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Subject headinggs: cosmic rays — Sun: coronal mass ejections (CMEs). 1. INTRODUCTION. The solar modulation of Galactic cosmic-ray (GCR) intensity.
The Astrophysical Journal, 625:441–450, 2005 May 20 # 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A.

CORONAL MASS EJECTIONS AND GALACTIC COSMIC-RAY MODULATION A. Lara,1 N. Gopalswamy,2 R. A. Caballero-Lo´pez,1 S. Yashiro,2,3 H. Xie,2,3 and J. F. Valde´s-Galicia1 Receivved 2004 March 12; accepted 2004 December 22

ABSTRACT We present a study of the long-term evolution of coronal mass ejections (CMEs) observed by the Large Angle and Spectrometric Coronograph ( LASCO) on board SOHO during the ascending, maximum, and part of the descending phases of solar cycle 23 and their relation with the modulation of galactic cosmic-ray (GCR) intensity observed at 1 AU by the Climax neutron monitor and IMP-8 spacecraft. We compare the long-term GCR modulation with the CME occurrence rate at all, low, and high latitudes, as well as the observed CME parameters (width and speed). Twenty-seven day averages of CME occurrence rates and CME properties from 1996 January to 2003 December are presented in the Appendix. The general anticorrelation between GCR intensity and the CME rate is relatively high (0.88). However, when we divide the CME rate into low- and high-latitude rates and compare them with the GCR intensity during the ascending phase of solar cycle 23, we find a lower anticorrelation between the low-latitude the CME rate and GCR intensity (0.71) and a very high anticorrelation between the highlatitude CME rate and GCR intensity (0.94). This suggests that, in general, CMEs could cause the decrease in the GCR flux in the inner heliosphere, as stated by the global merged interaction region (GMIR) theory. In particular, during the ascending phase of cycle 23 (qA > 0), this flux comes mainly from heliospheric polar regions. Thus, high-latitude CMEs may play a central role in the long-term cosmic-ray modulation during this phase of the cycle by blocking the polar entrance of GCRs to the inner heliosphere. This study supports the scenario in which CMEs, among other structures, are the building blocks of GMIRs, although we propose that the spherical shells (GMIRs) are closed separately at polar and equatorial regions by CMEs of different latitudes. Our results suggest that all CME properties show some correlation with the GCR intensity, although there is no specific property (width, speed, or a proxy of energy) that definitely has a higher correlation with GCR intensity. Subject heading gs: cosmic rays — Sun: coronal mass ejections (CMEs)

1. INTRODUCTION

lution of GMIRs at low latitudes are well understood (see the review of McDonald & Burlaga 1997). However, there is a lack of information about the formation and evolution of GMIRs at polar heliospheric regions. In general, a latitudinal symmetry is assumed. CMEs are magnetized structures, which can affect the heliospheric conditions, producing large fluctuations in the heliospheric magnetic field. CMEs traveling at different speeds tend to merge into what are known as complex ejecta, which are seen often in the interplanetary medium during times of high solar activity (Burlaga et al. 2001). The increase of the magnetic field during the passage of an ejecta at 1 AU is related to the GCR intensity decrease (Cliver et al. 2003). Traditionally, GCR intensity has been compared with sunspot number (SSN) and other solar activity indices, such as solar flares, 10.7 cm radio flux, and so on (see Belov 2000 and references therein). CMEs are large-scale phenomena that change the configuration of the interplanetary magnetic field (IMF) and clearly modulate the cosmic-ray intensity on short-term (few day) timescales (see Cane 2000 for a review of this subject). Therefore, it is natural to think that CMEs may also contribute to longer term modulation, in particular by contributing to the propagating barriers (GMIRs) that are believed to be the cause of the long-term modulation (Newkirk et al. 1981; McDonald & Burlaga 1997; Cliver & Ling 2001b). The increase of the HCS tilt angle also affects the largescale heliospheric structure, although models show that during positive-drift solar cycles (such as cycle 23), changes in the HCS tilt angle do not cause large decreases in GCR intensity (see Fig. 1h of Caballero-Lo´pez & Moraal 2003). Recently, Cliver & Ling (2001a) found a time lag of 9 months between the GCR intensity and the HCS tilt angle variations during the ascending phase of cycle 23. They interpreted this as a ‘‘limit’’ of

