Frontal Characteristics

• With help of:– Equivalent Thickness and – Thermal Front Parameter (TFP)

Thermal Front Parameters TFP

Zones of high thickness gradient

Use of Vertical Cross Sections

• Important view in third dimension• Reveals additional information• Parameters most indicative:

– Isentrops (constant potential temp, dry [ =T(1000/p) R/cp ], and wet)

– Humidity and humidity advection– Divergence and vertical motion – Temperature advection– Vorticity and vorticity advection – Potential vorticity– Isotachs

frontunstable

front

CA

CA

WA

frontal cloud

front

Frontal cloud

conv

convdiv

div

front

frontal cloud

Analyses on Isentropic Surfaces

Relative Streams and

Conveyor Belts

Relative Streams Approach

• Streams are on isentropic surfaces:

• Surface of constant potential/equivalent potential temperature = T (1000/p) exp (R/cp) e = exp (r qm/ cp T)

• Streams are relativ to a system velocity– Determination of system velocity from AMVs

frontal cloud pre-frontalCb

selectionof indicativeisentrops:

front