Clouds and the Earth's Radiant Energy System (CERES) Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) Data Set Abstract

• Created new PGE to read and IES file for input as well as an existing SSF, MOA and Spectral Calibration Coefficients.
• Installed updated algorithms for surface models LWA and LWB using a constrained near-surface air temperature.
• Applied Radiometric Scaling Factor.
• Twilight fix applied.
• SSF ID set to 1117

• Software recompile to operate on IBM hardware with SUSE linux.
• Uninitialized parameters were initialized and some bounds problems corrected. (CERES Fluxes SSF-38 through SSF-49 and cloud properties SSF-82 through SSF-114)
• Software recompile to use interface to GMAO G5-CERES MOA data. (CERES Fluxes SSF-38 through SSF-49, MOA parameters SSF-57 through SSF-62, and clouds mask and properties SSF-66, SSF-81, SSF-116, SSF-117, SSF-82 through SSF-114)
• Modified to handle higher surface pressure from G5-CERES. (cloud mask and properties SSF-82 through SSF-114)
• Modified to handle reprocessed radiation MODIS granules with different scan numbers than the geolocation file. (CERES Fluxes SSF-38 through SSF-49 and all imager based parameters SSF-60 through SSF-160)
• SSF ID set to 1117

• The variable MODIS derived IGBP map was used instead of the fixed map used in climate data sets.
• SSF ID set to 1117

• Software recompile to support MODIS Collection 5.
• SSF ID set to 1117

• SW Surface Flux Model B module was modified to switch back from MATCH broadband to Match GFDL aerosols. The following SSF SDSs will vary: SSF-46 and SSF-48.
• Software recompile to support upgrade to Toolkit version 5.2.12.
• SSF ID set to 1117

• SW Surface Flux Model A module was modified to switch from Match GFDL to MATCH aerosols at 550 nm. The following SSF SDSs will vary: SSF-38, SSF-41 and SSF-44.
• SW Surface Flux Model B module was modified to switch from Match GFDL to MATCH broadband aerosols. The following SSF SDSs will vary: SSF-46 and SSF-48.
• LW Surface Flux Model B module was modified to correct cloud pressure calculations. The following SSF SDSs will vary: SSF-39, SSF-47 and SSF-49.
• Terra Edition2B ADMs were used.
• SSF ID set to 1117

• Cloud Phase Algorithm was modified to have a more accurate cloud phase selection. The following SSF SDSs will vary SSF-82 through SSF-114.
• Water content map is re-generated to change defaults to zeros over Antarctica region. The following SSF SDSs will vary: SSF-25, SSF-66, SSF-81, SSF-116, SSF-117, SSF-82 through SSF-114.
• The problem over polar/non-polar transition ocean areas (mostly occured in Sea of Okhotsk and Hudson Bay in Terra-MODIS_Edition2-QC) is resolved by having a fix ocean albedo over non-polar region. SSF SDSs: SSF-66, SSF-81, SSF-116, SSF-117, SSF-82 through SSF-114 will vary over the transition ocean areas.
• 12 months of clear sky start-up maps are re-created for 0.6 um and 2.1 um respectively. Clear sky maps are the inputs for all algorithms, therefore the new maps will influence many SSF SDSs (mostly SSF-66, SSF-81, SSF-116, SSF-117,SSF-82 through SSF-114) to some degrees.
• The following summaries the changes in CERES mask algorithm, which will affect SSF SDSs: SSF-66, SSF-81, SSF-116, and SSF-117.
  • Daytime non-polar:
    • Consolidated the Terra and Aqua daytime cloud mask into one set for easier maintenance and higher efficiency.
    • Implemented the new daytime thin Cirrus detection tests over land and desert using MODIS 1.38, 8.55 - 11, 11 - 12 tests and the MOA precipitable water. It significantly improved the thin Ci detection over land. Daytime CERES  cloud mask structure has been changed.
    • In C3_land tests, improved the low clouds tests and the dark snow detection at high latitudes, smoothed the transition regions.
  • Daytime polar:
    • Improved both Aqua and Terra mini-mask for a better classification of the TBD pixels.
    • Reorganized and cleaned up the Aqua and Terra masks.
  • Twilight polar:
    • Improved the twilight Aqua and Terra cloud and snow detection for a smoother transition between polar and non-polar.
• When VISST algorithm returns no cloud retrieval, LBTM algorithm is applied. This modification will improve SSF SDSs: SSF-82 through SSF-114.
• CERES Overlapping Algorithm was implemented. None of SSF SDS is affected.
• Clouds QC structure is modified to include histograms for several cloud properties. None of SSF SDS is affected.
• Footprints influenced by a solar eclipse will be removed from the file.
• The Surface type percent coverage (SSF-25) land coverage is reduced based on the water content map. The reduced area is added to the ocean areal coverage.
• The Snow/Ice percent coverage from vis albedo (SSF-30) now includes permanent snow.
• The GRing module was modified to use correct coordinates for the no footprint case. A GRing that covers the entire globe was added.
• Aqua dynamic Spectral Correction Coefficients were used.
• Terra Edition2B ADMs were used.
• SSF ID set to 1117

