Sunphotometer measurements at Yellowknife
Principal Investigator: O'Neill, Norm T (3)
Licence Number: 14509
Organization: Université de Sherbrooke
Licenced Year(s): 2011 2010 2009
Issued: Apr 15, 2009
Project Team: Bruce McArthur (co-I, Environment Canada), Ihab Abboud (co-I, Environment Canada), Jim Freemantle (co-I, Environment Canada)

Objective(s): The objective of this study is to measure the aerosol optical depth and sky radiance at Yellowknife using an automated, sun-tracking, CIMEL sunphotometer.

Project Description: The objective of this study is to measure the aerosol optical depth and sky radiance at Yellowknife using an automated, sun-tracking, CIMEL sunphotometer.

Measurements of instruments in the researchers’ network (called AEROCAN, which is the Canadian sub-network of the world-wide NASA-led network called AERONET) are performed using a CIMEL sunphotometer / sky radiometer. This instrument tracks the solar disk all day and makes measurements of atmospheric extinction of the solar beam while occasionally scanning out along the solar almuncantar to measure sky radiance (the solar almucantar is the fixed elevation-angle circle defined by scanning a radiometer from the centre of the sun out to an azimuth angle of 180 degrees away from the sun). Both types of measurements give information about the columnar concentration, size and nature of the aerosols at the time of measurement.

The researchers will be installing this relatively small instrument on the roof of the Aurora College building in Yellowknife. The sunphotometer is a passive instrument (it does not emit radiation) and does not present any risk to the public. For more information on the CIMEL sunphotometer / sky radiometer go to the AEROCAN web site at: http://pages.usherbrooke.ca/cimel/index.php/Accueil and the AERONET’s website, at http://aeronet.gsfc.nasa.gov/ .

Results will be communicated to communities mostly through a web site. Dr. O'Neill and the rest of the co-Investigators have done many media presentations and would be happy to do interviews for local media.

The fieldwork for this study will be conducted from April 16 to November 01, 2009, on the roof of the Aurora College building in Yellowknife.