Terrestrial ecosystems function varies substantially within a single day: plant water and carbon exchange, canopy temperature, and land–atmosphere coupling all shift with light, heat, and moisture over the course of hours. Yet our understanding of ecosystem function is still largely built from daily-to-monthly observations, leaving sub-daily dynamics underexplored despite their relevance to heat and drought stress, phenological transitions, and rapid disturbance.
Recent advances are changing this. Eddy covariance networks continue to provide high-frequency flux records, while geostationary satellites (e.g. MSG, GOES, Himawari) now deliver sub-hourly imagery of vegetation, land surface temperature, and land–atmosphere exchange. Complementary tools, such as phenocams, proximal and UAS-based sensing, and diurnal solar-induced fluorescence, add further resolution to how ecosystems respond across the day.
This session invites contributions that use these and other approaches to characterize ecosystem function at the diurnal scale. We welcome studies on diurnal cycles of carbon, water, and energy exchange; vegetation and phenological dynamics at sub-daily resolution; formation of clouds, detection of rapid ecosystem stress or disturbance; and methodological advances in data fusion, upscaling or modelling that resolve sub-daily processes. We particularly encourage contributions that bridge observation platforms and spatial scales, from tower to landscape to continent, to build a more complete picture of how ecosystems function across the day.