MODIS/Aqua MYD21: Daily Land Surface Temperature and Emissivity at 1km Resolution

MYD21 Version 6 data products were decommissioned on July 31, 2023. The daily Level 2 swath data product provides land surface temperature and emissivity in five-minute increments, with a nadir resolution of 1,000 meters and a swath size of approximately 2,030 pixels along track and 1,354 pixels per line. It is produced by NASA using a physics-based algorithm that retrieves LST and spectral emissivity simultaneously from MODIS thermal infrared bands.

Use Cases

• Monitoring daily land surface temperature dynamics based on five-minute temporal increments.
• Analyzing spectral emissivity for different land cover types based on retrievals from MODIS bands 29, 31, and 32.
• Comparing temperature retrieval methodologies based on the ASTER TES technique versus split-window algorithms.
• Studying surface thermal properties in desert regions, noting potential contamination from undetected cloud and dust.
• Applying quality control filtering to identify and remove extreme high temperature outliers mentioned in known issues.

Strengths

• Provides daily data in five-minute temporal increments of satellite acquisition.
• Uses a physics-based Temperature/Emissivity Separation (TES) algorithm for simultaneous retrieval of LST and emissivity.
• Swath dimensions are approximately 2,030 pixels along track and 1,354 pixels per line at 1km nadir resolution.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Known issues include occurrences of extreme high temperature outliers, especially over desert regions, requiring user QC filtering.
• Products are available two months after acquisition due to latency of data inputs.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Produced from MODIS/Aqua satellite data using a physics-based algorithm.

Freshness

Last updated 2026-03-13 00:23:55.319035; freshness should be verified.

Geography

Global swath coverage.