Home
About
Program
and Events
Post-Meeting
Publications
Gallery
Registration
Abstract
Submission
Location and Accommodation
Travel Info
Presenter
Resources
Science Oversight
Committee
Student/Travel
Support
Sponsors and Contributors
Contact
Us
MKWC
Home
Abstract Review

Corresponding Author
Name
Gianluca Lombardi
Authors
NameAffiliation
Valentina Zitelli INAF - Bologna Astronomical Observatory
Sergio Ortolani Department of Astronomy, University of Padova
Marco Pedani FundaciĆ²n Galileo Galilei and Telescopio Nazionale Galileo
Abstract
Session4 (Applications of optical turbulence observations and custom forecasting in telescope astronomy.)
Title'El Roque de Los Muchachos site characteristics'
AbstractWe present an analysis of the mean meteo parameters taken at Telescopio Nazionale Galileo (TNG), Carlsberg Automatic Meridian Circle (CAMC) and Nordic Optical Telescope (NOT) at Observatorio del Roque de Los Muchachos, in the Canary Islands. More than 20 years of measurements at the CAMC are included. Analyses of data from the TNG, CAMC and NOT are compared in order to check local variations and long-term trends.
We compute the hourly averages and then the monthly averages in order to reduce the short-term fluctuations due to the day-night cycle. Particular care is taken to minimize any effect due to biases due to missing data. Finally, we compute the annual average. Wind direction is estimated by the annual percentage of the time in which the wind come from fixed directions.
We found similar temperature trends between TNG and CAMC. There is also an increase in temperature of about 1.0 deg per 10 yr from the annual means, and in addition, the annual minimums increase more rapidly than the maximums. We consider a correlation between the North Atlantic Oscillation (NAO) Index and annual downtime. There is no evidence that a positive NAO Index corresponds to a lower number of nonobservable nights.
Temperatures at different heights are correlated with the quality of astronomical seeing. We found that seeing deteriorates when the gradient of temperatures between 2 and 10 m above the ground is greater than -0.6 deg. Furthermore, influence of wind speed on the astronomical seeing is estimated to the aim to better understand the influence of wide scale parameters on local meteorological data. We found that seeing deteriorates when wind speed is lower than 3.3 m/s.
Relative humidity presents a negative correlation with temperature and pressure, while pressure is correlated to the temperature. The three telescopes show different prevailing wind direction, wind speed, relative humidity and air pressure confirming differences in local microclimate. Comparison in terms of wind speed and high relative humidity (> 90%) shows that TNG seems to have optimal observational conditions with respect to CAMC and NOT. Air pressure analysis shows that ORM is dominated by high pressure.
Finally, short time variations of pressure anticipate temperature variations tipically by 2-3 hours, this property vanishes in time scales higher than some hours and disappear in longer time scales.

Return to Program and Events

Updated on: Wed, Dec 17 2014 - 1849 UTC
Send comments to: MKWC Staff