MET 321 Atmospheric Thermo Test 1

Work of Expansion

Where a parcel of air rises in the atmosphere and its pressure decreases

Work of Expansion [Examples]

Orographic lifting, frontal lifting, low level convergence, buoyant rising of warm air, and mechanical mixing

First Law of Thermodynamics

heat added to the system (dq) → internal energy + kinetic energy → work

du = dq - dw  

Thermodynamic Special Process: Isothermal

Temperature is constant; dT = 0
dq = CpdT - αdp

Thermodynamic Special Process: Isobaric

Pressure is constant; dp = 0

dq = CpdT - αdp

Thermodynamic Special Process: Isochoric

Volume is constant; dα = 0

dq = CpdT - pdα

Thermodynamic Special Process: Adiabatic

Heat is constant; dq = 0

dq = CpdT - αdp

Enthalpy

Total heat content of a system

h = u + pα

Potential Temperature

The temperature an air parcel would have if it were expanded or compressed adiabatically from its existing pressure and temperature to a standard pressure

Potential Temperature (Equation)

Theta = T (p0/p1)^R/cp

Second Law of Thermodynamics

The maximum fraction of heat that is converted into useful work

Second Law Concepts 

Thermal energy will not spontaneously flow from colder to warmer objects

The entropy of the universe is constantly increasing

Entropy

The ratio change in heat to the absolute temperature

ds = dq/T

Reversible and Irreversible Processes

Reversible change: (ds) = 0
Irreversible change: (ds) > 0

Isentropic Process

Free Energy Functions: Helmholtz

Free Energy Functions: Gibbs