Dr. O. C. St. Cyr

Heliophysics Science Division
NASA/GSFC
Mail Code 670
Greenbelt, MD 20771

Office: 301-286-2575
Mobile: 240-938-1585
Fax: 301-286-1617
email: Chris.StCyr  - at - nasa.gov

Curriculum Vitae:  Orville Chris St. Cyr

CURRENT EMPLOYMENT:

EDUCATION:

PROFESSIONAL ACTIVITIES:

  • Heliophysics Science Support Office (2008-present)
  • Senior Project Scientist for the Living With a Star Program (2002-2007)
  • STEREO SECCHI COR1 website
  • Co-Investigator, Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI) on STEREO (1999-present)
  • Operations Scientist, Large Angle and Spectrometric Coronagraph (LASCO) on SOHO (1995-1998)
  • Science Lead for SOHO ground segment development (1991-1995)
  • Operations Scientist, Coronagraph/Polarimeter (C/P) on SMM (1984-1991)

RESEARCH INTERESTS:

  • Initiation and propagation of coronal mass ejections (CMEs)
  • The effects of CMEs at Earth, the planets, and throughout the solar system
  • Spectroscopic investigations of the Sun's corona at total solar eclipses
  • Sun-grazing comets
  • Economic impacts of space weather

AWARDS/HONORS:

  • 2003 International Academy of Astronautics Team Achievement Award (SOHO Ground Segment)
  • ESA and NASA Group Awards for SOHO Development (1996)
  • NCAR Incentive Awards for Solar Maximum Mission (1984 and 1988)

STUDENTS/POSTDOCS SUPERVISED:

  • Dr. Hebe Cremades (NPP)  University of Mendoza, Argentina
  • Dr. Nelson Reginald, (Postdoc)  The Catholic University of America
  • Dr. Hong Xie, (Postdoc)  The Catholic University of America
  • Leila Mayes; (REU)  Doctoral Candidate, UT/Austin

ADDITIONAL INFORMATION:

  • U.S. Army; Honorable Discharge (1969-1971)
  • NASA-State Department Libya Eclipse Documentary “Path of Totality” (2007)

 

INTERESTING OBSERVATION (1):

CAPTION:  The coronal mass ejection of 02-June-1998.  Here an extreme ultraviolet image of the Sun's Fe XII emission (195Å) acquired by the EIT telescope on SOHO has been superimposed on a white-light coronagraph image from LASCO.  The EIT image was obtained through the FeXII (19.5 nm) filter which shows emission at ~1.6 X106 °K.The south polar crown filament erupted into this beautiful flux-rope CME, and the filament's original extent and location are denoted by the two red lines.  This event demonstrates several important scientific facts: (1) The initial acceleration, the deflection toward the equator, and the initial expansion of the filament and the pre-existing flux-rope all take place beneath the LASCO occulting disk--within the first few solar radii of the photosphere; (2) Although the ejection is centered very far south, it was significantly deflected toward the solar equator, and hence it would at least graze the ecliptic and (if Earthward-directed) would possibly have caused a geomagnetic storm; and (3) the location of the prominence material with respect to the flux-rope is clear--the prominence material was entrained in the trailing portion of the helical flux-rope.  A manuscript describing this event has been written by Plunkett et al. (Solar Physics, 194, 371-391, 2000).  I call this CME morphology an “axial fluxrope.”

 

INTERESTING OBSERVATION (2):

SOHO LASCO C2  1998/05/19  11:02-10:02
 

CAPTION:  The coronal mass ejection of 19-May-1998.  At the left is a partial frame extreme ultraviolet image of the Sun's Fe XII emission (195Å) acquired by the EIT telescope on SOHO has been subtracted from a similar image a few minutes earlier (at 09:34 U.T.).  This image was obtained through the FeXII (19.5 nm) filter which shows emission at ~1.6 X106 °K.  The image shows the eruption of a filament that was originally oriented mostly North-South.  The right frame shows the resulting CME as detected by the LASCO C2 coronagraph.  The relative size and location of the solar disk are indicated by the white semi-circle superposed in the shadow of the occulting disk.  There are several interesting aspects seen in this event:  First, the shape of the erupting filament (seen dark because it is in absorption) is very similar to the bright knotty structure seen in LASCO C2.  This is not uncommon, so we identify the bright, knotty structure as “filament material”.  I call this CME morphology a “broadside fluxrope.”

