Abstract
We performed an extensive experimental campaign (the spread F Experiment, or SpreadFEx) from September to November 2005 to attempt to define the role of neutral atmosphere dynamics, specifically wave motions propagating upward from the lower atmosphere, in seeding equatorial spread F 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 analyses of SpreadFEx and related data indicate 1) extensive gravity wave (GW) activity apparently linked to deep convection predominantly to the west of our measurement sites, 2) the presence of small-scale GWactivity confined to lower altitudes, 3) larger-scaleGWactivity apparently penetrating to much higher altitudes suggested by electron density and TEC fluctuations in the E and F regions, 4) substantial GW amplitudes implied by digisonde electron densities, and 5) apparent direct links of these perturbations in the lower F region to spread F and plasma bubbles extending to much higher altitudes. Related efforts with correlative data are defining 6) the occurrence and locations of deep convection, 7) the spatial and temporal evolutions of plasma bubbles, the 8) 2D (height-resolved) structures of plasma bubbles, and 9) the expected propagation of GWs and tides from the lower atmosphere into the thermosphere and ionosphere.
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Abdu, M. A., Outstanding problems in the equatrial ionosphere-thermosphere system relevant to spread F, J. Atmos. Sol.-Terr. Phys., 63, 869, 2001.
Abdu, M. A., I. S. Batista, and J. H. A. Sobral, A new aspect of magnetic control of equatorial spread F, J. Geophys. Res., 97, 14,897, 1992.
Abdu, M. A., I. S. Batista, H. Takahashi, J. MacDougall, J. H. Sobral, A. F. Medeiros, and N. B. Trivedi, Magnetospheric disturbance induced equatorial plasma bubble development and dynamics: A case study in Brazilian sector, J. Geophys. Res., 108(A12), 1449, doi:10.1029/2002JA009721, 2003.
Abdu, M. A., E. A. Kherani, I. S. Batista, E. R. de Paula, and D. C. Fritts, An evaluation of the ESF/bubble irregularity growth conditions under gravity wave influences based on observational data from the SpreadFEx campaign, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Aggson, T. L., N. C. Maynard, W. B. Hanson, and L. Saba Jack, Electric field observations of equatorial bubbles, J. Geophys. Res., 97, 2997, 1992.
Anderson, D. N., A. D. Richmond, B. B. Balsley, R. G. Roble, M. A. Biondi, and D. P. Sipler, In situ generation of gravity waves as a possible seeding mechanism for equatorial spread-F, Geophys. Res. Lett., 9, 789–792, 1982.
Basu, B., On the linear theory of equatorial plasma instability: comparison of different descriptions, J. Geophys. Res., 107(A8), doi:10.1029/2001JA000317, 2002.
Batista, I. S. and M. A. Abdu, Ionospheric variability at Brazilian low and equatorial latitudes: comparison between observations and IRI model, Adv. Space Res., 34, 1894–1900, 2004.
Batista, P. P., B. R. Clemesha, A. S. Tokumoto, and L. M. Lima, Structure of the mean winds and tides in the meteor region over Cachoeira Paulista, Brazil (22.7°S,45°W) and its comparison with models, J. At-mos. Sol.-Terr. Phys., 66(6–9), 623–636, 2004.
Batista, I. S., M. A. Abdu, A. J. Carrasco, B. W. Reinisch, E. R. de Paula, and N. J. Schuch, Equatorial spread F and sporadic E-layer connections during the Brazilian Conjugate Point Equatorial Experiment—COPEX, J. Atmos. Sol.-Terr. Phys., 2008 (in press).
Buriti, R. A., W. K. Hocking, P. P. Batista, A. F. Medeiros, and B. R. Clemesha, Observations of equatorial mesospheric winds over Cariri (7.4 S) by a meteor radar and comparison with existing models, Ann. Geophys., 2007 (submitted).
Calais, E. and J. B. Minster, GPS, earthquakes, the ionosphere, and the Space Shuttle, Phys. Earth Planet. Inter., 105(3–4), 167–181, 1998.
