Note the gradation in definitions of potential vorticity

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Note the gradation in definitions of potential
vorticity Full (Ertel) PV PV ?
???????????? Isentropic PV IPV ?
(???f?????z Quasi-geostrophic PV q ? ????z
and for each definition there is a
conservation principle, i.e., D?PV?/Dt
0 for inviscid adiabatic flow
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The conservation of IPV is visualized
as compensation between ? increase and ?z
decrease
Isentropic surfaces
???f small ?z large
???f large ?z small
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There is also conservation of potential
temperature, i.e., D?/ Dt 0 for inviscid
adiabatic flow, (including bottom boundary)
Hence PV is conserved on isentropic
surfaces, and ? is conserved on a PV iso-surface.
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An examination of large-scale flow from the PV
perspective I The PV climatology - what are
typical PV values? - what is a PV anomaly? II
Examples of the instantaneous fields - PV and
jet streams III Illustrations of PV - PV
structures and links to geopotential height field
- PV streamers and cut-offs - PV
inversion - PV non-conservation IV Case
studies of extratropical cyclones -
attribution application of PV inversion - PV
tower analysis
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winter climatology of PV and ?
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winter climatology of PV and ?
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summer climatology of PV and ?
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Climatological PV patterns
High PV
Low PV
Low PV
Overworld entirely within the stratosphere High
PV in extra-tropics Middleworld High low
PV in extra-tropics Underworld entirely
within the troposphere Low PV in extra-tropics
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Climatological PV patterns
High PV
High PV
Low PV
Low PV
Low PV
Overworld entirely within the stratosphere High
PV in extra-tropics Middleworld High low
PV in extra-tropics Underworld entirely
within the troposphere Low PV in extra-tropics
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Relationship of Jet Stream to PV
Time-mean distribution
High PV
JET
Low PV
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Instantaneous (and idealized) Jet Stream Complex
THE PV STAIRCASE
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Instantaneous Jet-stream large
lateral gradient of PV
Depiction of wind (jet) strength PV gradient
on 320K
in a cross-section
Jet
Wind isotachs
Shading PV gradient
PV contours
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Evolution of large-scale PV distribution
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Accompanying evolution of 500 hPa field
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Break-up of a stratospheric PV-streamer
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Evolving upper-level PV distribution on an
isentropic surface
Water vapor satellite image
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positive upper-level PV anomaly
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negative upper-level PV anomaly
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Qualitative illustration of PV inversion
PV pattern on a tropopause intersecting
isentropic surface, and accompanying wind
field red green pos. PV
anomalies shades of blue neg. PV
anomalies Sea-level pressure pattern and
low-level moisture field Note linkage of PV
flow field!
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negative surface ?-anomaly
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positive surface ?-anomaly
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upper-level PV anomaly
low-level PV anomaly
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The non-conservation of PV latent
heating friction (cloud
condensation, radiation, ) Approximation on
synoptic scale outside the PBL
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Depiction of evolution of PV distbn. during
cyclogenesis (- LOTHAR !!)
Incipient system
Mature system
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PV 315K
PV, v 850hPa
? 850hPa, SLP
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PV 315K
PV, v 850hPa
? 850hPa, SLP
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PV 315K
PV, v 850hPa
? 850hPa, SLP
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US east coast cyclogenesis 4/5 Februar
1988 Davis and Emanuel 1991
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Z on 500hPa
Z on 1000hPa
12 UTC 4 Feb
12 UTC 5 Feb
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low PV (lt 0.25pvu)
PV tower (PV gt 0.75pvu)
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surface ?
surface ? anomaly
12 UTC 4 Feb
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surface ?
surface ? anomaly
00 UTC 5 Feb
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surface ?
surface ? anomaly
12 UTC 5 Feb
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PV inversion relative importance of various PV
anomalies to 850-hPa vorticity field
00 UTC 5 February contributions from upper-level
PV low-level PV boundary ?
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PV inversion relative importance of various PV
anomalies to 850-hPa vorticity field
12 UTC 5 February contributions from upper-level
PV low-level PV boundary PT
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Low-level PV and diabatic PV-generation
12 UTC 4 Feb
12 UTC 5 Feb
PV on 850hPa (dashed) diabatic PV production rate
on 850hPa (solid)
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Atlantic frontal wave development 23/24
November 1992 Rossa et al. 2000
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06 UTC 22 Nov
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18 UTC 22 Nov
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06 UTC 23 Nov
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18 UTC 23 Nov
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IR satellite images
06 UTC 22 Nov
19 UTC 23 Nov
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The PV tower at 18 UTC 23 Nov (PV and RH)
S-N cross section
W-E cross section
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The PV tower at 18 UTC 23 Nov (PV and backward
trajectories)
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Inversion of PV tower segments contributions to
SLP
400-300 hPa
700-600 hPa
900-800 hPa