Short-period mesospheric gravity waves and their sources at the South Pole
The sourcing locations and mechanisms for short-period, upward-propagating gravity waves at high polar latitudes remain largely unknown. Using all-sky imager data from the Amundsen–Scott South Pole Station, we determine the spatial and temporal characteristics of 94 observed small-scale waves in 3 a...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/17/911/2017/acp-17-911-2017.pdf |
| Summary: | The sourcing locations and mechanisms for short-period, upward-propagating
gravity waves at high polar latitudes remain largely unknown. Using all-sky
imager data from the Amundsen–Scott South Pole Station, we determine the
spatial and temporal characteristics of 94 observed small-scale waves in 3
austral winter months in 2003 and 2004. These data, together with background
atmospheres from synoptic and/or climatological empirical models, are used to
model gravity wave propagation from the polar mesosphere to each wave's
source using a ray-tracing model. Our results provide a compelling case that
a significant proportion of the observed waves are launched in several
discrete layers in the tropopause and/or stratosphere. Analyses of synoptic
geopotentials and temperatures indicate that wave formation is a result of
baroclinic instability processes in the stratosphere and the interaction of
planetary waves with the background wind fields in the tropopause. These
results are significant for defining the influences of the polar vortex on
the production of these small-scale, upward-propagating gravity waves at the
highest polar latitudes. |
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| ISSN: | 1680-7316 1680-7324 |