IHOP Workshop, Boulder, CO, March, 2003 DLR-DIAL Observations Instrument PI: Gerhard Ehret Instrument operation: Gorazd Poberaj, Andreas Fix, Martin Wirth Data processing: Christoph Kiemle and Harald Flentje Dropsonde operation: Reinhold Busen Institute for Atmospheric Physics, DLR Oberpfaffenhofen,Germany Falcon operation PI: Heinz Finkenzeller Falcon in-situ data: Andreas Giez, Martin Zöger Flight facility, DLR Oberpfaffenhofen,Germany Co-operation: Mike Hardesty, NOAA ETL, Ken Davis, PSU, V. Wulfmeyer, Uni Hohenheim

IHOP Workshop, Boulder, CO, March, 2003 Research objectives Falcon instrumentation DLR H 2 O-DIAL DIAL data from BL and CI missions Preliminary statistical analysis of BL data Data overview Conclusion and next steps Topics

IHOP Workshop, Boulder, CO, March, 2003 Research Objectives detailed structure of BL water vapour budgets and depth as well as its evolution moisture pooling (moist plume structures) along mesoscale boundaries and convective initiation answer the question: can remote sensing instrumentation on aircraft platforms provide flux divergence?

IHOP Workshop, Boulder, CO, March, 2003 Falcon Instrumentation T,p,q wind,TAS DropsondesHRDL DIAL DLR H 2 O-DIAL - 2-d H 2 O cross section - 2-d aerosol cross section - 2-d depolarisation NOAA HRDL - 2-d vertical wind - horizontal wind information - 2-d aerosol cross section Dropsondes - p,T,q, wind In-situ - p,T,q, wind Novelty: Co-located Doppler wind Lidar and H 2 O-DIAL on the Falcon Falcon flight performance

IHOP Workshop, Boulder, CO, March, 2003 DLR's H 2 O-DIAL on the Falcon DLR H 2 O-DIAL with nadir viewing telescope aboard the Falcon yes no (off-line) 1064* 532* Aerosol backscatter yes1850 (on/off) 925 (on/off-line) H 2 O mixing ratio AvailabilityEnergy (mJ) Repetition (Hz) Wavelength (nm) Measurement quantity * detection of s- and p-polarized backscatter Performance (H 2 O) boundary layer:  z = 250m,  x = 250m, range: full depth of PBL, rms ~ 5% free troposphere:  z = 300m,  x = 300m, range: 5 km, rms ~ 5% bias ~ 5% Selected parameter for IHOP

IHOP Workshop, Boulder, CO, March, 2003 H 2 O_DIAL validation during MAP 1999 Dropsonde release Altitude [km] ppmv H 2 O mixing ratio [ppmv] Distance [km] H 2 O mixing ratio [ppmv] Dropsonde Altitude [km] DIA L H 2 O-DIAL Validation in Troposphere Poberaj G., Fix A., Assion A., Wirth M., Kiemle C., and Ehret G.: All-Solid-State Airborne DIAL for Water Vapour Measurements in the Tropopause Region: System Description and Assessment of Accuracy Appl. Phys. B 75, , 2002

IHOP Workshop, Boulder, CO, March, 2003 H 2 O DIAL Validation in the low troposphere during IHOP

IHOP Workshop, Boulder, CO, March, 2003 OKC Homestead north-south direction from (39.5°,100.3°) to homestead: homogeneous moisture distribution, thermals clearly visible in moisture and aerosol cross sections west-east direction from homestead to OKC: strongly decreasing PBL depth while increasing moisture content BLH, 17 May (36.5°,100.6°) (39.5,100.3°) Homestead OKC

IHOP Workshop, Boulder, CO, March, 2003 South west area (35.4°,99.7°)-homestead: strongly structured BL top, thermals clearly visible in WV cross section, near homestead moist layer above BL top North east area (37.4°,97.5°) - (36.8°,97.5°): smooth PBL top, no turbulence elements visible, very thin and dry layer close above PBL top BLH, 21 May (35.4°,99.7°) (36.8°,97.5°) (37.4°,97.5°) homestead

IHOP Workshop, Boulder, CO, March, 2003 Spatial resolution example (BLH, 06 June) (37°,102°)(37°,101°) Data smoothing:  x = 70m (0.5s)  z = 100m - 300m rms (H 2 O) = 7% BL turbulence structure very well resolved in both cross sections

IHOP Workshop, Boulder, CO, March, 2003 km asl. water vapor variance profile (g/kg) uncorr. stat. err. variance (dashed) Preliminary Spectral Analysis ~5/3 H 2 O-Variance profile Autocovariance of H 2 O time series Instrumental noise H 2 O spectrum at 2.5 km H 2 O spectrum at 1.8 km

IHOP Workshop, Boulder, CO, March, 2003 WV cross section along broken cloud field Sharp horizontal and vertical WV gradient across dry line CI-Mission, 24 Mai 2002

IHOP Workshop, Boulder, CO, March, 2003 Moist plume Lifting BL, convection initiation CI-Mission, 15 June

Water Vapor DIAL Data Overview From a total of 21 flights (75h), 52 hours of lidar data were collected: BL heterogeneity: 11 flights for a total of 26 h 4 min. BL evolution: 2 flights for a total of 3 h 29 min. Convective Initiation: 4 flights for a total of 12 h 31 min. Low-level-jet: 4 flights for a total of 7 h 39 min. Quality of H 2 O-Data 9 flights are of high quality and 4 flights of moderate quality: BL heterogeneity: 17, 21, 28 and 29 May 20 and 25 May BL evolution: 14 June 14 June (2nd flight) Convective Initiation: 24 May, 2 and 15 June Low-level-jet: 9 June 3 June (1st flight) All lidar data are of high quality with respect to aerosol backscatter

IHOP Workshop, Boulder, CO, March, 2003 Conclusion large set of water vapor and aerosol data acquired during IHOP the measured data contains detailed information on BL water vapor budget, depth, heterogeneity, evolution as well as convective initiation the very high temporal resolution (0.5-2s) of the H 2 O-cross section is one of the most remarkable characteristics of the DIAL measurements H 2 O-DIAL fulfils the measurement requirements for flux divergence determination from airborne platform DIAL profiles show very good agreement to dropsonde data

IHOP Workshop, Boulder, CO, March, 2003 Next steps completion of data processing data intercomparison to other sensors in the field determination of entrainment flux as well as flux divergence Current collaborations: Flux divergence, M. Hardesty, NOAA, ETL Sensor intercomparison V. Wulfmeyer, University of Hohenheim ABL statistics, Ken Davis, Penn State Bore analysis LLJ, Steve Koch, NOAA, FSL