The dynamics associated with blocking events remain unclear and current operational predictions have low skill. The PI will study the dynamics of anticyclones that exist both at and above the surface over middle and high latitudes. Using reanalyses from the National Centers for Environmental Prediction (NCEP), the PI and his students will examine the relative importance of (1) upper tropospheric cold-air advection in the formation and intensification of anticyclones near the earth's surface; (2) deformation in the development of blocking, easterly flow around midtropospheric anticyclones; and (3) nonquasigeostrophic processes in the development of blocking and midtropospheric anticyclones. A climatology of the anticyclones will be compiled from NCEP reanalysis and cases chosen for detailed analysis. Diagnostics using the quasigeotrophic and nonquasigeostrophic height tendency equations will be applied to examine the importance of the suggested processes in developing and maintaining these anticyclones.
Results from this project have the potential to increase the understanding of the onset of blocking events and increase the forecast skill of them. The research will provide good educational opportunities for graduate students.
