Run and tune all 4 alternative models based on full bridge model for September Plan Team runs

[zandjyo]

• [x] Model 19_12 alt
• [x] Model 19_12A alt
• [x] Model 21_1 alt
• [x] Model 21_2 alt

Note 6/10/2022: Issues tuning variance parameters for selectivity in Model 19_12A alt using Grant's method, stopped to work on ESSAS presentation.

https://github.com/afsc-assessments/EBS_PCOD/tree/main/2022_ASSESSMENT/SEPTEMBER_MODELS/STEVE_MODELS