The solar modulation of Galactic cosmic-ray (GCR) intensity has been known since the work of Forbush (1954). The basis of the GCR transport theory was established by Parker (1965). This theory combines four modulation mechanisms: the convection effect, adiabatic energy changes, gradient and curvature drifts, and diffusion (Potgieter et al. 1993, 2001). The role of each of these mechanisms in the modulation has been discussed in many works (McDonald et al. 1991; Potgieter et al. 2001). The convection effect is due to the outward solar wind flux, which can reduce the cosmic-ray intensity at any point in the heliosphere. The expanding solar wind causes the adiabatic energy change of cosmic-ray particles, which is more important in the inner part of the heliosphere. Gradient and curvature drifts in the large-scale heliospheric magnetic field, as well as the drift related to the heliospheric current sheet ( HCS), have a major effect on the GCR modulation during periods of minimum solar activity (Potgieter 1997). Merged interaction regions (MIRs) and global MIRs (GMIRs) were proposed by Burlaga et al. (1985, 1991, 1993) as diffusive propagating barriers in the outer heliosphere in order to explain the steplike modulation of GCRs, and they play a major role during the increasing phase of solar activity (Potgieter 1997; McDonald 1998). GMIRs are thought to be due to various flows from the Sun, including coronal mass ejections (CMEs). GMIRs are idealized spherical shells that must be closed at all directions ( latitudinally and longitudinally). The formation and evo1

Instituto de Geof ´ısica, UNAM, Me´xico DF, Mexico. NASA Goddard Space Flight Center, Greenbelt, MD 20771. Department of Physics, The Catholic University of America , Washington, DC 20064. 2 3

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50 for the tilt angle, after which the HCS starts affecting the GCR intensity. In an apparent contradiction, Le Roux & Potgieter (1990) and Potgieter (1993) found that drifts in the HCS are important for long-term GCR modulation as long as the tilt angle is below the 35  5 limit. On the other hand, Cliver & Ling (2001a and references therein) noted that the CME rate changes quasi-discontinuously when the tilt angle passes through the value of 50 . Therefore, it is possible that the GCR intensity may be modulated by the latitudinal change in the CME rate (Cliver et al. 2003). In this paper we consider the effect of white-light CMEs, observed by the SOHO mission’s Large Angle and Spectrometric Coronograph ( LASCO), on the long-term modulation of GCR intensity. With SOHO LASCO data available since 1996, we have an excellent opportunity to study the CME-GCR variations for a large portion of solar cycle 23. We are able to determine the CME production rate at low and high latitudes and assess the possible influence of the CME latitudinal changes on the GCR flux. 2. OBSERVATIONS 2.1. Coronal Mass Ejections The acceleration, speed, angular width, and angular position of each CME observed by SOHO LASCO since 1996 are available in the CME catalog ( Yashiro et al. 2004),4 and Carrington rotation averages of these parameters are presented in Table 2 in the Appendix. Using this catalog, we obtained the approximate latitude of each CME from its position angle. Position angle is the angle of the axis of the CME-projected cone, measured counterclockwise from solar north ( Hundhausen 1993; Gopalswamy et al. 2003b). As the measured position angle is the projection of the CME space direction on the plane of the sky, the computed latitude is a good approximation when the CME direction is close to the plane of the sky (limb CMEs). It may not be so when the CME direction is far out of the plane of the sky. In the case when the CME is propagating toward or away from the observer, the apparent width may exceed 120 (partial halo) and may occasionally even reach 360 (full halo). Fortunately, only 3.5% of the total observed CMEs are halos (Gopalswamy 2004; Yashiro et al. 2004). In order to minimize the error due to projection effects in latitude computations, we used only CMEs with a maximum width of 120 . Approximately 89% of CMEs fall into this category. CMEs are related to closed magnetic regions, namely, active regions and prominence regions. Active regions are confined to the low-latitude active belt (35 from the limb is diminished by a factor of 2 compared to one at the limb. At angles of 60 the diminution factor is 10 and the visibility is zero at angles >70 (see Fig. A2 of Hundhausen 1993). This limitation is due to the Thompson-scattering process and applies to any white-light coronographic observations (at least at 2 solar radii). 2. Structures extending radially from active-regions belts would never be seen at projected latitudes >52 if they are located at longitudes 60 could have true latitudes in the 45 –90 range. We note that results 2 and 3 were obtained using SMM observations and may not apply directly to LASCO observations owing to the higher sensitivity of the latter instrument. LASCO is able to detect halo CMEs, which might have originated at low latitudes and close to the disk center. However, halo CMEs seems to be extreme cases, which are wider and faster than regular CMEs ( Yashiro et al. 2004; Gopalswamy 2004). This analysis is still applicable to regular CMEs that have a mean width of 47 . A detailed analysis for partial and full-halo CMEs, which is beyond the scope of this work, is necessary in order to establish these limits for LASCO observations. 2.2. Cosmic-Ray Data The cosmic-ray intensity used in this work comes from the Climax neutron monitor and the IMP-8 Goddard Medium Energy (GME) Experiment. The Climax, Colorado, neutron monitor is an IGY-design monitor located at 3475 m elevation and has a vertical cutoff rigidity of 3 GV. Medium- and high-latitude neutron monitors are most sensitive to the low-energy (1– 20 GeV ) portion of the GCR spectrum. The IMP-8 GME Experiment measures particle fluxes as a function of energy and makes elemental identification for protons, -particles, and heavier ions from 1 to 400 MeV nucleon1. In this work we use

