In order to derive time dependence of the atmospheric diffuse light, which consists of the airglow continuum emission and diffusely scattered radiations of the intergrated starlight, the diffuse Galactic light, and the zodiacal light, we have analyzed the meridian scan observations of the sky brightness at 5 , 080 |AA and 5 , 300 |AA . Amplitude of the time-variation becomes larger for lower elevation, and maximum amplitude is found to be about 50 S 10 ( V ) G 2 V at elevation 10 ˚ . The atmospheric diffuse radiation attains maximum brightness at around midnight, and afterward it decreases slowly with time. The time-variations for the two wavelengths are similar to each other. The observed brightness distribution of the diffuse light along the zenith distance is fitted to an empirical relation of two parameters. By making the two parameters time-dependent, we describe the spatial and time variations of the atmospheric diffuse light. This enables us to make time dependent correction for the atmospheric diffuse component in the reduction of zodiacal light brightness.

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. OBSERVATIONAL DATA AND CALIBRATION
Ⅲ. SIMULATION OF ARTIFICIAL SCANS
Ⅳ. LATITUDINAL AND TEMPORAL VARIATIONS
Ⅴ. CONCLUSION AND DISCUSSION
REFERENCES

• KWON SUK MINN(Department of Astronomy, Seoul National University)