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  • Enhanced Cloud Algorithm From Collocated CALIPSO, CloudSat and MODIS

    Sunny Sun-Mack1, Patrick Minnis2, Yuhong Yi1, Yan Chen1, Sharon Gibson1 Qing Trepte1, Pat Heck3, Seiji Kato2, Bruce Wielicki2 (PI)

    (1) SSAI, Hampton, VA, USA (2) NASA Langley Research Center, Hampton, VA, USA

    (3) CIMSS, Wisconsin, USA

    CERES STM May 6-8, 2008, Newport News, VA

  • • Develop an integrated data set to provide global vertical profiles of aerosols, clouds, and broadband radiative fluxes using combined NASA A-Train data from

    - Aqua CERES (broadband fluxes constrain RTM calcs) - MODIS aerosols (MOD04) - CERES-MODIS cloud properties (from CERES algorithms) - CALIPSO lidar aerosol and cloud data - CloudSat CPR cloud data

    • Use CALIPSO and CloudSat data products to

    - Develop improved algorithms for CERES-MODIS Ed3 clouds, and future NPP cloud algorithm.

    Objectives

  • Compute ice & water phase solution, select most likely phase based on temperature, model fits, LBTM classification, 2.1-µm reflectance

    DAY: VISST (Visible Infrared Solar-Infrared Split-Window Technique) 0.65, 3.8, 10.8, & 12.0 µm see Minnis et al. (1995, 1998, 2007b)

    NIGHT: SIST (Solar-infrared Infrared Split-Window Technique) 3.8, 10.8, & 12.0 µm see Minnis et al. (1995, 1998, 2007b)

    SNOW (DAY): SINT (Solar-Infrared Infrared Near-Infrared Technique) 2.1, 3.8, 10.8, & 12.0 µm see Platnick (JGR, 2001), Minnis et al. (2007b)

    CERES-MODIS Cloud Retrieval Methodology (Apply CERES algorithms to MODIS imager data)

  • Fr eq

    ue nc

    y

    CALIPSO Extinction QC Flag=0 & 1

    Transparent Clouds

    CALIPSO Optical Depth

    CALIPSO Extinction QC Flag=16 & 17 F

    re qu

    en cy Opaque Clouds

    CALIPSO Optical Depth Histogram (Single Ice Layer) for July 2006

    0 0.5 1 1.5 2 2.5 3

    0 0.5 1 1.5 2 2.5 3

  • Enhanced Cloud Retrieval Along A-Train Track

    For single layer and transparent CALIPSO clouds: - If CALIPSO optical depth > 4, no Tcld adjustment

    - If CALIPSO optical depth < 4, and if CERES- MODIS cloud is outside of CALIPSO cloud top and base

    Then adjust CERES-MODIS cloud temperature to CALIPSO value, redo some of the streamlined VISST / SINT/ SIST to try to retrieve the rest of cloud properties (tau, size….)

  • Possible CERES-MODIS Cloud Phase Changes (Before and After the Enhancement)

    CERES-MODIS Cloud Phase

    After Enhancement

    Before Enhancement

    For single transparent calipso clouds:

  • Before and After Cases

  • Clear CAL CSat Aero BothCld Ice wat (CERES)

    July 15, 2006, Hour 01 0

    1

    2

    3

    4 km

    Before Enhancement

    Day Time

    North Pacific Ocean

  • Clear CAL CSat Aero BothCld Ice wat (CERES)

    July 15, 2006, Hour 01 0

    1

    2

    3

    4 km

    Before Enhancement

    After EnhancementCERES Water Cloud

    CERES Clear

    0

    1

    2

    3

    4

    Day Time

    North Pacific Ocean

  • 2

    4

    6

    8

    1

    0 km

    2

    4

    6

    8

    10

    Clear CAL CSat Aero BothCld Ice wat (CERES)

    July 15, 2006, Hour 01

    CERES Ice

    After Enhancement

    Before Enhancement

    CERES Water

    Night Time

    North Siberia

  • 2

    4

    6

    8

    1

    0 km

    2

    4

    6

    8

    10

    Clear CAL CSat Aero BothCld Ice wat (CERES)

    July 15, 2006, Hour 01

    After Enhancement

    Before Enhancement

    CERES Clear

    CERES Water

    Night Time

    North Siberia

  • 2

    4

    6 8

    1 0

    1 2

    1 4

    k m

    2

    4

    6

    8

    10

    1 2

    1 4

    July 15, 2006, Hour 01

    CERES Ice

    Before Enhancement

    After Enhancement

    Night Time 0 .1 .2 .5 > .5

    CALIPSO Optical Depth

    West Europe

    CERES Clear

  • 2

    4

    6 8

    1 0

    1 2

    1 4

    k m

    2

    4

    6

    8

    10

    1 2

    1 4

    July 15, 2006, Hour 01

    CERES Water

    CERES Ice

    Before Enhancement

    After Enhancement

    Night Time 0 .1 .2 .5 > .5

    CALIPSO Optical DepthWest Europe

  • 2

    6

    1 0

    1

    4

    1 6

    July 15, 2006, Hour 01

    CERES Water

    CERES Ice

    Before Enhancement

    After Enhancement

    Night Time 0 .1 .2 .5 > .5

    CALIPSO Optical Depth

    2

    6

    10

    1 4

    16 k

    m 2

    6

    1

    0

    1 4

    1

    6

    West Africa

  • 3 Days of Merged CALIPSO, CloudSat and MODIS July 2006, day 08, 15, and 22

    (1) Non-Polar Region (2) CALIPSO: Single and Transparent Layer (3) CALIPSO: Optical Depth < 4

