Skip to main content

Description

This suite provides aerosol optical/microphysical properties retrieved over the oceans, along with coupled surface parameters used in the retrieval. The suite includes spectral aerosol optical depth (AOD), single-scattering albedo (SSA), complex refractive index (real/imaginary), size distribution metrics (e.g., fine/coarse effective radii and fine-mode fraction), and aerosol shape/fraction spherical; it also reports ocean surface roughness (glint/wind parameterization) and “ocean body” properties that define the water-leaving signal for consistency with the coupled atmosphere–ocean inversion. Use AER_RTAPOCEAN for aerosol-climate and air-quality studies, as aerosol context for ocean-color atmospheric correction, and for model evaluation and data assimilation; pair it with OCI/HARP2 products for cross-sensor analyses.

Core geophysical variables in this suite include:

  • alh – Aerosol layer height (km)
  • aot – Aerosol optical thickness (dimensionless)
  • aot550 – Aerosol optical thickness at 550 nm (dimensionless)
  • angstrom_440_670 – Ångström exponent, 440–670 nm (dimensionless)
  • angstrom_440_870 – Ångström exponent, 440–870 nm (dimensionless)
  • angstrom_490_670 – Ångström exponent, 490–670 nm (dimensionless)
  • chla – Chlorophyll-a concentration (mg m⁻³)
  • fmf – Aerosol fine mode fraction (dimensionless)
  • fvf – Aerosol fine mode volume fraction (dimensionless)
  • lidar_bsca_total – Aerosol lidar backscatter coefficient (km⁻¹ sr⁻¹)
  • lidar_depol_ratio – Aerosol lidar depolarization ratio (dimensionless)
  • lidar_ratio – Aerosol lidar extinction-to-backscatter ratio (sr)
  • mi – Aerosol refractive index, imaginary part (dimensionless)
  • mr – Aerosol refractive index, real part (dimensionless)
  • reff_coarse – Aerosol effective radius, coarse mode (µm)
  • reff_fine – Aerosol effective radius, fine mode (µm)
  • sph – Aerosol spherical fraction (dimensionless)
  • ssa – Aerosol single scattering albedo (dimensionless)
  • vd – Aerosol volume density (µm³ µm⁻²)
  • veff_coarse – Aerosol effective variance, coarse mode (dimensionless)
  • veff_fine – Aerosol effective variance, fine mode (dimensionless)
  • waterfrac_inland – Water fraction over inland pixels (dimensionless, 0–1)
  • wind_speed – Wind speed (m s⁻¹)

Product Summary

Platforms
PACE
Instruments
SPEXone
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
C3555840220-OB_CLOUD
Data State
ACTIVE
Number of Files/Granules
57055
Processing Level
2
Published
Updated
Science Keywords
Ocean Color ,
Aerosols ,
Aerosol Particle Properties ,
Chlorophyll Concentration

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

NASA Ocean Biology Processing Group. (2025). PACE SPEXone Level-2 Regional Aerosol Optical Properties Over Ocean, RemoTAP Algorithm, version 3.0 [Data set]. NASA Ocean Biology Distributed Active Archive Center. https://doi.org/10.5067/PACE/SPEXONE/L2/AER_RTAPOCEAN/3.0 Date Accessed: 2026-05-13

