caa a22 4500 445815787 CHVBK 20180317145228.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s11214-011-9818-4 doi (NATIONALLICENCE)springer-10.1007/s11214-011-9818-4 Review of Pi2 Models [Elektronische Daten] [Andreas Keiling, Kazue Takahashi] More than half a century after the discovery of Pi2 pulsations, Pi2 research is still vigorous and evolving. Especially in the last decade, new results have provided supporting evidence for some Pi2 models, challenged earlier interpretations, and led to entirely new models. We have gone beyond the inner magnetosphere and have explored the outer magnetosphere, where Pi2 pulsations have been observed in unexpected places. The new Pi2 models cover virtually all magnetotail regions and their coupling, from the reconnection site via the lobes and plasma sheet to the ionosphere. In addition to understanding the Pi2 phenomenon in itself, it has also been important to study Pi2 pulsations in their role as transient manifestations of the coupling between the magnetosphere and the ionosphere. The transient Pi2 is an integral part of the substorm phenomenon, especially during substorm onset. Key questions about the workings of magnetospheric substorms are still awaiting answers, and research on Pi2 pulsations can help with those answers. Furthermore, the role of Pi2 pulsations in association with other dynamic magnetospheric modes has been explored in the last decade. Thus, the application of Pi2 research has expanded over the years, assuring that Pi2 research will remain active in this decade and beyond. Here we review recent advances, which have given us a new understanding of Pi2 pulsations generated at various places in the magnetosphere during different magnetospheric modes. We review seven Pi2 models found in the literature and show how they are supported by observations from spacecraft and ground observatories as well as numerical simulations. The models have different degrees of maturity; while some enjoy wide acceptance, others are still speculative. Springer Science+Business Media B.V., 2011 ULF wave nationallicence Pi2 pulsation nationallicence Magnetosphere nationallicence Substorm nationallicence BBF : Bursty bulk flow nationallicence BBF-Pi2 : Bursty bulk flow Pi2 nationallicence BM-Pi2 : Ballooning mode Pi2 nationallicence CPS : Central plasma sheet nationallicence EIC : Equivalent ionospheric current nationallicence FAC : Field-aligned current nationallicence FLR : Field line resonance nationallicence IC : Inertia current nationallicence KAW : Kinetic Alfvén wave nationallicence KBI : Kinetic ballooning instability nationallicence KHI : Kelvin-Helmholtz instability nationallicence LEO : Low Earth orbit nationallicence MHD : Magnetohydrodynamics nationallicence PBI : Poleward boundary intensification nationallicence PCR : Plasmaspheric cavity resonance nationallicence PCR-Pi2 : Plasmaspheric cavity resonance Pi2 nationallicence PSBL : Plasma sheet boundary layer nationallicence PSM : Plasmaspheric surface mode nationallicence PSM-Pi2 : Plasmapause surface mode Pi2 nationallicence PVR : Plasmaspheric virtual resonance nationallicence PVR-Pi2 : Plasmaspheric virtual resonance Pi2 nationallicence RX-Pi2 : Pulsed reconnection Pi2 nationallicence SCW : Substorm current wedge nationallicence TR : Transient response nationallicence TR-Pi2 : Transient response Pi2 nationallicence ULF : Ultra-low frequency nationallicence WTS : Westward traveling surge nationallicence Keiling Andreas Space Sciences Laboratory, University of California-Berkeley, Berkeley, CA, USA aut Takahashi Kazue Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, USA aut Space Science Reviews Springer Netherlands 161/1-4(2011-11-01), 63-148 0038-6308 161:1-4<63 2011 161 11214 https://doi.org/10.1007/s11214-011-9818-4 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11214-011-9818-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Keiling Andreas Space Sciences Laboratory, University of California-Berkeley, Berkeley, CA, USA aut NATIONALLICENCE 700 1- Takahashi Kazue Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, USA aut NATIONALLICENCE 773 0- Space Science Reviews Springer Netherlands 161/1-4(2011-11-01), 63-148 0038-6308 161:1-4<63 2011 161 11214 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer