Spatiotemporal Variation of Tropospheric Temperature Lapse Rate Over the Chinese Mainland and Its Potential Influencing Factors

ABSTRACT Using daily data from 123 radiosonde stations in China, we characterise the spatiotemporal variation of tropospheric temperature lapse rate (TLR) during 1961–2024 and analyse its potential influencing factors. Over the Chinese mainland, the multi‐year annual mean TLR is 6.4°C/km, increasing from southeast to northwest, with maxima in spring (6.8°C/km) and minima in winter (6.1°C/km). Distinct regional patterns emerge: steep TLRs occur over the eastern Tibetan Plateau in cold seasons (> 7.2°C/km), while shallow winter TLRs are observed in the southern Yangtze River basin (< 5.0°C/km). Spatial variation is strongly linked to surface energy and moisture, with TLR negatively correlated with humidity and precipitation, and positively with sunshine duration and solar radiation. Three dominant contributors (i.e., radiative forcing, thermal dynamics and pressure/altitude effects) explain the large‐scale pattern. The tropospheric TLR exhibits distinct seasonal patterns: a winter pattern over the eastern Tibetan Plateau, summer patterns in the northern and southern regions of China, and a transitional spring pattern. Although both the northern and southern regions share a summer‐dominant TLR pattern, the former exhibits mid‐summer weakening coinciding with increased precipitation, whereas the latter shows an earlier reduction alongside enhanced cloud cover. In contrast to the consistent positive correlations between TLR and thermal variables observed in the northern and southern regions, the high‐altitude Tibetan Plateau region displays a reversed TLR–temperature relationship at seasonal scales, coexisting with in‐phase to quadrature coherence at sub‐biweekly scales. Wind speed shows weak domain‐averaged association but strong local coherence in specific regions and at certain timescale.