Aqua MODIS FLH: Global Near Real-time Phytoplankton Fluorescence Data

NASA Ocean Biology DAAC produces near real-time global maps of phytoplankton chlorophyll-a fluorescence. The data suite quantifies Fluorescence Line Height (FLH), a key indicator for detecting harmful algal blooms and assessing phytoplankton physiology. Inputs and calibration are less than optimal as the product prioritizes rapid delivery over final accuracy.

Use Cases

• Detecting and tracking harmful algal blooms (HABs) based on elevated fluorescence line height values.
• Identifying productive ocean waters for fisheries management based on phytoplankton activity.
• Assessing phytoplankton physiology and stress responses based on fluorescence emission patterns.
• Monitoring coastal water quality and ecosystem health based on ocean color anomalies.

Strengths

• Provides near real-time data, offering a snapshot of ocean conditions within a single orbit.
• Includes the geophysical variable 'nflh' (Normalized Fluorescence Line Height) measured in physical units (W m⁻² µm⁻¹ sr⁻¹).
• Derived from NASA's Aqua MODIS satellite sensor, a well-established source for ocean color observations.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Uncertainties increase in optically complex coastal and inland waters, as noted in the algorithm documentation.
• Row count and file formats are unknown, which may limit suitability assessment.

Provenance

Source

NASA Ocean Biology DAAC (OB_CLOUD).

Collection Method

Satellite remote sensing from the Aqua MODIS instrument, processed using best-available ancillary meteorological and ozone data.

Freshness

Near real-time (NRT).

Geography

Global.