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Fig. 2.—Scatter plot of the CMEHL (left) and CMELL (right) vs. Climax (top panels) and IMP-8 (bottom panels) GCR intensities. Triangles, circles, and plus signs correspond to the ascending, maximum, and descending phases of cycle 23, respectively. The fitted lines for the total period (dot-dashed line) and the ascending (solid line), maximum (dashed line), and descending (dotted line) phases are also plotted.

the flux of 121–229 MeV protons from 1997 January to 2002 December to study the GCR modulation at 1 AU. We have removed the enhancements due to solar energetic particles events from the observed proton flux. We use the CRot average of the cosmic-ray intensity for this analysis. The 11 yr cosmic-ray modulation begins a few months after the onset of sunspot activity and extends approximately 0.5– 1 yr after SSN maximum. This modulation seems to occur through a series of well-defined steplike decreases that propagate outward from 1 AU to the outer heliosphere ( McDonald et al. 1981). The steplike decreases are associated with GMIRs, as was shown by Burlaga et al. (1991, 1993) and McDonald et al. (1993). The times of the steplike decreases during cycle 23 (Caballero-Lo´pez & McDonald 2003) are marked by the thick vertical lines in Figure 1. 3. ANALYSIS AND RESULTS 3.1. CME Occurrence Rate and GCR Intensity According to the GCR transport theory, latitudinal changes are expected in the inflow of GCRs, depending on the solar magnetic polarity. During qA > 0 epoch (where the heliospheric magnetic field is directed outward in the north polar region and inward in the south polar region, as in the first half of cycle 23), the GCRs drift inward from the polar regions to the equatorial plane and then outward along the HCS; during qA < 0 epochs, the drift is inward through the HCS, from the equatorial plane to the poles (see Fig. 2 in Moraal 1993). Therefore, the effect of CMEs on the GCR modulation must be different depending

