@Article{LiNinAbdWanHu:2012:PrSiEv,
               author = "Li, Guozhu and Ning, Baiqi and Abdu, M. A. and Wan, Weixing and 
                         Hu, Lianhuan",
          affiliation = "Chinese Acad Sci, Beijing Natl Observ Space Environm, Inst Geol 
                         \& Geophys, Beijing 100029, Peoples R China. and Chinese Acad 
                         Sci, Beijing Natl Observ Space Environm, Inst Geol \& Geophys, 
                         Beijing 100029, Peoples R China. and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and Chinese Acad Sci, Beijing Natl 
                         Observ Space Environm, Inst Geol \& Geophys, Beijing 100029, 
                         Peoples R China. and Chinese Acad Sci, Beijing Natl Observ Space 
                         Environm, Inst Geol \& Geophys, Beijing 100029, Peoples R 
                         China.",
                title = "Precursor signatures and evolution of post-sunset equatorial 
                         spread-F observed over Sanya",
              journal = "Journal of Geophysical Research",
                 year = "2012",
               volume = "117",
               number = "A08321",
                month = "Aug.",
             keywords = "plasma bubbles, electric-field, irregularities, ionosphere, radar, 
                         campaign, drift.",
             abstract = "Recent case studies on the precursor signatures of equatorial 
                         spread-F (ESF) have shown a one-to-one correspondence between the 
                         large-scale wave structures (LSWS) and ESF development at 
                         equatorial latitude. In this study, the LSWS and the onset and 
                         development of the ESF are investigated over Sanya (18 degrees N, 
                         109 degrees E), a station located at 13 degrees north of the 
                         magnetic equator, during both geomagnetic quiet and disturbed 
                         conditions in September-October 2011. High-time-resolution 
                         ionograms from Digisonde Portable Sounder (DPS-4D) provided the 
                         satellite trace measurements that were used to indicate the 
                         occurrence of the LSWS. The development of local ESF activity was 
                         identified using GPS scintillation and VHF coherent radar echo 
                         measurements from the same site, together with the range type 
                         spread-F (RSF) in ionograms. Additionally, the Sanya VHF radar 
                         five-beam scanning measurements in east-west direction were used 
                         to characterize the longitudinal difference in establishing the 
                         initial conditions for ESF development. Correlative studies 
                         between the LSWS and ESF activities during the observational 
                         period offer consolidated evidence that the LSWS is a necessary 
                         precursor for the ESF development. It is shown that the LSWS and 
                         ESF have nearly a one-to-one relationship when the F layer 
                         undergoes an abrupt post-sunset rise (PSSR), revealing that the 
                         magnitude of the pre-reversal enhancement in zonal electric field 
                         (PRE) that elevates the F layer to a high enough altitude is an 
                         important parameter controlling the generation of post-sunset ESF. 
                         However, in the absence of the PSSR, the ESF and GPS scintillation 
                         did not always occur following the appearance of LSWS. Sometimes 
                         the LSWS events preceded the generation of bottom type spread-F 
                         (BSF) that did not develop vertically into ESF and radar plumes. 
                         This result may indicate that under inexpressive, weak, or even 
                         moderate PRE conditions, the appearance of the LSWS alone may not 
                         be sufficient to produce the post-sunset F region irregularities 
                         responsible for ionospheric scintillations. More factors, other 
                         than the LSWS, could play crucial roles favoring the growth of ESF 
                         instabilities responsible for ionospheric scintillations.",
                  doi = "10.1029/2012JA017820",
                  url = "http://dx.doi.org/10.1029/2012JA017820",
                 issn = "0148-0227 and 2156-2202",
             language = "en",
        urlaccessdate = "13 maio 2024"
}