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Full catalog/MODIST_L3m_FLH
MODIST_L3m_FLH·v2022.0·dataset

Glow from ocean plant life, fluorescence (Terra)

Terra MODIS Level-3 Global Mapped Fluorescence Line Height (FLH) Data, version 2022.0
ocean NASA OB_CLOUD Level 3 active netCDF-4
In plain English

What it measures. Captures the faint red glow given off by ocean phytoplankton (microscopic sea plants) as they photosynthesize, measured as the height of that glow above the surrounding light.

How it's made. Computed from the MODIS instrument on NASA's Terra satellite and mapped onto a global grid as a Level-3 product.

How & where you'd use it. Used to detect and track harmful algal blooms, find productive waters, and gauge the health and activity of ocean plant life.

What's measured

Oceans › Ocean Optics › FluorescenceBIOSPHERE › ECOSYSTEMS › AQUATIC ECOSYSTEMSBIOSPHERE › VEGETATION › SOLAR INDUCED FLUORESCENCEBIOSPHERE › ECOSYSTEMS › AQUATIC ECOSYSTEMS › PLANKTON › PHYTOPLANKTON

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 Fluorescence Line Height (FLH) data suite quantifies the red chlorophyll-a fluorescence (~678–683 nm) emitted by phytoplankton, computed as the height of the measured water-leaving radiance above a spectrally interpolated baseline. FLH is widely used for HAB detection and tracking, identifying productive waters, and assessing phytoplankton physiology; values tend to be elevated in active blooms and can be reduced in complex waters. As with all ocean-color products, uncertainties increase in optically complex coastal/inland waters, so users should refer to mission/algorithm notes for details. Geophysical variables in this suite include: - nflh — Normalized Fluorescence Line Height (W m⁻² µm⁻¹ sr⁻¹) - ipar — Instantaneous Photosynthetically Available Radiation (mol photons m⁻² s⁻¹)

Get the data

modist_l3m_flh_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="MODIST_L3m_FLH",
    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.