Skip to main content

Description

The CLOUD_GPC suite provides cloud properties derived from the GISS Polarimetric Cloud (GPC) algorithm, along with additional variables obtained through combination with the OCI CLOUD suite.

Given the novelty of implementing a polarimetric algorithm on a global scale, note that several experimental variables—particularly those intended for diagnostic purposes and future refinement—are included and may change in subsequent, more mature versions.
Core geophysical variables in this suite include:
• cloud_droplet_effective_radius / variance - Cloud droplet effective radius and variance (µm, unitless)
• cloud_droplet_number_concentration - Droplet number concentration (combining with OCI CLOUD) (cm⁻³)
• cloud_liquid_water_path - Cloud liquid water path (combining with OCI CLOUD) (g m⁻²)
• cloud_liquid_index - Index measuring polarized primary bow strength (unitless)
• cloud_optical_thickness - Cloud optical thickness (from OCI CLOUD) (unitless)
• cloud_bow_extinction_cross_section_Xnm – 355/532 nm extinction cross section based on Cloud Bow retrievals
• cloud_bow_lidar_ratio_Xnm – 355/532 lidar ratios based on Cloud Bow retrievals
• cloudrft* - Retrievals from Rainbow Fourier Transform (experimental and exploratory, intended for future substantial refinements)
• cloud_top_properties - Cloud top altitude (m), pressure (hPa), and temperature (K) (from OCI CLOUD)

Version Description

Reprocessing of Ocean Color (OC) Datasets

Product Summary

Platforms
PACE
Instruments
HARP2
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Location
GLOBAL OCEAN
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2024-02-05 to Present
Data Partner
Ocean Biology Processing Group (OBPG) ,
Ocean Biology Distributed Active Archive Center (OB.DAAC), Global Change Data Center, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/GCDC/OB.DAAC)
Concept ID
C3600169974-OB_CLOUD
Data State
ACTIVE
Number of Files/Granules
28475
Processing Level
2
Published
Updated
Science Keywords
Cloud Properties

