Back Menu

Precipitable Water Vapour measurements and forecasting at the Observatories.

Casiana Muñoz-Tuñón, Gabriel Pérez Jordán y Julio Castro-Almazán

October 9th, 2018


The precipitable water vapour (PWV) is the main absorber in the Earth's
atmosphere at infrared (IR) and microwave wavelengths. In the last years,
the IAC Sky team has been providing real-time PWV data from a monitor based
on the GNSS (GPS) technique (GNSS PWV Monitors; GPM). Among other things,
the PWV values help in the scheduling of the telescopes with IR
instrumentation. The GPM have undergone a continuous process of upgrading.
More recently, we have undertaken the PWV forecasting. We will present in
the talk a brief summary of the monitors and details of ForO ("Forecasting
the Observatories"), the forecasting system for PWV at the Observatories.
ForO is based on a mesoscale Numerical Weather Prediction (NWP) model. The
ForO system has been validated and calibrated with PWV data from the GPM
and will deliver accurate PWV daily predictions for ORM and OT on a 24, 48
and 72 hours windows. This is a definitive improvement to optimize the
flexible scheduling for IR observations, in particular for CanaryCAM and
EMIR at the GTC.