NOAA Airborne Doppler Update Mike Hardesty, Alan Brewer, Brandi McCarty and Christoph Senff NOAA/ETL and University of Colorado/CIRES Gerhard Ehret, Andreas Fix, Christoph Kiemle, and Goraszd Poberaj DLR/Lidar Group

Research Goals Reconfigure the NOAA High Resolution Doppler Lidar (HRDL) for operation on the DLR Falcon Install the lidar in the Falcon along with the DLR Water Vapor DIAL system Obtain airborne measurements of horizontal and vertical wind structure in the boundary layer during IHOP Combine DIAL/Doppler observations to measure water vapor flux profiles Combine Doppler/aerosol measurements to examine aerosol/vertical velocity correlations

Challenges Galore Limited room! - Like trying to fit and use your living room furniture in your car Limited time! 1 week to install the lidar Lots of equipment! Had to squeeze in around the DIAL (big system) On distant shores… Installation was done at DLR in Germany Lots of people! Two operators for each instrument Hot! 95 – 100 degrees in the cabin Murphy’s Law! Commercial seed laser failed two days before the ferry flight to the US Murphy’s Law II..Aircraft tire/wheel problem caused several down days after lidar was fixed

HRDL Data Summary Observations for flights on: –31 May, 2 June, 3 June (2 flights), 6 June, 7 June, 9 June, 14 June. Total Data available: 21 hours, 26 minutes High quality data: 14 hours, 30 minutes Focusing on five flight segments for intense analysis –Vertical fluxes: June 6, June 7 –Low level moisture transport: June 3, June 9 These data have been processed and quality checked (funding uncertainties delayed onset) Currently computing vertical fluxes (compare with DLR calculations) and horizontal moisture transport

Measurement Technique (vertical 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 measured atmospheric velocity Repeat aircraft tracks over multiple missions Comparisons: King-Air and surface flux measurements

Vertical velocities

Mean Velocity Profile

Vertical Velocity Variance

Skewness and Kurtosis Profile

NOAA-HRDL  x = 150 m  y = 150 m DLR-DIAL  x = 200 m  y = 150 m Combined Wind and Water Vapour Measurements Spatial Averaging:

High Spatial Resolution Water Vapour and Vertical Wind Speed

Preliminary Flux Profile First Measurement of Latent Heat Flux Profile by co- located airborne water vapour DIAL and Doppler wind lidars H 2 O-DIAL Power Spectrum Flux Profile from Eddy-Correlation (NOAA, DLR)

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 Meridional Winds Δz = 150 m Δx= 1.5 km Flight Track

Summary Demonstrated the capability to make high precision measurements of boundary layer vertical velocities Data show expected variance and skewness characteristics Ongoing steps –Cross-correlate wind, water vapor, and aerosol time series –Compute aerosol, moisture fluxes –Examine backscatter weighting of vertical velocity measurements (effect on a spacebased system) –Compare fluxes with in situ measurements from the surface and King Air Also computing horizontal water vapor transport for low-level jet study Acknowledge support of USWRP and NPOESS/IPO for this research