Bart Geerts and Rick Damiani, University of Wyoming Joseph Zehnder, Arizona State University

4th COPS meeting, Hohenheim, 25/9/06

CuPIDO(Cumulus Photogrammetric, In-situ, and Doppler observations over Orography)

a survey

July-August 2006Catalina Mountains, Arizona

Bart Geerts and Rick Damiani, University of WyomingJoseph Zehnder, Arizona State University

Mike Leuthold and Robert Kursinski, University of ArizonaBill Brown, Tim Lim, Greg Poulos, and Steve Horst, NCAR

Camera animations of cloud development can be found here.For more recent animations, contact Joe Zehnder.

http://prism.asu.edu/clouds/animations.asp

[email protected]

http://prism.asu.edu/clouds/animations.asp

mailto:[email protected]


Rationale• Cumulus convection

– is the primary mechanism for the vertical transfer of heat, moisture and momentum;

– operates at multiple scales and may transition from shallow to mediocre to deep convection;

– is largely controlled by the environment (stability & shear profile), but also alters it (cold pool development, detrainment aloft);

– in NWP models, cumulus parameterization is poorly coupled with BL parameterization, especially in complex terrain.

• An isolated mountain

– serves as a natural laboratory for the study of cumulus initiation and evolution,

– due to “predictable” anabatic flow.


Scientific Objectives

• Describe the initiation of shallow to deep convection and transition

• Broadly speaking, CuPIDO addresses several fronts of atmospheric research:

• fundamental cumulus dynamics• cumulus-environment interaction• surface fluxes and orographic circulations• orographic forcing of cumulus


600-800 m

2786 m

20 km


size comparisonCOPS „Natural

convection laboratory“

area 270 x 150 km2

Supersite

CuPIDO area 40 x 40 km2

~1000 m from valley to mountain

~2000 m from valley to

mountain


facilities

University of Wyoming King Air & Cloud Radar

Arizona State University Digital Cameras(2 stereopairs)

University of Arizona:GPS water vapor

U of A and NCAR & NOAA FSL:WRF modelling

NCAR/EOL 10 ISFF/PAM stations

2 M-GAUS mobile radiosondes


Flight summary

Number of flight hours: 60

Number of flights sampling transition from cloud-free to Cu congestus: 8

Number of flights sampling transition to deep convection: 7

Number of flight loops around the mountain, in the convective BL: 50


Orographic forcing of boundary layer flow: mass and moisture

convergencePotential Temperature (°K) (aircraft track)

Mixing Ratio (g/kg) (wind barbs)

5 15

300 m AGL

800 m above valley,(643 m below top)

2214 m above valley,(270 m above top)

25 J

uly

2006

, 16:

00-1

6:47

UT

C (

2:44

-3:3

1 hr

s af

ter

sunr

ise)


Orographic forcing of boundary layer flow: mass and moisture

convergenceEquivalent Potential

Temperature (°K)

Mixing Ratio (g/kg)5 15

N↑

25 J

uly

2006

, 16:

00-1

6:47

UT

C (

2:44

-3:3

1 hr

s af

ter

sunr

ise)


cumulus development

Successive shallow Cu developed, starting at 1735 UTC, and rapidly evolved into congestus two hours later

25 July 2006 1740 UTC 25 July 2006 1935 UTC


WCR antenna configurations

Vertical PlaneDual-Doppler

Horizontal Plane Dual-Doppler

Vertical Plane Profiling


18 July 2006 16:44:30 – 16:46:30 UTC 18 July 2006 16:48:15 – 16:50:15 UTC

Shallow Cutransects

droplet conctemperature

vertical velocity

density temp

vertical velocityrel. hum.

WCR vertical velocity

WCR reflectivity

wind wind


shallow Cuvertical plane dual-Doppler

a section of a turret tilting against the

main wind direction, located 1 km north

of Mt. Lemmon.18 July 2006 18:03:30 – 18:04:20 UTC


same cloud, 6 min laterhorizontal-plane dual-Doppler


HPDD

• Vertical vorticity and entrainment patterns

• Divergence (thermal top?)7200m MSL, 18 July 2006 18:09:20 – 18:09:50 UTC

Bart Geerts and Rick Damiani, University of Wyoming Joseph Zehnder, Arizona State University

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