LAUSR

This study presents initial scientific insights obtained from Radio Occultation (RO) observations of ionospheric irregularities and scintillation at equatorial and low latitudes collected by the Macau Science Satellite‐1 (MSS‐1). With a specific focus on the South Atlantic Anomaly (SAA) region, an Empirical Orthogonal Function (EOF) methodology is introduced for reconstructing three‐dimensional (3D) equatorial plasma bubbles (EPB). This method utilizes the first 3 months of RO data from MSS‐1 in conjunction with data from the Constellation Observing System for Meteorology, Ionosphere and Climate follow‐on mission (COSMIC‐2). The analysis assesses approximately 37,232 MSS‐1 RO profiles. The results highlight that the initial two EOF components effectively capture the climatic characteristics of EPB during the period from June to August in 2023. The reconstructed EPB map reveals promising insights, demonstrating a distinct pattern influenced by local time (LT), latitude, and altitude in the occurrence of ionospheric irregularities. MSS‐1 observations hold potential as a valuable addition to GNSS‐RO constellations such as COSMIC‐2, enhancing the comprehension of equatorial and low‐latitude ionospheric irregularities through improved resolutions in LT and vertical sounding.