1. Impact of Time Integration Scheme on Supercell Development
ATMS-597R
Alexandra Jones, Samantha Chiu, David Plummer
8 October 2010

2. Control vs. Test Simulation
Both used Thompson microphysics
Control run used 3rd-order Runge-Kutta differentiation in time
Test run used 2nd-order Runge-Kutta scheme
Larger amplification/phase error with lower-order scheme (Durran 69)

3. Mesocyclone track (Control run)

4. Mesocyclone track (Test run)

8. Low-level reflectivity field at t=60 minutes, when difference in vorticity advective term was most significant

11. Conclusions
Lower-order time differentiation resulted in noisier simulation, but general development was similar
In both cases, advection and stretching/divergent terms contributed most to relative vorticity tendency
Differences in tendency terms between runs generally small
Advection term larger for test run at 60 minutes, but difficult to identify persistent differences visually

12. Reference
Durran, D. R., 1999: Numerical Methods for Wave Equations in Geophysical Fluid Dynamics. Springer, 465 pp.