Using sounds from the ocean to measure winds in the stratosphere

Arrowsmith, Marie and Arrowsmith, Stephen and Marcillo, Omar
Eos, Transactions American Geophysical Union (Online), 97(SAND2015-6154J), 2016

Improving weather forecasts and climate models over both short and seasonal timescales requires a better understanding of the stratosphere [Shaw and Shepherd, 2008]. In this atmospheric layer (10–50 kilometers in altitude), temperature increases with altitude because of an increase in ozone, which absorbs ultraviolet light. This layer also plays a crucial role in weather generation.

Many properties of the atmospheric state—temperature, pressure, and density—are well understood or well modeled in the stratosphere. However, a critical property, wind state, is poorly understood because it varies considerably across time and space and because of a lack of direct measurements, which are generally limited to discrete samples obtained by very specialized instruments. The need for new ways to measure stratospheric dynamics is a topic of active study, including a major scientific initiative in Europe [World Meteorological Organization, 2013].

Recently, lidar (a laser technique that is similar to radar) has been employed to provide more detailed stratospheric wind measurements [Baumgarten, 2010]. Because aerosol and molecular densities are lower in the stratosphere, this technology requires a complicated setup of large-aperture telescopes and powerful lasers; such facilities are expensive to build and operate, and they provide wind profiles only at their particular location.