Splitting SupercellIdealized Simulation
Diff_6th_opt
Presented By: Jeff Curtis, Jason Keeler, and Cody Fritz
S. Nesbitt – ATMS 597
Objective• To track a simulated mesocyclone and assess the
contribution of the terms in the vorticity tendency equation.
• To change the 6th-order numerical diffusion option to 1 and compare to control simulation.
Outline• Brief background on numerical diffusion
option.• Track of vorticity maximum.• Comparison of vorticity maximum at
1.5km (video available)• Comparison of average vorticity between
0-3km..• Comparison of reflectivity (dBZ) (video
available).• Difference plots for Stretching, tilting, and
solenoid terms.
Background• The 6th-order horizontal diffusion acts as a short-wave
numerical noise filter (Chapter 5 – WRF Users Guide).
• 3 options are available:• 0 = no 6th-order numerical diffusion• 1 = 6th-order numerical diffusion• 2 = 6th-order numerical diffusion but with the
prohibiting of up-gradient diffusion
Maximum Vorticity Location
Vorticity – 1.5 kmControl – 00:05 Diff_6th – 00:05
Control – 01:00 Diff_6th – 01:00
Vorticity – 1.5 km
Control – 02:00 Diff_6th – 02:00
Vorticity – 1.5 km
Control – 03:00 Diff_6th – 03:00
Vorticity – 1.5 km
Vorticity – Averaged 0-3kmControl – 00:05 Diff_6th – 00:05
Control – 01:00 Diff_6th – 01:00
Vorticity – Averaged 0-3km
Control – 02:00 Diff_6th – 02:00
Vorticity – Averaged 0-3km
Control – 03:00 Diff_6th – 03:00
Vorticity – Averaged 0-3km
dBZControl – 00:15 Diff_6th – 00:15
dBZControl – 01:00 Diff_6th – 01:00
dBZControl – 02:00 Diff_6th – 02:00
dBZControl – 03:00 Diff_6th – 03:00
Stretching Term
00:05
Difference between control and diff_6th
option
Stretching Term
01:00
Difference between control and diff_6th
option
Stretching Term
02:00
Difference between control and diff_6th
option
Stretching Term
03:00
Difference between control and diff_6th
option
Tilting Term
00:05
Difference between control and diff_6th
option
Tilting Term
01:00
Difference between control and diff_6th
option
Tilting Term
02:00
Difference between control and diff_6th
option
Tilting Term
03:00
Difference between control and diff_6th
option
Solenoid Term
00:05
Difference between control and diff_6th
option
Solenoid Term
01:00
Difference between control and diff_6th
option
Solenoid Term
02:00
Difference between control and diff_6th
option
Solenoid Term
03:00
Difference between control and diff_6th
option