Gravity Wave Phase Speeds, Wavelengths, and Momentum Fluxes Observed Above the Southern Ocean

From March to December 2014, Loon LLC flew 107 super-pressure balloons in the lower stratosphere over the Southern Ocean. Their GPS sampling frequency of 1Hz allowed them to sample motion associated with atmospheric internal gravity waves generated by the Andes mountains, small islands, and non-orographic sources such as fronts. Analyzing the balloons’ data time series using wavelets, we present distributions of the gravity waves’ momentum fluxes, phase speeds, and wavelengths, both in the time-mean and as they vary from month to month. Many climate models parameterize gravity waves using a phase speed-momentum flux relationship, so we focus on the relationship between those quantities.