• Incorrect Spectral correction coefficients used in creating Aqua-FM4-MODIS_Edition1A

• All footprints with a viewing zenith greater than or equal to 63 degrees are included in the SSF. When the viewing zenith angle is less than 63 degrees and the packet number is even, then only footprints with an even value Scan sample number are placed in the SSF. When the viewing zenith angle is less than 63 degrees and the packet number is odd, then only footprints with an odd value Scan sample number are placed in the SSF.
• All PSF weighted imager parameters on the SSF (SSF-24 through SSF-26, SSF-30, SSF-54, SSF-64 through SSF-78, SSF-81 through SSF-113, and SSF-131) will be obtained using only imager pixels from every 2nd scanline and every 4th pixel (2x4) and a new point spread function.
• The Surface type percent coverage (SSF-25) sea ice areal coverage is reduced based on the ice fraction reported on the microwave ice map. The reduced area is added to the ocean areal coverage.
• ADM geo (SSF-30) now contains the percent snow or ice for polar region based on the overhead-sun albedo from CRH 0.6 µm map updated from the day before. The threshold over ocean is equal to the average IGBP type overhead sun albedo plus 3-sigma. The threshold over land IGBP types is its average overhead sun albedo plus 2-sigma.
• The Radiance and Mode flags (SSF-34) will identify when the footprint was under a solar eclipse.
• CERES ADM types and TOA fluxes-upward (SSF-27 through SSF-29 and SSF-38 through SSF-41) will be derived using the new Terra Edition2A ADMs.
• Notes on General Procedures (SSF-64) only footprints that have Stowe aerosol calculated on them are flagged as using the second generation algorithm.
• Total aerosol A optical depths (SSF-73 and SSF-74) will use satellite specific solar constants as provided by Dr. Ignatov to determine reflectance. The radiance channel for clear air optical depth using the Stowe algorithm was made selectable based on satellite. For Aqua, it will be 0.6 and 2.13.
• Clear, Clear/layer/overlap, All subpixel clear, All subpixel overcast cloud area percent coverage (SSF-66, SSF-81, SSF-116, and SSF-117) will vary due to
  • Added skin T restriction for Tlim test: (T > 270K)
  • Daytime Polar:
    • Added restriction to Cold Cloud Test, avoid calling Super Cold Plateau clouds.
    • Added thin cirrus clouds detection.
    • Tuned various thresholds to improve the results
    • Added mini-mask for TBD pixels, no more TBD in CERES daytime mask.
  • Nighttime Polar:
    • All the improvements in the Terra Edition 2 (SCCR467).
    • Filter out the bad T3.7 data (T3.7 > 300K)
  • Daytime non-polar:
    • Added sun-glint probability dependent T3-T4 thresholds in SunGlintTest.
    • Improved smoke detection over ocean.
    • Added a snow test region flag to avoid "tropic snow"
  • Special cloud detection tests over super cold plateau for night and twilight.
  • Welch mask will no longer be used when CERES mask in undetermined over polar region during daytime.
  • Added 30% adjustment on IR thresthold for cloud test.
  • The polar mask is no longer applied in nonpolar regions where skin temperature is less than 270 K
  • The imager pixel will not have an undetermined cloud fraction anymore.
• Cloudy Footprint Area SDS (SSF-82 through SSF-114) will be improved because over snow-ice non-elevated land, where an inversion cloud height was calculated from GEOS lapse rate, the MOA skin temperature used in calculations was replaced by the daily averaged MOA air surface temperature. Cloud thickness and clouds top emissivity calculations now uses cloud phase instead of cloud temperature.
• Footprint Imager Radiance Statistics (SSF-118 through SSF-131) for daytime footprints contain radiance for 2.13 micrometer.
• The Percentage of CERES FOV with MODIS land and ocean aerosol (SSF-132 and SSF-146) was corrected to represent the true coverage instead of anything over 1 percent being reported as 100 percent.
• PSF-wtd MOD04 corrected optical depths land, effective optical depth average ovean, and optical depth small average ocean (SSF-136 through SSF-138 and SSF-150 through SSF-159) now have an upper limit of 5.0
• Aqua dynamic Spectral Correction Coefficients were used.
• Terra Edition2A ADMs were used.
• SSF ID set to 1117

