A214-0009
Regional collaboration for nighttime cloud detection using a digital camera

Wednesday, 16 December 2020
Poster
Nofel Lagrosas1, Tatsuo Shiina1, Erdenetogtokh Jamsranjav2, Ziqi Peng3, Sheng Hsiang Wang4, Neng-Huei Lin5, Maria Cecilia Dandan Galvez6, Santo V Salinas Cortijo7, Soo Chin Liew7 and John Holdsworth8, (1)Graduate School and Faculty of Engineering, Chiba University, Chiba, Japan, (2)Mongolian Academy of Sciences, Ulaanbaatar, Mongolia, (3)Hunan University of Art and Science, Hunan, China, (4)National Central University, Atmospheric Sciences, Taoyuan, Taiwan, (5)National Central University, Taoyuang, Taiwan, (6)De La Salle University, Physics, Manila, Philippines, (7)National University of Singapore, Singapore, Singapore, (8)University of Newcastle, Callaghan, Australia
Abstract:
Ground-based detection of nighttime clouds has been scarce due to the lack of sensors that can perform the detection process. We propose a collaborative effort to detect nighttime clouds and measure nighttime cloud cover using a digital camera from southern to northern latitudes (Fig 1). At present, a camera system is operational in Chiba University and similar camera systems are planned to be deployed at strategic locations (Australia, Singapore, Philippines, Taiwan, China and Mongolia) to detect local nighttime clouds. Continuous operation of these camera system at these locations can provide and quantify seasonal trends of nighttime cloud cover (Gacal et al., 2018) and their variation with latitudinal changes. The cloud cover data from these camera systems can be compared to satellite data and be used to correct satellite cloud fraction products for low-level clouds. In this way, correction values at each latitude can be quantified. The camera system is composed of 2 cameras (Canon A2300). Each camera is operated with and without near infrared cut filter (Lagrosas et al., submitted). These cameras are programmed to automatically take sky images every 5 minutes (Gacal et al., 2016). The images from the NIR camera can be used to identify nighttime clouds types. Comparison of the cloud cover values with local temperature can aid in the understanding of the effect of nighttime clouds on nighttime radiation budget in the atmosphere. The data from each station is sent to Chiba University for processing. Open data policy system will be implemented for other researchers to use the data and for the advancement of remote sensing and cloud studies.

References:

  1. Gacal, et al., Ground-based detection of nighttime clouds above Manila Observatory (14.64°N, 121.07°E) using a digital camera, Applied Optics, 55, 22, 6040-6045, 2016.
  2. Gacal, et al., Trends of night-time hourly cloud-cover values over Manila Observatory: ground-based remote-sensing observations using a digital camera for 13 months, International Journal of Remote Sensing, 39, 21, 7628-7642, 2018.
  3. Lagrosas et al., Cloud cover observations and detection of thin clouds over Chiba, Japan using a digital camera and satellite images, Manuscript submitted for publication.

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