Calais, E., J. S. Haase, and J. B. Minster, Detection of ionospheric perturbations using a dense GPS array in Southern California, Geophys. Res. Lett., 30(12), 2003.
de Paula, E. R. and D. L. Hysell, The São Luis 30 MHz coherent scatter ionospheric radar: system description and initial results, Radio Sci., 39, RS1014, doi:10.1029/2003RS002914, 2004.
Dewan, E. M. and R. H. Picard, Mesospheric bores, J. Geophys. Res., 103(D6), 6295–6306, 1998.
Dewan, E. M. and R. H. Picard, On the origin of mesospheric bores, J. Geophys. Res., 106(D3), 2921–2928, 10.1029/2000JD900697, 2001.
Djuth, F. T., M. P. Sulzer, J. H. Elder, and V. B. Wickwar, High-resolution studies of atmosphere-ionosphere coupling at Arecibo Observatory, Puerto Rico, Radio Sci., 32, 2321–2344, 1997.
Djuth, F. T., M. P. Sulzer, S. A. Gonzales, J. D. Mathews, J. H. Elder, and R. L. Walterscheid, A continuum of gravity waves in the Arecibo thermosphere?, Geophys. Res. Lett., 31, doi:10.1029/2003GL019376, 2004.
Fechine, J., A. F. Medeiros, R. A. Buriti, H. Takahashi, and D. Gobbi, Mesospheric bore events in the equatorial middle atmosphere, J. Atmos. Sol-Terr. Phys., 67, 1774–1778, 2005.
Fechine, J., C. M. Wrasse, H. Takahashi, A. F. Medeiros, P. P. Batista, B. R. Clemesha, L. M. Lima, D. Fritts, M. J. Taylor, P. D. Paulet, M. G. Mlynczak, and J. M. Russell, Mesospheric bore event during SpreadsFEx campaign, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Fejer, B. G., Natural ionospheric plasma waves, in Modern Ionospheric Science, edited by H. Kohl, R. Rüster, and K. Schlegel, pp. 217–273, Max-Planck Institut für Aeronomie, Lindau, Germany, 1996.
Fejer, B. G., L. Scherliess, and E. R. de Paula, Effects of the vertical plasma drift velocity on the generation and evolution of equatorial spread F, J. Geophys. Res., 104, 19,859, 1999.
Fritts, D. C. and L. Yuan, An analysis of gravity wave ducting in the atmosphere: Eckart’s resonances in thermal and Doppler ducts, J. Geophys. Res., 94(D15), 18,455–18,466, 1989.
Fritts, D. C. and M. J. Alexander, Gravity dynamics and effects in the middle atmosphere, Rev. Geophys., 41, doi:10.1029/2001RG000106, 2003.
Fritts, D. C. and S. A. Vadas, Gravity wave penetration into the thermosphere: Sensitivity to solar cycle variations and mean winds, Ann. Geo-phys., 2008 (in press).
Fritts, D. C. et al., Overview and summary of the spread F Experiment (SpreadFEx), Ann. Geophys., SpreadFEx special issue, 2008a (in press).
Fritts, D. C. et al., Gravity wave and tidal influences on equatorial spread F based on observations during the spread F Experiment (SpreadFEx), Ann. Geophys., SpreadFEx special issue, 2008b (submitted).
Haerendel, G., J. V. Eccles, and S. Cakir, Theory of modeling the equatorial evening ionosphere and the origin of the shear in the horizontal plasma flow, J. Geophys. Res., 97, 1209–1223, 1992.
Heelis, R. A., P. C. Kendall, R. J. Moffett, D. W. Windel, and H. Rishbeth, Electrical coupling of the E and F regions and its effect on F-region drifts and winds, J. Planet. Space Sci., 22, 743, 1974.
Hocke, K. and K. Schlegel, A review of atmospheric gravity waves and traveling ionospheric disturbances: 1982–1995, Ann. Geophys., 14, 917–940, 1996.
Hofmann-Wellenhof, B., Global Positioning System: theory and practice, 355 pp., Springer-Verlag, New York, 1994.
Huang, C. S. and M. C. Kelley, Nonlinear evolution of equatorial spread-F. 1. On the role of plasma instabilities and spatial resonance associated with gravity wave seeding, J. Geophys. Res., 101, 283, 1996a.
