000005354 001__ 5354
000005354 005__ 20210528002219.0
000005354 0247_ $$2DOI$$a10.3847/1538-4357/ab8fae
000005354 037__ $$aSCART-2021-0095
000005354 100__ $$aPick, M.
000005354 245__ $$aRole of the Coronal Environment in the Formation of Four Shocks Observed without Coronal Mass Ejections at Earth's Lagrangian Point L1
000005354 260__ $$c2020
000005354 520__ $$aThe main goal of this study is to determine the solar origin of four single shocks observed at the Lagrange point L1 and followed by storm sudden commencements (SSCs) during 2002. We look for associated coronal mass ejections (CMEs), starting from estimates of the transit time from Sun to Earth. For each CME, we investigate its association with a radio type II burst, an indicator of the presence of a shock wave. For three of the events, the type II burst is shown to propagate along the same, or a similar, direction as the fastest segment of the CME leading edge. We analyze for each event the role of the coronal environment in the CME development, the shock formation, and their propagation, to finally identify its complex evolution. The ballistic velocity of these shocks during their propagation from the corona to L1 is compared to the shock velocity at L1. Based on a detailed analysis of the shock propagation and possible interactions up to 30 solar radii, we find a coherent velocity evolution for each event, in particular for one event, the 2002 April 14 SSC, for which a previous study did not find a satisfactory CME source. For the other three events, we observe the formation of a white-light shock overlying the different sources associated with those events. The localization of the event sources over the poles, together with an origin of the shocks being due to encounters of CMEs, can explain why at L1 we observe only single shocks and not interplanetary CMEs.
000005354 536__ $$aBRAIN.be project CCSOM/$$cBRAIN.be project CCSOM/$$fBRAIN.be project CCSOM
000005354 594__ $$aSTCE
000005354 700__ $$aMagdalenic, J.
000005354 700__ $$aCornilleau-Wehrlin, N.
000005354 700__ $$aGrison, B.
000005354 700__ $$aSchmieder, B.
000005354 700__ $$aBocchialini, K.
000005354 773__ $$pThe Astrophysical Journal$$v895$$y2020
000005354 8560_ $$fjasmina.magdalenic@observatoire.be
000005354 905__ $$apublished in
000005354 980__ $$aREFERD