TY - JOUR
T1 - Momentum Flux Spectra of a Mountain Wave Event Over New Zealand
AU - Bossert, Katrina
AU - Fritts, David C.
AU - Heale, Christopher J.
AU - Eckermann, Stephen D.
AU - Plane, John M. C.
AU - Snively, Jonathan B.
AU - Williams, Bifford P.
AU - Reid, Iain M.
AU - Murphy, Damian J.
AU - Spargo, Andrew J.
AU - MacKinnon, Andrew D.
N1 - Bossert, K., Fritts, D. C., Heale, C. J.,
Eckermann, S. D., Plane, J. M. C., Snively,
J. B., et al. (2018). Momentum flux
spectra of a mountain wave event over
New Zealand. Journal of Geophysical
Research: Atmospheres, 123, 9980–9991.
https://doi.org/10.1029/2018JD028319
PY - 2018/9/27
Y1 - 2018/9/27
N2 - During the Deep Propagating Gravity Wave Experiment (DEEPWAVE) 13 July 2014 research flight over the South Island of New Zealand, a multiscale spectrum of mountain waves (MWs) was observed. High-resolution measurements of sodium densities were available from ~70 to 100 km for the duration of this flight. A comprehensive technique is presented for obtaining temperature perturbations, T′, from sodium mixing ratios over a range of altitudes, and these T′ were used to calculate the momentum flux (MF) spectra with respect to horizontal wavelengths, λH, for each flight segment. Spectral analysis revealed MWs with spectral power centered at λH of ~80, 120, and 220 km. The temperature amplitudes of these MWs varied between the four cross-mountain flight legs occurring between 6:10UT and 9:10UT. The average spectral T′ amplitudes near 80 km in altitude ranged from 7–13 K for the 220 km λH MW and 4–8 K for the smaller λH MWs. These amplitudes decayed significantly up to 90 km, where a critical level for MWs was present. The average MF per unit mass near 80 km in altitude ranged from ~13 to 60 m2/s2 across the varying spectra over the duration of the research flight and decayed to ~0 by 88 km in altitude. These MFs are large compared to zonal means and highlight the importance of MWs in the momentum budget of the mesosphere and lower thermosphere at times when they reach these altitudes.
AB - During the Deep Propagating Gravity Wave Experiment (DEEPWAVE) 13 July 2014 research flight over the South Island of New Zealand, a multiscale spectrum of mountain waves (MWs) was observed. High-resolution measurements of sodium densities were available from ~70 to 100 km for the duration of this flight. A comprehensive technique is presented for obtaining temperature perturbations, T′, from sodium mixing ratios over a range of altitudes, and these T′ were used to calculate the momentum flux (MF) spectra with respect to horizontal wavelengths, λH, for each flight segment. Spectral analysis revealed MWs with spectral power centered at λH of ~80, 120, and 220 km. The temperature amplitudes of these MWs varied between the four cross-mountain flight legs occurring between 6:10UT and 9:10UT. The average spectral T′ amplitudes near 80 km in altitude ranged from 7–13 K for the 220 km λH MW and 4–8 K for the smaller λH MWs. These amplitudes decayed significantly up to 90 km, where a critical level for MWs was present. The average MF per unit mass near 80 km in altitude ranged from ~13 to 60 m2/s2 across the varying spectra over the duration of the research flight and decayed to ~0 by 88 km in altitude. These MFs are large compared to zonal means and highlight the importance of MWs in the momentum budget of the mesosphere and lower thermosphere at times when they reach these altitudes.
KW - gravity waves
KW - mountain waves
KW - momentum flux
KW - DEEPWAVE
UR - https://commons.erau.edu/publication/1153
U2 - 10.1029/2018JD028319
DO - 10.1029/2018JD028319
M3 - Article
SN - 2169-8996
VL - 123
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
ER -