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Atmospheric Monitoring has been assigned as the primary responsibility for Utah State University in the Telescope Array Low Energy Extension (TALE) Project TA/TAE US-Japan-ROC Collaboration.
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Atmospheric Monitoring has been assigned as the primary responsibility for Utah State University in the Telescope Array Low Energy Extension (TALE) ProjectTA/TAE US-Japan-ROC Collaboration
An Algorithm for Evaluation of Cloud Esmaiel Malek (Biometeorologist)Department of Plants, Soils and Biometeorology, Utah State University, Logan, UT 84322-4820, U.S.A. emalek@mendel.usu.edu
Clouds affect the radiation budget of our planet by: - Reflecting, - Absorbing, and - Scattering of solar radiation- Re-emission of the terrestrial radiation. They affect the weather and climate by positive or negative feedbacks.
The Vaisala model CT-12K laser beam ceilometer is used at the ASOS to measure the cloud base height and report the sky conditions on an hourly basis or at shorter intervals. This laser ceilometer is a fixed-type whose transmitter and receiver point straight up at the cloud (if any) base.
- It is unable to measure clouds that are not above the sensor. - Asingle cloud hanging overhead the sensor will cause overcast readings, whereas, a hole in the clouds could cause a clear reading to be reported.To report cloudiness at the local scale, many of these type of ceilometers are needed. This is not a perfect method for cloud measurement.
To overcome this problem, we have set up a ventilated radiation station at Cache-Logan Airport, Utah, U.S.A., since 1995, along with an algorithm for evaluation of the -cloud base temperature, - cloud base height, and - percent of skies covered by cloud at the local scale.