on the CME latitude and qA sign during the cycle. In particular, Caballero-Lo´pez et al. (2004) found that in order to fit the GCR observations throughout the heliosphere in 1977 and 1997, it is very important to reduce the drift and diffusion over the poles. Even though this result is for solar minimum conditions, it shows the role that polar region conditions have on the GCR intensity observed near the ecliptic plane during a qA > 0 epoch. Therefore, if we have an increase of the solar disturbances at high heliolatitudes, we should expect an effect on the GCR intensity observed at Earth. In this context, we will analyze the relation between GCR intensity at 1 AU and high-latitude CMEs. In Figure 1 we have plotted CMEtot in panel (a) and the SSN (dashed line) and the GCR intensity from Climax (circles) and IMP-8 (triangles) in panel (d ). CMEtot and SSN are well correlated, as expected, because both are manifestations of the general solar magnetic activity cycle, although the peak activity in SSN and CMEtot differs by 2 yr (Gopalswamy et al. 2003a). On the other hand, the GCR intensity is anticorrelated with both CMEtot and SSN; this is the so-called long-term cosmic-ray (solar) modulation. Taking into account the CME rate at different latitudes, we note that, as mentioned before, the CMELL activity slowly increased from the beginning of 1996 until the end of 1997, where CMELL had an increase from 20 to 70 CMEs per CRot. On the other hand, it is remarkable that the CMEHL activity started in 1998 March, almost at the same time as the first steplike decrease in GCR intensity. After this, the GCR intensity continued to decrease and CMEHL continued to increase. There was a local minimum in CMEHL during CRots 1954, 1955, and 1956, which

No. 1, 2005

CMEs AND COSMIC-RAY MODULATION

was not reflected in the GCR intensity. Long data gaps of 9.87 and 15.12 days, during CRots 1954 and 1956, respectively affected such counts. It is most likely that the local minimum (also seen in CMEtot plot) was due to these data gaps. The GCR intensity reached its minimum value in 2000 July for Climax and in 2001 January for IMP-8. A quasi-constant phase of GCR intensity followed both minima. It is interesting to see that the CMEHL activity had a local peak in 2000 September followed by a quasi-constant phase with an isolated peak (maximum value) in 2002 March. On the other hand, CMELL continued with an increasing trend until 2002 August. Because the GCR modulation strongly depends on the phase of the solar magnetic cycle, we divided the total period of observation into three parts: (1) the ascending phase, from 1996 January to 2000 March, when qA > 0; (2) the maximum phase, from 2000 April to 2001 October, when both poles had the same (negative) polarity; and (3) the declining phase, from 2001 November to 2003 December (the end of our study period), when qA < 0. The phases of the solar cycle were selected by means of the polarity reversal of the polar photospheric magnetic field (see Fig. 3 in Gopalswamy et al. 2003a). In Figure 2 we show the scatter plots of the smoothed (threeCRot running average) values of CMEHL (left) and CMELL (right) versus the GCR intensities from Climax (top) and IMP-8 (bottom). Triangles, circles, and plus signs correspond to the ascending, maximum, and declining phases, respectively. The overall correlation is relatively good, with high dispersion at low GCR intensities. To illustrate the differences in each phase, we have plotted the linear fits to the high-latitude data for the three phases. The best linear correlation is found for the relationship between CMEHL and GCR intensity during ascending with a correlation coefficient of 0.92 for Climax and 0.94 for IMP-8 data sets. The overall correlation coefficient (during the complete period of time) is relatively high, reaching a value of 0.88 for the relation between CMEHL and IMP-8 GCRs, and a value of 0.83 between CMELL and Climax GCRs. However, it is clear from the right panels of Figure 2 that the relationship between CMELL and GCRs is complex and nonlinear. The CME-GCR relationship is distinct during the three phases of the solar cycle, as shown by the linear fits in Figure 2. The slope is clearly different (higher in absolute value) for the ascending phase and tends toward zero for the maximum and declining phases. The correlation coefficients are also different, showing a very good correlation for CMEHL, a medium correlation for CMELL during the ascending phase, and a variable correlation from medium to low during the other phases. The minimum correlation is found between CMELL and GCR intensity during the declining phase. This is due mainly to the fact that our data set covers only a small part of the declining phase. This suggests a clear influence of CMEs over the GCRs during the ascending and a low influence during the maximum phase. In a similar study, Cliver & Ling (2001b) found a correlation coefficient of 0.61 between CMEs detected by Solwind and SMM and Climax GCRs. The period of time covered by that study was from 1979 to 1989, which includes the maximum and declining phases of cycle 21 and the ascending phase of cycle 22. Cliver & Ling (2001b) did not make any distinction between the phases of the solar cycle, and the study was done mainly during a qA < 0 epoch, Therefore, we cannot directly compare their results with ours. They found a correlation coefficient of 0.87 between the CME rate and SSN similar to our 0.88 for cycle 23. This is due to the fact that the CME rate and SSN are expressions of the solar activity cycle and there are no major differences between them during different phases of the cycle. In contrast, the

