Analysis of Trapped Small‐Scale Internal Gravity Waves Automatically Detected in Satellite Imagery

Abstract

In water vapor‐sensitive satellite imagery, small‐scale wave‐like perturbations of brightness temperature can be attributed to the presence of trapped internal waves in the troposphere. We present a method for detecting these local perturbations with wavelengths of about 10 km and apply it to imagery from the Advanced Baseline Imager on board the geostationary satellite GOES‐16. The algorithm allows us to analyze 4 years of sub‐hourly data in the southern part of the tropical eastern Pacific, where only a relatively low amount of medium and high clouds obscures the scene. By combining a measure of wave activity/trapping with ERA5 reanalysis data, we connect the occurrence of trapping with the presence of an increased upper‐tropospheric wind shear. This connection is more evident during December, January and February, when upper‐tropospheric jets are more likely. Our work supports existing case and model studies and is a step forward in the statistical and automated analysis of trapped small‐scale internal waves in the atmosphere.