Resonance vibrations of the Ross Ice Shelf and observations of persistent atmospheric waves

• Main Authors: Godin, Oleg A., Zabotin, Nikolay A.
• Other Authors: Naval Postgraduate School (U.S.), Physics
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: AGU Publications 2016
• Subjects: Simple physical models of long-period vibrations of floating ice shelves are developed; Ice shelf vibrations are studied as cause of persistent atmospheric wave activity in Antarctic MLT; The hypothesis of the Ross Ice Shelf-MLT coupling explains key features of recent lidar observations; Antarctic; Ross Ice Shelf; The Antarctic; Antarc*; Antarctica; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://hdl.handle.net/10945/57096

The article of record as published may be found at http://dx.doi.org/10.1002/2016JA023226 Recently reported lidar observations have revealed a persistent wave activity in the Antarctic middle and upper atmosphere that has no counterpart in observations at midlatitude and low-latitude locations. The unusual wave activity suggests a geographically specific source of atmospheric waves with periods of 3??0 h. Here we investigate theoretically the hypothesis that the unusual atmospheric wave activity in Antarctica is generated by the fundamental and low-order modes of vibrations of the Ross Ice Shelf (RIS). Simple models are developed to describe basic physical properties of resonant vibrations of large ice shelves and their coupling to the atmosphere. Dispersion relation of the long surface waves, which propagate in the floating ice sheet and are responsible for its low-order resonances, is found to be similar to the dispersion relation of infragravity waves in the ice-free ocean. The phase speed of the surface waves and the resonant frequencies determine the periods and wave vectors of atmospheric waves that are generated by the RIS resonant oscillations. The altitude-dependent vertical wavelengths and the periods of the acoustic-gravity waves in the atmosphere are shown to be sensitive to the physical parameters of the RIS, which can be difficult to measure by other means. Predicted properties of the atmospheric waves prove to be in a remarkable agreement with the key features of the observed persistent wave activity. Office of Naval Research N000141310348 National Science Foundation, award CNS-0821794 National Science Foundation University of Colorado Boulder Office of Naval Research Basic Research Challenge program