Unusual spectral features in multi-scale spectra of jovian decameter emission

Overview & Synopsis

We report the detection of intricate fine time-frequency structures and their complex temporal evolution in Jovian sporadic decametric emission (DAM). These patterns are identified in several wideband (WB), narrowband (NB), and mixed WB-NB components observed in high-resolution spectrograms. Their detailed characterization provides new insights into plasma processes in Jupiter's magnetospheric environment, enabling refinement of key plasma parameters and proper selection of models for DAM wave generation. The analyzed waveform data were acquired with the Ukrainian T-shape Radio Telescope (UTR-2) using a baseband digital receiver during an intense Jovian DAM storm on 26 th of November 2009. Spectral images were produced with custom software optimized for multiscale analysis and incorporating various digital filtering techniques to suppress narrowband radio-frequency interference. The resulting WB and NB patterns exhibit complex fine and superfine internal organization, whose principal characteristics are discussed; several features are described here for the first time.