Characterization of LBT atmospheric and turbulence conditions in the context of ALTA project

Abstract

ALTA project has been active since 2016, providing, at LBT observatory site, forecasts of atmospheric parameters, such as temperature, wind speed and direction, relative humidity and precipitable water vapor, and optical turbulence parameters, such as seeing, wavefront coherence time and isoplanatic angle with the final goal to support nightly the science operation of the LBT. Besides to the forecasts, during the years ALTA has been collecting statistics on the atmospheric conditions which can be used to draw a very accurate characterization of the climatology of the telescope site located on top of Mount Graham, Arizona. Such characterization can be used both for the optimization and calibration of the forecast model and as a reference for a model validation. The climatology of these parameters is conceived to be a further output of ALTA that will be upgraded on the website with time and it will be able to put in evidence trends at short as well as long time scales. In this contribution we present a climatological description of all the atmospheric parameters relevant for ground-based astronomy in order to provide to the scientific community a robust reference of the bserving conditions at LBT. The study is performed using on-site measurements provided by DIMM and atmospheric sensors over several years and made available in the telescope telemetry data.