Accession Number : ADA330935

Title :   Research Aircraft Observations and the Numerical Simulation of a Breaking Gravity Wave Event over Greenland Observed during FASTEX,

Corporate Author : NAVAL RESEARCH LAB MONTEREY CA

Personal Author(s) : Doyle, James D. ; Shapiro, M. A. ; Gall, Robert ; Bartels, Diana

PDF Url : ADA330935

Report Date : 1997

Pagination or Media Count : 2

Abstract : Measurements from the NOAA G-4 research aircraft and high-resolution numerical simulations are used to study the evolution and dynamics of a large-amplitude gravity wave event over Greenland that took place on 29 January 1997 during the Fronts and Atlantic Storm-Track Experiment (FASTEX). Vertical cross section analyses of continuous flight-level and dropwindsonde data, with 50-km horizontal spacing, documented the presence of a large-amplitude breaking gravity wave extending from above the 180 hPa level to 500 hPa. The dropwindsonde data measured deep layers with isentropic overturning and an upshear tilt to the gravity wave. Flight-level data (^180 hPa or 12 km) indicate a horizontal shear of over 0.001/s across the breaking wave with 25 K potential temperature perturbations. The wind speed downstream of the breaking wave decreased by 30 m/s resulting in the reduction of the cross mountain flow to near zero with localized regions of flow reversal.

Descriptors :   *GRAVITY WAVES, COMPUTERIZED SIMULATION, HIGH RESOLUTION, VERTICAL ORIENTATION, CROSS SECTIONS, WIND VELOCITY, RESEARCH AIRCRAFT, GREENLAND.

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE