UNIQUE HIGH-RESOLUTION STRATOSPHERIC OBSERVATIONS OF POLAR MESOSPHERIC CLOUDS

Abstract:

We present a unique data set consisting of high-resolution optical images of Polar Mesospheric Clouds (PMCs), observed serendipitously from a stratospheric balloon platform in January of 2013. Complex morphological structures in the PMC brightness distribution provide observable consequences of the deposition of energy and momentum by atmospheric gravity waves in the mesosphere and lower thermosphere. This data set represents the highest resolution set of optical images of this phenomenon to date, and therefore provides a unique window into the poorly understood instability and turbulent dynamics on the smallest scales (between roughly a meter and a few km). Through this analysis, morphological features identified in individual images will be compared with those predicted in numerical models in order to identify key dynamical features present in the data on these small scales. Multiple spatially-overlapping sequential images will be analyzed together in order to extract cloud velocities and to measure timescales for feature permanence. These image compilations will also be used to place the observed small-scale features in a broader context by using multiple images to re-construct larger features, as well as to compare to features simultaneously observed on much larger scales by the CIPS instrument flying on the AIM satellite.