Atmospheric Frame of Reference AFR and Earth Frame

Atmospheric Frame of Reference (AFR ) and Earth Frame of Reference (EFR)

Relating of Reference to = the Earthcirculation Frame of Reference A LOW isthe an Atmospheric Earth Frame of Reference Concept closed in the EFR Using the Occlusion Process as an Illustration Every circulation in the Atmospheric Frame of Reference is closed Vorticity to QS Low Evolution Motions in the Atmospheric Frame of Reference (AFR) Constant Rotation r r Decreasing Shear . S . . . S S Motions of the AFR Origin in the Earth Frame of Reference Decreasing Translation Vector Addition Of the 3 Vectors No Translation Of AFR within EFR Motions in the Earth Frame of Reference AFR=EFR r S r r S Incipient Closed Low in EFR

Vector Addition of the Atmospheric Frame of Reference Flows to Translation Vorticity to Cold Low Evolution Of the Atmospheric Frame in the Earth Frame of Reference Thus achieving the Motions in the Earth Frame of Reference This is the classic example of system occlusion. NO Low Vector Addition Of Atmospheric Rotation and Shear Plus the translation Of the Atmospheric Frame = Earth Frame motions Incipient Low Translating Low r X S r X X X X S Stationary Low X r S X Dry slot results from shear and grows with time and comma pattern age

Vector Addition of the Atmospheric Frame of Reference Flows to Translation Vorticity to Cold Low Evolution Of the Atmospheric Frame in the Earth Frame of Reference Thus achieving the Motions in the Earth Frame of Reference This is the classic example of system occlusion. NO Low Vector Addition Of Atmospheric Rotation and Shear Plus the translation Of the Atmospheric Frame = Earth Frame motions r X S Incipient Low r X S Translating Low r X Stationary Low X r S Equatorward Cyclonic Shear The Vorticity maximum drifts to the left and the rotational centre as shear diminishes The closed EFR low drifts to the right and the rotational centre as shear diminishes

Relating the Atmospheric Frame of Reference to the Earth Frame of Reference Using the Blocking High Process as an Illustration Vorticity to QS High Evolution Motions in the Atmospheric Frame of Reference Constant Rotation r r r Decreasing Shear S. S S Decreasing Translation . . r . Motions of the AFR Origin in the Earth Frame of Reference Motions in the Earth Frame of Reference – What Mets are familiar with. Vector Addition Of the 3 Vectors Sr S r r Incipient Closed High in EFR

Vector Addition of the Atmospheric of Reference Flows to Translation Vorticity to. Frame High Evolution Of the Atmospheric Frame in the Earth Frame of Reference Thus achieving the Motions in the Earth Frame of Reference This is the classic example of system occlusion. NO High Vector Addition Of Atmospheric Rotation and Shear Plus the translation Of the Atmospheric Frame = Earth Frame motions S N r Incipient High S N r Translating High Stationary High S N r Poleward Anticyclonic Shear The Vorticity minimum drifts to the right and the rotational centre as shear diminishes The closed EFR high drifts to the left and the rotational centre as shear diminishes

Forecast Implications l l l Circulations around vorticity minimum weak. NWP has difficulty in the placement and intensity of vorticity centers. ACYC circulations also tend to be rather dry. Cloud tracers for the circulation not always available. WV is the answer If you put the geography back on, the problems of getting good analyses of the wind and vorticity patterns over oceanic areas alleviated. Best NWP analyses for the older vorticity centers or in data rich areas and poorer analyses for younger vorticity centers or for areas where data is sparse. The correct placements of the vorticity minimum centers is very important to the placement of related dynamic features such as jet stream and deformation zones. All of these dynamic features must fit cohesively into the atmospheric puzzle. As a result the correct placement of a vorticity minimum might be the piece of the puzzle required to correctly identify and place other dynamic features.