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We analyse the characteristics of interplanetary coronal mass ejections(ICMEs) during Solar Cycles 23 and 24. The present analysis is primarily basedon the near-Earth ICME catalogue (Richardson and Cane, 2010). An importantaspect of this study is to understand the near-Earth and geoeffective aspectsof ICMEs in terms of their association (type II ICMEs) versus absence (non-typeII ICMEs) of decameter-hectometer (DH) type II radio bursts, detected byWind/WAVES and STEREOS/WAVES. Notably, DH type II radio bursts driven by a CMEindicate powerful MHD shocks leaving the inner corona and entering theinterplanetary medium. We find a drastic reduction in the occurrence of ICMEsby 56% in Solar Cycle 24 compared to the previous cycle (64 versus 147 events).Interestingly, despite a significant decrease in ICME/CME counts, both cyclescontain almost the same fraction of type II ICMEs (~47%). Our analysis revealsthat, even at a large distance of 1 AU, type II CMEs maintain significantlyhigher speeds compared to non-type II events (523 km/s versus 440 km/s). Whilethere is an obvious trend of decrease in ICME transit times with increase inthe CME initial speed, there also exists a noticeable wide range of transittimes for a given CME speed. Contextually, Cycle 23 exhibits 10 events withshorter transit times ranging between 20-40 hours of predominantly type IIcategories while, interestingly, Cycle 24 almost completely lacks such "fast"events. We find a significant reduction in the parameter $V_{ICME} \timesB_{z}$, the dawn to dusk electric field, by 39% during Solar Cycle 24 incomparison with the previous cycle. Further, $V_{ICME} \times B_{z}$ shows astrong correlation with Dst index, which even surpasses the consideration of$B_{z}$ and $V_{ICME}$ alone. The above results imply the crucial role of$V_{ICME} \times B_{z}$ toward effectively modulating the geoeffectiveness ofICMEs.

Near-Earth Interplanetary Coronal Mass Ejections and Their Association with DH Type II Radio Bursts During Solar Cycles 23 and 24