CSU RAMS/LPDM forecast
for the COBRA project

The above forecast is prepared using Lagrangian Particle Dispersion Model (LPDM) driven by CSU RAMS (Regional Atmospheric Modeling System). The RAMS forecast is initialized at 12z and run for 48 hours.

The air mass source area is presented in terms of influence functions [10^10 s/m^3] as a volume source contributing to a passive tracer concentration observed at the receptor during specific sampling period. The influence function is derived from particles released at the receptor and traced backward in time.

The calculations were performed under the following assumptions:

• receptor - a 10x10x0.5km box located at the WLEF tower at the height of 750 m
• 3 hour sampling periods covering the 2nd day of the RAMS forecast.
• source area - a layer from 0 to 2 km; active 24 hours before a given sampling period