Quantifying the spatial-seasonal patterns of land–atmosphere water, heat and CO2 flux exchange over the Tibetan Plateau from an observational perspective

Abstract

Land-atmosphere (LA) interactions, through the turbulent exchange of water, heat and CO2 fluxes, strongly influence regional micro-climates, water cycles, energy budgets, and ecosystem dynamics. The Tibetan Plateau (TP), characterized by its vast extent, high elevation, strong solar radiation and extreme weather variability, remains underexplored due to the scarcity of LA observation sites, particularly in its western and northern regions. This study introduces a newly established research and observation platform, comprising 16 planetary boundary layer towers that span diverse landscapes and dynamic meteorological conditions. Across these sites, mean annual air temperature, wind speed, and liquid precipitation range from -3.5 to 18.5 °C, 0.6 to 5.6 ms-1, and 43 to 2164 mm, respectively. Elevation exhibits significant correlations with all meteorological variables, highlighting the pronounced spatial heterogeneity of land–atmosphere coupling across the region. The turbulent fluxes of water and heat exhibit distinct seasonal patterns, with maximum sensible heat flux (SH) in April–May and latent heat flux (LE) in July–August. Most stations act as carbon sinks, with net ecosystem exchange (NEE; the net CO2 exchange between the ecosystem and the atmosphere, where negative values indicate net ecosystem CO2 uptake) ranging from -3.2 to -174.3 gCm-2 a-1, except the Medog station, which behaves as a carbon source likely linked to vegetation disturbance and human activity. LE is significantly correlated with SH, NEE and ecosystem respiration, revealing a strong coupling among water, heat and carbon fluxes. This high-resolution, quality-controlled dataset provides critical in situ observations for studying water–heat–carbon coupling, validating models and satellite algorithms, and improving understanding of climate-ecosystem interactions over the TP. The whole datasets are freely available at the National Tibetan Plateau Data Center (https://doi.org/10.11888/Atmos.tpdc.302428; Wang and Ma, 2025).