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| Titel |
Overview and summary of the Spread F Experiment (SpreadFEx) |
| VerfasserIn |
D. C. Fritts, M. A. Abdu, B. R. Batista, I. S. Batista, P. P. Batista, R. Buriti, B. R. Clemesha, T. Dautermann, E. R. Paula, B. J. Fechine, B. G. Fejer, D. Gobbi, J. Haase, F. Kamalabadi, E. A. Kherani, B. Laughman, P. P. Lima, H.-L. Liu, A. Medeiros, P.-D. Pautet, D. M. Riggin, F. S. Rodrigues, F. São Sabbas, J. H. A. Sobral, P. Stamus, H. Takahashi, M. J. Taylor, S. L. Vadas, F. Vargas, C. M. Wrasse |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 27, no. 5 ; Nr. 27, no. 5 (2009-05-11), S.2141-2155 |
| Datensatznummer |
250016532
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| Publikation (Nr.) |
 copernicus.org/angeo-27-2141-2009.pdf |
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| Zusammenfassung |
We provide here an overview of, and a summary of results arising from, an
extensive experimental campaign (the Spread F Experiment, or SpreadFEx)
performed from September to November 2005, with primary measurements in
Brazil. The motivation was to define the potential role of neutral
atmosphere dynamics, specifically gravity wave motions propagating upward
from the lower atmosphere, in seeding Rayleigh-Taylor instability (RTI) and
plasma bubbles extending to higher altitudes. Campaign measurements focused
on the Brazilian sector and included ground-based optical, radar, digisonde,
and GPS measurements at a number of fixed and temporary sites. Related data
on convection and plasma bubble structures were also collected by GOES 12,
and the GUVI instrument aboard the TIMED satellite.
Initial results of our SpreadFEx analyses are described separately by Fritts
et al. (2009). Further analyses of these data provide additional evidence of
1) gravity wave (GW) activity near the mesopause apparently linked to deep
convection predominantly to the west of our measurement sites, 2)
small-scale GWs largely confined to lower altitudes, 3) larger-scale GWs
apparently penetrating to much higher altitudes, 4) substantial GW
amplitudes implied by digisonde electron densities, and 5) apparent
influences of these perturbations in the lower F-region on the formation of
equatorial spread F, RTI, and plasma bubbles extending to much higher
altitudes. Other efforts with SpreadFEx data have also yielded 6) the
occurrence, locations, and scales of deep convection, 7) the spatial and
temporal evolutions of plasma bubbles, 8) 2-D (height-resolved) structures in
electron density fluctuations and equatorial spread F at lower altitudes and
plasma bubbles above, and 9) the occurrence of substantial tidal
perturbations to the large-scale wind and temperature fields extending to
bottomside F-layer and higher altitudes. Collectively, our various SpreadFEx
analyses suggest direct links between deep tropical convection and large GW
perturbations at large spatial scales at the bottomside F-layer and their
likely contributions to the excitation of RTI and plasma bubbles extending
to much higher altitudes. |
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