1：Experimental Design and Method Selection:

A resonance scattering lidar was used to measure Ca+ densities with high time-height resolution (5 s and 15 m) to observe fine structures in the Es layer. Ionosonde data were used for simultaneous electron density measurements.

2：Sample Selection and Data Sources:

Observations were conducted at Tachikawa (

3：7°N, 4°E) on December 24, 2014, from

09 to 21:26 UT. Ionosonde data from Kokubunji (35.7°N, 139.5°E) were used for correlation analysis.

4：7°N, 5°E) were used for correlation analysis. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Resonance scattering lidar with an injection-seeded alexandrite ring laser, SHG unit with BBO crystals, tunable diode laser, wavelength meter, Nasmyth-Cassegrain telescope, photomultiplier tube, band-pass filter, transient recorder. Ionosonde for electron density measurements.

5：Experimental Procedures and Operational Workflow:

The lidar transmitted laser pulses at 393.477 nm, detected photons with a PMT, recorded counts with 15 m range resolution and 5 s integration. Background noise was subtracted, and Ca+ densities were normalized using Rayleigh signals. Ionosonde ionograms were obtained every 15 min.

6：477 nm, detected photons with a PMT, recorded counts with 15 m range resolution and 5 s integration. Background noise was subtracted, and Ca+ densities were normalized using Rayleigh signals. Ionosonde ionograms were obtained every 15 min. Data Analysis Methods:

5. Data Analysis Methods: Correlation analysis between maximum Ca+ densities and electron densities from foEs, temporal and height variations were analyzed to identify structures like quasi-sinusoidal variations, clumps, and instabilities.