Multiple Scattering Effects in Noctilucent Clouds: Numerical Estimation and Application to Altitude and Particle Size Measurements

The simple 3-D radiative transfer model in the atmosphere of the Earth is built for numerical comparison of direct solar radiation and limb scattering background at the definite layer during the deep twilight period at the middle and upper atmosphere. This allows finding the contribution of multiple scattering in the field of high-altitude clouds such as polar stratospheric and noctilucent clouds. This is the factor that can influence the results of altitude and microphysical study of the particles based on the approximation of single scattering. The possible errors caused by this effect are estimated together with the contribution of multiple scattering for different altitudes of the clouds, wavelengths and solar zenith angles. The results are interpreted geometrically and optically, color effects observed for noctilucent clouds are described.