Huang, C. S. and M. C. Kelley, Nonlinear evolution of equatorial spread-F. 2. Gravity wave seeding of Rayleigh-Taylor instability, J. Geophys. Res., 101, 293, 1996b.
Huang, C. S. and M. C. Kelley, Nonlinear evolution of equatorial spread-F. 4. Gravity waves, velocity shear, and day-to-day variability, J. Geophys. Res., 101, 24,523, 1996c.
Huang, C. S., M. C. Kelley, and D. L. Hysell, Nonlinear Rayleigh-Taylor instabilities, atmospheric gravity waves, and equatorial spread-F, J. Geophys. Res., 98, 15,631, 1993.
Huang, C. S., J. C. Foster, L. P. Goncharenko, G. D. Reeves, J. L. Chau, K. Yumoto, and K. Kitamura, Variations of low-latitude geomagnetic fiels and Dst index caused by magnetospheric substorms, J. Geophys. Res., 109, A05219, doi:10.1029/2003JA010334, 2004.
Hysell, D. L., Radar imaging of equatorial F region irregularities with maximum entropy interferometry, Radio Sci., 31(6), 1567–1578, 1996.
Hysell, D. L. and J. D. Burcham, Long term studies of equatorial spread F using the JULIA radar at Jicamarca, J. Atmos. Sol.-Terr. Phys., 64, 1531–1543, 2002.
Hysell, D. L. and E. Kudeki, Collisional shear instability in the equatorial F region ionosphere, J. Geophys. Res., 109, A11301, doi:10. 1029/2004JA010636, 2004.
Hysell, D. L., M. C. Kelley, W. E. Swartz, and R. F. Woodman, Seeding and layering of equatorial spread-F, J. Geophys. Res., 95, 17,253, 1990.
Hysell, D. L., J. Chun, and J. L. Chau, Bottom-type scattering layers and equatorial spread F. Ann. Geophys., 22, 4061, 2004.
Hysell, D. L., M. F. Larsen, C. M. Swenson, A. Barjatya, T. F. Wheeler, M. F. Sarango, R. F. Woodman, and Chau, Onset conditions for equatorial spread Fdetermined during EQUIS II, Geophys. Res. Lett., 32, L24104, doi:10.1029/2005GL024743, 2005.
Kamalabadi, F. et al., Electron densities in the lower thermosphere from GUVI 1356 tomographic inversions in support of SpreadFEx, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Kelley, M. C., The Earth’s Ionosphere, 487 pp., Academic Press, San Diego, 1989.
Kelley, M. C. and D. L. Hysell, Equatorial spread F and neutral atmospheric turbulence: a review and a comparative anatomy, J. Atmos. Terres. Phys., 53, 695–708, 1991.
Kelley, M. C., M. F. Larsen, C. LaHoz, and J. P. McClure, Gravity wave initiation of equatorial spread F: A case study, J. Geophys. Res., 86, 9087–9100, 1981.
Keskinen, M. J., S. L. Ossakow, and P. K. Chaturvedi, Preliminary report of numerical simulations of intermediate wavelength collisional Rayleigh-Taylor instability in equatorial spread-F, J. Geophys. Res., 85, 1775, 1980.
Keskinen, M. J., S. L. Ossakow, S. Basu, and P. Sultan, Magnetic flux tube integrated evolution of equatorial ionospheric plasma bubbles, J. Geophys. Res., 103, 3957, 1998.
Keskinen, M. J., S. L. Ossakow, and B. G. Fejer, Three-dimensional nonlinear evolution of equatorial ionospheric spread-F bubbles, Geophys. Res. Lett., 30, 1855, doi:10.1029/2003GL017418, 2003.
Kherani, E. A., M. A. Abdu, E. R. de Paula, D. C. Fritts, J. H. A. Sobral, and F. C. de Meneses Jr., The impact of gravity waves rising from convection in the lower atmosphere on the generation and nonlinear evolution of equatorial plasma bubbles, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Klostermeyer, J., Nonlinear investigation of the spatial resonance effect in the nighttime equatorial F region, J. Geophys. Res., 83, 3753, 1978.
Kudeki, E., A. Akgiray, M. Milla, J. L. Chau, and D. L. Hysell, Equatorial spread-F initiation: post-sunset vortex, thermospheric winds, gravity waves, J. Atmos. Sol.-Terr. Phys., 69, 2416–2427, 2007.
