The impact of gravity waves rising from convection in the lower atmosphere on the generation and nonlinear evolution of equatorial bubble

Autor(es)

Kherani, E. Alam ^[1] ; Abdu, M. A. ^[1] ; de Paula, E. R. ^[1] ; Fritts, D. C. ^[2] ; Sobral, J. H. A. ^[1] ; de Meneses, Jr., F. C. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, BR-12201 Sao Jose Dos Campos, SP - Brazil

^[2] NW Res Associates Inc, Colorado Res Associates Div, Boulder, CO - USA

• Tipo de documento: Artigo Científico
• Fonte: Annales Geophysicae; v. 27, n. 4, p. 1657-1668, 2009.
• Citações Web of Science: 30

Resumo

The nonlinear evolution of equatorial F-region plasma bubbles under varying ambient ionospheric conditions and gravity wave seeding perturbations in the bottom-side F-layer is studied. To do so, the gravity wave propagation from the convective source region in the lower atmosphere to the thermosphere is simulated using a model of gravity wave propagation in a compressible atmosphere. The wind perturbation associated with this gravity wave is taken as a seeding perturbation in the bottomside F-region to excite collisional-interchange instability. A nonlinear model of collisional-interchange instability (CII) is implemented to study the influences of gravity wave seeding on plasma bubble formation and development. Based on observations during the SpreadFEx campaign, two events are selected for detailed studies. Results of these simulations suggest that gravity waves can play a key role in plasma bubble seeding, but that they are also neither necessary nor certain to do so. Large gravity wave perturbations can result in deep plasma bubbles when ionospheric conditions are not conducive by themselves; conversely weaker gravity wave perturbations can trigger significant bubble events when ionospheric conditions are more favorable. But weak gravity wave perturbations in less favorable environments cannot, by themselves, lead to strong plasma bubble responses. (AU)

• Processo FAPESP: 99/00437-0 - Estudos dos processos interativos do sistema ionosfera-termosfera equatorial
• Beneficiário: Mangalathayil Ali Abdu
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 07/00104-0 - Estudo experimental e teorico das irregularidades ionosfericas equatoriais.
• Beneficiário: Esfhan Alam Kherani
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado