Article

Abstract

• The meteorological control of gravity wave activity through filtering by winds and generation by spontaneous adjustment of unbalanced flows is investigated. This investigation is based on a new analysis of Rayleigh LiDAR measurements of gravity wave activity in the upper stratosphere-lower mesosphere (USLM,40-50km)on 152 nights at Poker Flat Research Range (PFRR), Chatanika, Alaska (65[white bullet] N, 147[white bullet] W), over 13 years between 1998 and 2014. The LiDAR measurements resolve inertia-gravity waves with observed periods between 1 h and 4 h and vertical wavelengths between 2 km and 10 km. The meteorological conditions are defined by reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications (MERRA). The gravity wave activity shows large night-to-night variability, but a clear annual cycle with a maximum in winter,and systematic interannual variability associated with stratospheric sudden warming events. The USLM gravity wave activity is correlated with the MERRA winds and is controlled by the winds in the lower stratosphere through filtering by critical layer filtering. The USLM gravity wave activity is also correlated with MERRA unbalanced flow as characterized by the residual of the nonlinear balance equation. This correlation with unbalanced flow only appears when the wind conditions are taken into account, indicating that wind filtering is the primary control of the gravity wave activity.

Creator

• Nielsen, Kim
• Mizutani, Kohei
• Triplett, Colin C.
• Collins, Richard L.
• Harvey, V. Lynn

Date Issued

• 2017-01-26

Academic Affiliation

• Laboratory for Atmospheric & Space Physics

Journal Title

• Atmosphere

Journal Issue/Number

• 2

Journal Volume

• 8

Subject

• gravity wave propagation
• stratospheric sudden warming (SSW)
• gravity wave generation
• Rayleigh LiDAR
• critical layer filtering
• ageostrophic adjustment

Zuletzt geändert

• 2019-12-09

Resource Type

• Article

Urheberrechts-Erklärung

• In Copyright

DOI

•  http://dx.doi.org/10.3390/atmos8020027

ISSN

• 2073-4433

Language

• English [eng]

License

• Creative Commons BY Attribution 4.0 International

Beziehungen

Artikel

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