOHKOH Soft X-Ray Telescope , 1996 .

[9]  W. Neupert,et al.  EIT: Extreme-ultraviolet Imaging Telescope for the SOHO mission , 1995 .

[10]  H. Zirin,et al.  High-Resolution Observation of Disk Spicules. I. Evolution and Kinematics of Spicules in the Enhanced Network , 1995 .

[11]  M. Karovska,et al.  Dynamical Structure of Extreme Ultraviolet Macrospicules , 1994 .

[12]  P. Lamy,et al.  The Large Angle Spectroscopic Coronagraph (LASCO): Visible light coronal imaging and spectroscopy , 1992 .

[13]  A. K. Sinha,et al.  Polymerization of N-vinylcarbazole by gaseous initiators , 1992 .

[14]  J. Mariska,et al.  Numerical Simulations of the Rebound Shock Model for Solar Spicules , 1990 .

[15]  J.-D. F. Bartoe,et al.  Explosive events in the solar transition zone , 1989 .

[16]  J.-D. F. Bartoe,et al.  Observations of high-energy jets in the corona above the quiet sun, the heating of the corona, and the acceleration of the solar wind , 1983 .

[17]  G. Brueckner,et al.  Chromospheric jets: Possible extreme-ultraviolet observations of spicules , 1983 .

[18]  J. Hollweg,et al.  Origin of solar spicules , 1982 .

[19]  J. D. Bohlin,et al.  A newly observed solar feature: macrospicules in He II 304 Å. , 1975 .

[20]  J. Roy.  The dynamics of solar surges , 1973 .

[21]  K. Shibata,et al.  Numerical hydrodynamics of the jet phenomena in the solar atmosphere , 1982 .

[22]  D. Galloway,et al.  Alfvén waves in the solar atmosphere , 1982 .