Portfolio

Research Highlights

Peer-reviewed and submitted work in the mesosphere–lower thermosphere, observed with meteor radars.

1

Diurnal and Seasonal Variations of Meteor Velocity Observed at Middle Latitude by the Mengcheng Meteor Radar

Wu et al. · Submitted to JGR: Space Physics · Oral, 20th National Symposium on Solar-Terrestrial Space Physics

Key Points

The azimuth of maximum meteor velocity rotates clockwise, from north (local morning) to south (local evening).
The velocity distribution has two Gaussian peaks at ~28 km/s and ~54 km/s, revealing bi-annual and annual variations respectively.
Major meteor showers produce 45–97% higher counts than the background, driving the velocity peaks upward.

Schematic of the Mengcheng Meteor Radar (MCMR) viewing geometry across the Earth's orbit and rotation. — **Fig. 3.** Viewing geometry of MCMR: its position through Earth's orbit and rotation, and how local time changes the observed meteor velocity and angle of arrival.

Distribution maps of meteor velocities by horizontal distance and azimuth, sorted into eight local-time intervals. — **Fig. 7.** Meteor-velocity distribution maps by distance and azimuth, over eight local-time intervals; each point colored by velocity, with matching histograms below.

Nine-year time series of daily meteor-velocity distributions with lower and higher velocity peaks. — **Fig. 9.** Nine years (2014–2023) of daily meteor-velocity distributions. Red and black mark the lower (μ₁) and higher (μ₂) peaks; the color bar is normalized number density. Panel (b) is the seasonal composite.

2

Climatology of the Global Mesospheric Diurnal Tides Observed by Meteor Radars

Yi et al. (incl. Wu, K.) · Submitted to Geophysical Research Letters

Key Points

The global diurnal tide climatology is resolved with fifteen meteor radars across the MLT region.
Diurnal tides are strong at low and mid-latitudes (10–50°N/S), and weak near the equator, higher-mid and polar latitudes.
The height of maximum tidal amplitude tracks the solar zenith angle at northern low and mid-latitudes.

World map of the fifteen meteor radar stations and their working frequencies. — **Fig. 1.** Locations and working frequencies of the fifteen meteor radars used in the global tidal climatology.

3

A Summary Report on Space Physics Practical Education

Wu et al. · Published in Reviews of Geophysics and Planetary Physics

Keywords

Practical education · Space Physics · Chinese Meridian Project

Solar disk images in six extreme-ultraviolet bands observed by the SDO satellite. — **Fig. 3.** Solar disks in six EUV bands (94, 335, 193, 304, 131, 171 Å) observed by the SDO satellite around 2022-02-01.

4

Perturbations from the 2022 Hunga-Tonga Eruption in the Mesosphere–Lower Thermosphere

Wu et al. · WACCM-X simulation & meteor-radar observations · Oral, 4th CGS Workshop · Poster, AGU 2023

Key Points

Wave perturbations from the eruption are tracked across four radar stations by projecting winds toward the great-circle direction from the epicenter.
Meteor-radar observations are compared directly against WACCM-X simulations in profile, amplitude, and wavelet space.

Fig. 1. One-hour high-pass filtered wind perturbations (Wp) at four stations — meteor radar vs. WACCM-X — across altitude profile, altitude-averaged amplitude, and wavelet magnitude & phase.