Overview

The Andes Lidar Observatory (ALO) is an Upper Atmosphere Facility supported by the U.S. National Science Foundation (NSF). It is located in Cerro Pachón, Chile, an astronomy facility managed by the NOIRLab, an NSF supported national center for optical astronomy. ALO was established in 2009 with the initial mission to make detailed measurement of the neutral atmosphere in the 80 to 110 km altitude region above the Andes, with a suite of ground based remote sensing instruments. ALO houses a Na resonance-fluorescence lidar, which is capable of making night time measurements of atmospheric temperature, 3D wind, and Na density at high temporal and vertical resolutions (~1 min, 500 m) between 80 and 110 km altitude, as well as several passive optical instruments, including an Aerospace Nightglow Imager and an All Sky Imager.

In 2019, supported by the U.S. National Science Foundation, a multi-static meteor radar system (named CONDOR) was installed with the transmitter next to ALO and three receiver systems at ALO, Las Campanas Observatory to the north, and Southern Cross Observatory (Cruz del Sur) to the south. This multi-static meteor radar system detects radio echoes from meteor trails and uses their measured Doppler frequency shift to infer neutral atmospheric wind in the 80–100 km region continuously. Quick look plots of the daily meteor counts, monthly horizontal wind contours, and wavelet power showing the amplitudes of oscillations at various time scales are shown here.

More detailed description of each instrument are available under the Instrument section. Summary plots and data download for some instruments are available in the Data section. Currently Na lidar data is available online. Links to other instruments are provided. The data collected at ALO are being used for a broad range of scientific research. This includes characterization of gravity waves, planetary waves, gravity wave-tide interactions, instability processes and gravity wave breaking, atmospheric composition, gravity wave flux, eddy flux and turbulence diffusion. More detailed description of current scientific projects are listed in the Science section.

The Andes Network for Middle and Upper Atmosphere Observations is built upon ALO and the CONDOR meteor radar system. With the support of the U.S. National Science Foundation, the network will be expanded to include two additional radar receivers in Argentina to the east, as well as multiple all sky imagers to form a dense network for detailed observation of 3D structure of small-scale atmospheric waves.