The Terrestrial System under Super-CME Conditions George Siscoe Boston University Main Theme: Three Worlds of Super-CMEs At home Birth, development, and release At play Acceleration, propagation, in-transit evolution At work Making superstorms Subtheme: Super-CMEs are rare and weird like natural wonders Epitomes of explosive phenomena in the local cosmos Hurricanes of space weather Radical transformers of magnetosphere coupling from solar wind dominated to ionosphere dominated

Super-CMEs at Home Birth, Development, and Release Relation to active region, prominences, and “sigmoids” Illustrated by event on November 4, 2001 Continuum Magnetogram H alpha Soft X-ray Composite

Photospheric Field Topology of Titov & Démoulin 1999 Model upper separatrix upper separatrix lower lower separatrix Basic topology of twisted magnetic configurations in solar flares Astronomy and Astrophysics, 351, pp.701-720, 1999 upper separatrix

Relation to magnetic arcades Illustrated by Bastille Day event

Release Mechanisms Flux Cancellation Breakout Terry Forbes Spiro Antiochos

Conditions at Eruption

Observable Implication of CME Models (Crooker, 2005) FLUX-CANCELLATION MODEL Dipolar fields reconnect Leading field matches dipolar component BREAKOUT MODEL Quadrupolar fields reconnect Leading field opposes dipolar component Taken at face value, imprint of dipolar component on leading field and leg polarity favors streamer over breakout model by ~80%.

Super-CMEs at Play Acceleration, propagation, in-transit evolution 50 100 150 200 250 500 750 1000 1250 1500 Jie Zhang data

Geometrical Dilation + Radial Expansion Phase Three Phases of CME Expansion CME Geometrical Dilation + Radial Expansion Phase Inflationary Phase MHD simulation Pete Riley Sun Pre-CME Growth Phase

Information on Interplanetary CME Propagation 50 100 150 200 400 600 800 1000 1200 1400 Gopalswamy et al., GRL 2000: statistical analysis of CME deceleration between ~15 Rs and 1 AU Reiner et al. Solar Wind 10 2003: constraint on form of drag term in equation of motion Gopalswamy, N. ; Lara, A. ; Lepping, R. P. ; Kaiser, M. L. ; Berdichevsky, D. ; St. Cyr, O. C. 2000 Interplanetary acceleration of coronal mass ejections Geophys. Res. Lett. Vol. 27 , No. 2 , p. 145 (1999GL003639) Velocity-distance relationship for the January 14, 2002 CME. “On the Deceleration of CMEs in the Corona and Interplanetary Medium deduced from Radio and White-Light Observations” M. J. Reiner, M. L. Kaisert and J.-L. Bougeret, in Solar Wind 10, 2003. drag  Cd ρ (V-Vsw)2 Standard Form Observed

Information on CME Parameters at 1 AU Vršnak and Gopalswamy, JGR 2002: velocity range at 1 AU << than at ~ 15 Rs Owen et al. 2004: expansion speed  CME speed; B field uncorrelated with speed; typical size ~ 40 Rs Lepping et al, Solar Physics, 2003: Average density ~ 11/cm2; average B ~ 13 nT Accelerate Decelerate 350 400 450 500 550 600 20 40 60 80 Vexp = 0.266 Vcme – 71.61 JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. A2, 10.1029/2001JA000120, 2002 Influence of the aerodynamic drag on the motion of interplanetary ejecta Bojan Vršnak Hvar Observatory, Faculty of Geodesy, Zagreb, Croatia Nat Gopalswamy Department of Physics, Catholic University of America, Washington, D. C., USA Characteristic magnetic field and speed properties of ICMEs and their sheath regions M.J. Owens, N.U. Crooker, G. Siscoe and C. Pagel Center for Space Physics, Boston University, Boston, Massachusetts. P.J. Cargill

Analytical model of CME Acceleration and Propagation Generalized buoyancy Elliptical cross section Variable drag coefficient Satisfies Gopalswamy template Satisfies Reiner template Virtual mass Comparison with MHD simulation 50 100 150 200 400 600 800 1000 1200 1400 Gopalswamy et al. Variable CD Fixed CD Velocity (km/s) Distance from the Sun (Rs) Circular CME 10 20 30 40 50 100 200 300 400 Velocity (km/s) Distance from Sun (Rs) MHD Simulation Analytical 1.5 2 2.5 3 3.5 4 4.5 5 200 400 600 800 1000 Acceleration (m/s/s) Distance from Sun Center (Rs) Virtual Mass No Virtual Mass drag  Cd ρ (V-Vsw)2 Standard Form Observed JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. A2, 10.1029/2001JA000120, 2002 Influence of the aerodynamic drag on the motion of interplanetary ejecta Bojan Vršnak Hvar Observatory, Faculty of Geodesy, Zagreb, Croatia Nat Gopalswamy Department of Physics, Catholic University of America, Washington, D. C., USA Characteristic magnetic field and speed properties of ICMEs and their sheath regions M.J. Owens, N.U. Crooker, G. Siscoe and C. Pagel Center for Space Physics, Boston University, Boston, Massachusetts. P.J. Cargill

