Introduction

 

ForO PWV (Precipitable Water Vapor forecasting system)

At IAC we have validated the Weather Research and Forecasting (WRF) model for precipitable water vapour (PWV) forecasting as a fully operational tool for optimizing astronomical infrared (IR) observations at Roque de los Muchachos (ORM) and Teide Observatory (OT). For the model validation we used GNSS-based (Global Navigation Satellite System) data from the PWV monitor located at the ORM. Excellent agreement was found between the model forecasts and observations, with R = 0.951 and R = 0.904 for the 24 and 48-h forecast time series respectively. The 48-h forecast was further improved by correcting a time lag of 2 h found in the predictions. The final errors, taking into account all the uncertainties involved, are 1.75 mm for the 24-h forecasts and 1.99 mm for 48 h. We found linear trends in both the correlation and RMSE of the residuals (measurements - forecasts) as a function of the forecast range within the horizons analysed (up to 48 h). Assuming a linear trend, the extrapolated forecast error up to 72 h is 2.4 mm. In summary, the WRF performance is excellent and accurate, thus allowing it to be implemented as an operational tool at ORM and OT (from Pérez-Jordán et al, 2018).

ForO Seeing (Atmospheric turbulence forecasting system)

We have also validated the Weather Research and Forecasting (WRF) model for optical turbulence forecasting as a fully operational tool for optimizing astronomical observations in the visible (λ≃0.5 μm) above Roque de los Muchachos (ORM) and Teide Observatory (OT). For the model validation we used G-SCIDAR vertical profiles of the refractive index structure constant (C_𝑁²) obtained during specific campaigns during years 2004 through 2009. From these profiles the integrated optical coherence parameters are then computed above the vertical of the observatory (Airmass=1), namely the total seeing, Boundary Layer (BL) seeing, Free Atmosphere (FA) seeing, coherence time (𝜏₀) and the isoplanatic angle (𝜃₀). Excellent agreement was found between the model forecasts and observations of total seeing, with R = 0.71 and R=0.65 for ORM and OT respectively. The Root Mean Square Error for the total seeing are 0.27’’ for ORM and 0.14’’ for OT. This preliminary results allows it to be implemented as an operational tool at ORM and OT. (from Pérez-Jordán et al, 2018).

The concept of ForO
Web Interface
ForO Operational Architecture
WRF Public Domain Notice
References