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
geophysical_data/angstrom_490_670_uncertainty Uncertainty of aerosol Angstrom exponent, 490 to 670 nm N/A float32 -32767 N/A N/A N/A
geophysical_data/aot Aerosol optical thickness N/A float32 -32767 N/A N/A N/A
geophysical_data/aot550 Aerosol optical thickness at 550 nm N/A float32 -32767 N/A N/A N/A
geophysical_data/aot550_uncertainty Uncertainty of aerosol optical thickness at 550 nm N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_coarse Aerosol optical thickness (coarse mode) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_coarse_uncertainty Uncertainty of aerosol optical thickness (coarse mode) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_fine Aerosol optical thickness (fine mode) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_fine_uncertainty Uncertainty of aerosol optical thickness (fine mode) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_mode1 Aerosol optical thickness (mode 1) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_mode1_uncertainty Uncertainty of aerosol optical thickness (mode 1) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_mode2 Aerosol optical thickness (mode 2) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_mode2_uncertainty Uncertainty of aerosol optical thickness (mode 2) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_mode3 Aerosol optical thickness (mode 3) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_mode3_uncertainty Uncertainty of aerosol optical thickness (mode 3) N/A float32 -32767 N/A N/A N/A
geophysical_data/aot_uncertainty Uncertainty of aerosol optical thickness N/A float32 -32767 N/A N/A N/A
geophysical_data/bpdf_nu Bi-directional surface polarization distribution function exponential (nu) parameter N/A float32 -32767 N/A N/A N/A
geophysical_data/bpdf_nu_uncertainty Uncertainty of bi-directional surface polarization distribution function exponential (nu) parameter N/A float32 -32767 N/A N/A N/A
geophysical_data/bpdf_scale Bi-directional surface polarization distribution function scaling parameter N/A float32 -32767 N/A N/A N/A
geophysical_data/bpdf_scale_uncertainty Uncertainty of bi-directional surface polarization distribution function scaling parameter N/A float32 -32767 N/A N/A N/A
geophysical_data/chla Chlorophyll-a concentration mg m^-3 float32 -32767 N/A N/A N/A
geophysical_data/chla_uncertainty Uncertainty of Chlorophyll-a concentration mg m^-3 float32 -32767 N/A N/A N/A
geophysical_data/column_number_mode1 Aerosol column number (mode 1) m^-2 float32 -32767 N/A N/A N/A
geophysical_data/column_number_mode1_uncertainty Uncertainty of aerosol column number (mode 1) m^-2 float32 -32767 N/A N/A N/A
geophysical_data/column_number_mode2 Aerosol column number (mode 2) m^-2 float32 -32767 N/A N/A N/A
geophysical_data/column_number_mode2_uncertainty Uncertainty of aerosol column number (mode 2) m^-2 float32 -32767 N/A N/A N/A
geophysical_data/column_number_mode3 Aerosol column number (mode 3) m^-2 float32 -32767 N/A N/A N/A
geophysical_data/column_number_mode3_uncertainty Uncertainty of aerosol column number (mode 3) m^-2 float32 -32767 N/A N/A N/A
geophysical_data/fmf Aerosol fine mode fraction (aot_fine/aot) N/A float32 -32767 N/A N/A N/A
geophysical_data/fvf Aerosol fine mode volume fraction (vd_fine/vd) N/A float32 -32767 N/A N/A N/A
geophysical_data/f_isotropic Surface isotropic scaling parameter for each band N/A float32 -32767 N/A N/A N/A
geophysical_data/lidar_bsca_total Diagnostic aerosol lidar backscatter coefficient N/A float32 -32767 N/A N/A N/A
geophysical_data/lidar_depol_ratio Diagnostic aerosol lidar depolarization ratio N/A float32 -32767 N/A N/A N/A
geophysical_data/lidar_p11_pi Phase function p11 in backscatter direction N/A float32 -32767 N/A N/A N/A
geophysical_data/lidar_ratio Diagnostic aerosol lidar ratio N/A float32 -32767 N/A N/A N/A
geophysical_data/li_sparse Bi-directional surface reflectance distribution function li-sparse kernel coefficient N/A float32 -32767 N/A N/A N/A
geophysical_data/li_sparse_uncertainty Uncertainty of bi-directional surface reflectance distribution function li-sparse kernel coefficient N/A float32 -32767 N/A N/A N/A
geophysical_data/mi Aerosol refractive index (volume density weighted, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_coarse Aerosol refractive index (coarse mode, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_fine Aerosol refractive index (fine mode, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_mode1 Aerosol refractive index (mode 1, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_mode1_uncertainty Uncertainty of aerosol refractive index (mode 1, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_mode2 Aerosol refractive index (mode 2, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_mode2_uncertainty Uncertainty of aerosol refractive index (mode 2, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_mode3 Aerosol refractive index (mode 3, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mi_mode3_uncertainty Uncertainty of aerosol refractive index (mode 3, imaginary part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mr Aerosol refractive index (volume density weighted, real part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mr_coarse Aerosol refractive index (coarse mode, real part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mr_fine Aerosol refractive index (fine mode, real part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mr_mode1 Aerosol refractive index (mode 1, real part) N/A float32 -32767 N/A N/A N/A
geophysical_data/mr_mode1_uncertainty Uncertainty of aerosol refractive index (mode 1, real part) N/A float32 -32767 N/A N/A N/A
You're viewing 100 of 175