Thousand‐Kilometer‐Scale Wavelike Undulations in Ionospheric Plasma Bubble Lifetime and Development Over Wide Longitudes

Abstract The irregularities of ionospheric plasma bubbles (EPBs) sequentially generated over wide longitudes are expected to share similar lifetime under normal conditions. In this study, we report a special case where the EPB irregularity lifetime over wide longitudes showed a quasi‐wavelike undulation pattern with wavelength of ∼3,000 km, that is, the lifetime of EPB irregularities sequentially generated at different longitudes experienced several gradually decreasing/increasing cycles. Irregularities with longer (shorter) lifetime corresponded to the EPBs with larger (smaller) development in latitude/altitude. Further observations revealed that smaller‐scale (hundred‐kilometer) and larger‐scale (thousand‐kilometer) waves may coexist at the bottomside of ionosphere around sunset. The former acted as the seeding source for EPB generation, whereas the latter superimposed on PRE and modulated EPB development in altitude over different longitudes, leading to the wavelike undulation morphology in irregularity lifetime ultimately. This study provides implications on how the complex wave structures influence EPB morphology over wide longitudes.