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Frictional EPV changes in the November 2005 TPV. Steven Cavallo. Hakim group meeting November 9, 2006. Obligatory big picture slide. Examining the mechanisms that cause tropopause polar vortices (TPVs) to strengthen and decay
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Frictional EPV changes in the November 2005 TPV Steven Cavallo Hakim group meeting November 9, 2006 Hakim group meeting
Obligatory big picture slide • Examining the mechanisms that cause tropopause polar vortices (TPVs) to strengthen and decay • Ertel’s theorem says only diabatic and frictional processes can do so • Analysis of diabatic term shows that cloud-top radiational cooling can significantly contribute to cyclone strengthening but weakening processes still unclear and will be examined in the future • Quantitative results rely on PV budget closing; Overall residual high, diabatic portion small; Friction? Better resolution? Hakim group meeting
Outline • How does friction get into Ertel PV (EPV)? • WRF and the momentum equations • Vertical frictional profiles, residuals, and time-height plots • Future strategies Hakim group meeting
What next? • Try even order advection and differencing schemes. This eliminates model diffusion. In preliminary runs, model crashes often and easily. • Increase horizontal resolution • Nesting • Residual calculation on nested domain. Tricky Task! Hakim group meeting
WRF nested small time step output procedure Hakim group meeting
WRF nested small time step output procedure Regular nested run Small time step output and on nest and residual calculation Hakim group meeting