2002: A climatology of stratospheric polar vortices and anticyclones

• Main Authors: V. Lynn Harvey, R. Bradley Pierce, Matthew H. Hitchman
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: discussed. INDEX TERMS; 3309 Meteorology and Atmospheric Dynamics; Climatology (1620; 3319 Meteorology and Atmospheric Dynamics; General circulation; 3334 Meteorology and Atmospheric Dynamics; Middle atmosphere dynamics (0341; 0342; KEYWORDS; polar vortex; stratospheric anticyclones; Arctic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.617.9436; http://www.aos.wisc.edu/~mag/polarvortices.pdf

create a global climatology of stratospheric polar vortices and anticyclones. New methodologies are developed that identify vortices in terms of evolving three-dimensional (3-D) air masses. A case study illustrates the performance of the identification schemes during February and March of 1999 when a merger of anticyclones led to a stratospheric warming that split the Arctic polar vortex. The 3-D structure and temporal evolution of the Arctic vortex and identified anticyclones demonstrates the algorithm’s ability to capture complicated phenomena. The mean geographical distribution of polar vortex and anticyclone frequency is shown for each season. The frequency distributions illustrate the climatological location and persistence of polar vortices and anticyclones. A counterpart to the Aleutian High is documented in the Southern Hemisphere: the ‘‘Australian High.’ ’ The temporal evolution of the area occupied by polar vortices and anticyclones in each hemisphere is shown as a function of potential temperature. Large polar vortex area leads to an increase in anticyclone area, which in turn results in a decrease in the size of the polar vortex. During Northern winter and Southern spring, 9 years of daily anticyclone movement are shown on the 1200 K (36 km, 4 hPa) isentropic