CEDAR: Analysis of High Resolution Stratospheric Observations of Polar Mesospheric Clouds

Columbia University, New York NY

Investigators

Abstract

A unique data set consisting of high-resolution optical images of Polar Mesospheric Clouds (PMCs) observed from a stratospheric balloon platform in January of 2013 will be analyzed. PMCs have proven to be excellent tracers of dynamics in the mesosphere and lower thermosphere (MLT). Complex morphological structures in their brightness distribution provide observable consequences of the deposition of energy and momentum by atmospheric gravity waves (GW) in the MLT. This high-resolution data set of optical images 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. Despite the limited field of view available in these images, the analysis of this data set will enable the identification of features that show a range of dynamics, providing evidence for transitional scales and instability accompanying GW breaking or Kelvin-Helmholtz instabilities. It will also enable the identification of features that place bounds on the local Reynolds number, and therefore the background turbulence level. This project will provide research opportunities for graduate, undergraduate, and high school students.