Numerical Simulation of Gravity Wave Propagation, Instability Dynamics, and Spectral Evolution in the Mesosphere and Lower Thermosphere (MLT)

Investigator(s):

David Fritts (PI) ; Thomas Lund (Co-PI)

Sponsor:

NorthWest Research Associates, Incorporated, WA 98007 4256449660

Start Date/Expiration Date

2003-07-01 to 2006-06-30 (amended 2005-04-04)

Awarded Amount to Date:

$379,464

Abstract: The investigators will conduct a comprehensive modeling effort aimed at understanding gravity wave propagation, spectral energy transfers, mean-flow interactions, and wave and turbulent transports in the mesosphere and lower thermosphere (MLT). The approach involves two modeling methodologies: a highly-parallel incompressible direct simulation code and a newly-tested spectral-element code. Specific topics to be addressed include (1) the role of instabilities in limiting gravity wave amplitudes and fluxes, (2) the competition between wave-wave interactions and local instability processes in controlling wave amplitudes, (3) the role of wave superposition in controlling interaction processes, (4) the mixing and turbulent transports of heat and momentum, and (5) the effects of gravity wave dynamics on the large-scale wave fields in the MLT. The results will help quantify important gravity wave dynamics that remain largely unknown and have significant implications for modeling gravity wave effects. These results will have application to climate change, tropospheric and space weather, solar forcing of the atmosphere, and tropospheric optical turbulence.

NSF Org:

ATM - Division of Atmospheric Sciences

Award Number:

0314060

Award Instrument:

Continuing grant

Program Manager:

Robert B. Kerr
ATM Division of Atmospheric Sciences
GEO Directorate for Geosciences

NSF Program(s):

AERONOMY

Field Application(s):

Space

Program Reference Code(s):

UNASSIGNED, 0000

Program Element Code(s):

1521