Absolute Instability

• consider the diagram to the right, notice that at 2 km (or anywhere for that matter):

• T_sp > T_up > T_e

• Hence, an unsaturated or saturated parcel will always be warmer than the environment and will continue to ascend

• This is an example of absolute instability

• The condition for absolute instability is:

  • G_e>G_d>G_m

• G_e is the environmental lapse rate (30°C km^-1)
• G_d is the dry adiabatic lapse rate (10°C km^-1)
• G_m is the moist adiabatic lapse rate (6°C km^-1)