Numerical modeling of lower stratospheric Doppler ducted gravity waves over Jicamarca, Peru

Abstract

Persistent jet structures along zonal and meridional fields, believed to be caused by stationary gravity waves, were detected in February 1999 in MST wind measurements of the troposphere and lower stratosphere over Jicamarca, Peru. Over a seven day span, two days of observations showed signatures of a Doppler ducted gravity wave in the upper troposphere/lower stratosphere. Herein we present the observations, their characteristics, and results of numerical simulations used to mimic these observed features. Though a fair replication of the observed ducted structure in the numerical model is found, the observed period of ~90 min is nonetheless longer than anticipated and raises concern as to the specific physical nature of the observed structures. However, given the high quality of the observations, we demonstrate that continued analysis of this data set and concurrent modeling will allow for a better understanding of Doppler ducts at high spatial and temporal resolution which can ultimately be applied to studies of mesospheric ducts and bores.