Download Cirrus preliminary results - Ensembles

Cirrus Measurements during the
EAQUATE Campaign
C. Lee, A.J. Baran, P.N. Francis, M.D. Glew, S.M. Newman and J.P. Taylor
© Crown copyright 2004
Page 1
Outline
 Overview of frontal cirrus case on 15th Sept 2004
 Aircraft remote sensing and in-situ instrumentation
 Measurements and preliminary results
ARIES infrared interferometer
SWS visible and NIR spectrometer
Cloud physics probes
 Summary and conclusions
© Crown copyright 2004
Page 2
IR satellite images at approx AQUA overpass times
Frontal cirrus case on 15th Sept 2004
1200
© Crown copyright 2004
1400
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AIRS (AQUA) 11m images on 15/09/04
12:23:26-12:29:25
© Crown copyright 2004
13:59:26-14:05:25
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FAAM BAe146-301 ARA Instrumentation
Upward and Forward Video
Cameras
FAGE Inlet
CVI on other side
ADA on
other
side
SWS on
other side
Air sample inlets
BBRs
5 port
turbulence
probe
SHIMS
Cloud Physics
Probes
Total water probe
JW Liq water
Nevzerov total/liq
water probe
Rosemount temp
probes
Dropsonde on
other side
MARSS
Deimos
or IR
Camera
TAFTS
ARIES
BBRs
SHIMS
Lidar
Rearward and
Downward Video
Cameras
Cloud Physics Probes
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Remote Sensing instrumentation on FAAM
on 15/09/04
Instrument
Type
Spectral range
SWS
Short Wave Spectrometer
0.3 - 1.7µm
ARIES
Airborne Research Interferometer Evaluation
System
550 - 3000cm-1
MARSS
Microwave Airborne Radiometer Scanning
System
89 - 183GHz (upward and
downward)
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In-situ instrumentation on FAAM
Core Chemistry
O3, CO, NOxy, SO2
Nephelometer
Total scattering and hemispheric backscattering coefficient at three visible
wavelengths (450, 550 and 700nm)
SID1
Small Ice Detectors. Spherical Equivalent size spectrum (1 - 50µm)
PCASP
Aerosol Size Spectrum optical probe. Aerosol particle concentration, mean volume
radius and size spectrum (0.1 - 3µm)
2DC
Two Dimension Cloud particle imaging probe. Particle number concentration,
condensed water content, mean volume radius, precipitation rate and size
spectrum (25 - 800µm)
2DP
Two Dimension Precipitation particle imaging probe. Particle number concentration,
condensed water content, mean volume radius, precipitation rate and size
spectrum (200 - 6400µm)
AVAPS (Dropsonde)
Airborne Vertical Atmospheric Profiler System (Dropsonde). Profiles of pressure,
temperature, relative humidity, wind speed and direction
Johnson Williams
Liquid Water Content Probe Concentration of liquid water in clouds
General Eastern
Hygrometer Water Vapour (damp atmosphere)
Nevzorov
Liquid and Total Water Content Probe. Liquid and total water in clouds
TWC
Total Water Content Probe Water (H2O)
FWVS
Fluorescence Water Vapour Sensor Water Vapour (dry atmosphere)
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FAAM BAE146 flight track
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Aircraft profile
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ARIES average spectra at overpass 2
280
start of run
end of run
Brightness Temperature [K]
270
260
250
240
230
220
210
600
700
800
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900
1000
1100
Wavenumber [cm-1]
1200
1300
1400
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ARIES BTs at select wavelengths during
run at 2nd overpass
270
260
14
12
10
255
8
250
6
245
240
4
235
2
230
13:58:45
14:00:45
14:02:45
14:04:45
 Brightness Temperature [K]
Brightness Temperature [K]
265
8um
10um
11um
12um
8um-12um
0
14:06:45
Time
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Page 11
Modelled IR and ARIES data
270
Brightness Temperature [K]
Extinction optical thickness=3.7
260
Re=46um
250
240
230
220
ARIES 10 cm-1 res
Edwards-Slingo Model
210
700
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1200
1700
-1
Wavenumber [cm ]
2200
2700
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SWS nadir example spectra for thin and thick cirrus
300
thick cirrus
thin cirrus
Radiance [W/m /ster/um]
250
2
200
150
100
50
0
0.4
© Crown copyright 2004
0.6
0.8
1
1.2
Wavelength (um)
1.4
1.6
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SWS radiance variation through the flight
100
Radiance [W/m2/ster/um]
90
zenith
Orbits
zenith
nadir
zenith
80
0.87um
1.6um
70
60
50
40
30
20
10
0
11:00:00
11:30:00
© Crown copyright 2004
12:00:00
12:30:00
Time
13:00:00
13:30:00
14:00:00
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SWS radiance measured during the 2 orbits
banked at 45 deg
300
Orbit 1 at 0.87um
Orbit 2 at 0.87um
Orbit 1 at 1.6um
Orbit 2 at 1.6um
Radiance [W/m /ster/um]
250
2
200
150
100
50
0
0
© Crown copyright 2004
20
40
60
Scattering angle [degrees]
80
100
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Phase functions
6-branched bullet-rosette
=0.87 μm
Dist=0.12
Orbit 1
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Orbit 2
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Phase functions
Polycrystal (Macke et al. 1996)
=0.87 μm
Dm=100 μm for all ice crystals
Orbit 1
Orbit 2
First Results – Scaled Radiances at 10o - NO multiple scattering
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Page 17
Phase Functions
=0.87 μm
Analytic Phase function g=0.70 (Baran et al. 2001)
Orbit 1
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Orbit 2
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Phase functions
Polycrystal
=1.60 μm
Orbit 1
Orbit 2
50 μm
100 μm
800 μm
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Page 19
Cloud Physics in-situ observations
 Full analysis still needs to be performed
 Graupel
 No larger than 200um diameter seen in flight
 50 to 200/litre
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Page 20
Summary and conclusions
 Remote sensing and in-situ measurements have been obtained
using FAAM BAE-146, for a frontal cirrus case on 15 Sept 2004,
coincident with 2 AIRS (AQUA) overpasses.
 The effective particle radius is larger than 50um, of graupel (nonsymmetrical) type, with a large variability in optical thickness.
 The analysis of this data set is on going.
 It demonstrates the importance of using coincident observations
at wavelengths from visible to submm, to determine a wide range
of cirrus parameters and check the physical consistency of the
models.
 Future flights - CASEAR campaign based in UK in Nov 2005, May
2006 and July 2007, coincident with Chilbolton radar, AQUA,
Cloudsat.
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Page 21
Acknowledgements
 FAAM
 Direct Flight
 BAE
 Met Office instrument operators
 Walter Wolf
 Dave Pollard
© Crown copyright 2004
Page 22
Visible MSG satellite images at AQUA overpass
times on 15 Sept 2004
Frontal cirrus case
1230
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1400
Page 23
AIRS 8m -12m for 2nd overpass
13:59:26-14:05:25
© Crown copyright 2004
Page 24
Phase functions
Distorted Aggregate (Yang
and Liou 1998)
=0.87 μm
Dist=0.13
Orbit 1
© Crown copyright 2004
Orbit 2
Page 25