 

Second, compare the geometry in Interesting Observation (1) where the south polar crown filament was mostly East-West.  In that case, we identified the flux rope as the multiple, concentric, circular structures (the “slinky seen end-on”) in the LASCO CME.  If this May 1998 CME possesses the same physical features, then we are now seeing them at right-angles to the June 1998 CME since the magnetic neutral lines (identified by the dark filaments) are perpendicular with respect to the Sun’s limb.  A statistical study of both kinds of morphologies (axial versus broadside fluxropes) should give us a measure of the three-dimensional sizes of this type of CME.  [See Cremades and Bothmer, Geometrical Properties of Coronal Mass Ejections, in IAU Proceedings No. 226, 2005]

 

BIBLIOGRAPHY:

Xie, H., N. Gopalswamy, O. C. St. Cyr, and S. Yashiro (2008), Effects of solar wind dynamic pressure and preconditioning on large geomagnetic storms, Geophys. Res. Lett., 35, L06S08, doi:10.1029/2007GL032298.

 

Kaiser M.L., Kucera T.A., Davila J.M., St. Cyr O.C., Guhathakurta M., Christian E., The STEREO Mission: An Introduction, Spa. Sci. Rev., doi: 120.1007/s11214-007-9277-0, 2007.

 

Biesecker D.A., Webb D.F., St. Cyr O.C., STEREO Space Weather and the Space Weather Beacon, Spa. Sci. Rev., doi: 10.1007/s11214-007-9165-7, 2007.

 

Eichstedt J., Thompson W.T., St. Cyr O.C., STEREO Ground Segment, Science Operations, and Data Archive, Spa. Sci. Rev., doi: 10.1007/s11214-007-9249-4, 2007.

 

Howard R.A., J.D. Moses, A. Vourlidas, J.S. Newmark, D.G. Socker, S.P. Plunkett, C.M. Korendyke, J. W. Cook, A. Hurley, J. M. Davila, W. T. Thompson, O.C. St Cyr, E. Mentzell, K. Mehalick, J.R. Lemen, J.P. Wuelser, D.W. Duncan, T.D. Tarbell, C.J. Wolfson, A. Moore, R. A. Harrison, N. R. Waltham, J. Lang, C.J. Davis, C.J. Eyles, H. Mapson-Menard, G.M. Simnett, J.P. Halain, J.M Defise, E. Mazy, P. Rochus, R. Mercier, M. F. Ravet, F. Delmotte, F. Auchere, J.P. Delaboudiniere, V. Bothmer, W. Deutsch, D. Wang, N. Rich, S. Cooper, V. Stephens, G. Maahs, R. Baugh, D. Mcmullin, Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI), Spa. Sci. Rev., in press, 2008.

 

Mierla, M., J. Davila, W. Thompson, B. Inhester, N. Shrivastava, M. Kramar, O.C. St Cyr, G. Stenborg, R.A. Howard, A Quick Method for Estimating the Propagation Direction of Coronal Mass Ejections using STEREO-COR1 Images, Astrophys. J., submitted, 2008.

 

Sheeley, N.R., Herbst, A.D., Palatchi, C.A., Wang, Y.-M., Howard, R.A., Moses, J.D.,  Vourlidas, A., Newmark, J.S., Socker, D.G., Plunckett, S.P., Korendyke, C.M., Burlaga, L.F., Davila, J.M., Thompson, W.T., St Cyr, O.C., Harrison, R.A., Davis, C.J., Halain, J.P., Wang, D., Rich, N.B., Battams, K., Esfandiari, E., Stenborg, G., Heliospheric images of the solar wind at Earth,  Astrophys. J., in press, 2008.St. Cyr, O.C., J.M. Davila, M. Guhathakurta, and R. Senseney, Science Eclipses Politics During 2006 U.S. Eclipse Expedition to Libya, Eos, Transactions American Geophysical Union, Volume 88, Issue 49, p. 539-540, 2007.

