Original paper
Transmission formulation for random stacks of clouds
Gierens, Klaus
Meteorologische Zeitschrift Vol. 33 No. 1 (2024), p. 51 - 54
6 references
published: Jun 5, 2024
published online: Jul 13, 2023
manuscript accepted: May 10, 2023
manuscript revision received: May 8, 2023
manuscript revision requested: Apr 18, 2023
manuscript received: Jan 17, 2023
Open Access (paper may be downloaded free of charge)
Abstract
We present a formulation for calculations of photon transmission for random cloud stacks (maximum-random overlap) that can be applied in contrail avoidance experiments, for instance. Other applications are not excluded. In contrail avoidance experiments, the application of the method is to estimate in advance whether contrails are detectable with a satellite instrument and whether therefore the result of the experiment can be validated. For an established contrail avoidance procedure, the method can help to decide whether a contrail should be avoided if cirrus clouds in below the contrail would render the expected infrared radiation effect quite low. The method is derived in some detail, and a practical example is provided. For applications it is necessary to empirically determine or estimate a transmission threshold, that likely depends on the viewing geometry, the spatial resolution and the wavelength of the satellite instrument. An IDL-code is available to interested users.
Keywords
clouds and contrails • radiation transmission • satellite data • visibility