VNP21A2: 8-Day Global Land Surface Temperature and Emissivity at 1km

VNP21A2 is an 8-day composite product providing land surface temperature and emissivity data at a 1-kilometer spatial resolution. It contains 11 science datasets within a single HDF file, including daytime and nighttime LST, quality control, view zenith angle, time of observation, and emissivity for three spectral bands. The product is algorithmically compatible with MODIS data to ensure continuity in Earth observation.

Use Cases

• Monitoring urban heat island intensity based on daytime and nighttime land surface temperature layers.
• Estimating surface energy fluxes for climate models using emissivity data for bands M14, M15, and M16.
• Assessing drought and vegetation stress via temporal analysis of the 8-day composite temperature time series.
• Validating and cross-calibrating MODIS LST products based on shared algorithmic approaches and atmospheric inputs.

Strengths

• Provides both daytime and nighttime observations within a single file, facilitating diurnal cycle analysis.
• Contains 11 distinct science datasets, including quality control and angular information for data fidelity.
• Algorithmically developed in synergy with MODIS Version 6.1 products, promoting data continuity.

Limitations

• Known issue of increased extreme high temperature outliers in unfiltered data, as noted in platform descriptions.
• Key metadata such as row count, file size, and specific license details are missing or conflicting across sources.
• Spatial resolution is 1km, which may be too coarse for localized or micro-scale applications.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Satellite remote sensing from the Suomi NPP spacecraft's VIIRS instrument, processed via a simple-averaging algorithm over 8-day periods.

Time Range

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Freshness

2026-04-09 20:57:07.002572

Geography

Global coverage on a sinusoidal (SIN) grid projection.