STATISTICAL STUDY OF THEEARTH'S MAGNETOPAUSEBOUNDARY LAYER PARTICLEPOPULATIONS
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
While double ion populations, with a cold population originating from the solar windand a hotter one from the magnetosphere, are frequently observed in the Earth’s lowlatitudeboundary layers, similar double electron populations are seldom recorded.We performed a statistical study of ion and electron double populations near themagnetopause by using 7 years of THEMIS particle data. After a preliminary study ofmagnetopause crossings characteristics, in particular by determining the typicalenergies of ion and electron populations in regions near the magnetopause, we setup an automated detection algorithm for identifying regions with combined ion andelectron double populations.The statistical study carried out with respect to IMF conditions in the upstream solarwind during and just before the events suggests that such combined ion and electronDouble Population Boundary Layers (DPBL) form preferentially under northward IMFbut with a significant BY component.We interpret this trend as a result of reconnection of the same magnetosheath fieldline in both hemispheres, but with at least one end reconnecting in its hemisphere atlower latitude with a closed magnetospheric field line which already contains a hotelectron source.
Place, publisher, year, edition, pages
2015. , 35 p.
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-175780OAI: oai:DiVA.org:kth-175780DiVA: diva2:862298
Karlsson, Tomas, Associate Professor