Anelastic Internal Wave Transmission

• Main Authors: J. T. Nault, B. R. Sutherl
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Jan Mayen; Sion; Jan Mayen Island
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.510.949; http://www.math.ualberta.ca/~bruce/papers/igwlinan/reprint_style.pdf

An anelastic extension to the Taylor-Goldstein equation is derived and a numerical method is developed to compute the transmission of small amplitude, two-dimensional internal waves in non-rotating, inviscid fluid having arbitrarily specified stratification and background ve-locity. Two particular applications are discussed. First, internal waves incident upon a piecewise-linear shear layer are examined and their transmission is computed as a function of the bulk Richardson number, Rib, and the ratio of the density scale height relative to the depth of the shear layer. The waves are found to transmit partially across critical levels if they coincide with heights where the gradient Richardson number is less than 1/4. Transmis-sion is larger if Rib is smaller. Decreasing the density scale height reduces the frequency and wavenumber range over which internal waves propagate, but this does not significantly affect the magnitude of transmission. Second, internal waves generated by flow over Jan Mayen island are examined. Although the waves are ducted, the waves are found to transmit par-tially through the top of the duct. The results are used to interpret the discrepancy between predictions of ray theory and the fully nonlinear numerical simulations of Eckermann et al. 2006. 1