IHOP_OSA

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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
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Topics

• Research objectives
• Falcon instrumentation
• DLR H2O-DIAL
• DIAL data from BL and CI missions
• Preliminary statistical analysis of BL data
• Data overview
• Conclusion and next steps

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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?

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Falcon Instrumentation
Novelty Co-located Doppler wind Lidar
and H2O-DIAL on the Falcon

• DLR H2O-DIAL
• - 2-d H2O 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

Falcon flight performance
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DLR's H2O-DIAL on the Falcon
Selected parameter for IHOP
detection of s- and p-polarized backscatter
DLR H2O-DIAL with nadir viewing telescope aboard
the Falcon
Performance (H2O) 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
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H2O-DIAL Validation in Troposphere
H2O_DIAL validation during MAP 1999

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, 165-172, 2002
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H2O DIAL Validation in the low troposphere during
IHOP
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Spatial resolution example (BLH, 06 June)
(37,102)
(37,101)
Data smoothing ? x 70m (0.5s) ? z 100m -
300m rms (H2O) 7
BL turbulence structure very well resolved in
both cross sections
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Preliminary Spectral Analysis
Autocovariance of H2O time series
5/3
H2O spectrum at 2.5 km
H2O spectrum at 1.8 km
Instrumental noise
H2O-Variance profile
km asl.
3.0
2.5
2.0
2
water vapor variance profile (g/kg)
uncorr. stat. err. variance (dashed)
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CI-Mission, 24 Mai 2002
WV cross section along broken cloud field Sharp
horizontal and vertical WV gradient across dry
line
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CI-Mission, 15 June
Moist plume
Lifting BL, convection initiation
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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 H2O-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
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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 H2O-cross
• section is one of the most remarkable
  characteristics of the
• DIAL measurements
• H2O-DIAL fulfils the measurement requirements
• for flux divergence determination from
  airborne platform
• DIAL profiles show very good agreement to
  dropsonde data

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• 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