Blar i forfatter "Heino, Erkka"

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    • Energetic electron precipitation occurrence rates determined using the Syowa East SuperDARN Radar 

      Bland, Emma; Partamies, Noora; Heino, Erkka; Yukimatu, Akira Sessai; Miyaoka, Hiroshi (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-04)
      We demonstrate that the Super Dual Auroral Radar Network (SuperDARN) radar at Syowa station, Antarctica, can be used to detect high frequency radio wave attenuation in the <i>D</i> region ionosphere during energetic electron precipitation (EEP) events. EEP‐related attenuation is identified in the radar data as a sudden reduction in the backscatter power and background noise parameters. We focus ...

    • Observational Validation of Cutoff Models as Boundaries of Solar Proton Event Impact Area 

      Heino, Erkka; Partamies, Noora (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-20)
      High energy protons accelerated during solar proton events (SPEs) can access the Earth's middle atmosphere at high and middle latitudes causing large‐scale ionization and chemical changes. In this study, we have compared the performance of two cutoff latitude models that predict the limit of the SPE impact area in the atmosphere during 73 SPEs from 1997 to 2010. We use observations from 13 riometer ...

    • Patch Size Evolution During Pulsating Aurora 

      Partamies, Noora; Bolmgren, Karl; Heino, Erkka; Ivchenko, Nickolay; Borovsky, Joseph E.; Sundberg, Hanna (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-30)
      We report both decreasing and increasing trends in the patch sizes during pulsating aurora events. About 150 pulsating auroral events over the Fennoscandian Lapland have been successfully analyzed for their average patch size, total patch area, and number of patches as a function of event time, typically 1–2 hr. An automatic routine has been developed to detect patches in the all‐sky camera images. ...