• The Aqua processing variations began with a Terra Edition1A baseline.
• Clear, Clear/layer/overlap, All subpixel clear, All subpixel overcast cloud area percent coverage (SSF-66, SSF-81, SSF-116, and SSF-117) will vary due to
  • New start-up maps for 2.1 µm albedo and 2.1 µm albedo standard deviation were implemented.
  • The Kriebel Bidirectional model for 2.1 µm was implemented.
  • Both sub-Arctic summer and sub-Arctic winter snow reflectance models for 2.1 µm were implemented.
  • Welch mask will no longer be used when CERES mask in undetermined over polar region during daytime.
  • 2.1 µm daytime polar cloud mask used.
  • Improved polar nighttime and non-polar datime CERES mask.
• Cloudy Footprint Area SDS (SSF-82 through SSF-114) will be improved because
  • The 2.1 µm cloud model used in polar regions was implemented so that the NoVis cloud retrieval algorithm automatically uses the 2.13 µm cloud model.
  • The observed 1.6 µm reflectance and clear sky predicted 1.6 µm reflectance were replaced by 2.1 µm observed reflectance and clear sky predicted 2.1 µm reflectance respectively.
• PSF-wtd MOD04 dust weighting factor land (SSF-135) is filled with default values.
• Mean and Stddev of imager radiances (SSF-118 through SSF-129) contain the same radiance channels as used for Terra.
• Static Aqua spectral correction coefficients were used.
• Terra Edition1A ADMs were used.
• SSF ID set to 1117

• Created new PGE to read and IES file for input as well as an existing SSF, MOA and Spectral Calibration Coefficients.
• Installed updated algorithms for surface models LWA and LWB using a constrained near-surface air temperature.
• Applied Radiometric Scaling Factor.
• Twilight fix applied.
• SSF ID set to 1117

• Software recompile to use interface to GMAO G5-CERES MOA data. (CERES Fluxes SSF-38 through SSF-49, MOA parameters SSF-57 through SSF-62, and clouds mask and properties SSF-66, SSF-81, SSF-116, SSF-117, SSF-82 through SSF-114)
• SSF ID set to 1117

• Software recompile to support MODIS Collection 5.
• SSF ID set to 1117

• Terra Edition2B ADMs are used.
• Name changes in SSF SDS:
  • ADMGEO changed to Snow/ice percent coverage clear-sky overhead-sun vis albedo (SSF-30)
  • CERES WN ADM type for inversion process changed to Cloud classification (SSF-29)
• SSF ID remains 1117