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Fig. 3.—Cross-correlation as a function of lag (in CRot) between GCR intensities from Climax (top) and IMP-8 (bottom) and CMEs. Solid and dashed lines correspond to the ascending phase of the solar cycle, while the dotted lines correspond to the cross-correlation between GCRs and SSN during the entire period of observation.

CME-GCR relationship is more complex, as shown by the variation of the correlation coefficient as a function of the CME latitude and the phase of the solar activity cycle. The linear correlation does not give any information about the time differences between the variables. A simple way to compare two time series is a cross-correlation analysis, which gives the cross-correlation coefficient rl as a function of the shift or lag (l) between the two series. For this study the basic time unit is a CRot, so the cross-correlation lag is in units of CRot. In Figure 3 we show the cross-correlation curves between the Climax (top) or IMP-8 (bottom) cosmic-ray data and CMEHL, CMELL, and CMEtot, during ascending with thick, medium, and thin lines, respectively. We have also plotted the cross-correlation curves between SSN and GCR intensity for ascending phase and the total period. Similar plots have been made for both Climax and IMP-8 data. There is a remarkable similarity between the crosscorrelation curves for both Climax and IMP-8. It is clear in Figure 3 that the maximum anticorrelation is obtained between CMEHL and GCR intensity during ascending. This high value of rl (0.94) is reached without time lag, suggesting that, in this phase, the GCR diffusion barriers may start acting at distances 0 epochs of GCR modulation. 5. Based on (1) the cosmic-ray transport theory, which predicts that during qA > 0 epochs the cosmic rays reach the inner heliosphere mainly from the polar regions; (2) the model of global merged interaction regions, which proposed that CMEs ( besides other structures, e.g., corotating interaction regions) merging in large-scale structures, effectively block the cosmicray flux; and (3) the high correlation found between the cosmicray intensity and the high-latitude CME rate, this study suggests

that in general, CME occurrence is important for GCR modulation. They are the building blocks of the GMIR at all latitudes. In particular, during the ascending phase of solar cycle 23, the high-latitude CMEs seem to have played a very important role in the long-term modulation of GCRs, because they effectively close the GMIRs at polar heliospheric latitudes. In order to establish a definitive relationship between the latitudinal changes of the CME production and the GCR intensity, it is necessary to investigate both domains further: CMEs and GCRs. For CMEs we have to minimize the possibility of error in the latitude evaluation (this problem will be overcome with the availability of STEREO observations). On the other hand, it is possible to perform numerical simulations of the GCR flux using the CME rate as an input.

We thank the anonymous referee for his/her comments and suggestions to improve this paper. This work was supported by UNAM (PAPIIT IN119402 and 108904), NASA/LWS, and NSF/ SHINE (ATM 02-04588). SOHO is a project of international cooperation between ESA and NASA. Climax data are available at University of New Hampshire, NSF (ATM-9912341). We thank R. E. McGuire for IMP-8 data and S. Nunes for compiling the SOHO LASCO downtimes.

APPENDIX CME RATES Table 2 presents the computed number of CMEs per Carrington rotation from CRot 1905 to CRot 2010. Column (1) is the Carrington rotation number, and the initial date is in column (2). Columns (3) and (4) give the total number of CMEs observed and the LASCO downtime during each CRot, respectively. The mean speed (km s1) and width (degree) per CRot of the observed CMEs are given in columns (5) and (6), respectively. We note that for some events it is not possible to measure the speed and/or width because they fall partially within data gaps. The CME numbers per CRot are grouped as follows: the low-latitude numbers, from 40 to 40 , are in column (7), and the high-latitude numbers in the southern (60 ) plus northern (60 ) hemispheres are in column (8). To compute the CME latitude, we take into account only CMEs with width lower or equal to 120 . TABLE 2 CME Occurrence Rate

CRot (1) 1905...................... 1906...................... 1907...................... 1908...................... 1909...................... 1910...................... 1911...................... 1912...................... 1913...................... 1914...................... 1915...................... 1916...................... 1917...................... 1918...................... 1919...................... 1920...................... 1921...................... 1922...................... 1923...................... 1924...................... 1925......................

