How the ocean reflects sunlight, live (PACE)
What it measures. How the upper ocean reflects sunlight, given as 'remote sensing reflectance' (essentially the ocean's color signal) along with haze over the water, a fluorescence signal from plants, and uncertainty estimates.
How it's made. Produced from the OCI instrument on the PACE satellite as a quick 'near real-time' product; values are stored as scaled numbers and come with quality flags to mask clouds, land, and glare.
How & where you'd use it. An input for studying ocean color, phytoplankton, and water quality. As reflectance data, it is often a stepping stone toward higher-level ocean products, and the fast version suits timely monitoring.
What's measured
Coverage & cadence
- Time span2024-03-05 → ongoing
- Measured byPACE (OCI)
- 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
The Ocean Biology DAAC produces near real-time (NRT) products using the best-available combination of ancillary data from meteorological and ozone data. As such, the inputs and the calibration used are less than optimal. Near real-time products provide a snapshot of the data during a short time period within a single orbit. The Apparent Optical Properties (OC_AOP) data suite provides satellite-derived measures of the interaction between solar radiation and the upper ocean. AOPs are “apparent” because they depend not only on the inherent optical properties (IOPs) of seawater and its constituents but also on the ambient light field. These variables are critical for studying light penetration, primary productivity, and biogeochemical cycling. Usage notes: - Rrs and Rrs_unc are stored as scaled integers; use the scale_factor and add_offset attributes to obtain physical values. - Quality control should use l2_flags per the flag_meanings attribute to mask clouds, land, high glint, and other conditions. Geophysical variables in this suite include: - Rrs — Remote sensing reflectance (sr⁻¹) - Rrs_unc — Uncertainty in remote sensing reflectance (sr⁻¹) - aot_865 — Aerosol optical thickness at 865 nm (unitless) - angstrom — Aerosol Ångström exponent, 443–865 nm (unitless) - avw — Apparent Visible Wavelength (nm) - nflh — Normalized Fluorescence Line Height (W m⁻² µm⁻¹ sr⁻¹) - l2_flags — Level-2 processing flags (bitmask; see per-variable attributes for flag_masks and flag_meanings)
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="PACE_OCI_L2_AOP_NRT",
version="3.1",
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
- OCI 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
- Data structure file for processing level L2 VIEW RELATED INFORMATION
- Sample data file for processing level L2 VIEW RELATED INFORMATION