lab11. introduction to calipso productsirina.eas.gatech.edu/eas8803_fall2015/lab11_slides.pdf ·...
TRANSCRIPT
![Page 1: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/1.jpg)
Lab11.
Introduction to CALIPSO products
CALIPSO: http://www-calipso.larc.nasa.gov/
CALIPSO Data User's Guide:
http://www-calipso.larc.nasa.gov/resources/calipso_users_guide/
Browse Image Tutorial:
http://www-calipso.larc.nasa.gov/resources/calipso_users_guide/browse/index.php
Data Availability
http://www-calipso.larc.nasa.gov/tools/data_avail/
![Page 2: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/2.jpg)
What is a CALIPSO?
• CALIPSO: Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations
• Three co-aligned instruments:
– 3-channel lidar (CALIOP) : 532 nm (ll, ᅩ), 1064 nm
– Imaging IR radiometer (IIR)
– Wide-field camera (WFC)
• Launch: April 28, 2006
• A-train constellation
– Orbit: 705 km, in formation with Aqua, CloudSat, Parasol, and Aura
– TERRA crosses the equator at approximately 10:30 a.m., local time (about 3 hours before Aqua)
Approx equatorial crossing times
AIRS/AMSU-A/HSB
AMSR-R
CERES
MODIS
CPRCALIOP
IIR
WFC
POLDERHIRDLS
MLS
OMI
TES
CALIPSO and A-Train
![Page 3: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/3.jpg)
CALIPSO payload:
• polarization-sensitive, two-wavelength lidar (CALIOP)
• three-channel (8.65, 10.6 and 12.05 microns) Infrared Imaging Radiometer (IIR)
• visible channel Wide Field Camera (WFC)
![Page 4: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/4.jpg)
Wavelength: 1064 nm, 532 nm
1064 nm energy/pulse: 105-115 mJ
532 nm energy/pulse: 105-115 mJ
Repetition rate: 27 Hz
Pulse width: 24 ns (nominal) - 7 m length
1064 nm line width: < 90 pm (24 GHz) - 0.09 nm
532 nm line width: < 45 pm (48 GHz) - 0.045 nm
Beam quality: < 6 mm-mrad
Cooling: < 6 mm-mrad
Lifetime: > 3 billions shots
The CALIPSO satellite was launched on April 28, 2006.As of June 2011 the LIDAR system was operating well with more than 3 billion shots logged. The laser transmitter output has remained stable to within 5% of initial performance both in the infrared and visible output channels.
Lidar parameters
![Page 5: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/5.jpg)
Polarization-sensitive, two-wavelength lidar (CALIOP)
Etalon
532
Polarization
Beam Splitter
|| +
1064
532
Interference Filter
Laser
Backscatter
from
Clouds/
Aerosols
Detectors and
Electronics
Depolarizer
(Calibrate)
Transmitter
• Two-wavelength (532 nm and 1064 nm)
polarization-sensitive lidar
• Has three receiver channels: one measuring the
1064-nm backscattered intensity, and two channels
measuring orthogonally polarized components
(parallel and perpendicular to the polarization plane
of the transmitted beam) of the 532-nm
backscattered signal.
• Footprint at the Earth's surface (from a 705-km
orbit) of about 90 meters and vertical resolution of
30 meters (actual nominal resolution ~15 m vertical
and 333 m horizontal)
![Page 6: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/6.jpg)
CALIPSO lidar spatial and temporal coverage
• 532 nm total attenuated backscatter, km-1 sr-1
(Level 1B data)
1 day coverage area, Cover whole area: 16 days
Footprint (70m) spacing: 333 m (1 km~3 points)
70 m
333 m
Cover whole area: 16 days
Ground Track on Day 1
![Page 7: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/7.jpg)
CALIPSO data:
• CALIPSO data product description:
http://www-calipso.larc.nasa.gov/resources/calipso_users_guide/data_summaries/
• CALIPSO data products are available from the Langley DAAC (http://eosweb.larc.nasa.gov/).
Data products are grouped into the following categories:
• LIDAR level 1, level 2, and level 3 products
• IIR level 1 and level 2 products
• WFC level 1 products
![Page 8: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/8.jpg)
![Page 9: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/9.jpg)
Total Attenuated Backscatter at the 532 nm (Level 1, 1B profile) is one of the primary lidar Level 1 data products. It is the
product of the 532 nm volume backscatter coefficient and the two-way optical transmission at 532 nm from the lidar to the sample
volume. The attenuated backscatter profiles are derived from the calibrated (divided by calibration constant), range-corrected, laser
energy normalized, baseline subtracted lidar return signal.
“Total” means the combined signal from molecular, aerosol and/or cloud backscattering.
The 532 nm attenuated backscatter coefficients are reported for each laser pulse as an array of 583 elements that have been
registered to a constant altitude grid defined by the Lidar Data Altitude field.
Note that to reduce the downlink data volume, an on-board averaging scheme is applied using different horizontal and vertical
resolutions for different altitude regimes, as shown in the following table.