• Terra Edition2 ADMs are used.
• The Aqua processing variations began with a Terra Edition1A baseline.
• All footprints with a viewing zenith greater than or equal to 63 degrees are included in the SSF. When the viewing zenith angle is less than 63 degrees and the packet number is even, then only footprints with an even value Scan sample number are placed in the SSF. When the viewing zenith angle is less than 63 degrees and the packet number is odd, then only footprints with an odd value Scan sample number are placed in the SSF.
• All PSF weighted imager parameters on the SSF (SSF-24 through SSF-26, SSF-30, SSF-54, SSF-64 through SSF-78, SSF-81 through SSF-113, and SSF-131) will be obtained using only imager pixels from every 2nd scanline and every 4th pixel (2x4) and a new point spread function.
• Clear, Clear/layer/overlap, All subpixel clear, All subpixel overcast cloud area percent coverage (SSF-66, SSF-81, SSF-116, and SSF-117) will vary due to
  • New start-up maps for 2.1 µm albedo and 2.1 µm albedo standard deviation were implemented.
  • The Kriebel Bidirectional model for 2.1 µm was implemented.
  • Both sub-Arctic summer and sub-Arctic winter snow reflectance models for 2.1 µm were implemented.
  • Welch mask will no longer be used when CERES mask in undetermined over polar region during daytime.
  • 2.1 µm daytime polar cloud mask used.
  • Improved polar nighttime and non-polar datime CERES mask.
• Cloudy Footprint Area SDS (SSF-82 through SSF-114) will be improved because
  • The 2.1 µm cloud model used in polar regions was implemented so that the NoVis cloud retrieval algorithm automatically uses the 2.13 µm cloud model.
  • The observed 1.6 µm reflectance and clear sky predicted 1.6 µm reflectance were replaced by 2.1 µm observed reflectance and clear sky predicted 2.1 µm reflectance respectively.
• PSF-wtd MOD04 dust weighting factor land (SSF-135) is filled with default values.
• Mean and Stddev of imager radiances (SSF-118 through SSF-129) contain the same radiance channels as used for Terra.
• SSF ID set to 1117

• This SSF product contains Edition1A cloud parameters and new fluxes using Beta5 Terra ADMs.
• SW Model B surface flux algorithm was modified to correct the cloud temperature parameter used to compute the SW surface flux.
• LW Model A surface flux algorithm was modified to use the MOA surface temperature.
• LW Model B surface flux algorithm was modified to use the MOA surface temperature.
• SSF ID set to 1117

• The 1.6 micrometer imager radiance values are saved for all footprints with CERES solar zenith <= 90 degrees.
• Cloud Phase Algorithm was modified to correctly classify cloud phase for thin cirrus cases.
• The CERESmask was updated to improve cloud detection over strong sunglint ocean (sunglint probability > 40%) to reduce false clouds. Over sunglint ocean, the clear sky standard deviation of the brightness temperature difference between 3.7 µm and 11 µm was changed from a constant number (2.5K) to 0.0255K*sunglint_probability + 2.45K.
• The extinction ratios and single scattering albedos were updated.
• SW Model A surface flux algorithm was modified to retrieve the GFDL aerosol parameters from the correct hemisphere.
• SSF ID set to 1117

• TRMM Edition2B ADMs were updated for snow.
• SW TOA flux algorithm was updated to apply earth-sun distance correction to unfiltered SW radiance in the SW flux calculation for snow and the default SW ADM type was set to 592.
• LW model A Surface algorithm module: Effective pressure (used to compute air temp) now computed based on ocean/land and surface pressure (previously based on tropics/extra-tropics). New sets of coefficients for Land (no longer split based on tropics/extra-tropics).
• Aerosol correction removed from SW model B surface flux algorithm.
• Cloud retrieval model for 1.6µm was changed to higher angle resolutions.
• Cloud retrieval models for 3.7µm were changed to higher angle resolutions.
• CERES Mask algorithm was updated. The updates include:
  1. Clear sky night time.
  2. Polar daytime mask.
  3. Polar nighttime mask.
  4. CERES non_polar night time.
• The twilight definition was changed for solar zenith angle range from 82.0-87.5 degrees to 82.0-88.5 degrees.
• Improved version of MODIS classifier.
• New IR cloud phase algorithm.
• Updated overlapping algorithm.
• Spectral correction algorithm modified to use dynamic Spectral Correction Coefficients based on instrument gains.
• Combined NSDC and NESDIS snow/ice maps used as input.
• Aerosol A algorithm has been changed to process each channel independently (single-channel) using the input tables from the third-generation algorithm.
• SSF ID remains 117

