Some Results of the Comparison of the Solar Almucantar Sky Brightness Observed Under the Cirri Conditions and the Calculated One
Petrushin, A.G.(b), Shukurov, A.K.(a), Shukurov, K.A.(a), and Golitsyn, G.S.(a), A.M. Obukhov Institute of Atmospheric Physics, RAS (a), Institute of Experimental Meteorology, NPO "Typhoon" (b)
Thirteenth Atmospheric Radiation Measurement (ARM) Science Team Meeting
The selected measurements of the solar almucantar sky brightness were carried out at the Zvenigorod Research Facility of the A.M.Obukhov Institute of Atmospheric Physics (IAPh) RAS using the scanning photometer [1] developed in IAPh. These measurements were took place at the cloudy sky and the clear one and at various optical depth t that was controlled with an actinometer. The experimental information about the sky brightness under rarely condition of thin and weakly differing by t cloudiness is interesting for comparison with the same information that obtained from calculations. The specified conditions were realized at April 12 of 2002 at t 1. the measurements were carried out at wavelength l 593 and 1010 nm and at the sun altitude h 400. the distinct halo has been visually observed during measuring that is typical for the cirri. The comparison of the measured solar almucantar sky brightness with the calculated one was realized using expressions [2]. The scattering phase function of a scattering volume of the crystalline cloud was calculated using both the model of the microstructure of the crystalline cloud [3] and the design procedure that described in [4]. Calculations were carried out at l 593 and 1000 nm. The comparison shows that it is a very close agreement between the solar almucantar sky brightness and the calculated one by l as well as by angle range corresponding to a halo. REFERENCE 1. A.Kh.Shukurov, K.A.Shukurov and G.S.Golitsyn. Scanning Filter Photometer for Measuring the Sky Brightness in the Solar Almucantar. ARM, Atlanta, Georgia. March 19-23, 2001, p.99. 2. Pyaskovskaya-Fesenkova E.V. The study of light scattering in the Earth atmosphere. Izvestiya AN USSR, M., 1957, P.218. 3. Petrushin A.G. Phase scattering function by an elementary volume of the crystalline cloud medium under small scattering angles. Atmospheric and Oceanic Physics. 1996. V.32. pp.189-198. 4. Petrushin A.G. Basic optical characteristics of light scattering by mixed clouds. Izvestiya Atmospheric and Oceanic Physics. 2001. V.37. Suppl.1. pp.149-156.
Note: This is the poster abstract presented at the meeting; an extended version was not provided by the author(s).
