## Abstract

In this paper, we derive the atmospheric gravity waves (GWs) and acoustic waves excited by an ocean surface wave packet with frequency ω_{F} and duration χ in an f plane, isothermal, windless, and inviscid atmosphere. This packet is modeled as a localized vertical body force with Gaussian depth σ_{z}. The excited GW spectrum has discrete intrinsic frequencies (ω_{Ir}) at ω_{F} and ω_{F}±2π/χ ("sum" and "difference") and has a "continuum" of frequencies for ω_{Ir}<ω_{F}+2π/χ. The momentum flux spectrum peaks at ω_{Ir}∼ω_{F} and decreases rapidly as ω_{Ir} decreases. To simulate the effect these GWs have on the thermosphere, we present a new scheme whereby we sprinkle N GW spectra in the ocean wave packet region, ray trace the GWs, and reconstruct the GW field. We model the GWs excited by ocean wave packets with horizontal wavelengths of λ_{H} = 190 km, periods of τ_{F} = 2π/ω_{F} = 14 - 20 min and χ = 30 - 50 min. The excited GWs begin to arrive at z = 250 km at t ∼ 75 - 80 min. Those with the largest temperature perturbations T′ have large ω_{Ir} and arrive at t ∼ 90 - 130 min. If |α|=ω_{F}+2π/χ is a solution of the GW dispersion relation and |α| is less than the buoyancy frequency at z = 250 km, the sum and highest-frequency continuum GWs have much larger phase speeds and arrive 50-60 min earlier with larger T′ than the GWs with frequency ω_{F}. For a packet with λ_{H} = 190 km, τ_{F} = 14 min, χ = 30 min, and height h_{0}=1.3 m, the maximum T′ at z = 250 km is ∼9, 22, and 40 K for σ_{z} = 1, 2, and 4 m, respectively.

Original language | English (US) |
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Pages (from-to) | 9748-9780 |

Number of pages | 33 |

Journal | Journal of Geophysical Research: Space Physics |

Volume | 120 |

Issue number | 11 |

DOIs | |

State | Published - Nov 1 2015 |

## Keywords

- gravity waves
- ocean surface wave
- ray tracing
- thermosphere
- tsunami

## ASJC Scopus subject areas

- Geophysics
- Space and Planetary Science