Geoactivity in Response to CIR/CME Events - A ... - Science Direct

Phgs.

Chem. Earth

(C), Vol. 24, No. 1-3, pp. 113-117,

1999 0 1998 Elsevier Science Ltd All rights reserved

Pergamon

1464-1917/99/$-see

S1464-1917(98)00017-S

PII:

Geoactivity B. Wilken’,

in Response

to CIR/CME

Q.-G. Zong’, G. D. Reeves2,

Events -

A Synoptic

2

20 September

1997; accepted

17 February

Tokyo,

Japan

1998

2.2

Observation

GEGTAIL Observations

Figure 2 gives an overview of the HEP-LD and MGF measurements from January 1 to June 9,1994, which show energetic ions with energy larger than 800 keV, energetic oxygen, helium, and proton ion fluxes, together with the magnetic field in GSE coordinates. The top two panels in Figure 2 show a line plot of energetic protons (energy, E 2 800 keV) and color-coded ion spectrograms, respectively. The third and fourth panel in Figure 2 show energy - integrated ion counting rates versus time profiles. The solid line labeled “All Ions” represents a rate summed over all ion species and energies, usually dominated by protons; the dashed line labeled CNO refers to oxygen ions summed over all energies. The fourth panel shows energy integrated rates for selected particle species (solid and dashed lines for hydrogen and helium, respectively). The fifth to eighth pan els display the GSE components and the magnitude of the magnetic field. Magnetic field spikes (except Geotail perigee encounters) are inherent to developed ‘corotating interaction regions’ or CMEs (shock). These spikes lasted only about 1 day whereas IMF negative Bz component appeared almost the whole geoactivity (10 to 14 days). So, these strong field events have not obvius evidence to relate to IMF negative Bz component (Figure 1). The magnitude of the background magnetic field in the distant tail (X < -100 Re, after 2 March, 1994, see Figure 2) is below 10 nT, this is consistant with ISEE 3 measurement(Tsurutani et al., 1986). The bottom 2 panels give the Geotail position in the GSM system. The proton peaks correspond in phase and magnitude accurately to the IMP-8 measurements in Figure 1. This correspondence is independent of the actual GEGT’ position in geospace (inside/outside of the magnetosphere). The implication is that the transient high energy component seen in some of the events are actually of interplanetary origin even if the vantage point was inside the magnetosphere. Vertical color-coded lines in the figure amplify the very good correlation between the fast stream (FS) and CME con-

The data to be presented are obtained by the HEP-LD instrument (Doke et al., 1994; Wilken et al., 1993) and the Magnetic Field Experiment (MGF) on board the GEOTAIL spacecraft (Kokubun et al., 1994). The HEP-LD is an advanced ion spectrometer with time-of-flight(T) and energy(E) detection systems which determine the mass of incident energetic particles. Combined with the sectored spin plane of the spacecraft this allows the imaging of flux distributions over the complete unit sphere in phase space. The energy ranges for hydrogen, helium and oxygen are approximately 40 - 3100 keV, 70 - 4000 keV, and 140 - 4000 keV, respectively. The instrument is not sensitive to the ionic charge state of nuclear particles; the mass resolution is marginal for separating carbon, nitrogen and oxygen ions. For the purpose of this paper the CNO group is referred to as ‘oxygen’ because this species is the major constituent. 2.1

