Weather and Climate Systems

How to make a TPV Dance

Nick Szapiro

School of Meteorology

20 April 2016, 3:00 PM

National Weather Center, Room 5600
120 David L. Boren Blvd.
University of Oklahoma
Norman, OK

Cyclonic tropopause polar vortices (TPVs) are common, coherent features with clear manifestations on the dynamic tropopause in polar regions.
There are possible mechanisms for TPVs to impact surface cyclones, sea ice, water vapor transport, and stratosphere-troposphere exchange in the Arctic and lower-latitude cyclogenesis and wave amplification. Modifying TPVs in controlled simulations can quantify the causal role of TPVs in these processes.
The two core questions of this seminar are: can we control the intensity, size, and track of TPVs? Can we use controlled TPVs to quantify the role of TPVs in associated processes?

WRF single column and global MPAS-A sensitivity experiments will explore strategies for controlling TPVs, including direct modifications to vertical vorticity, wind, temperature, water vapor, and cloud profiles. As the effectiveness of each strategy is intimately tied to the driving dynamics, the corresponding TPV response will be discussed in an Ertel's potential vorticity framework.

Example impact experiments will focus on Arctic surface cyclones in the summers of 2006, 2007, and 2012. These show that TPVs can have a crucial role in the formation and intensification of Arctic surface cyclones. Implications for extending sea ice predictions and future directions to apply these tools will be discussed.