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Full catalog/MODIST_L3m_RRS
MODIST_L3m_RRS·v2022.0·dataset

How the ocean reflects color (Terra)

Terra MODIS Level-3 Global Mapped Remote-Sensing Reflectance (RRS) Data, version 2022.0
ocean NASA OB_CLOUD Level 3 active netCDF-4
In plain English

What it measures. How the ocean surface reflects sunlight at different colors (wavelengths), measured as the ratio of light leaving the water to light coming down onto it. This is the core color signal of the sea.

How it's made. Derived from the MODIS instrument on the Terra satellite and mapped into a global Level-3 product organized by color band.

How & where you'd use it. The foundational observable for ocean color science, used to estimate chlorophyll, water clarity, and water properties, and to develop and validate algorithms.

What's measured

Oceans › Ocean Optics › Reflectance

Coverage & cadence

  • Time span2000-02-24 → ongoing
  • Measured byTerra (MODIS)
  • Processing levelLevel 3
  • 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 Remote Sensing Reflectance (RRS) suite provides the remote sensing reflectance at wavelength λ (nm)—the ratio of water-leaving radiance to downwelling irradiance just above the surface (units sr⁻¹). Variables are named by their band center (e.g., Rrs_412, Rrs_443). Rrs_λ is the foundational observable used to retrieve products such as chlor_a, Kd_490, IOPs, and to support algorithm development, validation, water-quality, and ecosystem applications. Users should review per-file quality flags (e.g., land, cloud, sun glint, high aerosol) and mission documentation—especially in optically complex coastal/inland waters. Geophysical variables in this suite include: - Rrs — Remote sensing reflectance (sr⁻¹)

Get the data

modist_l3m_rrs_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="MODIST_L3m_RRS",
    version="2022.0",
    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.