CALIPSO Ocean Products: Progress Advisors: Mike Behrenfeld and Chuck McClain Ball Aerospace: Carl Weimer CNES: Jacques Pelon NASA LaRC: Yongxiang Hu, Sharon Rodier, Chip Trepte, Bill Hunt NASA NRC Postdoc Program: Pengwang Zhai and Damien Josset Stevens Institute of Tech: Knut Stamnes ODU: Richard Zimmerman and Victoria Hill SAIC: Jim Koziana Bigelow: William Balch HSRL and RSP instruments: Chris Hostetler and Brian Cairns Supported by NASA HQ ocean biogeochemistry program and radiation science program Paula and Hal: Thanks!
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CALIPSO Ocean Products: Progress Advisors: Mike Behrenfeld and Chuck McClain Ball Aerospace: Carl Weimer CNES: Jacques Pelon NASA LaRC: Yongxiang Hu, Sharon.
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CALIPSO Ocean Products: ProgressAdvisors: Mike Behrenfeld and Chuck McClain
Ball Aerospace: Carl WeimerCNES: Jacques Pelon
NASA LaRC: Yongxiang Hu, Sharon Rodier, Chip Trepte, Bill Hunt
NASA NRC Postdoc Program: Pengwang Zhai and Damien JossetStevens Institute of Tech: Knut Stamnes
ODU: Richard Zimmerman and Victoria HillSAIC: Jim Koziana
Bigelow: William BalchHSRL and RSP instruments: Chris Hostetler and Brian Cairns
Supported by NASA HQ ocean biogeochemistry program and radiation science programPaula and Hal: Thanks!
Outline• CALIPSO lidar measurements: introduction
• Sub-surface particulate backscatter from cross-polarization profiling: progress
Highlight: a self-calibration method is developed for CALIPSO ocean subsurface lidar backscatter product (good for future trend analysis)
• Air-sea gas exchange velocity from lidar measurements of ocean surface mean square slope
• Other studies that supports ocean color program1. aerosol optical depth estimates without microphysics assumption 2. identification of smoke aerosols3. modeling and sensitivity studies with polarimeter measurements
CALIPSO and A-Train
CALIPSO: Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation
CALIPSO is 75 seconds behind Aqua, with MODIS, CERES, AMSR, …, onboard
CALIPSO PayloadThree Near Nadir Viewing Instruments
CALIOPCloud-Aerosol Lidar with Orthogonal Polarization
2 wavelength polarization sensitive lidar:
1064 nm, 532 nm (parallel and perpendicular)
Wide Field Camera (WFC)
High-resolution image (125m resolution)
Vertical profiles of atmosphere
Lidar Imaging Infrared Radiometer (IIR)
High-resolution image (swath product)
IIR
WFC
CALIOPLaser Transmitter
CALIPSO Payload
CALIOPReceiver Telescope
1 meter
Altitude Region
0.3 degree
Ocean Study Using Lidar in Space
• 532nm Cross-Polarization: Particulate Backscatter • 1064nm: Air-sea gas transfer velocity; wind
• Solving issues related to instrumentation new crosstalk correction (co-polarization vs cross polarization); cross-pol low-gain
change from Feb 2007; …
• Monte Carlo simulation of multiple scattering and its impact on the signal: significant contribution from multiple scatter; more going studies; needs help on characterizing particulate scattering phase matrix
CALIPSO sub-surface backscatter: 2007 and 2008
CALIPSO sub-surface backscatter: Night vs Day
No big problem with daytime:Self calibration worked!
CALIPSO sub-surface backscatter: MarAprMay vs SepOctNov
CALIPSO sub-surface backscatter: DecJanFeb vs JunJulAug
Integrated lidar subsurface backscatter [Sum(Lc)] is proportional to (1+m)Bbp/beam
When (1+m)*(beam attenuation ) of a size bin is >>1, 1-exp(-2beam H/(1+m))]=1
Backscatter of individual vertical bin, Lc, of the profile is proportional to Bbp
when H is small and 1-exp(-2beam H/(1+m))= 2beam H/(1+m)Effective depth and backscatter profile product (under development): extra information help separate Bbp and beam
Validating Aerosol Correction using Ocean Surface Co-polarization Component
(HSRL: Sept. 04, 2007; from Chris Hostetler, John Hair, and others of the NASA LaRC HSRL group. Thanks!)