![Page 10: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/10.jpg)
Level 2 products
(http://www-calipso.larc.nasa.gov/resources/calipso_users_guide/data_summaries/layer/index.php)
CALIPSO Cloud and Aerosol Layer Products have two tightly coupled data types: column properties and layer properties
Column properties describe the temporal and spatial location of the vertical column (or, for averaged data, curtain) of atmosphere being
sampled. Column properties include satellite position data and viewing geometry, information about the surface type and lighting
conditions, and the number of features (e.g., cloud and/or aerosol layers) identified within the column. For each set of column
properties, there is an associated set of layer properties.
Layer properties specify the spatial and optical characteristics of each feature found, and include quantities such as layer base and top
altitudes, integrated attenuated backscatter, layer-integrated volume depolarization ratio, and optical depth.
Clouds and aerosol products are reported separately.
The layer products are generated at three different spatial resolutions.
• The 1/3 km layer products report cloud detection information obtained at the highest spatial resolution of the lidar: 1/3 km
horizontally and 30-m vertically. Due to constraints on CALIPSO's downlink bandwidth, this full resolution data is only available from
~8.3 km above mean sea level, down to -0.5 km below sea level.
• The 1 km layer products report cloud detection information obtained at a horizontal resolution of 1 km, over a vertical range extending
from ~20.2 km above mean sea level, down to -0.5 km below sea level.
• The 5 km layer products report (separately) cloud and aerosol detection information on a 5 km horizontal grid. At present there is no
separate stratospheric data product. Stratospheric features are recorded in the 5 km aerosol product.
![Page 11: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/11.jpg)
CALIOP Browse Image Tutorial
http://www-calipso.larc.nasa.gov/resources/calipso_users_guide/browse/index.php
LIDAR BROWSE IMAGES
http://www-calipso.larc.nasa.gov/products/lidar/browse_images/production/
LIDAR BROWSE IMAGES [V3-01]
http://www-calipso.larc.nasa.gov/products/lidar/browse_images/show_calendar.php
![Page 12: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/12.jpg)
Lidar equation (Lecture 14)
where C is the lidar constant (includes Pt, receiver cross-section
and other instrument factors);
kb/4p (in units of km-1sr-1) is called the backscattering factor or
lidar backscattering coefficient or backscattering coefficient;
ke is the volume extinction coefficient; and
tp is the lidar pulse duration (h=ctp)
))(2exp(42
)(2
rdrkkh
R
CRP e
R
o
br
p
Attenuated backscatter
(CALIPSO product)
![Page 13: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/13.jpg)
Illustration of the adaptive threshold technique (profile measured by LITE)
http://www-calipso.larc.nasa.gov/resources/pdfs/SPIE_5575-4.pdf
CALIOP retrievals: concepts of “feature” and feature boundaries
The term “feature” describes any extended and contiguous region of enhanced backscatter signal that rises significantly above the expected molecular (Rayleigh)
value (that is, clouds, aerosol layers, and surface returns).
A feature finding algorithm is required to separate the genuine features from noise (see CALIOP SYBIL algorithm)
![Page 14: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/14.jpg)
Example of analysis of space lidar data:
(a) scene measured by LITE;
(b) single-shot profile showing thin cirrus and aerosol layers;
(c) as in b, but averaged to a 20-km horizontal resolution;
(d) single-shot profile showing strong cirrus overlying stratus;
(e) single-shot profile showing thin stratus overlying PBL aerosols.
http://www-calipso.larc.nasa.gov/resources/pdfs/SPIE_5575-4.pdf
![Page 15: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/15.jpg)
Desert dust Biomass
smoke
Cirrus
56.7132.16
47.8528.57
39.9225.78
31.9423.46
23.9321.42
15.9019.55
7.8117.77
-0.2316.05
-8.2814.23
-16.3112.56
-24.3310.69
-32.328.64
-40.276.30
Alt
itu
de,
km
Alt
itu
de,
km
Alt
itu
de,
km
Fire locations in southern
Africa from MODIS, 6/10/06
CALIPSO Data – All Three Lidar Channels
Ratios of Channels give estimate of particle size, particle shape, and differentiate water/ice clouds
![Page 16: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/16.jpg)
EXAMPLE: Integration of CALIPSO and MODIS
Hurricane Bill nears Cuba in 2009
![Page 17: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/17.jpg)
EXAMPLE: Integration of CALIPSO and CloudSat
![Page 18: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/18.jpg)
Importance of dust in the Earth system
18
