Particle density-
The mass per unit volume of the soil particles.It usually expressed in grams per cubic centimeter.
Particle mass-
The average energy is independent of particle mass.
Perturbation technique-
A mathematical technique to eliminate linear terms in an equation in order to retain the nonlinear (turbulence) terms.
Ptprt-
ARPS model variable. Perturbation potential temperature at a given time level (K).
Pprt-
ARPS model variable Perturbation pressure at a given time level (Pascal).
Ptbar-
ARPS model variable Pressure;BaseState.
