dow observations in ihop and analyses of ci yvette richardson, nettie arnott and joshua wurman
TRANSCRIPT
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