Comparison with MODIS(January 2007)
532nm optical depth from CALIPSO/AMSR 1064nm optical depth from CALIPSO/AMSR
550nm optical depth from MODIS
Identifying Absorbing Aerosols
Using Lidar Ratio (e.g. smoke: around 70) from Ocean Surface Backscatter
Effective Lidar Ratio = Beam Attenuation / Backscatter = [1-exp(-2)]/(2)]
Application of lidar measurements: gas transfer velocity
Ocean and the missing carbon sink
From Woods Hole Reserch Center Website
Atmospheric increase (3.2 PgC/yr) =Emissions from fossil fuels (6.3) + Net emissions from changes in land use (2.2)
Combined with errors in partial pressure, the uncertainty of a factor of two in air-sea gas transfer velocity can lead to unacceptable error in global ocean flux of CO2 (Wallace, 1995)
CO2 Uptake = Air-sea Gas transfer velocity k x (660/Sc)n x solubility x (Pco2)
Application of lidar measurements: gas transfer velocity
Relation between carbon uptake and gas transfer velocitty
Air-sea gas transfer – wind speed relation : A source of uncertainty in Ocean Carbon Uptake
R.A. Feely, C.L. Sabine, T. Takahashi, and R. Wanninkhof, 2001: Uptake and Storage of Carbon Dioxide in the Ocean: The Global CO2 Survey, Oceanography, 14/4, 18-32.
C / <tan2> At 532nm and 1064nm, Fresnel reflection is valid for all surface waves
04/19/23
Carbon Uptake Comparison: F(Wind) (AMSR) vs F(<S2>) (CALIPSO)
Combined Active/passive:Modeling and Sensitivity Studies for ACE
1. Fast and accurate coupled ocean-atmospheric model for polarized radiative transfer
2. Sensitivity studies: how can polarization help
3. Objectives: using polarization measurements to help improve lidar data analysis
Model Description• A vector radiative transfer model has been
developed for a coupled atmosphere ocean system.• It is based on successive order of scattering method.• It converges fast for optically thin or absorptive
media.• Various state of art techniques have been employed
to enhance performance.• A reference can be found at:
Peng-Wang Zhai, Yongxiang Hu, Charles R. Trepte, and Patricia L. Lucker, "A vector radiative transfer model for coupled atmosphere and ocean systems based on successive order of scattering method," Opt. Express 17, 2057-2079 (2009) http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-4-2057
Sensitivity of Radiance and Degree of Polarization to Layer Depth
P PP
I1, P1: plankton layer at 10 m below surface
I2, P2: 50 m below surface
Unit of I1 and I2:
Wm-2m-1
Radiance and Degree of Polarization Sensitivity to Size
P PP1
Case 1:
effective size 1 m
Case 3:
effective size 30 m
Unit of I1 and I2:
Wm-2m-1
Summary and Discussion• Highlight: a self-calibration method is developed for
CALIPSO ocean subsurface lidar backscatter product (good for trend analysis)
• CALIPSO sub-surface integrated lidar backscatter (cross-polarization) is ready to release; depolarization ratio and vertical profiling of backscatter are still work in progress
• Preliminary study is done on the air-sea gas transfer velocity product
• ACE proof of concept: modeling and sensitivity studies of combined lidar/polarimeter for ocean color
HSRL lidar and RSP polarimeter flights over routes where
in situ measurements are available
Purpose: Learning from the success of ocean color vacarious calibration, we want to examine the potential of using several well defined targets (e.g. ocean surface) as the “moby” equivalent for lidar/radar and polarimeter
How: A few aircraft measurement flights supported by CALIPSO over various targets, in situ measurements of optical properties, and polarized radiative transfer modeling to assess how well we can understand those targets
Preliminary plan: flights this summer/fall near NASA Stennis and/or Langley (exact time and location to be decided: need your suggestions and collaborations on in situ measurements )