Automated atmospheric profiling with the Robotic Lift (RoLi) at the Amazon Tall Tower Observatory

Abstract. The Amazon rain forest plays an important role in the biogeochemistry, water cycle, and climate of the South American continent and the Earth system. The Amazon Tall Tower Observatory (ATTO) has been established to study and quantify forest-atmosphere interactions under natural conditions, as well as the transformation of the Amazon ecosystem as a result of increasing perturbations related to deforestation and climate change. Here, we present the design and first results of a custom-made Robotic Lift system, RoLi, installed to automatically measure high-resolution vertical profiles along the 325-meter tall ATTO tower at high spatial and temporal resolution at vertical profiling speeds up to 0.5 ms⁻¹. The RoLi payload of up to 80 kg can be flexibly adjusted and comprises meteorological, trace gas, and aerosol instruments with short inlet lines, minimizing potential wall losses and related artifacts that may occur in longer sampling tubes of the tall tower. First measurement results show pronounced spatiotemporal patterns in the altitude profiles of temperature, humidity, fog, and aerosol particle concentration and size, providing new insights into the diel interplay of convectively mixed daytime and stable stratified nighttime conditions. The RoLi data will help to better constrain the gradients and exchange of air masses, gases, and particles across the forest-atmosphere interface and related mixing processes in the lowermost planetary boundary layer.