In a previous study (Cane and Richardson, J. Geophys. Res. 108(A4), SSH6-1, 2003), we investigated the occurrence of interplanetary coronal mass ejections in the nearEarth solar wind during 1996 -2002, corresponding to the increasing and maximum phases of solar cycle 23, and provided a "comprehensive" catalog of these events. In this paper, we present a revised and updated catalog of the ≈300 near-Earth ICMEs in 1996 -2009, encompassing the complete cycle 23, and summarize their basic properties and geomagnetic effects. In particular, solar wind composition and charge state observations are now considered when identifying the ICMEs. In general, these additional data confirm the earlier identifications based predominantly on other solar wind plasma and magnetic field parameters. However, the boundaries of ICME-like plasma based on charge state/composition data may deviate significantly from those based on conventional plasma/magnetic field parameters. Furthermore, the much studied "magnetic clouds", with flux-rope-like magnetic field configurations, may form just a substructure of the total ICME interval.

[1] We summarize the occurrence of interplanetary coronal mass ejections (ICMEs) in the near-Earth solar wind during 1996-2002, corresponding to the increasing and maximum phases of solar cycle 23. In particular, we give a detailed list of such events. This list, based on in situ observations, is not confined to subsets of ICMEs, such as ''magnetic clouds'' or those preceded by ''halo'' coronal mass injections (CMEs) observed by the Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph, and provides an overview of 214 ICMEs in the near-Earth solar wind during this period. The ICME rate increases by about an order of magnitude from solar minimum to solar maximum (when the rate is $3 ICMEs per solar rotation period). The rate also shows a temporary reduction during 1999 and another brief, deeper reduction in late 2000 to early 2001, which only approximately track variations in the solar 10-cm flux. In addition, there are occasional periods of several rotations duration when the ICME rate is enhanced in association with high solar activity levels. We find an indication of a periodic variation in the ICME rate, with a prominent period of $165 days similar to that previously reported in various solar phenomena. It is found that the fraction of ICMEs that are magnetic clouds has a solar cycle variation, the fraction being larger near solar minimum. For the subset of events that we could associate with a CME at the Sun the transit speeds from the Sun to the Earth were highest after solar maximum.

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A study of solar proton events with well‐identified sources has been carried out using data from Goddard particle experiments on IMPs 4, 5, 7, and 8 and ISEE 3. The experiments cover the energy range from about 1 to 300 MeV. The 235 events of our study represent approximately 70% of all increases above 10−3 particles cm−2 sr−1 s−1 MeVminus;1 at energies > 20 MeV detected in a 19.7‐year period commencing mid‐May 1967. It is shown that intensity‐time profiles of solar proton events display an organization with respect to heliolongitude. Whilst it has been known for many years that the profile of a proton event depends on the longitude of the solar event relative to the observer, we suggest that the major controlling agent is the existence of an interplanetary (IP) shock. Furthermore, we explain the change in shape as a function of heliolongitude within the framework of a recently derived model for the large‐scale structure of IP shocks. In particular, the long delay to maximum intensity for far eastern events (a property previously ascribed to coronal processes) and the overall extended duration can be accounted for by IP shock acceleration and continued magnetic connection to the shock even after it has propagated beyond 1 AU.

Occurrences of solar wind plasma with abnormally low proton temperatures (T?) have long been associated with the interplanetary manifestations (which we term "ejecta") of coronal mass ejections (CMEs). We survey the National Space Science Data Center Omni solar wind database for 1965-1991, and data from the Helios 1 and 2 spacecraft for more limited periods, to identify plasma in which Tp is less than the temperature expected (Tex) from the well-established correlation between the solar wind speed and Tp for normal solar wind expansion. The occurrence rate of low-temperature plasma (specifically with Tp/Te x -< 0.5) is shown to be correlated with solar activity levels.Individual low-temperature regions have durations from 1 to -80 hours with a mean of -10 hours. Around one third are encounters with the heliospheric plasma sheet (HPS). These events are observed most frequently during the increasing phase of solar activity when the HPS lies closer to the ecliptic. The abnormally low temperatures may be intrinsic to the HPS or may provide support for the proposal that the coronal streamer belt underlying the HPS is a frequent source of ejecta. The remaining events have an occurrence rate which shows a particularly clear correlation with solar activity levels and with the CME rate at the Sun (when CME observations are available),. consistent with an association with ejecta. These events also show greater than chance associations with other ejecta signatures. We suggest that the Omni plasma data can provide ihf0rmation on the rate of ejecta passing the Earth, and hence give an indication of the CME rate, for a period commencing before spacecraft coronagraph CME observations became available in the early 1970s. Our findings suggest that T e depressions may provide a more comprehensive indication of the presence of ejecta than other ejecta signatures, such as bidirectional solar wind electron heat fluxes and energetic ion flows, which alone do not identify all ejecta. Paper,number 95JA02684. 0148-0227/95/95JA-02684505.00 basis of the high electron thermal conductivity. On the other hand, the rapid entry of solar energetic particles into some ejecta [Kahler and Reames, 1991; Farrugia et al., 1993a, b] suggests that field lines in some ejecta are connected to the Sun. In more recent studies 6f ejiecta material the abnormally low Tp signature has received less attention than others. In particular, bidirectional solar wind electron heat fluxes (BHFs) have been advocated as perhaps the best method of identifying ejecta in the solar Wind [e.g., Gosling, 1990; Gosling et al., 1992i Phillips et al., 1992; Gosling et al., 1994]. In the work by Richardson and Cane [ 1993] we examined the occurrence of various ejecta signatures following 40 interplanetary shocks and concluded that no single signature reliably indicates the presence and true duration of ejecta [see Zwickl et al. 1983]. However, abnormal Tp depressions were found to be among the more reliable indicators of the [iresence or absence of ejecta material. To infer when T...

[1] We examined the properties and associations of 280 solar proton events that extended above 25 MeV and occurred in the years 1997-2006. The properties include early peak intensities of five species over several energy ranges and the intensity-time profiles. Solar event associations were made for as many events as possible. The solar parameters determined include coronal mass ejection and flare properties and radio emissions from a wavelength range of meters to kilometers. The events were divided into five representative types based on the relative abundances and particle profiles to more easily illustrate how particle characteristics vary with the solar parameters. We find a continuum of event properties with no indication of specific parameters that clearly separate out groups of events. There is, however, a reasonable separation of events based on the timing of the associated type III emissions relative to the H a flare. Type III bursts indicate the presence of flare particles that escape to the interplanetary medium. The least intense, relatively short-lived, proton events that are electron-rich (and generally Fe-rich and He-rich) have associated type III bursts that occur at the start of the flare (i.e., in the impulsive phase), indicating rapid acceleration and escape of particles. In the largest events the type III emissions occur after the impulsive phase. It is likely that this late acceleration and/or release of particles results in a composition different from that of impulsive acceleration and release. A scenario in which concomitant flare processes contribute particles in the majority of solar energetic particle events is consistent with the observations.

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high-speed streams ,_35%, slow solar wind ,-_30%, and CME-associated _35%. These compositions show little cycle-to-cycle variation, at least for the interval considered in this paper. Despite the change in the occurrences of different types of solar wind over the solar cycle (and less significant changes from cycle to cycle), overall, variations in the averages of the aa index and IMF closely follow those in corotating streams. Considering solar cycle averages, we show that high-speed streams account for _44%, "-48%, and ,--,40% of the solar wind composition, aa, and the IMF strength,, respectively, with corresponding figures of,-_22%, ,-_32%, and -,-25% for CME-related structures, and ,--,33%, _19%, and _33% for slow solar wind.