Kudeki, E. and S. Bhattacharyya, Postsunset vortex in equatorial F-region plasma drifts and implications for bottomside spread F, J. Geophys. Res., 104, 28,163, 1999.
Lane, T. P. and R. D. Sharman, Gravity wave breaking, secondary wave generation, and mixing above deep convection in a three-dimensional cloud model, Geophys. Res. Lett., 33, L23813, doi:10. 1029/2006GL027988, 2006.
Lane, T. P., M. J. Reeder, and T. L. Clark, Numerical modeling of gravity waves generated by deep tropical convection, J. Atmos. Sci., 58, 1249–1274, 2001.
Lane, T. P., R. D. Sharman, T. L. Clark, and H.-M. Hsu, An investigation of turbulence generation mechanisms above deep convection, J. Atmos. Sci., 60, 1297–1321, 2003.
Lanyi, G. E. and T. Roth, A comparison of mapped and measured total ionospheric electron-content using global positioning system and beacon satellite-observations, Radio Sci., 23(4), 483–492, 1988.
Laughman, B., D. C. Fritts, and J. Werne, Numerical simulation of bore generation and morphology in thermal and Doppler ducts, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
McClure, J. P., W. B. Hanson, and J. F. Hoffman, Plasma bubble and irregularities in the equatorial ionosphere, J. Geophys. Res., 82, 2650, 1977.
McClure, J. P., S. Singh, D. K. Bamgboye, F. S. Johnson, and H. Kil, Occurrence of equatorial F region irregularities: Evidence for tropospheric seeding, J. Geophys. Res., 103, 29,119–29,135, 1998.
Medeiros, A. F, R. A. Buriti, E. A. Machado, H. Takahashi, P. P. Batista, D. Gobbi, and M. J. Taylor, Comparison of gravity wave activity observed by airglow imaging at two different latitudes in Brazil, J. Atmos. Sol.-Terr. Phys., 60, 647–654, 2004.
Medeiros, A. F, J. Fechine, R. A. Buriti, H. Takahashi, C. M. Wrasse, and D. Gobbi, Response of OH, O2, and OI5577 airglow emissions to the mesospheric bore in the equatorial region of Brazil, Adv. Space Res., 35, 1971–1975, 2005.
Mendillo, M. and A. Tyler, The geometry of depleted plasma regions in the equatorial ionosphere, J. Geophys. Res., 88, 5778, 1983.
Meriwether, J., M. Faivre, C. Fesen, P. Sherwood, and O. Veliz, New results on equatirla thermospheric winds and the midnight temperature maximum, Ann. Geophys., 2008 (in press).
Oliver, W. L., Y. Otsuka, M. Sato, T. Takami, and S. Fukao, A climatology of F region gravity wave propagation over the middle and upper atmosphere radar, J. Geophys. Res., 102, 14,499–14,512, 1997.
Ossakow, S. L., Spread-F theories—A review, J. Atmos. Terres. Phys., 43, 437, 1981.
Piani, C., D. Durran, M. J. Alexander, and J. R. Holton, A numerical study of three-dimensional gravity waves triggered by deep tropical convection, J. Atmos. Sci., 57, 3689–3702, 2000.
Prakash, S., Production of electric field perturbations by gravity wave winds in the E region suitable for initiating equatorial spread F, J. Geophys. Res., 104, 10,051–10,069, 1999.
Rodrigues, F. S., E. R. de Paula, M. A. Abdu, A. C. Jardim, K. N. Iyer, P. M. Kintner, and D. L. Hysell, Equatorial spread F irregularity characteristics over São Luis, Brazil, Radio Sci., 39, doi:10.1029/2002RS002826, 2004.
Scannapieco, A. J. and S. L. Ossakow, Nonlinear spread-F, Geophys. Res. Lett., 3, 451, 1976.
Sekar, R. and M. C. Kelley, On the combined effects of vertical shear and zonal electric field patterns on nonlinear equatorial spread F evolution, J. Geophys. Res., 103, 20,735–20,747, 1998.
