Patel, Binal D.Binal D.PatelJoshi, BhuwanBhuwanJoshiCho, Kyung SukKyung SukChoKim, Rok SoonRok SoonKimMoon, Yong JaeYong JaeMoon2025-08-312025-08-312022-10-0110.1007/s11207-022-02073-72-s2.0-85140623052https://d8.irins.org/handle/IITG2025/25922We analyse the characteristics of interplanetary coronal mass ejections (ICMEs) during Solar Cycles 23 and 24. The present analysis is primarily based on the near-Earth ICME catalogue (Richardson and Cane, 2010). An important aspect of this study is to understand the near-Earth and geoeffective aspects of ICMEs in terms of their association (type II ICMEs) versus absence (non-type II ICMEs) of decameter-hectometer (DH) type II radio bursts, detected by Wind/WAVES and STEREOS/WAVES. Notably, DH type II radio bursts driven by a CME indicate powerful MHD shocks leaving the inner corona and entering the interplanetary medium. We find a drastic reduction in the occurrence of ICMEs by 56% in Solar Cycle 24 compared to the previous cycle (64 versus 147 events). Interestingly, despite a significant decrease in ICME/CME counts, both cycles contain almost the same fraction of type II ICMEs (≈ 47%). Our analysis reveals that, even at a large distance of 1 AU, type II CMEs maintain significantly higher speeds compared to non-type II events (523 km s⁻¹ versus 440 km s⁻¹). While there is an obvious trend of decrease in ICME transit times with increase in the CME initial speed, there also exists a noticeable wide range of transit times for a given CME speed. Contextually, Cycle 23 exhibits 10 events with shorter transit times ranging between 20 – 40 hours of predominantly type II categories while, interestingly, Cycle 24 almost completely lacks such “fast” events. We find a significant reduction in the parameter V<inf>ICME</inf>× B<inf>z</inf>, the dawn to dusk electric field, by 39% during Solar Cycle 24 in comparison with the previous cycle. Further, V<inf>ICME</inf>× B<inf>z</inf> shows a strong correlation with Dst index, which even surpasses the consideration of B<inf>z</inf> and V<inf>ICME</inf> alone. The above results imply the crucial role of V<inf>ICME</inf>× B<inf>z</inf> toward effectively modulating the geoeffectiveness of ICMEs.falseActive regions | Coronal mass ejections | Interplanetary | Magnetic fields | Meter-wavelengths and longer (m, dkm, hm, km) | Radio bursts | Type IIArticlehttps://arxiv.org/pdf/2210.145351573093XOctober 20228139arJournal10