 

Cremades, H., O. C. St. Cyr, and M.L. Kaiser, A Tool to Improve Space Weather Forecasts: Kilometric Radio Emissions from Wind/WAVES, The Space Weather Journal, , VOL. 5, S08001, doi:10.1029/2007SW000314, 2007.

Xie, H., N. Gopalswamy, L. Ofman, O. C. St. Cyr, G. Michalek, A. Lara, and S. Yashiro, Improved input to the empirical coronal mass ejection (CME) driven shock arrival model from CME cone models, Space Weather, 4, S10002, doi:10.1029/2006SW000227, 2006.

 

Cremades, H., and St. Cyr, O. C., Coronal Mass Ejections: Solar Cycle Aspects, 2nd International Symposium on Space Climate, Sinaia, Romania, September 13-16 2006, Advances in Space Research, 2007.

 

Krall, J., and O.C. St. Cyr, Flux-Rope Coronal Mass Ejection Geometry and its Relation to Observed Morphology, 2006ApJ...652.1740K.

 

Mays, L. et al., An Attempt to Detect Coronal Mass Ejections in Lyman-alpha using SOHO SWAN, Solar Physics, 10.1007/s11207-007-0196-8, 2007.

 

Reginald, N.L., J.M. Davila, and O.C. St. Cyr, The effects of streamers on the shape of the k-coronal spectrum, Solar Physics, DOI: 10.1007/s11207-004-3516-2.

 

deKoning, C.A., J.T. Steinberg, J.T. Gosling, D.B. Reisenfeld, R.M. Skoug, O.C. St.Cyr, M.L. Malayeri, A. Balogh, and D.J. McComas, An unusually fast CME observed by Ulysses at 5 AU on November 15, 2003, Journal of Geophysical Research, Volume 110, Issue A1, CiteID A01102.

 

Ko, Y-K, J.C. Raymond, S.E. Gibson, D. Alexander, L. Strachan, T. Holzer, H. Gilbert, O.C. St. Cyr, B.J. Thompson, C.D. Pike, J. Burkepile, W. Thompson, L. Fletcher, Observations of a coronal jet during the third whole sun month campaign, Astrophysical Journal, 623, 519-539, 2005.

 

Yashiro et al, A catalogue of white light coronal mass ejections observed by the SOHO spacecraft, 109, A07105, 10.1029/2003JA010282, Journ.Geophys.Res., 2004.

 

Burkepile, J.T., A.J. Hundhausen, A.L. Stanger, O.C. St. Cyr, and J.A. Seiden, The role of projection effects on coronal mass ejection properties, 109, A03103

doi:10.1029/2003JA010149, Journ.Geophys.Res., 2004.

 

Forbes, K. F., and O. C. St. Cyr, Space weather and the electricity market: An initial assessment, The Space Weather Journal, 2, S10003, doi:10.1029/2003SW000005, 2004.

 

Reginald, N. L., O. C. St. Cyr, J. M. Davila, and J. W. Brosius, Electron temperature and speed measurement in the low solar corona: Results from the 2001 June eclipse, Astrophysical Journal, 599, 596-603, 2003.

 

Reisenfeld, D.B., J.T. Gosling, F.J. Forsyth, P. Riley, and O.C. St.Cyr, Properties of high latitude coronal mass ejections during Ulysses second northern polar passage, in press Geophysical Research Letters, 2003.

 

Reiner, M.J., A. Vourlidas, O.C. St.Cyr, R.A. Howard, M.L. Kaiser, N.P. Prestage, and J.-L. Bougeret, Constraints on CME dynamics from simultaneous radio and white-light observations, Astrophysical Journal, 590, 533-546, 2003.

 

Biesecker, D.A., Lamy, P., St. Cyr, O.C., Llebaria, A., Howard, R.A., Sungrazing comets discovered with the SOHO/LASCO coronagraphs 1996-1998, Icarus, 157, 323-348, 2002.