Impact on the
radiative energy
balance
Impact on clouds and
precipitation
Impact on major
biogeochemical cycles
Impact on
socioeconomic
systems and human
well-being
Impact on
atmospheric
composition and
chemistry
Impact on
ecosystem
functioning
![Page 19: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/19.jpg)
Effect of dust on radiation balance: importance of vertical profiles
19
dust
Vertical profiles of dust affect:
heating/cooling rates in dust layers
TOA radiative forcing in longwave
transport and lifecycle of dust
dynamics and thermodynamics of the atmosphere
dust interaction with clouds CCN, IN
CALIPSO lidar is a single satellite sensor capable of measuring vertical profiles (day&night)
![Page 20: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/20.jpg)
Regional signatures of mineral dust
Complexity of dust: Distinct sources, varying transport pathways, aging, the
decrease of coarse particles (deposition and precipitation)
Different surface albedo
20
![Page 21: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/21.jpg)
Complexity of dust microphysical properties
Complexity of dust:
GCMs (IPCC) use the Mie-theory (shape = Sphere)
Compositions (refractive index)
Modeling of nonspherical particles &Analysis of CALIPSO lidar data
21
![Page 22: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/22.jpg)
22
The aerosol extinction-to-backscatter (lidar) ratio
MeasuredSignal
Molecular Backscatter Coefficient
Molecular Extinction Coefficient
CalibrationConstant
Assumption of value required for backscatter lidar retrieval
(Sa=40sr at 532 nm in the retrieval of CALIOP level 2
version 3 data)
KnownRange from Instrument
Determined frommeasured signals andmeteorological data
RetrievedParameters
Particulate Backscatter Coefficient
Particulate Extinction Coefficient
2 Unknown
r
pemepbmb drrrrrr
CrP
0
'
,
'
,,,2')()(2exp)()()(
Extinction/Backscatter
Srk
rk
pb
pe
)(
)(
,
, Sa
2. CALIOP Data
![Page 23: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/23.jpg)
2. CALIOP Data
CALIOP Data
Level 2 version 2 data (as of January 2008)
• Integrated attenuated backscatter
γ' = ∫ β(r)T2(r)dr
• Vertical feature mask (aerosol vs. cloud)
• Layer-integrated volume depolarization ratio
δv = γ'532, I / γ'532, II
• Layer-integrated attenuated total color ratio
χv,layer = γ'1064 / γ'532
• Aerosol optical depth of a layer
γ' = 1-exp(-2ητ) / 2ητ
23
Level 2 version 3.01 data (as of June 2010)
•Layer-integrated particulate depolarization ratio
δp = βp 532, I / βp 532, II
• Layer-integrated particulate color ratio
χp,layer = βp,1064 / βp,532
• Improved vertical feature mask
• Improved Aerosol optical depth of a layer
• NewAerosol subtype image (aerosol type)
nonsphericity of particles
(higher values => more nonsphericity)
sensitive to coarse particles and
composition
Some biases in level 2 version 2
dustPolluted dust
dust
cloud
![Page 24: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/24.jpg)
24
Reconstruction of long-range transported Asian Dust
Vertical structure of long-range
transported Asian dust changes
during the transport
Maximum height of dust layers is
up to 14 km
Dust layers are mixed with clouds
Backward trajectory Forward trajectory
Reconstructed long-range transport of Asian dust
![Page 25: Lab11. Introduction to CALIPSO productsirina.eas.gatech.edu/EAS8803_Fall2015/Lab11_slides.pdf · product of the 532 nm volume backscatter coefficient and the two-way optical transmission](https://reader034.vdocuments.us/reader034/viewer/2022042712/5f9ccf7d7cfc1568c14507b5/html5/thumbnails/25.jpg)
Comparative analyses of Asian and Saharan dust
25
Asian dust profiles are mixed with some cloud, Saharan dust layer in cloud-free
Through observed δv, layer: Saharan dust profile-one homogeneous layer, Asian dust-two layers
No changes in δv, layer: between Asian and Saharan dust during mid- and long-range transport
CALIPSO aerosol optical depth: unrealistically low => Selected Lidar ratio (40 sr for dust) is
inadequate.
Case of Asian dust (3/30 ~ 4/2, 2007) Case of Saharan dust (8/17~8/23, 2007)
From Liu et al. (2008)
Data CALIOP lidar CALIOP HSRL lidar
Date 30 Mar 31 Mar 1 Apr 18 Aug 19 Aug 20Aug 28 Aug
Location
(degree)
Gobi
(Source)
East China
(mid-range
transport)
Japan
(mid-range
transport)
Toyama,
Japan
Northwest
coast of Africa
Atlantic Ocean
~1300 km from
the coast
Atlantic Ocean
~2400 km from
the coast
Gulf of Mexico
~7600 km away
from the source
Vertical extent
(km)
0-3 km,
3-4 km
0.3-2.7 km,
5.3-5.9 km
0.5-3 km,
2.3-5 km0-4 km 1 - 6 km 1.5 – 5 km 2 – 5 km 1.5 – 3.3 km
Depolarization 0.01-0.36 0.05-0.34 0.11-0.34 above 0.3 0.31 ± 0.01 0.31 ± 0.01 0.32 ± 0.01 0.32 ± 0.01
Optical depth 0.02-1.5 0.01-1.48 0.02-2.5 0.6 – 1.2 0.3 – 0.45 0.29 ± 0.03 0.08 – 0.09