View

T. Doke3 and T. Yamamoto4

‘Max-Planck Institute fiir Aeronomie, Katlenburg-Lindau, Germany 2Los Alamos National Laboratory, Los Alamos, New Mexico, U.S.A. 3Advanced Research Center for Science and Engineering, Waseda University, 41nstitute of Space Astronautical and Science, Sagamihara, Japan Received

front matter

Interplanetary Conditions and Geomagntic Activity

Long term plots (first 160 days in 1994) of interplanetary parameters and planetary indices are shown Figure 1. Interplanetary and planetary data show that the existence of six recurrent (27 days period) fast solar wind streams (FS) can be identified (third panel from the top): The sequence labeled CIR No.1 through 6 correspond to No.23 to No. 28 in the ULYSSESS notation(Simnett et al., 1994, 1995). Each CWFS is associated with high energy protons (E> 1 MeV/ IMP-8) as shown in the second upper panel. The CIR/FS events are very well related to periodic planetary activity as demonstrated by the indices Ap, Kp, and Dst, which are given in the lower three panels. The two largest geomagnetic storms in 1994 are noticeably caused by a shock (A, 21 to 25 Febuary, 1994) and CME (B, 14 April to 20 April, 1994) - The storm A (Dst=-139 nT) is initiated by a compressional phase which is clearly visible in the Dst trace. - The even stronger storm B (Dst=-203 nT) has no indication for a preceding compression in the Dst parameter. 113

114

B. Wilken ef al.: Geoactivity in Response to CWCME Events

Fig. 1. Threegroupsof stacked line plor~ of

interplanetaryand planetary parametersfor the time interval January I to June 6, 1994. Group 1 (top): Group 2: High energy (E 2 1 MeV) solar protonsand solar wind speed(in km/s). Group3: PlanetaryKp index and equatorialDst (ii LIT).Vertical lines 1 to 6 and A and B mark CIRs and CMEs, nspeztively.

Interplanetarymagneticfield (in 0).

trolled energetic particle enhancements and compressional spikes in the magnetic field magnitude (inside and outside the magnetosphere). Magnetic field spikes are corresponding to each ‘corotating interaction regions’ or CME. 2.3 Geosynchronous Observations Figure 3 displays geosynchronous data for the first 160 days of 1994 taken from the LANL S/C 1989-046. It can be seen that effects of the CIRs, shock and CME are noticeable in all energy channels of electrons and protons. However, the quality of the flux modulations is quite different, particles with higher energies show more details than particles with low energies. The high energy protons (2 1MeV) of interplanetary origin are not noticeable in the geosynchronous magnetosphere

with the exception of the rather intense storm A. In contrast, proton events are easily identified in Geotail observations in all parts of the outer magnetosphere and in the distant tail. Energetic electrons show clearly defined flux profiles with steep leading and trailing edges in response to all CIR, shock and CME events. These flux profiles show a delay of 2 to 3 days with reference to the Kp and Dst traces, but the latter are reasonably well in phase with GEOXUL energetic particle profiles obtained elsewhere in the distant geospace. 3

Discussion

In the time interval January to June 1994 a series of high speed solar wind streams (FS) passed the Earth. These streams reappeared with a high degree of periodicity for at least seven solar rotations in the declining phase of the Solar Cycle 22.

B.

Wilken

er

al.: Geoactivity in Response to CIRKME Events

,,ay 0101.

2101.

10.02.

M PAe,UoB

01 .01.-09 x)6 1994

G-tail_HEP-LD

02.03.

22.03.

11.04.

01.05.

115

21.05.

h”lh”i~“Ih.1505111.“191,1)1L.1

Fig. 2. GEOTAIL

HEP/LD

overview

plot from Jan. 01 to June 06. 1994.

From the top the panels show: line plot of energetic protons (E

2

800

keV):

color-coded ion spectmgmms; integral

rates for hydmgen and helium; GSE components and magnitude

of Ihe magnetic field (in nanotcslas)

are the same as in Fig.

countingrates ‘AllIons’and ‘CNO Ions’; counting and OUrrAIL positions in OSMsystem. Vertical lines

