HR: 1340h
AN: A13A-0888 [Abstracts]
TI: Analysis of the Seasonal and Spatial Structure of the Gravity Waves Over the Central USA Using Data
From the NOAA Wind Profiler Network
AU: * Karabanov, O G
EM: karabanov@eas.gatech.edu
AF: Georgia Institute of Technology, 311 Ferst Drive.
School of Earth and Atmospheric Sciences, Atlanta, GA 30332-0340
United States
AB:
Gravity waves are important atmospheric phenomenon, as they transport momentum and energy, affecting the dynamic structure of
the troposphere, stratosphere and mesosphere. However, the spatial and seasonal distribution, and sources of generation of
the tropospheric gravity waves are not completely understood. The high-resolution (6 min in time and 250m in height domain)
wind data from the NOAA wind profiler network (NPN) for 2002-2005 were used to analyze the seasonal and height structure of
gravity waves in midlatitudes. For altitudes from 1 km to 14-16 km, the distribution of high frequency (periods of 12
minutes-1 hour), medium-frequency (periods of 12 minutes-3 hours) and low-frequency (periods of 3 hours-12 hours)
oscillations of zonal, meridional and vertical components of the wind vector were calculated, and compared to variations of
profilers' mean wind, wind shear and reanalysis' rainfall data.
In the observed seasonal structure, the of maximums of low- and mid-tropospheric wave activity generally coincide with
maximums in reanalysis rainfall rate data, suggesting a convective source for high- and medium-frequency waves, while for low
frequency waves in mid- and upper troposphere the source seems to be associated with variations in the mean horizontal wind.
We speculate that the part of the variance of gravity wave activity between different locations that is not explained by
variations in the horizontal wind and precipitation fields can be attributed to the difference in the topography with
resulting orographic generation of gravity waves.
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3360 Remote sensing
DE: 3362 Stratosphere/troposphere interactions
DE: 3389 Tides and planetary waves
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005