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@Article{LiNWAOYWC:2018:StDePo,
               author = "Li, Guozhu and Ning, Baiqi and Wang, Chi and Abdu, Mangalathayil 
                         Ali and Otsuka, Yuichi and Yamamoto, M. and Wu, Jian and Chen, 
                         Jinsong",
          affiliation = "{Chinese Academy of Sciences} and {Chinese Academy of Sciences} 
                         and {Chinese Academy of Sciences} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Nagoya University} and {Kyoto 
                         University} and {Research Institute of Radio Wave Propagation} and 
                         {Research Institute of Radio Wave Propagation}",
                title = "Storm-enhanced development of postsunset equatorial plasma bubbles 
                         around the meridian 120 degrees E/60 degrees W on 7-8 September 
                         2017",
              journal = "Journal of Geophysical Research: Space Physics",
                 year = "2018",
               volume = "123",
               number = "9",
                pages = "7985--7998",
                month = "Sept.",
             keywords = "equatorial plasma bubbles, geomagnetic storm, disturbance electric 
                         field, west-tilted structure, westward drifts, international space 
                         weather meridian circle program.",
             abstract = "Storm time development of equatorial plasma bubbles (EPBs) around 
                         the meridian 120 degrees E/60 degrees W during early September 
                         2017, when the Bz component of interplanetary magnetic field (IMF) 
                         experienced two large southward excursions, producing a strong 
                         geomagnetic storm that included two main phase decreases, was 
                         investigated. The observations from networks of Global Navigation 
                         Satellite Systems total electron content receivers, very high 
                         frequency radars, and ionosondes operated around the meridian 
                         reveal that in the American and Asian sectors, intense EPB 
                         irregularities developed and extended to dip latitudes of similar 
                         to 30 degrees N and 46 degrees N, respectively, following rapid 
                         sunset F layer height rises during two episodes of strong 
                         southward IMF Bz excursions. The storm-enhanced EPB 
                         irregularities, however, were not observed following the sunset 
                         terminator in the Pacific sector, where the sunset rise of F layer 
                         was not detected. More interestingly, the EPBs in the Asian sector 
                         were observed to drift toward the west, with velocity increasing 
                         from similar to 30 m/s at low latitude to similar to 95 m/s at 
                         middle latitude. The poleward increasing westward drifts drove the 
                         formation of west-titled structure of irregularities. For the EPBs 
                         in the American sector, no apparent west-tilted structure was 
                         detected. The results indicate that the prompt penetration 
                         undershielding electric fields (PPEF) of eastward polarity 
                         resulting from the two IMF Bz southward excursions dominated the 
                         generation of postsunset EPBs in the American and Asian sectors, 
                         respectively. The westward drifts of PPEF-induced EPBs in the 
                         Asian sector could be attributed dominantly to disturbance 
                         westward wind, with a possible contribution to it arising from the 
                         PPEF. Plain Language Summary The development and evolution of 
                         equatorial plasma bubbles (EPBs) exhibit complex global behavior 
                         during geomagnetic storms. In recent years, an international space 
                         weather meridian circle program, which aims to provide a global 
                         picture of unfolding space weather events by using diverse 
                         instruments along the approximate meridian 120 degrees E/60 
                         degrees W, that is, the Asian and American longitude sectors, was 
                         launched. Considering the sunset interval (similar to 12 hr) 
                         between the two longitudes, it is expected that the development of 
                         postsunset EPBs, if enhanced in one region by short-lived prompt 
                         penetration electric fields (PPEF), would be inhibited in the 
                         other region under the delayed and long duration effect of 
                         disturbance dynamo electric fields. Here we report a unique case 
                         of significantly enhanced postsunset EPBs developments by PPEF in 
                         both the American and Asian sectors, but their total absence by 
                         disturbance dynamo electric fields in the Pacific sector during 
                         the September 2017 geomagnetic storm sequence. Moreover, the 
                         PPEF-induced EPBs along the meridian show different 
                         characteristics, with apparent west-tilted structure in the Asian 
                         sector but not in the American sector. This sort of study based on 
                         the international space weather meridian circle program 
                         observations will strengthen our understanding on the generation 
                         and evolution characteristics of EPBs during geomagnetic storms.",
                  doi = "10.1029/2018JA025871",
                  url = "http://dx.doi.org/10.1029/2018JA025871",
                 issn = "2169-9402",
             language = "en",
           targetfile = "li-storm.pdf",
        urlaccessdate = "03 dez. 2020"
}


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