Turbulence nowcast for the Cerro Paranal and Cerro Armazones observatory sites

TL;DR

This paper presents an empirical method leveraging measurements from two nearby observatory sites to improve short-term optical turbulence forecasts, aiding the scheduling and efficiency of large ground-based telescopes.

Contribution

It introduces a novel empirical approach based on spatial diversity and simultaneous measurements to forecast optical turbulence for observatory operations.

Findings

High correlation between turbulence measurements at Cerro Paranal and Cerro Armazones.

Potential for improved short-term turbulence forecasts using empirical data.

Supports operational planning for VLT and ELT observatories.

Abstract

Optical turbulence affects significantly the quality of ground-based astronomical observations. An accurate and reliable forecast of optical turbulence can help to optimise the scheduling of the science observations and to improve both the quality of the data and the scientific productivity of the observatory. However, forecasts of the turbulence to a level of accuracy that is useful in the operations of large observatories are notoriously difficult to obtain. Several routes have been investigated, from detailed physical modelling of the atmosphere to empirical data-driven approaches. Here, we present an empirical approach exploiting spatial diversity and based on simultaneous measurements between two nearby sites, Cerro Paranal, host of the Very Large Telescope (VLT), and Cerro Armazones, future host of the Extremely Large Telescope (ELT) in Chile. We study the correlation between the high-altitude turbulence as measured between those two sites. This is part of the on-going efforts initiated by the European Southern Observatory (ESO), to obtain short-term forecasts of the turbulence to facilitate the operations of the VLT and prepare the ELT mode of operations.