• Clear sky snow and ice reflectance models and albedo models for 0.6µm, 1.6µm and 3.7µm changed to higher angle resolutions.
• Clear sky, snow and ice reflectance models and albedo models updated for 0.6µm at TOA, 1.6µm and 3.7µm at surface
• The Cloud Phase Algorithm modified for a better cloud detection, especially for thin cirrus clouds.
• A MODIS 3.7µm calibration implemented. This calibration includes Response-Function-Weighted wavelength and VIRS radiance normalization.
• The CERES mask algorithm (including polar mask algorithm) re-tuned based on the 3.7µm calibration.
• The Relative Azimuth was changed from CERES to the imager for the Stowe aerosol optical thickness calculation.
• Over polar regions and over snow-ice surfaces, the NoVis algorithm was turned on.
• Welch MODIS classifier implemented.
• Monthly clear sky start-up maps for Terra used.
• Additional Vgroups and SDSs containing the MODIS Aerosol parameters are on the SSF HDF files. There are 14 land and 15 ocean parameters.
• TRMM Edition 2B SW, LW, and WN ADMs are used.
• SW Model A and SW Model B use GFDL climatology to compute aerosol optical depth.
• LW Model A Air Temperature at 950mb was replaced with air temperature at effective pressure. The effective pressure was computed based on FOV location (tropics/extra tropics) and surface pressure. Parameter name remained temp950mb even though contents changed.
• SSF ID remains 117

• Using updated MOA interface to correct end-of-year access problem
• SSF ID remains 117

• Edition2_TRMM ADMs used to invert data to surface 
• Added MODIS Welch classifier
• Added preliminary polar nighttime mask
• Expanded imager viewing zenith bins in the QC report to support MODIS angles beyond 50 degrees. This corrects the bogus cloud detection problem found in Beta1.
• SW and LW Model A surface fluxes only computed for FOVs for which clear coverage exceeds 99.9%
• SSF ID remains 117

• All footprints with one or more pixels of imager coverage included in SSF
• Implemented MODIS Correlated K calculation
• Implemented 1.6 micron/ NoViS cloud property retrival
• Improved 1.6 micron clear sky prediction over snow/ice
• Updated CERES Polar Mask Algorithm
• MODIS radiance channels for footprint statistics are selected based on solar zenith angle and day of the month
• Beta2_TRMM ADMs are used for all-sky fluxes; SW ADMs are based on renormalized optical depths for all Terra viewing angles
• Metadata G-rings do not specify individual hourly swaths
• SSF ID remains 117

• Nighttime IR emissivities computed
• Terra (FM1, FM2) Aerosol A parameters set to CERES default
• MODIS 3.7 micron calibration correction
• MODIS version of Correlated K algorithm
• Polar Mask added
• IR emissivity range changed from 0..1 to 0..2
• MODIS input subsetted to 2x2 sampling (every other pixel on every other scanline)
• Cloud fraction change due to an adjustment of the brightness temperature clear sky stddev based on imager viewing zenith angle
• SSF ID remains 117

• TRMM Edition2B ADMs were updated for snow.
• SW TOA flux algorithm updated to apply earth-sun distance correction to unfiltered SW radiance in the SW flux calculation for snow.
• LW model A Surface algorithm module: Effective pressure (used to compute air temp) now computed based on ocean/land and surface pressure (previously based on tropics/extra-tropics). New sets of coefficients for Land (no longer split based on tropics/extra-tropics).
• The SW Model B surface flux algorithm no longer uses GFDL climatology to compute optical depth.
• The Model A algorithm for CERES downward/net SW surface fluxes corrected to include the GFDL aerosol correction and process only for clear-sky.
• Aerosol A algorithm has been changed to process each channel independently (single-channel) using the input tables from the third-generation algorithm.
• SSF ID remains 117

• Aerosol A optical depth calculation corrected to use imager relative azimuth
• Using updated MOA interface to correct end-of-year access problem
• SSF ID remains 117

