Investigation of Two Anomalous Thin Layers Descending Through the Lower Mesosphere and Upper Stratosphere

On the night of February 19-20, 2004 at Logan, Utah (41.74 N, 111.81 W), LIDAR observations with a Rayleigh scatter LIDAR revealed two anomalous thin layers. These layer are roughly 1.5 km thick. The first layer was detected at 11 pm local time and descended from approximately 55 km to 30 km in a span of 7 hours. The second layer was detected around 6 am and descended from roughly 55 km to 41 km over a span of 24 minutes. Approximations were made about the rate of descent of the layers to be nearly linear. Though the densities and radii of these layers are not known, estimates for these quantities are made by comparing the layers’ rates of descent to the rates of known aerosol layers. The source of these layers is speculated to originate from an object entering high in the atmosphere and breaking up lower in the atmosphere.