1. Diagnostic Wind Model Initialization
Using the Airborne Doppler Wind lidar Data
Yansen Wang1, Chatt Williamson1, David Emmitt2, and Steve Greco2
1U. S. Army Research Laboratory
2Simpson Weather Associates
AMS 4th Symposium on Lidar Atmospheric Application

2. . Very accurate boundary treatment, structured Cartesian grids.
Brief 3DWF Model Description
Given a limited number of observations or coarsely modeled wind field in a complex terrain, the wind field is physically interpolated in such way that the mass conservation is satisfied. Mathematically, to Minimize the following functional (Sasaki, 1970; Sherman 1978):
. Very accurate boundary treatment, structured Cartesian grids.
Bi-CGSTAB numerical and multigrid numerical solvers.
Building and steep topographic wake parameterizations.
Lidar data assimilation/initialization.
Vegetation canopy flow parameterization.
Validation and improvement with observation data sets. dV V z w y v x u E ò ú û ù ê ë é + - = ) ( , 2 1 l b

3. 3DWF Askervein Hill Simulation
Simulstion in Complex Terrain
3DWF Askervein Hill Simulation

4. 3DWF wind field at 10m AGL A B AA A B AA

5. Comparison of model results with observations at Askervein Hill

6. 3DWF model simulation wind field at Salinas Valley initialized by the airborne Doppler lidar data

7. Airborne Doppler Wind Lidar Optical Particle Counters
Aircraft Platform
Optical Particle Counters
PCASP m
FSSP m
CAPS m
NPS CIRPAS Twin Otter
Naval Postgraduate School
Center for Interdisciplinary Remotely-piloted Aircraft Studies
TODWL Instrument
µm, coherent detection
2 mJ, 330 nsec (FWHM), 500 Hz
10 cm telescope
two axis scanner, 30 & 120 deg, side door mount
Weight: 425lb Power: 1.5KW
~7-10% total system efficiency
TODWL Scanner

8. TODWL vs. Ft. Ord microwave sounder
TODWL Flight Level

9. TODWL Flight Patterns

10. TODWL OBSERVATIONS

11. 3DWF wind field at 10m AGL

12. Zoom in a small area

13. Comparison with NWS observations

14. Summary
New 3DWF model performed well in a simple low hill with strong wind condition.
Airborne Doppler lidar data can be used for the 3DWF initialization with an objective analysis method.
The complex Salinas valley case with lidar data initialization gives reasonably good results.

15. TODWL Characteristics

16. 0030 UTC 13 March 2002 TODWL sounding looking up (20seconds)
Aircraft flight level
TODWL sounding
looking down (20 sec)
Microwave sounding
Ft Ord (30 minutes)