Aerosol and ocean optical properties over water (PACE SPEXone)
What it measures. Describes tiny airborne particles (haze, smoke, dust) over the ocean and properties of the water surface below them, including how much light the particles block, their size and brightness, and chlorophyll in the water.
How it's made. Derived from the SPEXone polarimeter on NASA's PACE satellite, which measures how light is polarized; a model untangles the atmosphere and ocean together to produce these properties.
How & where you'd use it. Used for studying air quality and aerosol effects on climate, and as context for cleaning up ocean-color data. It pairs with PACE's other instruments for cross-checking.
What's measured
Coverage & cadence
- Time span2024-02-05 → ongoing
- Measured byPACE (SPEXone)
- Processing levelLevel 2
- Spatial extent-180, -90, 180, 90
- FormatsnetCDF-4
- StatusACTIVE
What you can do with it
- Watch sea-surface temperature and marine heatwaves
- Spot algal blooms and ocean-colour shifts
- Support fisheries and coastal monitoring
Official 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)
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="PACE_SPEXONE_L2_AER_RTAPOCEAN",
version="3.0",
bounding_box=(-122.5, 37.2, -121.8, 37.9), # your area (W,S,E,N)
temporal=("2024-01-01", "2024-12-31"), # your dates
)
files = earthaccess.open(results) # stream straight from OB_CLOUD Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package. Official links
- Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. GET DATA
- View the version history of this product. VIEW RELATED INFORMATION
- NASA's Ocean Color Web - Data Distribution Site GET DATA
- PACE Homepage VIEW RELATED INFORMATION
- SPEXone Homepage VIEW RELATED INFORMATION
- Satellite data procesing can be difficult. We're here to help! Visit the Oceandata Help Hub to navigate learning content for accessing visualizing, and analyzing data products. VIEW RELATED INFORMATION
- Algorithm Theoretical Basis Document for Ocean Properties, RemoTAP Algorithm VIEW RELATED INFORMATION