Predictability (Crooker) 50 100 150 200 250 500 750 1000 1250 1500 from Crooker, 2004 Cloud axis Aligns with filament axis (low) and HCS (high) Directed along dipolar field distorted by differential rotation Leading field Aligns with coronal dipolar field (high) Application First part predicts the rest (Chen et al., 1997) Cloud axis orientation, Fair 28/50 (56%) align within 30° of neutral line [Blanco et al., 2005] Leading field, Good 33/41 (80%) match solar dipolar component with 2-3 year lag [Bothmer and Rust, 1997] 28/38 (74%) from PVO match [Mulligan et al., 1998]

CME Propagation Models 50 100 150 200 250 500 750 1000 1250 1500 Gopalswamy Template Empirical model of CME deceleration (Gopalswamy et al., 2000) Analytical model of CME propagation (Siscoe, 2004) Numerical simulation 0.5 to 50 AU (Odstrcil et al., 2001) Numerical simulation 1 Rs to 1 AU with two codes (Odstrcil et al., 2002) 50 100 150 200 400 600 800 1000 1200 1400

Super-CMEs at Work Making Superstorms Dynamic Pressure (nPa) Psw distributions in CIRs and CMEs (Lindsay et al., 1995) Ey distributions in CIRs and CMEs (Lindsay et al., 1995) GeoImpact of CMEs (Gosling, 1990) Ionosphere Dominated Solar Wind

The Terrestrial System under Super-CME Conditions Vasyliunas Dichotomization Solar wind dominated Ionosphere dominated Global force balance via Chapman-Ferraro current system Dst responds to ram pressure Global force balance via region 1 current system Neutral flywheel effect No (direct) Dst response to ram pressure Magnetopause erosion Transpolar potential saturation (TPS) Equivalent to ionosphere dominated regime Evidence for TPS and the Hill model parameterization

Vasyliunas Dichotomization Vasyliunas (2004) divided magnetospheres into solar wind dominated and ionosphere dominated depending on whether the magnetic pressure generated by the reconnection-driven ionospheric current is, respectively, less than or greater than the solar wind ram pressure. The operative criterion is oPVAε ~ 1 P = ionospheric Pedersen conductance VA = Alfvén speed in the solar wind ε = magnetic reconnection efficiency Key Point By this criterion, the standard magnetosphere is solar wind dominated; the storm-time magnetosphere, ionosphere dominated.

Pertinent Properties of the Standard Magnetosphere Chapman & Ferraro, 1931 Pertinent Properties of the Standard Magnetosphere Chapman-Ferraro Current System Midgley & Davis, 1963 x z ICF = BSS Zn.p./o  3.5 MA C-F compression = 2.3 dipole field 2x107 N

Ram Pressure Contribution to Dst A Chapman-Ferraro property April 2000 storm Huttunen et al., 2002 GOES 8 JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 107, NO. A12, 1440, doi:10.1029/2001JA009154, 2002 April 2000 magnetic storm: Solar wind driver and magnetospheric response K. Emilia J. Huttunen,1 Hannu E. J. Koskinen,1,2 Tuija I. Pulkkinen,2 Antti Pulkkinen,2 Minna Palmroth,2 E. Geoffrey D. Reeves,3 and Howard J. Singer4 Psw compresses the magnetosphere and Increases the magnetic field on the dayside. Chapman-Ferraro Compression

Interplanetary Electric Field Determines Transpolar Potential A magnetopause reconnection property 5 10 15 20 100 200 300 400 500 Transpolar Potential (kV) Ey (mV/m) Magnetopause reconnection Equals transpolar potential Transpolar potential varies linarly with Ey (Boyle et al., 1997) Magnetosphere a voltage source as seen by ionosphere B E V Burton, R. K., R. L. McPherron, and C. T. Russell, The terrestrial magnetosphere: A half-wave rectifier of the interplanetary electric field, Science, 189, 717, 1975. Burton, R. K., R. L. McPherron, and C. T. Russell, An empirical relationship between interplanetary conditions and Dst, J. Geophys. Res., 80, 4204-4214, 1975. Kan, J. R., and L. C. Lee, Energy coupling function and solar wind-magnetosphere dynamo, Geophys. Res. Lett, 6, 577-580, 1979. Boyle, C. B., P. H. Reiff, and M. R. Hairston, Empirical polar cap potentials, J. Geophys. Res., 102, 111-125, 1997. IMF = (0, 0, -5) nT

Solar Wind Dominated Magnetosphere Summary Psw compresses the magnetospheric field and increases Dst. Ey increases the transpolar potential linearly. Magnetosphere a voltage source Key Point Field compression and linearity of response to Ey hold for only one of the two modes of magnetospheric responses to solar wind drivers—the usual one.

Then Came Field-Aligned Currents Iijima & Potemra, 1976 Region 1 Region 2 Atkinson, 1978 R 1 C-F Tail 3.5 MA 5.5 MA 1 MA/10 Re Total Field-Aligned Currents for Moderate Activity (IEF ~1 mV/m) Region 1 : 2 MA Region 2 : 1.5 MA Question: How do you self-consistently accommodate the extra 2 MA?