 

Burlaga, L.F., S.P. Plunkett, and O.C. St.Cyr, Successive CMEs and complex ejecta, Journ.Geophys.Res., in press, 2001.

 

Li, Y., J.G. Luhmann, T. Mulligan, J.T. Hoeksema, C.N. Arge, S.P. Plunkett, and O.C. St.Cyr, Earthward directed CMEs seen in large-scale coronal magnetic field changes, SOHO LASCO coronagraph and solar wind, Journ.Geophys.Res., 106, 25,103-25,120, 2001.

 

Gopalswamy, N., O.C. St.Cyr, M.L. Kaiser, and S. Yashiro, X-ray ejecta, white light CMEs, and a coronal shock wave, Solar Physics, 203, 149-163, 2001.

 

Plunkett, S.P., B.J. Thompson, O.C. St.Cyr, and R.A. Howard, Solar source regions of coronal mass ejections, Journal of Atmospheric and Solar-Terrestrial Physics, 63, 389-402, 2001.

 

Kocharov, L., J. Torsti, O.C. St.Cyr, and T. Huhtanen, A relation between dynamics of coronal mass ejections and production of energetic particles, Astronomy and Astrophysics, 370, 1,064-1,070, 2001.

 

St.Cyr, O.C., and J.M. Davila, The STEREO space weather beacon, in Space Weather Chapman Conference Proceedings, editors P. Song and G. Siscoe, Geophysical Monograph 125, 205-209, 2001.

 

Webb, D.F., N.U. Crooker, S.P. Plunkett, and O.C. St.Cyr, The solar sources of geoeffective structures, in Space Weather Chapman Conference Proceedings, editors P. Song and G. Siscoe,. Geophysical Monograph 125, 123-141, 2001.

 

Cane, H.V., I.G. Richardson, and O.C. St.Cyr, Coronal mass ejections, interplanetary ejecta and geomagnetic storms, Geophysical Research Letters, 27, 3,591-3,594, 2000.

 

St.Cyr, O.C., R.A. Howard, N.R. Sheeley, Jr., S.P. Plunkett, D.J. Michels, S.E. Paswaters, M.J. Koomen, G.M. Simnett, B.J. Thompson, J.B. Gurman, R. Schwenn, D.F. Webb,E. Hildner, and P.L. Lamy, Properties of coronal mass ejections: SOHO LASCO observations from January 1996 to June 1998, Journ.Geophys.Res., 105, 18,169-18,185, 2000.

 

Gopalswamy, N., A. Lara, R.P. Lepping, M.L. Kaiser, D. Berdichevsky, and O.C. St.Cyr, Interplanetary acceleration of coronal mass ejections, Geophysical Research Letters, 27, 145-148, 2000.

 

Webb, D.F., E.W. Cliver, N.U. Crooker, O.C. St.Cyr, and B.J. Thompson, Relationship of halo coronal mass ejections, magnetic clouds, and magnetic storms, Journ. Geophys. Res., 105, .7,491-7,508, 2000.

 

Thompson, B.J., B. Reynolds, H. Aurass, N. Gopalswamy, J.B. Gurman, H.S. Hudson, S.F. Martin, and O.C. St.Cyr, Observations of the 24 September 1997 coronal flare waves, Solar Physics, 193, 161-180, 2000.

 

Raymond, J.C., B.J. Thompson, O.C. St.Cyr, N. Gopalswamy, S. Kahler, M. Kaiser, A. Lara, A. Ciaravella, M. Romoli, and R. O'Neal, SOHO and radio observations of a CME shock wave, Geophysical Research Letters, 27, 1,439-1,442, 2000.

 

St.Cyr, O.C., M.A. Mesarch, H.M. Maldonado, D.C. Folta, A.D. Harper, J.M. Davila, and R.R. Fisher, Space Weather Diamond: A four spacecraft monitoring system, Journal of Atmospheric and Solar-Terrestrial Physics, 62, 1,251-1,255, 2000..

