Control quality of seeing measurements provided by the DIMMA at the ORM Antonia M. Varela, Casiana Muñoz-Tuñón & Julio Castro-Almazán Feb-2013- Technical report ------------------------------------- An automatic DIMM is installed near the GTC site. Data have been validated and the results presented in this document. Real time values are accessible at http://www.iac.es/site-testing/DIMMA_ORM. The comparison baseline spans from April to October 2012. Mean and median values in this period are 0.95” and 0.86” respectively.

INTRUSIONES DE POLVO SOBRE EL ORM Sky Quality Team Instituto de Astrofísica de Canarias Marzo 2010

The report concludes that the Canary Islands observatories (Roque de los Muchachos and Teide; ORM and OT) show an extremely clean air and pristine skies, only partially affected by some dust loaded African air mass intrusions in summer time (July‐September). Long term simulations (1958‐2006) of TSP (Total Suspended Particles) for OT and ORM show that no positive trend has been detected since 1958, in good agreement with the in‐situ observations. No positive trend in the inter‐annual variation of dust‐loaded air masses over the OT and ORM scientific facilities. Model simulations show a lower incidence of African air masses over ORM compared to OT, as it was expected by the geographical location of both observatories.

Concerning the astroclimatological comparison of the Paranal Observatory and El Roque De Los Muchachos Observatory (Temperature trends) J.A. Castro-Almazán, C. Muñoz-Tuñón and J.J. Fuensalida Instituto de Astrofísica de Canarias 15 Oct 2009 In response to the paper “The astroclimatological comparison of the Paranal Observatory and El Roque de Los Muchachos”. MNRAS, 399-2, p.783-793. 10/2009 (Lombardi, G.; Zitelli, V.; Ortolani, S.)

ANALYSIS OF SEEING MEASUREMENTS FROM THE LA PALMA RoboDIMM1* May 2009 Antonia M. Varela(1), Casiana Muñoz-Tuñón(1), Jesús J. Fuensalida(1) & Jean Vernin(2) (1) Instituto de Astrofísica de Canarias (2) Departement of Astrophysics; Nice University

Héctor Vázquez Ramió, casiana Muñoz Tuñón, Antonia M. Varela, Jesús J. Fuensalida. Complementary note: DIMM (ELT-DS) calibration