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We report on a comparison between space weather events that occurred aroundthe two peaks in the sunspot number (SSN) during solar cycle 24. The two SSNpeaks occurred in the years 2012 and 2014. Even though SSN was larger duringthe second peak, we find that there were more space weather events during thefirst peak. The space weather events we considered are large solar energeticparticle (SEP) events and major geomagnetic storms associated with coronal massejections (CMEs). We also considered interplanetary type II radio bursts, whichare indicative of energetic CMEs driving shocks. When we compared the CMEproperties between the two SSN peaks, we find that more energetic CMEs occurredduring the 2012 peak. In particular, we find that CMEs accompanying IP type IIbursts had an average speed of 1543 km/s during the 2012 peak compared to 1201km/s during the 2014 peak. This result is consistent with the reduction in theaverage speed of the general population of CMEs during the second peak. All SEPevents were associated with the interplanetary type II bursts, which are betterthan halo CMEs as indicators of space weather. The comparison between the twopeaks also revealed that the discordant behavior between the CME rate and SSNwas more pronounced during the second peak. None of the 14 disk-center haloCMEs was associated with a major storm in 2014. The lone major storm in 2014was due to the intensification of the (southward) magnetic field in theassociated magnetic cloud by a shock that caught up and propagated into themagnetic cloud.

CMEs during the Two Activity Peaks in Cycle 24 and their Space Weather Consequences