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The Conveyor Belt Conceptual Model. The Conveyor Belt Conceptual Model. The Conveyor Belt Conceptual Model - Introduction. The Warm Conveyor Belt (notes pages information). That’s all the “clicking” for this page. 5. 9. 2. 4. 6. 3. 8. 7. 1.
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The Warm Conveyor Belt (notes pages information) That’s all the “clicking” for this page. 5 9 2 4 6 3 8 7 1
The Poleward view along the warm conveyor belt That’s all the “clicking” for this page. 1 2
The View perpendicular to the warm conveyor belt That’s all the “clicking” for this page. 2 1 3
Cold Conveyor Belt - CCB That’s all the “clicking” for this page. 3 1 2 4
Dry Conveyor Belt - DCB That’s all the “clicking” for this page. 1 3 2 4 5
WCB Cold Frontal Cross-section along Poleward Branch of the Dry Conveyor Belt (DCB) B Common area for deep instability A DCB WCB oriented for less frontal lift Mixing Zone CCB Surface Cold Front B A Cold air in Cold Conveyor Belt (CCB) deep and moist Warm Conveyor Belt (WCB) is deep, warm and moist CCB backs with height consistent with cold advection WCB just ahead of cold front also typically backs with height Frontal slope is steeper than the typical 1:50 Backing winds above the frontal zone indicative of anabatic cold front
Preliminary Dry Conveyor Belt - PDCB That’s all the “clicking” for this page. 3 5 2 1 4 6
C C C C C C WCB DCB CCB PDCB Vertical Deformation Zone Distribution and the CBMSummary That’s all the “clicking” for this page. 1 2 4 3 5
Anabatic and Katabatic Fronts Related to the CBCM • Consider the winds in the warm air above the frontal surface and apply the principle of continuity • If the winds back either above a warm or cold frontal surface, convergence results above the front and the air must rise • If the winds veer either above a warm or cold frontal surface, divergence results above the front and the air must sink • Anabatic and Katabatic fronts can be located using the Deformation Zone CM applied to the Conveyor Belt CM.
Active or Anabatic Warm Front That’s all the “clicking” for this page.
Inactive or Katabatic Warm Front That’s all the “clicking” for this page.
Active or Anabatic Cold front That’s all the “clicking” for this page.
Inactive or Katabatic Cold Front That’s all the “clicking” for this page.
Another Look at: • Conveyor Belts, • Vertical Wind Shear, • Anabatic/Katabatic Fronts, • Vertical Deformation Zone Stacking • Stability Generalizations
C C C WCB CCB DCB PDCB Vertical Deformation Zone Distribution and the CBMSimplified Summary The WCB overrides the warm front The CCB undercuts the warm front The frontal surface overlies the mixing layer Wind shear in the CCB is variable • Looking along the flow: • In WCB to the right of the Col expect veering winds with height – Katabatic warm front • In WCB approach to the right of the Col expect maximum divergence – the eagle pattern with ascent and increasing pcpn • In WCB to the left of the Col expect backing winds with height – Anabatic warm front
The Precipitation Area Conceptual Model and the CBCM • The virga trick is a subset of the precipitation area conceptual model • The precipitation area (reaching the ground) increases with: • Increasing relative humidity of the CCB • CCB relative humidity is related to: • CCB characteristics given the source region • CCB moistening by precipitation (and/or surface characteristics) • Increasing vertical dynamics and isentropic lift along the frontal surface. • Vertical dynamics is related to: • Warm frontal slope • WCB component perpendicular to the frontal surface • Katabatic versus anabatic frontal diagnosis
B Warm Frontal Cross-section along Leading Branch of the Warm Conveyor Belt (WCB) Common location for virga A WCB WCB oriented for maximum frontal lift Virga Precipitation Increasing CCB Moistening WCB oriented for less frontal lift Lower Hydrometeor Density Mixing Zone Surface Warm Front CCB B A Cold air in Cold Conveyor Belt (CCB) deep and dry Moist portion of Warm Conveyor Belt (WCB) is high and veered from frontal perpendicular – katabatic tendency Dry lower levels of WCB originate from ahead of the system and backed from frontal perpendicular WCB typically veers with height (it is after all, a warm front) Frontal slope is more shallow than the typical 1:200 Precipitation extends equidistant into the unmodified CCB Precipitation extends further into the moistened, modified CCB
B Warm Frontal Cross-section along Central Branch of the Warm Conveyor Belt (WCB) A Virga likely only on leading edge of WCB WCB WCB oriented for maximum frontal lift Virga Precipitation Increasing CCB Moistening Lower Hydrometeor Density Mixing Zone Precipitation At Surface Surface Warm Front CCB B A Cold air in Cold Conveyor Belt (CCB) more shallow and moist Moist portion of Warm Conveyor Belt (WCB) is thicker, higher and perpendicularto front Lower levels of WCB have the same origin as the upper level of the WCB - frontal perpendicular WCB shows little directional shift with height. A greater WCB depth is frontal perpendicular Frontal slope is near the typical 1:200 Precipitation extends further into the moistened, modified CCB. Horizontal rain area begins to expand as CCB moistens.
B Warm Frontal Cross-section along Trailing Branch of the Warm Conveyor Belt (WCB) A Virga unlikely except along the leading edge of the WCB WCB WCB oriented for maximum frontal lift Virga Precipitation Increasing CCB Moistening Lower Hydrometeor Density Mixing Zone Precipitation At Surface Surface Warm Front CCB B A Cold air in Cold Conveyor Belt (CCB) even more shallow and more moist Moist portion of Warm Conveyor Belt (WCB) is thicker, higher and backed from frontal perpendicular – anabatic tendency Lower levels of WCB have the same origin as the upper level of the WCB WCB probably backs slightly with height in spite of the warm air advection. A greater WCB depth is frontal perpendicular Frontal slope likely steeper than the typical 1:200 Precipitation extends further into the moistened, modified CCB. Horizontal rain area expands rapidly as CCB moistened.
The Precipitation Phase CM and the CBCM • The precipitation area (reaching the ground) increases with: • Increasing relative humidity of the CCB • CCB relative humidity is related to: • CCB characteristics given the source region • CCB moistening by precipitation (and/or surface characteristics) • Increasing vertical dynamics and isentropic lift along the frontal surface. • Vertical dynamics is related to: • Warm frontal slope • WCB component perpendicular to the frontal surface • Katabatic versus anabatic frontal diagnosis • Add in a temperature parameter to deduce this.