• CERES instrument is powered off (no CERES measurements are available)
• CERES geolocation generated by simulating CERES crosstrack scan mode
• Cloud algorithms have not changed (still Edition2)
• Aerosol A algorithm has not changed (still using 3rd generation algorithm where possible)
• Updated SW model B surface flux algorithm
• All TOA fluxes and most surface fluxes set to CERES default
• SSF ID remains 117

• Edition2_TRMM ADMs used for all-sky fluxes
• Actual G-rings placed in metadata
• New Cloud property parameterizations to resolve optical depth problems
• VIRS 1.6 micron radiance correction based on detector temperature
• Cloud subcategory propagated onto FOV when property retrieval failed; coverage added to Notes on cloud algorithms
• Aerosol A algorithm modified to use 3rd generation where possible; flag added to Notes on cloud algorithms
• "Reclassified" clear over land/desert where WN exceeds threshold; coverage added to Notes on cloud algorithms
• "bad data" coverage added to Notes on general procedures
• WN channel unfiltered radiance and flux no longer per micron
• Modified LW model B and SW model B surface flux algorithms
• SSF ID remains 117

• All footprints with one or more pixels of imager coverage included in SSF
• Beta2_TRMM ADMs used for all-sky fluxes. When ADM not available, flux and ADMtype are set to CERES default
• New Cloud property parameterizations to resolve optical depth problems
• VIRS 1.6 micron radiance correction based on detector temperature
• Cloud subcategory propagated onto FOV when property retrieval failed; coverage added to "Notes on cloud algorithms"
• Aerosol A algorithm modified to use 3rd generation where possible; flag added to "Notes on cloud algorithms"
• "Reclassified" clear over land/desert where WN exceeds threshold; coverage added to "Notes on cloud algorithms"
• "bad data" coverage added to "Notes on general procedures"
• WN channel unfiltered radiance and flux no longer per micron
• Modified LW model B surface flux algorithm
• SSF ID remains 117

• Cloud properties, aerosol properties, and spatial matching identical to TRMM-PFM-VIRS_Edition1
• Clear and cloudy TOA fluxes available
• ADMs updated to Beta2_TRMM ADMs supplemented with VIRS12B
• Units altered for parameters CERES WN radiance - upwards, CERES WN TOA flux - upwards, and CERES downward WN surface flux - Model A
• SW surface - Model B downward and net fluxes consistent and available for clear and cloudy sky
• SSF ID remains 117

• N₂O absorption added to Correlated K calculation
• Surface emissivity maps improved
• 0.6 micron model improved
• TISA night time cloud retrieval added
• 1.6 micron ratio model modified
• CERES mask algorithm improved
• Aerosol A algorithm processes each channel independently (single-channel) with updated tables for the spectral responses for 0.66 and 1.6 micrometer MODIS channels.
• SSF ID remains 117

• Vgroups added to hdf file; Vgroups map to parameter groupings
• SSF_Header Vdata updated (Added Beta angle)
• Added SSF FOV parameters Column averaged relative humidity, Cloud property extrapolation over cloudy region, Cloud-mask clear-strong percent coverage, Cloud-mask clear-weak percent coverage, Cloud-mask percent coverage supplement, Aerosol A supplements 1-4, Mean water particle radius for cloud layer (1.6), Mean ice particle effective diameter for cloud layer (1.6), and Mean cloud particle phase for cloud layer (1.6)
• Deleted SSF FOV parameters: Colatitude of CERES FOV at TOA, Longitude of CERES FOV at TOA, CERES spectral albedo, Shadowed imager pixels percent coverage, Imager sun glint percent coverage, Imager-based fire percent coverage, Area percent coverage for cloud layer, and Stddev of cloud particle phase for cloud layer.
• Other SSF FOV parameter updates include: parameter names adjusted, clear and cloudy percent coverage data types switched to 32-bit real.
• MOA input generated from ECMWF data. Using MOA ozone information.
• VIRS Release 5 imager data used as input
• CRH startup maps replaced (corrects problem over tundra ecosystems)
• Surface emissivity maps replaced (now based on ECMWF/AVHRR 1986 data)
• CERES calibration adjustment to 1.6 micron VIRS radiances. Most adjustments to imager radiances included in SSF imager radiance statistics.
• Nighttime cloud algorithm added
• Polar snow and ice cloud mask added
• Potential cloud layer overlap algorithm added
• Correction to twilight drop in cloud fraction
• New Welch algorithm incorporated
• CERES Cloud Mask (improvements in sunglint areas, added shadowed algorithm) updated. Mask decision tree uses Welch results as needed.
• Added code to handle saturation of 3.75 channel
• Added reflectance calculation for 3.75 channel
• VISST algorithm modified to accommodate new science algorithms. New models for 3.7 channel ice and water phases. Handles cloud inversions.
• Particle size calculation adjusted
• Aerosol optical depth calculations use 2x2 pixel uniformity test for channel 1 reflectance and land/water map on 10 minute grid
• Keep cloudy FOVs with limited or no cloud property coverage; extrapolate layer coverages and properties where possible
• Single broadband surface albedo and surface emissivity calculation for FOV (previously calculated for every pixel)
• New Slope Intercept Spectral Correction algorithm and coefficients to unfilter CERES radiances
• ADMs updated to VIRS12B
• TOA fluxes referenced at surface
• Only FOVs which are 99.90r more clear have valid CERES flux values. All others CERES derived flux values set to CERES default.
• SSF ID set to 117

