The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite...

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The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By Patrick Santurette and Christo Georgiev Elsevier Academic Press
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Page 1: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

The PV-perspective Part I

Based partly on:

Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis

By Patrick Santurette and Christo Georgiev

Elsevier Academic Press

Page 2: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Storyline:

Why is PV weather relevant?

How can you read a PV chart

Link between WV imagery and PV

Certain “extreme” weather phenomena and their PV signature

Page 3: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

PV = (ζ θ + f )(−g∂θ

∂p)

vertical stabilityof the atmosphere

Ertel Potential Vorticity

vertical component of rel. vorticity potential temperature f planetary vorticity p pressureg gravitational constant

A measure of the rotation of an air mass

1

PV = *

Page 4: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

PV = (ζ θ + f )(−g∂θ

∂p)

A measure of the rotation of an air mass

+ PV anomalies are associated with a cyclonic wind field

Ertel potential vorticity

f planetary vorticity vertical component of rel. vorticity potential temperature p pressureg gravitational constant

19

Page 5: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

PV anomalies and the wind field

PV and wind - 12 Nov 1996 12UTC

2

0

PVU

6

Figures courtesy Linda Schlemmer

PVU

Alps Alps

Page 6: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

PV = (ζ θ + f )(−g∂θ

∂p)

vertical stabilityof the atmosphere

+ PV anomalies indicate areas ofreduced vertical Stability underneath

Ertel potential vorticity

f planetary vorticity vertical component of rel. vorticity potential temperature p pressureg gravitational constant

22

Page 7: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Stability / CAPE (convective available potential energy)

100 200 500 1000 J/kg

© NERC Satellite Receiving Station Dundee

figures courtesy Linda Schlemmer

PV stre

amer

23

Alps

Alps

Page 8: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Cross-section

Vertical cross-section

shading: PVcontours: potential temperature

hPa

100

200

300

400

500

600

700

-40 -30 -20 -10 0 10 lon

Static stability

> 0 stable

< 0 unstable

colder

less stable

stable

∂∂z

∂∂z

CF

Page 9: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Funatsu and Waugh 2008

Santurette and Georgiev2005

2D

Jet

EW

3D

Page 10: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

0 0.25 1 2 4 6 8 10 PVU

stratosphericair (high PV)

tropospheric air(low PV)

Pole

Alps

tropopause

MotivationA first look at instantaneous PV2

wind > 25m/s

Page 11: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Winter Summer

X X

-height of isentropes varies with season-latitude of intersection of dyn. TP with isentropes varies with season-daily plots might differ substantially from these zonal and seasonal mean plots

320K good in winter, 335K good in summer for mid-latitudes

Page 12: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

310K

Nov. 1996

Page 13: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

320K

Nov. 1996

Page 14: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

330K

Nov. 1996

! Some features are cut-off on one level and connected on an other

Page 15: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

340K

Nov. 1996

Page 16: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

350K

Nov. 1996

Page 17: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Winter Summer-theta on PV2 mapse.g. from the University of Reading

! Problems in the tropics, not always uniquely defined -> tropopause folds

Page 18: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Theta on PV2

K

Page 19: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Tropopause height

30000 45000 60000 75000 90000 10500 12000 135000 [m2/s2]

Page 20: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

[103 m]5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6

Geopotential height [m]

Comparison to geopotential height3

0 0.25 1 2 4 6 8 10

Potential vorticity [PVU]

[PVU]wind vectors vel > 25 m/s

Page 21: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Cross-section

Vertical cross-section

shading: PVcontours: potential temperature

hPa

100

200

300

400

500

600

700

-40 -30 -20 -10 0 10 lon

Static stability

> 0 stable

< 0 unstable

colder

less stable

stable

∂∂z

∂∂z

CF

Page 22: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

0 0.25 1 2 4 6 8 10

Potential vorticity

wind vectors vel > 25 m/s

Thetae on 850 hPa

LL L L

2 10 18 26 34 42 50 58 66 [K]

SLP < 1005hPa, 5hPa contours

Link to surface fields4

cold and dry air

Page 23: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

There is a clear relation between PV and water vapour imagery:

•A low tropopause can be identified in the WV imagery as a dark zone.

•As a first approximation, the tropopause can be regarded as a layer with high relative humidity, whereas the stratosphere is very dry, with low values of relative humidity.

•The measured radiation temperature will increase if the tropopause lowers. This is because the radiation, which is measured by the satellite, comes as a first approximation from the top of the moist troposphere.

•High radiation temperatures will result in dark areas in the WV imagery.

http://www.zamg.ac.at/docu/Manual/SatManu/main.htm

Page 24: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

tropopause

stratosphere (dry)

stratosphere (dry)

troposphere (moist)

troposphere (moist)

tropopause

WV signal

WV signal

cross-section through atrough

cross-section through the jet

http://www.zamg.ac.at/docu/Manual/SatManu/main.htm

Page 25: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Geopotential

Tropopauseheight

Page 26: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Concept

TP heightblue

Page 27: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.
Page 28: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Upper-level PV signature of several (extreme) weatherevents

Page 29: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Schlans November 2002 Gondo October 2000

Heavy precipitation along the Alpine south-side

Page 30: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Example case: Schlans November 2002

IR

850hPa vel + rain

320K PV

16.11.2002

figures courtesyEvelyn Zenklusen

Page 31: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

PV on 320KSLP

strong convective activityalong eastern flank

formation of low pressure systems

L

Floods in Algeria November 2001

cyclonic windfield which can reach the surface

wind on 850hPa

precipitation

IR meteosat

Page 32: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Kona lows

occurrence:from October until March in the subtropical central- and north Pacific

weather impact: strong rain fall, hail showers, land slides, flooding, storm winds, high surf, waterspouts and severe thunderstorms

Hawaii as a kona low reaches maui (John Fischer, 2002)

Slide courtesy Michael Graf

Page 33: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

„kona low“ November 1996

figures courtesy Michael Graf

PV on 330K, SLP

PV on 330K, SLP GOES-9 IR

HI

HI

Page 34: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

„kona low“ November 1996

PV on 330K, SLP GOES-9 IR

L

L

L

L

Page 35: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

blocks identified as persistent upper-level low PV anomalies (Schwierz et al. 2004)

Blocking from a PV persepctive

TP

Z

block

Page 36: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

January 2007 Atlantic Blocking

PVU

Page 37: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

PV anomalies and polar lows

290 K 290 K 290 K

05 Feb 2001 18 UTC25 Dec 1995 06 UTC 18 Jan 1998 00 UTC

PV

on

290K

isen

trop

ic s

urfa

ce

Page 38: The PV-perspective Part I Based partly on: Weather analysis and forecasting: Applying Satellite Water Vapor Imagery and Potential Vorticity Analysis By.

Links - PV loops on the web:

University of Washington:http://www.atmos.washington.edu/~hakim/tropo/trop_theta.html

University of Reading:http://www.met.rdg.ac.uk/Data/CurrentWeather/index.html

DLR (analysis)http://www.pa.op.dlr.de/arctic/

At ETH see course website

Satellite pictures and PV manual:http://www.zamg.ac.at/docu/Manual/SatManu/main.htm