Answer: You Don’t. You replace the Chapman-Ferraro current with it. IMF = (0, 0, -5) nT

Region 1 Force on Earth Region 1 Current Contours Streamlines 5x106 N We move now to slides dealing with the region 1 currents. They are taken from an ISM run in which the IMF is straight south. This slide gives a view of the northern polar cap in which parallel current is depicted in colored contours (blue = negative, tan = positive) and a set of current streamlines is shown in red. The symmetrical pair of closed contours of strong parallel current is the ionospheric expression of the region 1 current. The red current streamlines will now tell us (in the next slide) where the region 1 currents go in the magnetosphere. In particular, we are interested in where they close. One school of though says that they close in the cross-tail current sheet, another school says on the high-latitude magnetopause. IMF = (0, 0, -5) nT

Impact of Region 1 Currents on Understanding Solar Wind-Magnetosphere Coupling Summary Ionosphere and solar wind in “direct” contact Solar wind can pull on ionosphere as well as push on earth. Region 1 currents can usurp Chapman-Ferraro currents. Influence of ionosphere coupling increases relative to Chapman-Ferraro coupling as interplanetary electric field (Ey) increases. Key Point During major magnetic storms, this leads to an ionosphere dominated magnetosphere

What does this mean? It means that whereas the standard magnetosphere interacts with the solar wind mainly by currents that flow in and on the magnetosphere, the storm-time magnetosphere interacts with the region 1 current system that links the ionosphere to the solar wind in the magnetosheath and the bow shock.

Transpolar Potential Saturation IMF = 0 Chapman- Ferraro Region 1 IMF Bz = -30 10 20 30 40 50 100 150 200 250 300 350 Ey (mV/m) Transpolar Potential (kV) PSW=10 Baseline (PSW=1.67, Σ=6) Σ=12 Linear regime (small ESW) 6 1 . 57 / sw P E H = F Saturation regime (big ESW)

And most important Bow Shock Streamlines Region 1 Current Reconnection Ram Pressure Cusp Region 1 current gives the J in the JxB force that stands off the solar wind And communicates the force to the ionosphere Which communicates it to the neutral atmosphere as the flywheel effect Winds in the high-latitude lower thermosphere: Dependence on the interplanetary magnetic fieldAuthors: Richmond, A. D.; Lathuillère, C.; Vennerstroem, S.Journal: Journal of Geophysical Research (Space Physics), Volume 108, Issue A2, pp. SIA 10-1, CiteID 1066, DOI 10.1029/2002JA009493 (JGRA Homepage)Publication Date: 02/2003 Richmond et al., 2003

Evidence of Two Coupling Modes Transpolar potential saturation Instead of this You have this No dayside compression seen at synchronous orbit Hairston et al., 2004 5 10 15 20 100 200 300 400 500 Transpolar Potential (kV) Ey (mV/m) Cahill & Winckler, 1999 Dipole Field April 2000 storm Huttunen et al., 2002 GOES 8 Saturation of the ionospheric polar cap potential during the October-November 2003 superstorms Marc R. Hairston, Kelly Ann Drake, Ruth Skoug The geostationary field during dayside erosion events 1996-2001: A joint Wind, ACE, and GOES studt, Muehlbachler st al., JGR, A12, 2003 Foster, Coster, et al, Stormtime observations of the flux of plasmaspheric ions to the dayside cusp/magntopause, GRL, 31, 2004.

To Resume Transpolar potential saturation No dayside compression seen at synchronous orbit No compression term (b) in the Burton-McPherron-Russell equation: dDst*/dt = E – Dst*/ Dst* = Dst - b√Psw Instead of this You have this Ring current model fits storm main phase better without pressure correction Possibly related: Large parallel potential drops Sawtooth events Lee et al., 2004 b = 11.7 McPherron, 2004 Jordanova, 2005 Saturation of the ionospheric polar cap potential during the October-November 2003 superstorms Marc R. Hairston, Kelly Ann Drake, Ruth Skoug

The Bimodal Magnetosphere Summary Quiet Magnetosphere Dominant current system Chapman-Ferraro (Region 1 lesser) Magnetopause current closes on magnetopause Magnetopause a bullet-shaped quasi-tangential discontinuity Transpolar potential proportional to IEF Solar wind a voltage source for ionosphere Compression strengthens dayside magnetic field Minor magnetosphere erosion Main dynamical mode: substorms Force transfer by dipole Interaction Superstorm Magnetosphere Dominant current system Region 1 (no Chapman-Ferraro) Magnetopause current closes through ionosphere and bow shock Magnetopause a system of MHD waves with a dimple Transpolar potential saturates Solar wind a current source for ionosphere Stretching weakens dayside magnetic field Major magnetosphere erosion Main dynamical mode: storms Force transfer by ion drag Dichotomization, transpolar potential saturation, no Dst response to ram pressure, magnetopause erosion, neutral flywheel effect all part of one story.

THE END Thank You

You have this Cahill & Winckler, 1999 45o 5 nT 0o 5 nT Dipole Field

Properties of Ionosphere-Dominated Magnetosphere Region 1 Current System Fills Magnetopause Region 1 Current Contours