Date (2) 1996 1996 1996 1996 1996 1996 1996 1996 1996 1996 1996 1996 1996 1997 1997 1997 1997 1997 1997 1997 1997

Jan 17 Feb 13 Mar 11 Apr 4 May 5 Jun 1 Jun 28 Jul 25 Aug 22 Sep 18 Oct 15 Nov 11 Dec 9 Jan 5 Feb 1 Mar 1 Mar 28 Apr 24 May 22 Jun 18 Jul 15

CME Number (3)

Downtime (days) (4)

Speed ( km s1) (5)

Width (deg) (6)

Low Latitude (7)

High Latitude (8)

6 10 16 17 10 8 20 20 12 15 23 24 24 15 20 16 20 24 31 29 26

13.42 19.81 16.88 16.07 6.17 2.49 2.62 4.78 0.75 0.69 2.63 4.07 1.48 2.77 0.17 1.89 2.52 0.00 0.38 0.47 0.31

223 175 204 195 314 216 377 233 230 224 239 334 224 185 239 247 329 263 287 241 303

48 40 33 45 53 51 41 50 35 36 33 47 42 52 35 46 57 48 47 43 53

5 9 16 16 9 7 17 15 11 10 18 21 20 14 14 11 18 18 28 27 19

0 0 0 0 0 0 1 1 0 1 1 1 0 0 0 1 0 0 0 0 3

TABLE 2—Continued

CRot (1) 1926...................... 1927...................... 1928...................... 1929...................... 1930...................... 1931...................... 1932...................... 1933...................... 1934...................... 1935...................... 1936...................... 1937...................... 1938...................... 1939...................... 1940...................... 1941...................... 1942...................... 1943...................... 1944...................... 1945...................... 1946...................... 1947...................... 1948...................... 1949...................... 1950...................... 1951...................... 1952...................... 1953...................... 1954...................... 1955...................... 1956...................... 1957...................... 1958...................... 1959...................... 1960...................... 1961...................... 1962...................... 1963...................... 1964...................... 1965...................... 1966...................... 1967...................... 1968...................... 1969...................... 1970...................... 1971...................... 1972...................... 1973...................... 1974...................... 1975...................... 1976...................... 1977...................... 1978...................... 1979...................... 1980...................... 1981...................... 1982...................... 1983...................... 1984...................... 1985...................... 1986...................... 1987...................... 1988...................... 1989......................

Date (2) 1997 1997 1997 1997 1997 1997 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1999 1999 1999 1999 1999 1999 1999 1999 1999 1999 1999 1999 1999 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2000 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2001 2002 2002 2002 2002 2002

Aug 11 Sep 7 Oct 5 Nov 1 Nov 28 Dec 26 Jan 22 Feb 18 Mar 18 Apr 14 May 11 Jun 7 Jul 5 Aug 1 Aug 28 Sep 24 Pct 22 Nov 18 Dec 15 Jan 12 Feb 8 Mar 7 Apr 4 May 1 May 28 Jun 24 Jul 21 Aug 18 Sep 14 Oct 11 Nov 7 Dec 5 Jan 1 Jan 28 Feb 25 Mar 23 Apr 19 May 17 Jun 13 Jul 10 Aug 6 Sep 2 Sep 30 Oct 27 Nov 23 Dec 21 Jan 17 Feb 13 Mar 13 Apr 9 May 6 Jun 2 Jun 30 Jul 27 Aug 23 Sep 19 Oct 17 Nov 13 Dec 10 Jan 7 Feb 3 Mar 2 Mar 30 Apr 26

CME Number (3)

Downtime (days) (4)