In general, the leading ramps of these streams showed solar wind signatures of ‘corotating interaction regions’ (CIRs) as smooth fransitions rather than a steep pair of shocks which is rather common at 1 AU. The passage of these CWFS systems caused in all cases 10 to 14 days of continuous geoactivity. The planetary activity, as measured by Kp, goes typically through a sudden increase followed by a slow decay over a period of 10 to 14 days. In the course of the above mentioned time interval, the GEOTAIL spacecraft observed the interplanetary streams and their effects in geospace from a variety of vantage points inside the magnetosphere (mostly in the tail) and in the dusk and dawn magnetosheath. (Figure 2 shows these positions in geospace between January 1 and June 9,1994.) Kokubun et al. (1996) point out that most large field events in the distant tail seen by Geotail appear in the main phases of storms, our observation is consistent with this result. Furthermore, the magnetic field spikes (except Geotail satellite

I

3 times perigee encounter) are inherent to developed ‘corotating interaction regions’ or CMEs (shock). The strong increase of the magnetic field strength inside the tail is not obviusly related to IMF negative Bz component. In fact, it may be mainly related to an increase in the sheath or solar wind pressure(Ho and Tsurutani, 1997), not a dayside reconnection effect. The HEP-LD spectrometer measured the mass composition and velocity distribution of energetic ion populations resulting from these sustained magnetospheric activities inside the magnetosphere (near Earth and distant tail) and outside the magnetopause (magnetosheath and interplanetary space). Intense proton and helium fluxes with spectral distributions extending to rather high energies (up to 2 MeV or higher) are a magnetospheric product of these disturbances. Short bursts of oxygen ions emanating most likely from reconnection regions were detected on interplanetary field lines. The enhanced and sustained level of planetary activity cause{

116

Fig. 3. Longtermgeosynchronous (satellite1989446) observations plots for the selected proton (top) and electron energy channels. Vertical lines are the same as in Fig. 1.

by the CIRs, shock and CME frequently produced bursts of energetic oxygen ions in the magnetosphere(Wilken et al., 1997; Zong et al., 1997a). It is also known that substorm related oxygen burst events in the distant magnetotail (Wilken et al., 1995; Zong and Wilken, 1997; Zong et al., 1996.199713) appear in time intervals of enhance geoactivity caused by CIR events.

4

Conclusions

Interplanetary corrotating interaction regions (CIRs), shock and isolated coronal mass ejections (CMEs) between January

and CME events. The multi-point (GEOTAIL, geosynchronous platforms and IMP-I) observation can be summarised as follows: ?? Eight high speed solar wind streams determine the interplanetary conditions in the first half of 1994: six CIR and

two CME sequences. ?? The passage of a high speed solar wind sector created magnetospheric activity for a period of about ten days. ??

A shock and a CME occurred in the period of interest

on March I and April 1. The passage of CME(shock) casued a higher level of activity in Kp/Ap and stronger storms indicated by Dst than for CIRs.

1,1994and June 9, I994 created intervals with enhanced activity in the magnetosphere, each about IO days in duration. A total of six such quasi-periodic intervals was monitored by

??GEOTAIL observed these events inside and outside the magnetosphere and in the deep tail. Pratically all flux enhancements observed by GEOTAIL elsewhere in geospace

GEOTAIL from different vantage points in geospace. The interplanetary medium was strongly structured by recurrent high speed solar wind streams and associated CIRs, shock

can be traced to the passage of a high speed stream in the solar wind. Magnetic field spikes are inherent to developed ‘corotat-

??

B. Wilken et al.: Geoactivity in Response to CIRKME Events

of the magnetic field strength inside the tail may be mainly related to an increase in the sheath or solar wind pressure, and not to dayside reconnection. ??High energy protons (in the MeV range), frequently observed at the leading ramp of a CIR, are detected inside and outside the magnetosphere. They are most likely of interplanetary origin (not a product of the excited magnetosphere). . The response of the energetic particle population at geosynchronous altitude is rather sharp for high energy particles with a fair amount of detail. The presence of high energy protons in the outer parts of the magnetosphere is not reflected in geosynchronous measurements. The flux profiles of geostationary observation show a delay of 2 to 3 days with reference to Kp and Dst traces. But Kp and Dst are reasonably well in phase with GEOTAIL energetic particle profiles obtained elsewhere in geospace.

References Barnes, C. W. and Simpson, J. A., Evidence for interplanetary acceleration of n&eons in comtating interactionregions, Astrophys. .l. LetL91,210215,1976. Croaker, N. U. and CIiver, E. W., Postmodem view of m-regions, J. Geophys. Rex, 99, ‘23,38323,390, 1994. Doke, T., Fujii, M., Fujimoto, M., Fujiki, K., Fukui, T., Gliem, F., Giittler, W., Hasebe, N., Hayashi, T., Ito, T., Itsumi, K, Kashiwagi, T., Kikuchi, I., Kohno, T., Kokubun, S., Livi, S., Maezawa, K., Moriya, H., Munakata, K, Murakami, H., Muraki, Y., Nagoshi, H., Nakamoto, A, Nagata, K., Nishida, A., Rathje, R., Shine, T., Sommer, H., Takashima, T., Terasawa, T., UllaIand, S., Weiss, W., Wdken, B., Yamamoto, T., Yamaginachi, T., and Yanagita, S., The energetic partide spectrometer HEP onboard the GEtYIiUL spacea&& J. Geomagrh Geoekctx, 46,713-733,1994. Dryer, M., Interplanetary Studies: Propagation of Disturbances between the son and the magnetosphere, Space Sci Rev., 67,363-419,1994. Gosling, J. T., Coronal mass ejedions and magnetic flux mpes in interplanetary space, in Physics of Magnetic Flux Ropes, edited by C. T. Russell, E. R. Priest, and L. C. Lee, pp.343-364, Geophysical Monograph 58, Washington, U.S.A, 1990. Gosling, J. T., Magnetic topologies of coronal mass ejection events: Effects of 3-dimensional reconnection, in Solar Wutd 8, edited by D. Winterhalter, J. T. Go&g, S. R. HabbaI, W. S. Kurth, and M. Neugebauer, pp. 438-441, AIP Conference Proceedings 382 Woodbury, New York, 1996. Go&g, J. T., Baker, D. N., Bame, S. J., Feldman, W. C., Zwicid, R. D., and Smith, E. J., BiionaI solar wind eledron heat flux events, J. Geophys. Res., 92,8X=539, 1987. Gosliig, I. T., Mamas, D. I., Phillips, J. L., and Bame, S. I., Geomagnetic activity associated with earth passage of interplanetary shock disturbance and coronal mass ejections,1 Geophys. Res., %, 7831-1839,199l. GosIii J. T., Bame, S. J., McComas, D. J., Phillips, I. L., Pi, V. J., Goldstein, B. E., and Neugebauer, M., Latitudinal variation of solar wind cornrating stream interaction regions: Ulysses, Geophys. Res. Len., 20. 2789-2192.1993.