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
bin_attributes/nadir_view_time Time bin was viewed at nadir view seconds from UTC midnight float64 -32767 0 to 86400.999 N/A
geolocation_data/latitude Latitude of bin locations degrees_north float32 -32767 -90 to 90 N/A
geolocation_data/longitude Longitude of bin locations degrees_east float32 -32767 -180 to 180 N/A
geophysical_data/cloud_bow_auxiliary_fit Auxiliarly_fit parameters C, B, A, accounting for linear addition offset, Rayleigh term and P12 scaling, respectively (Alexandrov et al., RSE 2012, Eq. 3). One set per wavelength used in fit. 1 float32 -32767 N/A N/A
geophysical_data/cloud_bow_cirrus_correlation Correlation of cirrus fit to retrieved cloud droplet radius and variance obtained using Cloud Bow. 1 float32 -32767 -1 to 1 N/A
geophysical_data/cloud_bow_droplet_effective_radius Cloud droplet effective radius obtained using Cloud Bow. The bands used in the retrieval are (665). um float32 -32767 3 to 53.368961334229 N/A
geophysical_data/cloud_bow_droplet_effective_radius_stddev Standard deviation of cloud droplet effective radius obtained using Cloud Bow. um float32 -32767 0 to 30 N/A
geophysical_data/cloud_bow_droplet_effective_variance Cloud droplet effective variance obtained using Cloud Bow. The bands used in the retrieval are (665). 1 float32 -32767 0.0015036390395835 to 0.49751242995262 N/A
geophysical_data/cloud_bow_droplet_effective_variance_stddev Standard deviation of cloud droplet effective variance obtained using Cloud Bow. 1 float32 -32767 0 N/A
geophysical_data/cloud_bow_droplet_number_concentration_adiabatic Cloud droplet number concentration assumes that the liquid water content is increasing with some assumed fraction of the adiabatic value. The assumptions and formulae used are summarized in Grosvenor et al. 2018 doi:10.1029/2017RG000593. # cm-3 float32 -32767 0 to 2500 N/A
geophysical_data/cloud_bow_extinction_cross_section_355nm 355 nm extinction cross section based on 865 nm cloud bow effective radius and variance retrieval. um2 float32 -32767 0 to 1732767.5 N/A
geophysical_data/cloud_bow_extinction_cross_section_532nm 532 nm extinction cross section based on 865 nm cloud bow effective radius and variance retrieval. um2 float32 -32767 0 to 18056.5 N/A
geophysical_data/cloud_bow_fit_correlation Correlation of data fit to retrieved cloud droplet radius and variance obtained using Cloud Bow. 1 float32 -32767 -1 to 1 N/A
geophysical_data/cloud_bow_lidar_ratio_355nm Ratio at 355 nm of extinction to backscatter at 180° scattering angle based on 865 nm cloud bow effective radius and variance retrieval. sr float32 -32767 0 to 100 N/A
geophysical_data/cloud_bow_lidar_ratio_532nm Ratio at 532 nm of extinction to backscatter at 180° scattering angle based on 865 nm cloud bow effective radius and variance retrieval. sr float32 -32767 0 to 100 N/A
geophysical_data/cloud_bow_liquid_water_path Cloud liquid water path (LWP) is obtained from the product of optical thickness and droplet effective radius. It is assumed that the liquid water content is increasing linearly with height from cloud base. g m-2 float32 -32767 0 to 1000 N/A
geophysical_data/cloud_bow_quality_retrieval_fail If no bits are set (=0), the results are concluded OK. If bits are set, there is an issue with the retrieval. Fill value is used when there is no cloud or no data to check for cloud. 1 uint16 65535 0 to 4095 N/A
geophysical_data/cloud_bow_rms Root mean square of data fit to retrieved cloud droplet radius and variance obtained using Cloud Bow. 1 float32 -32767 0 to 300 N/A
geophysical_data/cloud_liquid_index Index indicating the strength of the primary rainbow in the observed polarized reflectances owing to scattering on liquid drops. A liquid index <0.3 is considered to exclude presence of liquid drops in the tops of the observed clouds, and thus indicates glaciated cloud tops (van Diedenhoven et al., JAS 2012). 1 float32 -32767 -10 to 10 N/A
geophysical_data/cloud_optical_thickness Cloud optical thickness obtained from AUX file. 1 float32 -32767 0 N/A
geophysical_data/cloud_quality If no bits are set (=0), the results are concluded OK. If bits are set, there is an issue with the retrieval. Fill value is used when there is no cloud or no data to check for cloud. 1 uint16 65535 0 to 255 N/A
geophysical_data/cloud_rft_decomp_size_correlation Correlation between the mode decomposition of the RFT and the size distribution. 1 float32 -32767 0 to 1 N/A
geophysical_data/cloud_rft_droplet_effective_radius_mode_0 Cloud droplet modes effective radius from RFT retrievals for mode 0. um float32 -32767 0 to 100 N/A
geophysical_data/cloud_rft_droplet_effective_radius_mode_1 Cloud droplet modes effective radius from RFT retrievals for mode 1. um float32 -32767 0 to 100 N/A
geophysical_data/cloud_rft_droplet_effective_variance_mode_0 Cloud droplet modes effective variance from RFT retrievals for mode 0. 1 float32 -32767 0 to 0.5 N/A
geophysical_data/cloud_rft_droplet_effective_variance_mode_1 Cloud droplet modes effective variance from RFT retrievals for mode 1. 1 float32 -32767 0 to 0.5 N/A
geophysical_data/cloud_rft_mode_fraction_0 Cloud droplet modes fraction from RFT retrievals for mode 0. 1 float32 -32767 0 to 1 N/A
geophysical_data/cloud_rft_mode_fraction_1 Cloud droplet modes fraction from RFT retrievals for mode 1. 1 float32 -32767 0 to 1 N/A
geophysical_data/cloud_rft_quality_retrieval_fail If no bits are set (=0), the results are concluded OK. If bits are set, there is an issue with the retrieval. Fill value is used when there is no cloud or no data to check for cloud. 1 uint16 65535 0 to 4095 N/A
geophysical_data/cloud_top_altitude Cloud top altitude m float32 -32767 -500 to 50000 N/A
geophysical_data/cloud_top_pressure Air pressure at the cloud top Pa float32 -32767 0 to 110000 N/A
geophysical_data/cloud_top_temperature Air temperature at the cloud top K float32 -32767 0 to 500 N/A
You're viewing 32 of 32