The Role of Gravity Wave Drag Optimization in the Splitting of the Antarctic Vortex in the 2002 Sudden Stratospheric Warming

• Published in: Geophysical Research Letters
• Main Authors: Scheffler, Guillermo Federico, Pulido, Manuel Arturo, Rodas, Claudio José Francisco
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union
• Subjects: DATA ASSIMILATION; GRAVITY WAVES; STRATOSPHERIC CIRCULATION; SUDDEN STRATOSPHERIC WARMING; https://purl.org/becyt/ford/1.5; https://purl.org/becyt/ford/1; Antarctic; The Antarctic; Argentina; Nordeste; Antarc*
• Online Access: http://hdl.handle.net/11336/86646

The impact of gravity wave drag on the Antarctic sudden stratospheric warming (SSW) in 2002 is examined through a mechanistic middle atmosphere model combined with a variational data assimilation system. Significant differences in the SSW representation are found between a model integration that uses reference gravity wave parameters and one that uses parameters estimated using data assimilation. Upon identical wave forcings at 100 hPa, the vortex breakdown may arise as either a vortex splitting event or a displacement vortex event depending on gravity wave parameters. A local enhancement of Rossby waves is found in the integration with estimated parameters, leading to a split SSW. The changes in the vortex breakdown are associated with changes in the vortex geometry caused entirely by modifying the gravity wave parameters. Gravity wave drag proved to play an instrumental role in preconditioning the stratosphere near a resonant excitation point that triggers the split SSW. Fil: Scheffler, Guillermo Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Universidad Nacional del Nordeste; Argentina Fil: Pulido, Manuel Arturo. University of Reading; Reino Unido. Universidad Nacional del Nordeste; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; Argentina Fil: Rodas, Claudio José Francisco. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; Argentina