Analysis of simultaneous observations of ionospheric irregularities with different scale sizes

• Grant number: 14/19588-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2014
• Effective date (End): October 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Marcio Tadeu de Assis Honorato Muella
• Grantee: Pâmela Rita Pereira Meibach Rosa
• Host Institution: Instituto de Pesquisa e Desenvolvimento (IP&D). Universidade do Vale do Paraíba (UNIVAP). São José dos Campos , SP, Brazil

Abstract

During the last solar minimum period (2008-2010) the group of Space Physics from UNIVAP carried out ionospheric monitoring through different instruments, installed in a network of observatories located in the Brazilian sector. The signatures of the ionospheric plasma irregularities can be identified in the data registered by these instruments. The irregularities of major interest are those observed during nighttime in the upper layer of the ionosphere. The collisional Rayleigh-Taylor instability is the largely accepted mechanism to explain the generation of the irregularities in the bottom side of the ionospheric F region. However, a hierarchy of secondary instability mechanisms gives origin to irregularities with different scale sizes. Plasma bubbles are considered the irregularities with large scale sizes detected from some of the instruments. In the walls of the bubbles the ionospheric density gradients are sharper, consequently, during the development phase of the bubbles such gradients become unstable due to the action of secondary instability mechanisms, favoring the triggering of the smaller scale irregularities. In this proposal the student will analyze simultaneous data of ionospheric irregularities registered in the measurements from different instruments and techniques conducted during the last solar minimum period. The aim is to investigate the morphological characteristics and the physical properties that explain the coexistence of the irregularities with different scale sizes, during a period of expected minimum occurrence of plasma irregularities. This topic is of great interest of the community involved in the ionospheric space weather study. Throughout this proposal are presented the aims and objectives, the project justification, the infrastructure available, the methodology and the plan of activities for the 12 months of research.