Physics
Scientific paper
Dec 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998jgr...10331523m&link_type=abstract
Journal of Geophysical Research, Volume 103, Issue D24, p. 31523-31540
Physics
75
Meteorology And Atmospheric Dynamics: Middle Atmosphere Dynamics
Scientific paper
Climate simulations of the middle atmosphere circulation with general circulation models are now starting to include parameterizations of the momentum flux deposition due to unresolved gravity wave spectra. A current uncertainty in the application of such parameterizations is the specification of the imposed gravity wave spectrum. The aim of this work is to quantify the effect of varying within a realistic range the source spectrum of a gravity wave parameterization in a general circulation model. Results from two simulations with the gravity wave spectrum launched at two different heights, the surface and the 110-hPa pressure level, respectively, are compared. Noteworthy differences found in the simulated middle atmosphere response include the following (1) The average temperature in the southern winter upper stratosphere is about 40 K warmer in the experiment with the surface as the launching height, virtually eliminating the typical cold polar bias that affects many general circulation models. (2) Stronger easterlies in the subtropical summer mesosphere, again in the experiment with the surface as the launching height. Diagnostics of the parameterized gravity waves indicate that in the experiment with the surface as the launching height, the net zonal momentum flux transported by the gravity waves is negative just above the troposphere at middle latitudes. This negative net momentum flux facilitates the deceleration of the mesospheric winter westerlies. The meridional circulation induced by such deceleration is thereafter responsible for the substantial polar winter warming. In contrast, in summer the negative net momentum flux limits the upper mesospheric deceleration of the easterlies. In the experiment with launching height at 110-hPa, the gravity wave net momentum flux is instead zero by construction at the launching height.
Manzini Elisa
McFarlane N. A.
No associations
LandOfFree
The effect of varying the source spectrum of a gravity wave parameterization in a middle atmosphere general circulation model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The effect of varying the source spectrum of a gravity wave parameterization in a middle atmosphere general circulation model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The effect of varying the source spectrum of a gravity wave parameterization in a middle atmosphere general circulation model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1294364