Full catalog/MODISA_L2_OC_NRT
MODISA_L2_OC_NRT·v2022.0·dataset

Ocean color and tiny plant life, live (Aqua MODIS)

Aqua MODIS Level-2 Regional Ocean Color (OC) - Near Real-time (NRT) Data, version 2022.0
ocean NASA OB_CLOUD Level 2 active netCDF-4
In plain English

What it measures. Ocean color readings that reveal chlorophyll from tiny floating plants (phytoplankton), how clear or murky the water is, and how light interacts with the upper ocean, delivered quickly for a single satellite pass.

How it's made. Captured by the MODIS instrument on NASA's Aqua satellite and processed in near-real-time, which trades some calibration accuracy for speed.

How & where you'd use it. Useful for keeping an eye on ocean plant life, water clarity, and biological activity as it unfolds; the quick-turnaround tradeoff means it's better for timely snapshots than precise long-term records.

What's measured

Oceans › Ocean Optics › Ocean ColorOceans › Ocean Optics › ReflectanceAtmosphere › Aerosols › Aerosol Optical Depth/ThicknessAtmosphere › Aerosols › Aerosol Optical Depth/Thickness › Angstrom ExponentOceans › Ocean Optics › Chlorophyll › Chlorophyll ConcentrationOceans › Ocean Optics › Attenuation/TransmissionOceans › Ocean Chemistry › Organic CarbonOceans › Ocean Chemistry › Inorganic CarbonOceans › Ocean Optics › FluorescenceOceans › Ocean Optics › Photosynthetically Active Radiation

Coverage & cadence

  • Time span2002-07-04 → ongoing
  • Measured byAqua (MODIS)
  • 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 Ocean Color (OC) data suite provides calibrated, atmospherically corrected ocean-optics measurements and derived biogeophysical products. This data suite includes the Apparent Optical Properties (AOP) and 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. Geophysical variables in this suite include: - Kd_490 - Diffuse attenuation coefficient at 490 nm, KD2 algorithm (m⁻¹) - Rrs - Remote sensing reflectance (sr⁻¹) - angstrom - Aerosol Angstrom exponent, 443 to 865 nm - chlor_a - Chlorophyll Concentration, OCI Algorithm (mg m⁻³) - l2_flags - Level-2 Processing Flags - aot_869 - Aerosol optical thickness at 869 nm - ipar - Instantaneous Photosynthetically Available Radiation (einstein m⁻² s⁻¹) - nflh - Normalized Fluorescence Line Height (W m⁻² um⁻¹ sr⁻¹) - par - Photosynthetically Available Radiation, R. Frouin (einstein m⁻² day⁻¹) - pic - Calcite Concentration, Balch and Gordon (mol m⁻³) - poc - Particulate Organic Carbon, D. Stramski, 2007 (443/555 version) (mg m⁻³)

Get the data

modisa_l2_oc_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="MODISA_L2_OC_NRT",
    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.