Nocturnal Temperature and Wind Structures of the Mesosphere and Lower Thermosphere Region Over Yuzhong (36°N, 104.2°E) Based on Sodium Lidar Observation

Abstract We present an analysis of thermal and dynamical structures in the mesopause and lower thermosphere (MLT) region (82–106 km) using ∼1,870 hr of sodium (Na) lidar observations at Yuzhong (36.0°N, 104.2°E) from March 2023 to May 2025. Mesopause altitudes exhibit strong seasonal dependence, ranging from 88 km in summer to 102 km in winter, with dual temperature minima observed in spring (89/101 km) and autumn (85/100 km). Minimal vertical temperature variation occurs in spring (∼5 K at 85–100 km), contrasting with larger gradients in autumn/winter. Temperature biases between lidar and TIMED/SABER satellite data show altitude‐dependent thresholds (∼92 km summer, ∼97 km autumn/winter), revealing satellite negative biases (3–5 K) below and positive biases (12–20 K) above these levels. Comparisons with the Starfire Optical Range station (35°N, 106.5°W) highlight 1–10 K springtime temperature differences linked to localized inversion layers. Zonal winds reverse from eastward to westward at ∼102 km (spring/summer) and ∼100 km (autumn/winter), while meridional winds display pronounced seasonal heterogeneity, including enhanced northward flows in spring (90–96 km) and winter (>91 km) inconsistent with horizontal wind model (HWM14) and the NCAR Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM‐X). The discrepancies between lidar observations and model predictions highlight the need for improved gravity wave parameterization and regional‐scale wind characterization. These results advocate for multi‐instrument networks (lidar, meteor radar, Fabry‐Perot interferometers) under the Chinese Meridian Project to constrain regional atmospheric models and improve understanding of MLT dynamical processes.