author = "Pimenta, Alexandre Alvares and Sahai, Y. and Bittencourt, 
                         Jos{\'e} Augusto and Rich, F. J.",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         de Pesquisa e Desenvolvimento. Universidade do Vale do 
                         Para{\'{\i}}ba (UNIVAP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and Space Vehicles Directorate, Air Force 
                         Research Laboratory",
                title = "Ionospheric plasma blobs observed by OI 630 nm all-sky imaging in 
                         the Brazilian tropical sector during the major geomagnetic storm 
                         of April 6-7, 2000",
              journal = "Geophysical Research Letters",
                 year = "2007",
               volume = "34",
               number = "2",
                pages = "L02820 (5pp)",
                month = "Jan.",
             keywords = "equatorial-spread-F, airglow.",
             abstract = "This paper presents first observations of plasma blobs ( localized 
                         plasma density enhancements) associated with large-scale plasma 
                         density depletions ( plasma bubbles) in the nighttime low-latitude 
                         F-region during a major geomagnetic disturbance. Ground-based 
                         observations of the OI 630 nm all-sky images obtained at Cachoeira 
                         Paulista (22.7 degrees S, 45.0 degrees W), Brazil, in the Appleton 
                         anomaly region, showed the presence of plasma blobs during the 
                         major geomagnetic storm of April 6 - 7, 2000 (Sigma Kp = 38 -/ 
                         40+; \Dst\(max) = 288 nT). The OI 630 nm emission images were 
                         used to map the spatial and temporal locations of plasma blobs and 
                         bubbles in the bottomside of the F-region. The F-region 
                         parameters, presented in this work, were obtained from ionosondes 
                         operating near the same site and also at Sao Luis (2.6 degrees S, 
                         44.4 degrees W), Brazil. Ionospheric plasma blobs and bubbles 
                         zonal drift velocities, measured by the all-sky imaging system, 
                         showed that both the plasma blobs and the bubbles moved westward ( 
                         normally the plasma drift is eastward during nighttime) on this 
                         magnetically disturbed night. Furthermore, the plasma blobs showed 
                         typically east-west and north-south extensions in the range of 110 
                         160 km and 200 - 450 km, respectively. It appears that the DMSP-15 
                         satellite, orbiting at about 850 km altitude, passed through one 
                         of the blobs detected by the ground-based observations on this 
                         night while crossing the Brazilian sector. This indicates the 
                         enormous altitude extent [ from about 275 km ( OI 630.0 nm 
                         emission) to 850 km ( DMSP satellite) altitude] of the localized 
                         plasma density enhanced regions. In this work, we present and 
                         discuss several features related to the dynamics of the localized 
                         plasma density enhancements and large-scale plasma density 
                         depletions during this major geomagnetic disturbance.",
                  doi = "10.1029/2006GL028529",
                  url = "http://dx.doi.org/10.1029/2006GL028529",
                 issn = "0094-8276",
             language = "en",
           targetfile = "grl22612.pdf",
        urlaccessdate = "18 jan. 2021"