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DOW Observations in IHOP and Analyses of CI
Yvette Richardson, Nettie Arnott
and Joshua Wurman
Outline
• Data Navigation Issues
• Summary of DOW cases
• Examination of two CI cases
• Quicklook at boundary layer cases
Navigation of Data
• Multiple Doppler analyses require synthesis of radial velocity wind fields
• Winds must be put on a common grid before synthesis– Requires accurate ‘navigation’ of the data– Need location of trucks (gps) and pointing
angle of the radar
Radar1 Radar2
Data
Determination of Pointing Angle
• Possible Methods – Use clutter targets
• Have to have targets to use
– Use reflectivity features and align• Tedious
• Accuracy is questionable
– Use the sun as a target – solar calibration• Do very slow scans across the sun
• Sub-beam accuracy
• Usually Possible – not good at noon
Solar Calibrations
Find the azimuth of max average power and compare to known sun location for your time and location
Available for all IHOP cases where a solar calibration scan was performed
• http://met.psu.edu/~narnott/SolarCals.html
• Agree very well with other techniques
DOW Missions
• All CI
• 3 BLH (20 and 29 May, 7 June)– Looking for collaborators
• 4 QPF (16 May, 23 May, 26 May, 4 June)– Collaborating with Anagnostou
• Three ABLE – Collaborating with Weckwerth
CI Cases
• 10 June
• 19 June
• 24 May (collaborating with Ziegler and others)
10 June
Quasi-stationary cold front
Great coordinationCells initiated all along
the front – just outside the IOR but within overdetermined dual-Doppler coverage
17.6
18
15
15
DOW2 20:55 UTC – 1.5 degree tilt
N
DOW2 20:55 UTC – 4.4 degree tilt
N
DOW2 20:56 UTC – 8.4 degree tilt
N
DOW2 20:56 UTC – 12.8 degree tilt
N
DOW3 20:57 UTC – 1.4 degree tilt
N
DOW3 20:57 UTC – 4.3 degree tilt
N
DOW3 20:57 UTC – 8.3 degree tilt
N
DOW3 20:58 UTC – 12.7 degree tilt
N
XPOL 20:57 UTC – 1.3 degree tilt
N
XPOL 20:58 UTC – 13.4 degree tilt
N
XPOL 21:06 UTC – 1.3 degree tilt
N
XPOL 21:06 UTC – 7.3 degree tilt
N
Scientific Questions
• What controls the difference in convective modes on either side of the boundary?
• Why did the growing cumulus field suddenly cease its growth? Is this related to changes in the boundary?
• Role of the thin line which intersected the boundary. – unable to result in initiation – why?
• Role of the circulations along the boundary play? Related to preferred locations for clouds even though not initiation?
• What caused the initiation outside the box?
19 June 2002
• Boundary near Colby, KS
• Very interesting vortices along boundary
• Very well coordinated• CI occurred – possibly
within dual-Doppler coverage
• Satellite loop
19:08 20:08 21:08
22:08 23:08
14
15
18
IOR
DOW3 19:30
N
Dual-Doppler AnalysisAt 19:30At z=0
Deployment #2 – 21:20+ UTC
2514
13.5
2nd Deployment Sequence• DOW2 begins moving around
21:00 And gets in position at 21:20
• XPOL stays in position to provide DD with DOW3 over original triangle until 21:20 – breaks down on way to next deployment
• DOW3 switches to new sector at 21:20
• Initiation occurs at approximately 21:22
• Loop
21:33
DOW3 21:23
N
DOW2 21:22 – 8.4 degree tilt N
DOW2 21:25 – 14.3 degree tilt N
DOW2 21:25 – 2.1 degree tiltN
DOW3 21:30 – 3.5 degree tiltN
Scientific Questions
• What role did the misocyclones play in the initiation of convection?
• Was water vapor enhanced near the misocyclones? Collaboration with lidar?
• What determined the locations of the misocyclones (intersections?)? Did these deepen the moisture field?
5/29 BLH Mission
0.5 degree
1.0 degree
1.4 degree
2.1 degree
Future Work
• Finish dual-Doppler analyses
• Combine wind analyses with water vapor measurements (lidar)
• Continue QPF and BLE collaborations
• Many thanks to all collaborators
My Favorite IHOP Project
CompletedNew Year’s Eve, 2002