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Abstract Gravity waves impacting ice shelves illicit a suite of responses that can affect ice shelf integrity. Broadband seismometers deployed on the Ross Ice Shelf, complemented by a near‐icefront seafloor hydrophone, establish the association of strong icequake activity with ocean gravity wave amplitudes (AG) below 0.04 Hz. The Ross Ice Shelf‐front seismic vertical displacement amplitudes (ASV) are well correlated withAG, allowing estimating the frequency‐dependent transfer function from gravity wave amplitude to icefront vertical displacement amplitude (TGSV(f)).TGSV(f) is 0.6–0.7 at 0.001–0.01 Hz but decreases rapidly at higher frequencies. Seismicity of strong icequakes exhibits spatial and seasonal associations with different gravity wave frequency bands, with the strongest icequakes observed at the icefront primarily during the austral summer when sea ice is minimal and swell impacts are strongest.
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Seasonal and Latitudinal Variability of the Gravity Wave Spectrum in the Lower Stratosphere
Abstract Superpressure balloon data of unprecedented coverage from Loon LLC is used to investigate the seasonal and latitudinal variability of lower stratospheric gravity waves over the entire intrinsic frequency spectrum. We show that seasonal variability in both gravity wave amplitudes and spectral slopes exist for a wide range of intrinsic frequencies and provide estimates of spectral slopes in five latitudinal regions for all four seasons, in five different frequency windows. The spectral slopes can be used to infer gravity wave amplitudes of intrinsic frequencies as high as 70 cycles/day from gravity waves resolved in model and reanalysis data. We also show that a robust relationship between the phase of the quasi‐biennial oscillation and gravity wave amplitudes exists for intrinsic frequencies as high as the buoyancy frequency. These are the first estimates of seasonal and latitudinal variability of gravity wave spectral slopes and high‐frequency amplitudes and constitute a significant step toward obtaining observationally constrained gravity wave parameterizations in climate models.
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- Award ID(s):
- 1921409
- PAR ID:
- 10455542
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Atmospheres
- Volume:
- 125
- Issue:
- 18
- ISSN:
- 2169-897X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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