    131, 385 pixels

    0.032.4615.59 (%)10.5 (%)71.42 (%)%

    Bad Data

    NoRetWaterIceClearCERES (Before)

    73.8726.1314.8985.1176.0223.97%

    WaterIceWaterIceWaterIceCERES (After)

    Before Enhancement

    After Enhancement

  • 3 Days of Merged CALIPSO, CloudSat and MODIS July 2006, day 08, 15, and 22

    (1) Non-Polar Region (2) CALIPSO: Single and Transparent Layer (3) CALIPSO: Optical Depth < 4

    131, 385 pixels

    0.032.4615.59 (%)10.5 (%)71.42 (%)%

    Bad Data

    NoRetWaterIceClearCERES (Before)

    73.8726.1314.8985.1176.0223.97%

    WaterIceWaterIceWaterIceCERES (After)

    Before Enhancement

    After Enhancement

    Majority of missing clouds are water

  • 3 Days of Merged CALIPSO, CloudSat and MODIS July 2006, day 08, 15, and 22

    (1) Non-Polar Region (2) CALIPSO: Single and Transparent Layer (3) CALIPSO: Optical Depth < 4

    131, 385 pixels

    0.032.4615.59 (%)10.5 (%)71.42 (%)%

    Bad Data

    NoRetWaterIceClearCERES (Before)

    73.8726.1314.8985.1176.0223.97%

    WaterIceWaterIceWaterIceCERES (After)

    Before Enhancement

    After Enhancement

    CERES phase

    successful rate ~ 80%

  • 35.0664.94Water-->Water (74%) 77.8722.13Water-->Ice (26%)

    40.7559.25Ice-->Water (15%) 46.5453.46Ice-->Ice (85%)

    64.6135.39Clear-->Water (76%) 97.752.25Clear-->Ice (24%)

    Less than 0.3 (%)

    Greater than 0.3

    (%)

    CALIPSO Tau CERES (before-->after)

    Each Phase Category of CALIPSO Optical Depth > 0.3 and Ice

  • 35.0664.94Water-->Water (74%) 77.8722.13Water-->Ice (26%)

    40.7559.25Ice-->Water (15%) 46.5453.46Ice-->Ice (85%)

    64.6135.39Clear-->Water (76%) 97.752.25Clear-->Ice (24%)

    Less than 0.3

    (%)

    Greater than 0.3

    (%)

    CALIPSO Tau CERES (before-->after)

    Assuming CF for single transparent cloud ~ 20%, then CF for missing water cloud with tau > 0.3 is ~ 4% (0.2 x 0.71 x 0.76 x 0.35), missing water CF ~ 7% for tau < 0.3.

    Each Phase Category of CALIPSO Optical Depth > 0.3 and Water

  • 21.29

    4.81

    20.60

    1.68

    30.73

    5.62

    Undetermined (%)

    60.8917.82Water-->Water(74%)

    14.9780.22Water-->Ice (26%)

    69.869.54Ice-->Water (15%)

    4.2594.07Ice-->Ice (85%)

    52.716.58Clear-->Water (76%)

    12.581.87Clear-->Ice (24%)

    Water (%)

    Ice (%)

    CALIPSO Phase CERES (before-->after)

    Cloud Phase Comparisons between CALIPSO and CERES

    • CALIPSO is confident with it’s ice phase • Enhanced CERES ice cloud phase is ~ 80-95 % in agreement with CALIPSO ice phase

  • CERES Optical Depth After the Enhancement Compared with CALIPSO Optical Depth

    Clear (before enhancement) ---> Cloud (after enhancement)

    CE RE

    S O

    pt ic

    al D

    ep th

    CALIPSO Cloud Optical Depth Optical Depth Diff (CERES-CALIPSO)

    0.1 x 0.1: 32.40 % 0.3 x 0.3: 55.65 % 0.5 x 0.5: 66.99 % 1.0 x 1.0: 82.50 %

  • CERES Optical Depth After the Enhancement Compared with Calipso Optical Depth

    0.1 x 0.1: 4.14 % 0.3 x 0.3: 20.8 % 0.5 x 0.5: 32.1 % 1.0 x 1.0: 49.6 %

    Cloud (before enhancement)--> cloud (after enhancement)

    CE RE

    S O

    pt ic

    al D

    ep th

    CALIPSO Cloud Optical DepthOptical Depth Diff (CERES - CALIPSO)

  • CERES Cloud Top Height Before t

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