• Partial Earth FOVs added
• G-Ring expanded to better define data
• Cloud mask TLim test modified (pressure level temperature for determining cloud/no cloud threshold)
• CRH startup maps in southern hemisphere adjusted
• Correlated K profile derivation algorithms improved
• Algorithms computing total aerosol optical depth at 0.6 microns and at 1.6 microns allow negative values
• Coefficients applied to WN channel to determine SW thermal adjustment updated
• SSF ID remains 113

• HDF SSF format updated - each parameter is a separate SDS
• VIRS Release 4 imager data used as input
• "Note for cloud layer" contains strong cloud, weak cloud, and sunglint from cloud assessments
• "Notes on cloud algorithms" contains strong clear and weak clear assessments
• Visible optical depth no longer logarithmically averaged. Corresponding parameters now Mean logarithm of visible optical depth for cloud layer and Stddev of logarithm of visible optical depth for cloud layer
• VIRS based direction models used
• Correlated K profile derivation improved
• VINT phase determination algorithm improved
• Cloud mask improvements
• CRH startup maps improved for 0.6 albedo, 1.6 albedo, ratio of 1.6 to 0.6 reference, and 10.8 brightness temperature
• Low cloud detection improved
• VIRS 1.6 micron channel thermal leak correction made before computing Total aerosol optical depth at 1.6 microns in clear area
• Imager-based aerosol percent coverage and associated flag modified
• Algorithms for computing Percentiles of visible optical depth for cloud layer and Percentiles of IR emissivity for cloud layer expanded
• VIRS12A Angular Direction Model used to invert radiances to fluxes
• Missing microwave precipitable water corrected - microwave values properly flagged on MOA and copied onto SSF
• SSF ID set to 113

• CERES mask within VINT algorithm improved
• CRH start-up maps and emissivity maps improved
• SSF ID remains 112

• Geocentric/geodetic issues resolved
• Window channel units to "per micron"
• Full Julian date replaces fractional Julian day
• Calibration corrections to VIRS version 1 data
• Cloud mask and cloud properties improved - additional tests added
• Correlated K algorithm modified
• Bilinear interpolation of MOA data within Clouds
• Viewing zenith cutoff increased from 76.2 to 80.0 deg
• Revised spectral correction coefficients
• SSF ID set to 112

• First software delivery to process 1 month of data

Mail Stop 420
Atmospheric Sciences Research
NASA Langley Research Center
Hampton, Virginia 23681-2199
USA
FAX: (757) 864-7996

Patrick Minnis, Imager and Cloud Retrieval
E-mail: p.minnis@nasa.gov
Telephone: (757) 864-5671

Norman G. Loeb, TOA Radiances and Fluxes
E-mail: norman.g.loeb@nasa.gov
Telephone: (757) 864-5688

David P. Kratz, Surface Fluxes
E-mail: david.p.kratz@nasa.gov
Telephone: (757) 864-5669