Speed ( km s1) (5)

Width (deg) (6)

Low Latitude (7)

High Latitude (8)

14 40 33 48 25 49 66 70 85 85 93 85 0 0 0 2 87 63 18 7 42 93 72 81 84 115 103 89 70 85 57 62 74 127 140 105 135 128 147 111 129 120 109 109 95 99 99 95 140 108 107 112 73 80 158 126 120 102 107 108 88 140 162 150

2.19 0.64 0.28 2.14 4.75 0.14 1.12 2.70 0.15 1.89 0.00 10.71 27.34 27.34 27.34 20.93 5.78 8.63 22.20 24.06 12.68 0.23 2.01 2.41 3.86 0.40 7.05 0.84 9.87 1.22 15.12 3.91 5.86 0.31 2.96 0.35 0.00 0.00 0.00 4.30 0.00 0.00 3.65 1.75 3.82 5.03 0.38 2.01 0.00 0.27 0.13 2.21 2.63 5.58 0.15 0.88 1.39 0.95 0.00 3.10 6.32 0.14 0.00 0.00

218 352 381 398 242 348 364 331 368 467 413 383 0 0 0 164 366 359 318 481 500 472 453 444 487 424 456 574 566 461 418 435 528 422 501 463 531 466 512 475 462 449 445 456 431 386 364 447 477 512 479 517 472 411 360 379 396 343 412 366 392 407 491 552

64 57 66 54 59 50 47 46 50 47 46 47 0 0 0 113 45 43 46 62 52 42 50 55 54 57 59 59 43 55 54 57 48 40 45 47 40 46 42 41 55 46 46 51 59 51 54 46 48 49 54 48 39 46 50 60 50 47 43 42 41 42 42 45

13 34 26 36 18 40 55 58 60 56 68 59 0 0 0 0 57 37 11 3 26 56 46 35 52 56 53 33 45 56 35 28 40 69 78 56 75 62 76 66 68 49 61 66 41 58 43 56 81 58 54 67 43 44 101 61 64 55 66 60 48 63 66 97

0 1 0 0 0 1 2 2 8 5 6 9 0 0 0 1 6 8 2 1 7 20 11 11 7 20 11 35 9 9 11 15 18 19 29 25 22 34 34 16 27 37 19 14 17 12 17 13 19 21 14 14 14 17 12 15 14 15 8 17 11 29 38 15

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CRot (1) 1990...................... 1991...................... 1992...................... 1993...................... 1994...................... 1995...................... 1996...................... 1997...................... 1998...................... 1999...................... 2000...................... 2001...................... 2002...................... 2003...................... 2004...................... 2005...................... 2006...................... 2007...................... 2008...................... 2009...................... 2010......................

Date (2) 2002 2002 2002 2002 2002 2002 2002 2002 2002 2003 2003 2003 2003 2003 2003 2003 2003 2003 2003 2003 2003

May 23 Jun 19 Jul 16 Aug 13 Sep 9 Oct 6 Nov 2 Nov 30 Dec 27 Jan 23 Feb 20 Mar 19 Apr 15 May 13 Jun 9 Jul 6 Aug 2 Aug 29 Sep 26 Oct 23 Nov 19

CME Number (3)

Downtime (days) (4)

Speed ( km s1) (5)

Width (deg) (6)

Low Latitude (7)

High Latitude (8)

87 125 123 163 145 144 117 73 108 95 82 119 100 128 41 52 75 61 91 79 62

4.52 0.33 0.00 0.57 0.00 2.04 0.00 0.00 0.00 0.74 3.35 0.00 0.62 0.47 15.77 3.99 0.44 0.21 2.54 0.96 0.00

469 406 429 445 496 571 497 466 491 474 472 502 494 515 470 406 500 436 617 664 470

45 39 43 45 46 48 39 45 53 52 43 45 41 42 42 40 36 47 43 51 40

51 67 68 99 77 87 59 40 62 57 50 73 54 76 19 33 59 31 67 42 36

10 21 18 17 19 17 22 6 17 11 8 18 15 19 5 9 7 13 9 6 8

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