Sekar, R., R. Suhasini, and R. Raghavarao, Evolution of plasma bubbles in the equatorial F region with different seeding conditions, Geophys. Res. Lett., 22, 885, 1995.
Sentman, D. D., E. M. Wescott, R. H. Picard, J. R. Winick, H. C. Stenbaek-Nielson, E. M. Dewan, D. R. Moudry, F. T. São Sabbas, and M. J. Heavner, Simultaneous observation of mesospheric gravity waves and sprites generated by a Midwestern thunderstorm, J. Atmos. Sol.-Terr. Phys., 65, 537–550, 2003.
Seyler, C. E., Internal waves and undular bores in mesospheric inversion layers, J. Geophys. Res., 110, D09S05, doi:10.1029/2004JD004685, 2005.
Sobral, J. H. A., M. A. Abdu, and I. S. Batista, Airglow studies on the ionosphere dynamics over low latitude in Brazil, Ann. Geophys., 36(2), 199–204, 1980a.
Sobral, J. H. A., M. A. Abdu, I. S. Batista, and C. J. Zamlutti, Association between plasma bubble and airglow disturbances over Brazilian low latitudes, Geophys. Res. Lett., 11(7), 980–982, 1980b.
Sobral, J. A. H., H. Takahashi, M. A. Abdu, M. J. Taylor, H. Sawant, D. C. Santana, D. Gobbi, A. F. de Medeiros, C. J. Zamlutti, N. J. Schuch, and G. L. Borba, Thermospheric F-region travelling disturbances detected at low latitude by an OI (630 nm) imager system, Adv. Space Sci., 27, 1201–1206, 2001.
Sobral, J. H. A, M. A. Abdu, H. Takahashi, M. J. Taylor, E. R. de Paula, C. J. Zamlutti, and G. L. Borba, A study of the ionospheric plasma bubbles climatology over Brazil, based on 22 years (1977–1998) of OI 630 nm airglow observation, J. Atmos. Terr. Phys., 64(12–14), 1517–1524, 2002.
Stolle, C., H. Luhr, M. Rother, and G. Balasis, Magnetic signatures of equatorial spread F as observed by the CHAMP satellite, J. Geophys. Res., 111, A02304, doi:10.1029/2005JA011184, 2006.
Su, S.-Y., C. K. Chao, and C. H. Liu, On monthly/seasonal/longitudinal variations of equatorial irregularity occurrencesand their relationship with the postsunset vertical drift velocities, J. Geophys. Res., 113, A05307, doi:10.1029/2007JA012809, 2008.
Sultan, P. J., Linear theory and modeling of the Rayleigh Taylor instability leading to the occurrence of equatorial spread F, J. Geophys. Res., 101, 26875–26891, 1996.
Swartz, W. E. and R. F. Woodman, Same night observations of spread-F by the Jicamarca Radio Observatory in Peru and CUPRI in Alcantara, Brazil, Geophys. Res. Lett., 25, 17–20, 1998.
Takahashi, H., M. J. Taylor, P.-D. Pautet, A. F. Medeiros, D. Gobbi, C. M. Wrasse, J. Fechine, M. A. Abdu, I. S. Batista, E. Paula, J. H. A. Sobral, D. Arruda, S. Vadas, F. S. Sabbas, and D. Fritts, Simultaneous observation of ionospheric plasma bubbles and mesospheric gravity waves during the SpreadFEx Campaign, Ann. Geophys., SpreadFEx special issue, 2008 (in review).
Taylor, M. J. and M. A. Hapgood, Identification of a thunderstorm as a source of short period gravity waves in the upper atmospheric nightglow emissions, Planet. Space Sci., 36, 975, 1988.
Taylor, M. J., J.-M. Jahn, S. Fukao, and A. Saito, Possible evidence of gravity wave coupling into the mid-latitude F region ionosphere during the SEEK campaign, Geophys. Res. Lett., 25, 1801–1804, 1998.
Taylor, M. J. et al., Gravity waves in the OH airglow layer observed during the SpreadFEx campaign in Brazil, SpreadFEx special issue, Ann. Geophys., 2008 (submitted).