117

Gc&g, J. T., Bame, S. J., Feldman, W. C., M&m=, D. J., Phillips, J. L., GoIdsteIn, B. E, Neugebauer, M., BtukcpiIe, 1.. Hundhausen, A. I., and Acton, L, The baad of solar wind variabiity at low heliographic latitudm near solar x&ity minimum: Plasma resul& form the ulysse-srapid Iatiluk scan, Gaqphys. Ra. Lett., 22,33%3335 1995. Ho, C M. and Tsura@d, B. T., Distant taiI behavior during high speed solar wind strrams and magnetic stonns,J. Geqhya. Res., 202,14,16514,175, 1997. Kokubon, S., Yamamoto, T., Acuna, M., KHayashii Shiokawq K, and H.Kawano, The GEOTAL Magnetic Field Experiment, J. Geomogn Gwelectr., 46,7-21,1994. K&bun, S., Frank, L. A., Hayashi, K, Kamide, Y., Lepping, R. P., Mukai, T., Nakamura, R., Paterson, W. R., Yamamoto, T., and Yumoto, K, Large field events in the distant magnetolail during magnetic storms, J. Geomagn GeoeLxtr., 48,561-575,1996. Simnctt, G., Sayle, K., Rcclof, B., and Tappin, S., Corotating particle enhancements out of the ecliptic plane, Geophys. Res. Len, 21,1561-155X, 1994. Simne& G., Sayle, K., and Roelof, E., Differences between the 0.35-1.0 mevhmcleon b/be ratio in solar and co-rotating events at high heliolatitude, Geophys. Res. Lea, 22,3365-3368,159s. Smith, P. H. and Wolfe, J. H., Observations of interaaion regions and coretating shocks between one and five au: Pioneers 10 and 11, Geophys. Rex Len, 3,137-140,1976. Tsurutani, B. T., Smith, E. 1.. Pyle, K R., and Simpsoa, J. A., Energetic pmtons accelerated at comtating shocks: Pioneer and llobservation~ from 1 to 6 au, J. Geophys. Res., 87,7389-7404, 1982. Tsurutaoi B. T., Goldstein, B. E., Burton, M. E., and Jones, D. E., A review of the isee- geotaiI magnetic field results, P&m% Space Sci, 34,931960.1986. Wdkeo, B., GiittIer, W., Korth, A., Livi, S., Weiss, W., Gliem, E. Miillen, A., Rathje, R.. Fritz, T. A., FeMeii, J. F., Borg, H., Grande, M., Hall, D., McKenna-Lawlor, S., Saris, E. T., Tanskanen, P., URaland, S., Ssraas, F., and Erslaod, L.. RAPID: The imaging energetic partide spectrometer on Cluster, in Cluster: Mission, Payload and Supporting A&irks, pp. 185-217. Eur. Space Agency Spec. Publ., SP-1159.1993. Wdken. B., Zong, Q.-G., DagIii, I. A., Doke, T., Liii, S., Maezawq K, Pu, 2. Y., URaland, S., and Yamamoto, T., Tailward flowing energetic oxygen ion bursts associated with multiple flux ropes in the distant magnetotail: GeotaiI observations, Geophys. Res. Len., 22.3267-3270.1995. Wdken, B., Zong, Q.-G., Doke, T., Maezawa, K, Reeves, G. D,, Mukai, T., UUaIand, S., and Yamamoto, T., A isolating substonn occurred at first phase of cir GeotaiI observations, J. Geophys. Res., revised, 1997. Zoog, Q.-G. and Wdken, B., Energetic oxygen ion bunts in the distant mag netotail, in MRATPmceedings of the COSPARSerks, edited by A. T. Y. Lui, p. In Printing, Elsevier Science, United Kington, 1997. Zong, Q.-G., Wdken B., DagIis, I., Livi, S., Woch, J., Reeves, G., Iyemori, T., T.Mukai, and Yamamoto, T., Geotail observation of energetic ion species and magnetic Beld in plasmoid-Iii s&uchres, in Pmceedings of the Third Inrernabwl Conference on Subs~omts (ICS-3). pp. 61w24, Eur. Space Agency Spec. Publ., SP - 389, ESA, 1996. Zong, Q.-G., Wilken, B., Reeves, G.. Daglis, I., Doke, T., Liii, S., Maezawa, K, Woch, J., Iyemori, T., T.Mukai, Kokobun, S., Pu, Z.-Y., URaland, S., and Yamamoto, T., GeotaiI observation of energetic ion specia and magnetic field in plamoid-like stmctores in the course of an isolated substorm event, J. Geophys. Res., 102,11,40!+11,428,1997a. Zang. Q.-G.,WiIken, B., Woch, J., Reeves, G.. Doke, T., Kokubun, S., and Yamamoto, T..,Bursty energetic oxygen events in dayside magnetosheath : GeotaiI observation, J. Geophys. Res., 102, to be Submitted to JGR, 1997l-l.