Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Transient Structures and Stream Interaction Regions in the Solar Wind: Results from EISCAT Interplanetary Scintillation, STEREO HI and Venus Express ASPERA-4 Measurements
AU - Dorrian, Gareth
AU - Breen, Andy
AU - Davies, Jackie
AU - Rouillard, Alexis
AU - Fallows, Richard
AU - Whittaker, Ian
AU - Brown, Daniel
AU - Harrison, Richard
AU - Davis, Chris
AU - Grande, Manuel
PY - 2010
Y1 - 2010
N2 - We discuss the detection and evolution of a complex series of transient and quasi-static solar-wind structures in the days following the well-known comet 2P/Encke tail disconnection event in April 2007. The evolution of transient solar-wind structures ranging in size from <105 km to >106 km was characterised using one-minute time resolution obser- vation of Interplanetary Scintillation (IPS) made using the European Incoherent SCATter (EISCAT) radar system. Simultaneously, the global structure and evolution of these features was characterised by the Heliospheric Imagers (HI) on the Solar TERrestrial RElations Ob- servatory (STEREO) spacecraft, placing the IPS observations in context. Of particular in- terest was the observation of one transient in the slow wind, apparently being swept up and entrained by a Stream Interaction Region (SIR). The SIR itself was later detected in-situ at Venus by the Analyser of Space Plasma and Energetic Atoms (ASPERA-4) instrument on the Venus Express (VEX) spacecraft. The availability of such diverse data sources over a range of different time resolutions enables us to develop a global picture of these com- plex events that would not have been possible if these instruments were used in isolation. We suggest that the range of solar-wind transients discussed here may be the interplanetary counterparts of transient structures previously reported from coronagraph observations and are likely to correspond to transient magnetic structures reported in in-situ measurements in interplanetary space. The results reported here also provide the first indication of heliocen- tric distances at which transients become entrained.
AB - We discuss the detection and evolution of a complex series of transient and quasi-static solar-wind structures in the days following the well-known comet 2P/Encke tail disconnection event in April 2007. The evolution of transient solar-wind structures ranging in size from <105 km to >106 km was characterised using one-minute time resolution obser- vation of Interplanetary Scintillation (IPS) made using the European Incoherent SCATter (EISCAT) radar system. Simultaneously, the global structure and evolution of these features was characterised by the Heliospheric Imagers (HI) on the Solar TERrestrial RElations Ob- servatory (STEREO) spacecraft, placing the IPS observations in context. Of particular in- terest was the observation of one transient in the slow wind, apparently being swept up and entrained by a Stream Interaction Region (SIR). The SIR itself was later detected in-situ at Venus by the Analyser of Space Plasma and Energetic Atoms (ASPERA-4) instrument on the Venus Express (VEX) spacecraft. The availability of such diverse data sources over a range of different time resolutions enables us to develop a global picture of these com- plex events that would not have been possible if these instruments were used in isolation. We suggest that the range of solar-wind transients discussed here may be the interplanetary counterparts of transient structures previously reported from coronagraph observations and are likely to correspond to transient magnetic structures reported in in-situ measurements in interplanetary space. The results reported here also provide the first indication of heliocen- tric distances at which transients become entrained.
KW - stream interaction regions
KW - solar wind
KW - transients
KW - interplanetary scintillation
KW - STEREO
U2 - 10.1007/s11207-010-9599-z
DO - 10.1007/s11207-010-9599-z
M3 - Journal article
VL - 265
SP - 207
EP - 231
JO - Solar Physics
JF - Solar Physics
SN - 0038-0938
IS - 1-2
ER -