Transcript DLR-DIAL Observations

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:
IHOP Workshop, Boulder, CO, 24-26 March, 2003
Mike Hardesty, NOAA ETL, Ken Davis, PSU, V. Wulfmeyer,
Uni Hohenheim
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
IHOP Workshop, Boulder, CO, 24-26 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, 24-26 March, 2003
Falcon Instrumentation
• DLR H2O-DIAL
Novelty: Co-located Doppler wind Lidar
and H2O-DIAL on the Falcon
- 2-d H2O cross section
- 2-d aerosol cross section
- 2-d depolarisation
wind,TAS
T,p,q
• NOAA HRDL
DIAL
Dropsondes
HRDL
- 2-d vertical wind
- horizontal wind information
- 2-d aerosol cross section
• Dropsondes
- p,T,q, wind
• In-situ
- p,T,q, wind
IHOP Workshop, Boulder, CO, 24-26 March, 2003
Overall length
17.2 m
Wingspan
16.3 m
M aximum takeoff w eight (M TOW)
13.2 t
Engines
M aximum Altitude
M aximum Range
M aximum Endurance
M aximum Payload (w ith max fuel)
M aximum Speed (TAS)
Falcon flight performance
Garret TFE 731-5BR-2C
45000 ft (13.7km)
3700 km (2000 nm)
5:30 h
1.1 t
917 km/ h (0.865 M ach)
DLR's H2O-DIAL on the Falcon
Selected parameter for IHOP
Measurement
quantity
Wavelength
(nm)
Repetition
(Hz)
Energy
(mJ)
Availability
H2O mixing
ratio
925
(on/off-line)
50
(on/off)
18
yes
925 (off-line)
50
18
yes
1064*
100
50
yes
532*
100
40
no
Aerosol
backscatter
* 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 ~ 5%
IHOP Workshop, Boulder, CO, 24-26 March, 2003
H2O-DIAL Validation in Troposphere
H2O mixing ratio [ppmv]
ppmv
6
10
Altitude [km]
H2O_DIAL validation
during MAP 1999
60
600
9
8
Dropsonde release
7
6
5
0
50
100
150
200
200
250
300
Distance [km]
Altitude
Altitude [km] [km]
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
11
11
10
10
99
88
77
Dropsonde
DIAL
DIA
DIAL
L
Dropsonde
(13:44:54 UTC, 11.99E, 46.98N)
66
77
66
55
55
0
0
20
40
60
80
100
20
40
60
80
100
H O mixing
ratio
[ppmv]
2
IHOP Workshop, Boulder, CO, 24-26 March, 2003
Dropsonde
11
11
10
10
99
88
Dropsonde
(13:01:39 UTC, 12.25E, 46.71N)
DIA
L
DIAL
0
0
50
100 150 200 250
H2O mixing ratio [ppmv]
H2O mixing ratio
[ppmv]
100
200
300
300
H2O DIAL Validation in the low troposphere during
IHOP
5
H2O DIAL
Dropsonde
Altitude [km]
4
June 9, 2002, 12:51 UT
3
100.21W, 36.56N
2
Altitude [km]
5
H2O DIAL
Dropsonde
June 9, 2002, 13:17 UT
4
3
102.71W, 36.55N
2
1
6
8
10
12
H2O Mixing Ratio [g/kg]
IHOP Workshop, Boulder, CO, 24-26 March, 2003
14
1
2
4
6
8
10
12
H2O Mixing Ratio [g/kg]
14
BLH, 17 May
(39.5,100.3°)
Homestead
(36.5°,100.6°)
OKC
(39.5,100.3°)
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
IHOP Workshop, Boulder, CO, 24-26 March, 2003
Homestead
OKC
BLH, 21 May
(37.4°,97.5°)
homestead
(36.8°,97.5°)
(35.4°,99.7°)
homestead
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
IHOP Workshop, Boulder, CO, 24-26 March, 2003
Spatial resolution example (BLH, 06 June)
(37°,102°)
Data smoothing:
 x = 70m (0.5s)
 z = 100m - 300m
rms (H2O) = 7%
BL turbulence
structure very
well resolved in
both cross
sections
IHOP Workshop, Boulder, CO, 24-26 March, 2003
(37°,101°)
Preliminary Spectral Analysis
autocovariance of horizontal water vapor series at 1820m asl.
energy spectra of horizontal water vapor series at 2450m asl.
0.1
energy spectra of horizontal water vapor series at 1820m asl. (g/kg)
0.1
2
(g/kg)
2
~5/3
H2O spectrum
at 2.5 km
(g/kg)
2
H2O spectrum at
1.8 km
0.01
Autocovariance of H2O time series
0.6
Instrumental
noise
0.4
0.01
0.2
0.001
0.001
0.0
0.0001
0.0001
10000
wavelength [m]
1000
10000
wavelength [m]
1000
-0.2
-2000
-1000
0
1000
lag [m]
2000
3000
4000
H2O-Variance profile
km asl.
3.0
2.5
2.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2
water vapor variance profile (g/kg) 2
uncorr. stat. err. variance (dashed)
IHOP Workshop, Boulder, CO, 24-26 March, 2003
CI-Mission, 24 Mai 2002
IHOP 05/24: Falcon flight route
F1
F2
35.4
F3
F4
F5
F6
7
0
Latitude [deg]
35.3
1,2,3
W1
35.2
IP1
F7
leg0
leg1
leg2
leg3
leg4
leg5
leg6
leg7
E1
35.1
6
4,5
35.0
W2
IP2
E2
34.9
-102
-101
-100
-99
-98
Longitude [deg]
IHOP Workshop, Boulder, CO, 24-26 March, 2003
WV cross section
along broken cloud
field
Sharp horizontal and
vertical WV gradient
across dry line
CI-Mission, 15 June
A4
B1IHOPB206/15:
B3Falcon flight route
B4
B5
B6
Latitude [deg]
3,4,5,6
C1
37.0
C2
C3
D1
36.5
D2
D3
C4
2
leg1
leg2 C6
leg3
leg4
leg5
leg6 D6
leg7
C5
D4
D5
W-29
E-29
7
B7
C7
Lifting BL,
convection
initiation
1
F2
F3
-102
-101
F4
-100 F5
W1 Longitude
IP1[deg]
W2
IP2
-99
F6
E1
E2
IHOP Workshop, Boulder, CO, 24-26 March, 2003
Moist plume
D7
36.0
F1
B8
F7
Water Vapor DIAL Data Overview
From a total of 21 flights (75h), 52 hours of lidar data were collected:
• BL heterogeneity:
• BL evolution:
• Convective Initiation:
• Low-level-jet:
11 flights for a total of 26 h 4 min.
2 flights for a total of 3 h 29 min.
4 flights for a total of 12 h 31 min.
4 flights for a total of 7 h 39 min.
Quality of H2O-Data
9 flights are of high quality
•
•
•
•
BL heterogeneity:
BL evolution:
Convective Initiation:
Low-level-jet:
and
4 flights of moderate quality:
17, 21, 28 and 29 May
14 June
24 May, 2 and 15 June
9 June
20 and 25 May
14 June (2nd flight)
3 June (1st flight)
All lidar data are of high quality with respect to aerosol backscatter
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
IHOP Workshop, Boulder, CO, 24-26 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
IHOP Workshop, Boulder, CO, 24-26 March, 2003