 

St.Cyr, O.C., J.T. Burkepile, A.J. Hundhausen, and A.R. Lecinski, A comparison of ground-based and spacecraft observations of coronal mass ejections from 1980-1989, Journ.Geophys.Res., 104, 12,493-12,506, 1999.

 

Ofman, L., M. Romoli, G. Noci, G. Poletto, J.L. Kohl, R.A. Howard, C. St.Cyr, and C.E. Deforest, SOHO observations of density fluctuations in coronal holes, Space Science Reviews, 87, 287-290, 1999.

 

Ciaravella, A., J.C. Raymond, L. Strachan, B.J. Thompson, O.C. St.Cyr, L. Gardner, A. Modgliani, E. Antonucci, J. Kohl, and G. Noci, Ultraviolet and optical observations of a coronal transient with SOHO, Astrophysical Journal, 510, 1053-1063, 1999.

 

Thompson, B.J., J.B. Gurman, W.M. Neupert, J.S. Newmark, J.-P. Delaboudiniere, O.C. St.Cyr, S. Stezelberger, K.P. Dere, R.A. Howard, and D.J. Michels, SOHO/EIT observations of the 1997 April 7 coronal transient: Possible evidence of coronal Moreton waves, Astrophysical Journal, 517, L151-L154, 1999.

 

Wang, Y.-M., N.R. Sheeley, Jr., R.A. Howard, O.C. St.Cyr, and G.M. Simnett, Coronagraph observations of inflows during high solar activity, Geophysical Research Letters, 26, 1,203-1,206, 1999.

 

Thompson, B.J., O.C. St.Cyr, S.P. Plunkett, J.B. Gurman, N. Gopalswamy, H.S. Hudson, R.A. Howard, D.J. Michels, and J.-P. Delaboudiniere, The correspondence of EUV and white light observations of coronal mass ejections with SOHO EIT and LASCO, In Sun-Earth Plasma Connections, 31-46, Geophysical Monograph #109, American Geophysical Union, 1999.

 

Funsten, H.O., J.T. Gosling, P. Riley, O.C. St.Cyr, R.J. Forsyth, R.A. Howard, and R. Schwenn, Combined Ulysses solar wind and SOHO coronal observations of several west limb coronal mass ejections, Journ.Geophys.Res., 104, 6,679-6,689, 1999.

 

Cane, H., I.G. Richardson, and O.C. St.Cyr, The interplanetary events of January-May, 1997 as inferred from energetic particle data, and their relationship with solar events, Geophysical Research Letters, 25, 2,517-2,520, 1998.

 

Hudson, H.S., J.R. Lemen, O.C. St.Cyr, A.C. Sterling, D.F. Webb, X-ray coronal changes during halo CMEs, Geophysical Research Letters, 25, 2,481-2,484, 1998.

 

Kaiser, M.L., M.J. Reiner, R.A. Howard, N. Gopalswamy, O.C. St.Cyr, B.J. Thompson, and J.-L. Bougeret, Type II radio emissions in the frequency range from 1 to 14 MHz associated with the April 7, 1997 solar event, Geophysical Research Letters, 25, 2,501-2,504, 1998.

 

Plunkett, S.P., B.J. Thompson, R.A. Howard, D.J. Michels, O.C. St.Cyr, S.J. Tappin, R. Schwenn, and P.L. Lamy, LASCO observations of an Earth-directed coronal mass ejection on May 12, 1997, Geophysical Research Letters, 25, 2,477-2,480, 1998.

 

Thompson, B.J., S.P. Plunkett, J.B. Gurman, J.S. Newmark, O.C. St.Cyr, D.J. Michels, SOHO/EIT observations of an Earth-directed coronal mass ejection on May 12, 1997, Geophysical Research Letters, 25, 2465-2468, 1998.

 

Webb, D.F., E.W. Cliver, N. Gopalswamy, H.S. Hudson, O.C. St.Cyr, The solar origin of the January 6, 1997, coronal mass ejection, magnetic cloud, and geomagnetic storm, Geophysical Research Letters, 25, 2469-2472, 1998.