Taylor, M. J., P. D. Pautet, A. F. Medeiros, R. Buriti, J. Fechine, D. C. Fritts, S. Vadas, H. Takahashi, and F. São Sabbas, Characterizing mesospheric gravity waves near the magnetic equator, Brazil during the SpreadFEx campaign, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Tsuda, T., M. Nishida, and C. Rocken, A global morphology of gravity wave activity in the stratosphere revealed by the GPS occultation data (GPS/MET), J. Geophys. Res., 105, 7257–7274, 2000.
Tsunoda, R. T., Time evolution and dynamics of equatorial backscatter plumes: 1. Growth phase, J. Geophys. Res., 86, 139–149, 1981.
Tsunoda, R. T., On the enigma of day-to-day variability in equatorial spread F, Geophys. Res. Lett., 32, L08103, doi:10. 1029/2005GL022512, 2005.
Tsunoda, R. T., Day-to-day variability in equatorial spread F: Is there some physics missing?, Geophys. Res. Lett., 33, L16106, doi:10.1029/ 2006GL025956, 2006.
Tsunoda, R. T., Seeding of equatorial plasma bubbles with electric fields from an Es-layer instability, J. Geophys. Res., 112, A06304, doi:10.1029/2006JA012103, 2007.
Vadas, S. L., Horizontal and vertical propagation and dissipation of gravity waves in the thermosphere from lower atmospheric and thermospheric sources, J. Geophys. Res., 112, A06305, doi:10.1029/2006JA011845, 2007.
Vadas, S. L. and D. C. Fritts, Gravity wave radiation and mean responses to local body forces in the atmosphere, J. Atmos. Sci., 58, 2249–2279, 2001.
Vadas, S. L. and D. C. Fritts, The importance of spatial variability in the generation of secondary gravity waves from local body forces, Geophys. Res. Lett., 29(20), 10.1029/2002GL015574, 2002.
Vadas, S. L. and D. C. Fritts, Thermospheric responses to gravity waves arising from mesoscale convective complexes, J. Atmos. Sol.-Terr. Phys., 66, 781–804, 2004.
Vadas, S. L. and D. C. Fritts, Thermospheric responses to gravity waves: Influences of increasing viscosity and thermal diffusivity, J. Geophys. Res., 110, D15103, doi:10.1029/2004JD005574, 2005.
Vadas, S. L. and D. C. Fritts, The influence of increasing temperature and solar variability on gravity wave structure and dissipation in the thermosphere, J. Geophys. Res., TIMED special issue, 111, A10812, doi:10.1029/2005JA011510, 2006.
Vadas, S. L. and D. C. Fritts, Reconstruction of the gravity wave field from convective plumes via ray tracing, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Vadas, S. L., D. C. Fritts, and M. J. Alexander, Mechanism for the generation of secondary waves in wave breaking regions, J. Atmos. Sci., 60, 194–214, 2003.
Vadas, S. L., M. J. Taylor, P.-D. Pautet, P. Stamus, D. C. Fritts, F. São Sabbas, and V. Thiago, Convection: The likely source of the medium-scale gravity waves observed in the OH airglow layer near Brasilia, Brazil, during the SpreadFEx campaign, Ann. Geophys., SpreadFEx special issue, 2008 (submitted).
Valladares, C. E., W. B. Hanson, J. P. McClure, and B. L. Cragin, Bottomside sinusoidal irregularities in the equatorial F region, J. Geophys. Res., 88, 8025, 1983.
Woodman, R. F. and C. LaHoz, Radio observations of F-region equatorial irregularities, J. Geophys. Res., 85, 5447, 1976.
Zalesak, S. T. and S. L. Ossakow, Nonlinear equatorial spread F: Spatially large bubbles resulting from large horizontal scale initial perturbations, J. Geophys. Res., 85, 2131, 1980.
Zalesak, S. T., S. L. Ossakow, and P. K. Chaturvedi, Nonlinear equatorial spread F: The effect of neutral winds and background Pedersen conductivity, J. Geophys. Res., 87, 151, 1982.
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Fritts, D.C., Abdu, M.A., Batista, B.R. et al. The spread F Experiment (SpreadFEx): Program overview and first results. Earth Planet Sp 61, 411–430 (2009). https://doi.org/10.1186/BF03353158
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DOI: https://doi.org/10.1186/BF03353158