CIMEL Sunphotometer Helps Researchers See the Light in Australia

 
Published: 31 May 2004

A CIMEL sunphotometer, similar to this one in Tinga Tingana, Australia, will be installed at the ARM Climate Research Facility Darwin site. Photo courtesy of NASA Goddard Space Flight Center.

Science collaborators at the Australian Bureau of Meteorology (BOM) and the Australian Commonwealth Scientific and Industry Research Organization (CSIRO) are using the ARM Climate Research Facility Darwin site in Australia to evaluate aerosol optical properties during the tropical dry season. As part of the Darwin Aerosol Intensive Operational Period (IOP), a CIMEL sunphotometer was installed by CSIRO staff in mid-April at Darwin. The CIMEL sunphotometer is a sun-and-sky scanning radiometer that measures direct solar irradiance and sky radiance at the Earth’s surface. During the IOP, the CIMEL will allow intercomparison and validation of aerosol optical depths obtained from the multifilter rotating shadowband radiometer in routine operation at the ARM Climate Research Facility Darwin site. In addition, sky radiance retrievals will be used to infer microphysical aerosol properties needed to evaluate aerosol radiative forcing.

In addition to the Darwin site, the ARM Climate Research Facility Tropical Western Pacific locale includes sites at Nauru and Manus Islands. A CIMEL has been operating at the Nauru site since May 1999 as a part of NASA’s Aerosol Robotic Network (AERONET), but the ARM Program could not secure another CIMEL through AERONET for the Darwin site. The new CIMEL at Darwin is identical to the CIMEL at Nauru, but is owned by the CSIRO. Data derived from the CIMEL at Darwin is available on the AERONET at aeronet.gsfc.nasa.gov. It is expected that the CIMEL will be extracted from Darwin at the end of the southern hemisphere wet season (December) and may be redeployed as part of the Tropical Warm Pool International Cloud Experiment the following year.