The prospect of studying atmospheric gravity waves with balloon lidars

Kurzfassung

Long duration balloons are ideal platforms to study atmospheric gravity waves with remote sensing Rayleigh lidar instruments. Using a laser beam and receiving telescope, atmospheric density and temperature are sounded throughout the stratosphere and mesosphere at high vertical and temporal resolution. Sources of gravity waves that induce temperature perturbations are flow over orography, convection or jet imbalances. Under optimal wind conditions such as in the vicinity of the polar vortex edge, gravity waves can propagate long distances both vertically and horizontally and deposit momentum and exert drag in regions where they break. Successive balloon launches of several identical payloads from Antarctica would allow for mapping gravity wave sources, characterize their horizontal and vertical distribution and observe their evolution in different background conditions. Our group has developed high-power lidar instruments and flown them on a NASA long duration balloon in the Arctic (PMC-Turbo) and on the High altitude Long Distance (HALO) aircraft in South America (SouthTRAC-GW). As HALO cannot operate in Antarctica due to logistical constraints, only balloons can fill this gap in observations from ground-based stations that lack the spatial coverage and satellite measurements of coarse vertical and temporal resolution. Based on our experience with building the first Rayleigh lidar to fly successfully on a balloon, we propose to take this next step in miniaturizing lidar instruments to be carried by smaller hand-launched balloons.