Abstract : 1A.3
Mountain waves entering the stratosphere
Jensen Woods, Bryan Woods, Jorgen Jensen, William Cooper, James Doyle, Qingfang Jiang, Vanda Grubisic
Using the new NSF/NCAR Gulfstream V and the U. of Wyoming King Air research aircraft, six cases of Sierra Nevada mountain waves entering the stratosphere were surveyed with126 cross-mountain legs. The goals were to identify the influence of the tropopause, and to distinguish. background wind layering from wave perturbations. Three of the diagnostic methods utilized the new GPS altitude measurements.
In the stratosphere, wind layering was found, heaving up and down in the waves, with magnitudes up to 10m/s and vertical scales of 100 to 200m. The ozone and water vapor layering correlated with Bernoulli function and cross-flow speed, suggesting that the stratosphere has a chemical-dynamical layered texture arising from horizontal interleaving. Methods for distinguishing layers from waves are discussed. GPS altitude-corrected static pressure was used to compute the vertical energy flux, confirming the Eliassen-Palm relation between momentum and energy flux (EF=-U*MF). No jump in MF or EF was detected at the tropopause.
The EQuipartition Ratio (EQR=PE/KE) jumps across the tropopause, indicating partial wave reflection. In one case (April 16, 2006) systematically reversed momentum and energy fluxes were found in the stratosphere above 12km. An explanation is proposed related to secondary generation near the critical level at 21km.