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

MYD21 Version 6.1 provides daily land surface temperature and 3-band emissivity data in five-minute temporal increments from the MODIS instrument on NASA's Aqua satellite. The swath data has a nadir spatial resolution of 1,000 meters, with approximately 2,030 pixels along track and 1,354 pixels per scan line. The product is generated by the LPCLOUD organization using a physics-based Temperature/Emissivity Separation algorithm on thermal infrared bands.

Use Cases

• Monitor diurnal land surface temperature cycles using the five-minute acquisition intervals.
• Analyze surface emissivity in MODIS bands 29, 31, and 32 for material classification and energy budget studies.
• Detect thermal anomalies like wildfires or volcanic activity by identifying extreme high-temperature values retained in the output.
• Assess atmospheric correction performance under warm, humid conditions using the integrated Water Vapor Scaling scheme.
• Compare retrieval accuracy between the TES-based MYD21 and split-window-based MYD11 algorithms over different land covers.

Strengths

• High temporal resolution with data produced in five-minute increments of satellite acquisition.
• Simultaneous retrieval of both land surface temperature and spectral emissivity for three MODIS bands.
• Algorithm employs a physics-based Temperature/Emissivity Separation technique combined with Water Vapor Scaling atmospheric correction.

Limitations

• Known issue of extreme high-temperature outliers, especially over desert regions like the Sahara due to undetected cloud and dust.
• Contaminated pixels are retained in the output and may cause overestimated temperatures, requiring user-applied QC filtering.
• Product is susceptible to errors from high atmospheric aerosol optical depth during vast dust outbreaks.

Provenance

Source

NASA MODIS instrument on the Aqua satellite, processed by LPCLOUD.

Collection Method

Derived from MODIS thermal infrared bands 29, 31, and 32 using the ASTER Temperature/Emissivity Separation algorithm.

Time Range

Daily production.

Freshness

Produced daily.

Geography

Global coverage from satellite swath data.