Airborne Measurement of Horizontal Wind and Moisture Transport Using Co-deployed Doppler and DIAL lidars Mike Hardesty, Alan Brewer, Brandi McCarty, Christoph

Airborne Measurement of Horizontal Wind and Moisture Transport Using

Co-deployed Doppler and DIAL lidars

Mike Hardesty, Alan Brewer, Brandi McCarty, Christoph Senff, and Ed

TollerudNOAA/ETL and University of

Colorado/CIRES

Gerhard Ehret, Andreas Fix, Goraszd Poberaj, Martin Wirth, and

Christoph Kiemle DLR/Lidar Group

2Working Group on Space-based Lidar Winds

Measurement Technique (horizontal winds)

• Installed a wedge scanner to direct the lidar beam 20 degrees off-nadir

• Fixed the beam azimuth direction at 90 degrees relative to the aircraft

• Adjusted azimuth to compensate for aircraft yaw using real time ground hits

• Measure winds, water vapor and aerosol with 150 m vertical and horizontal resolution (processed to 1.5 km resolution)

• Subtract residual ground velocity from each measured atmospheric velocity

• Fly box patterns to measure moisture convergence

• Comparisons: Dropsondes


Horizontal Winds: 9 June

Forecast showed low level jet

Flight track to measure jet


Lidar/Dropsonde Comparisons


Northern leg wind and water vapor


Lidar and dropsonde flux comparison

DIAL/Doppler lidar

Dropsonde


Dropsonde/Lidar comparison near jet max

• Dropsonde/lidar flux comparisons show good agreement for north-south component

• Non-negligible east-west component at higher altitudes (lidar will underestimate)

• Could be improved by noting the orientation of the jet axis and correcting velocity measurements

• Lidar measurements have higher resolution, see smaller scales

• Analyzing data to see if this is important


Dropsonde-Scale Moisture Transport

South (blue) and North (black) transportDropsonde transport

measurements


Vertical Wind Measurements

• Direct the lidar beam vertically through a nadir port in the Falcon

• Use the real-time estimate of the surface velocity to determine vertical pointing

• Adjust turning mirror to compensate for Falcon pitch angle

• Measure winds, water vapor and aerosol with 150 m vertical and horizontal resolution

• Subtract residual ground velocity from each atmospheric velocity

• Repeat aircraft tracks over multiple missions

• Comparisons: King-Air and surface flux measurements


Vertical velocities


Vertical Velocity Variance


Lidar/King Air Comparison June 7

Lidar

King Air


Repeat over same track


17:40 17:41 17:42 17:43 17:44 17:45DLR DIAL water vapour mixing ratio

-101.90 -101.80 -101.70 -101.60 -101.50 -101.40 -101.30longitude

1.0

1.5

2.0

2.5

3.0

height (km)

1.0

1.5

2.0

2.5

3.0

3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 g/kg

UTC

17:40 17:41 17:42 17:43 17:44 17:45NOAA HRDL vertical wind velocity

0 10 20 30 40 50distance (km)

1.0

1.5

2.0

2.5

3.0

height (km)

1.0

1.5

2.0

2.5

3.0

-3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 m/s

UTC

NOAA-HRDL

x = 150 my = 150 m

DLR-DIAL

x = 200 m

y = 150 m

Combined Wind and Water Vapour Measurements

Spatial Averaging:


-0.05 0.00 0.05 0.10 0.15 0.20 0.25 0.30g/kg*m/s

1500

2000

2500

3000

3500

altitude asl in m

0 200 400 600W/m2

Preliminary Flux Profile

First Measurement of Latent Heat Flux Profile by co-located airborne water vapor DIAL and

Doppler wind lidars

1

10

100

1000

10000

S(f)

0.0001 0.0010 0.0100

wavenumber [1/m]

10000 1000

wavelength [m] 2600m asl

H2O-DIALPower Spectrum

Flux Profile from Eddy-Correlation

(NOAA, DLR)


Future : HRDL Upgrades

• HRDL is being repackaged for better aircraft performance• Modular design, fiber coupling• New processor under development for higher prf (1 kHz)• Deployment on NOAA ship this summer for New England

air quality experiment• Future plans: co-deployment with ozone lidar during

2005/2006 air quality studies


Summary

• Demonstrated the capability to make high precision measurements of boundary layer horizontal and vertical velocities using co-deployed DIAL and Doppler lidars

• Computed vertical fluxes using eddy correlation• Computed horizontal wind component and single

component moisture transport• Compared turbulence measurements using King Air in

situ measurements• Compared lidar and dropsonde transport measurements• Underway: examine backscatter weighting of vertical

velocity measurements (effect on a spacebased wind system)

• Gratefully acknowledge support of USWRP and NPOESS/IPO for this research

Documents

Airborne Measurement of Horizontal Wind and Moisture Transport Using Co-deployed Doppler and DIAL lidars Mike Hardesty, Alan Brewer, Brandi McCarty, Christoph