 

Willson, R.F., S.L. Redfield, K.R. Lang, B.J. Thompson, and O.C. St.Cyr, First VLA observations of nonthermal metric bursts associated with coronal mass ejections detected by the Solar and Heliospheric Observatory, Astrophysical Journal, 504, L117-L121, 1998.

 

Brueckner, G.E. J.-P. Delaboudiniere, R.A. Howard, S.E. Paswaters, O.C. St.Cyr, R. Schwenn, P. Lamy, G.M. Simnett, B. Thompson, and D. Wang, Geomagnetic storms caused by coronal mass ejections (CMEs): March 1996 through June 1997, Geophysical Research Letters, 25, 3019-3022, 1998.

 

Wang, Y.-M., N.R. Sheeley, D.G. Socker, R. A. Howard, G.E. Brueckner, D.J. Michels, D. Moses, O.C. St.Cyr, A. Llebaria, and J.-P. Delaboudiniere, Observations of correlated white-light and extreme-ultraviolet jets from polar coronal holes, Astrophysical Journal, 508, 899-907, 1998.

 

Chen, J., R.A. Howard, G.E. Brueckner, R. Santoro, J Krall, S.E. Paswaters, O.C. St.Cyr, R. Schwenn, P. Lamy, and G.M. Simnett, Evidence of an erupting magnetic flux rope: LASCO coronal mass ejection of 1997 April 13, Astrophysical Journal, 490, L-191-L-194, 1997.

 

Dere, KP., and 33 co-authors, EIT and LASCO observations of the initiation of a coronal mass ejection, Solar Physics, 175 601-612, 1997.

 

Schwenn, R., and 23 co-authors, First view of the extended green line emission corona at solar activity minimun using the LASCO-C1 coronagraph on SOHO, Solar Physics, 175, 667-684, 1997.

 

Simnett, G.M., and 18 co-authors, LASCO observations of disconnected magnetic structures out to beyond 28 solar radii during coronal mass ejections, Solar Physics, 175, 685-698, 1997.

 

Plunkett, S.P., and 20 co-authors, The relationship of green-line transients to white-light coronal mass ejections, Solar Physics, 175, 699-718, 1997.

 

Sheeley, N.R., Jr., Y.-M. Wang, S.H. Hawley, G.E. Brueckner, K.P. Dere, R.A Howard, M.J. Koomen, C. M. Korendyke, D.J. Michels, S.E. Paswaters, D.G. Socker, O.C. St.Cyr, D. Wang, P.L. Lamy, A. Llebaria, R. Schwenn, G.M. Simnett, S. Plunkett, and D.A. Biesecker, Measurements of flow speeds in the corona between 2 and 30 Rsun, Astrophysical Journal, 484, 472-478, 1997.

 

St.Cyr, O.C., L. Sanchez-Duarte, P.C.H. Martens, J.B. Gurman, and E. Larduinat, SOHO ground segment, science operations, and data products, Solar Physics, 162, 39-59, 1995.

 

Hundhausen, A.J., J.T. Burkepile, and O.C. St.Cyr, Speeds of coronal mass ejections: SMM observations from 1980 and 1984-1989, Journ.Geophys.Res., 99, 6543-6552, 1994.

 

Gopalswamy, N., M.R. Kundu, and O.C. St.Cyr, Nonthermal radio emission associated with a coronal disconnection event, Astrophys.J., 424, L135-L138, 1994.

 

St.Cyr, O.C., and D.F. Webb, Activity associated with coronal mass ejections at solar minimum: SMM observations from 1984-1986, Solar Physics, 136, 379-394, 1991.

 

MacQueen, R.M., and O.C. St.Cyr, Sungrazing comets observed by the  Solar Maximum Mission coronagraph, Icarus, 90, 96-106, 1991.

 

St.Cyr, O.C., and S.B. St.Cyr, An archival period study of the eclipsing binary KT Hydrae, Astronomical Journal, 91, 416-418, 1986.

 

St.Cyr, C., J.T. Pollock, A.J. Pica, and D.B. Caton, Observations of the eclipsing variable KT Hydrae, Pub.Astron.Soc.Pac., 95, 639-643, 1983.

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