Array · collection · 2025
ENVISAT MERIS Level-4 Global Mapped Apparent Visible Wavelength (AVW) Data, version 2022.0
Listed in NASA Earthdata CMR
AVW (Apparent Visible Wavelength) quantifies the spectral “center” of ocean color by summarizing the shape of the water‐leaving reflectance spectrum (Rrs) across the visible range.
Description
Reported in nanometers (nm), AVW is lower for bluer, clearer (oligotrophic) waters and higher for greener/browner, more optically complex or productive waters influenced by phytoplankton, colored dissolved organic matter (CDOM), or suspended sediments.
Users apply AVW for water-type classification, algorithm selection/blending (e.g., guiding chlorophyll retrievals), regional change detection, and as context alongside chlor_a, Kd_490, IOPs, and PAR. As with all ocean-color products, review quality flags (cloud/glint/aerosol) and note that interpretations can vary in optically complex coastal/inland waters. Geophysical variables in this suite include: - avw — Apparent Visible Wavelength (nm)
Links
Get the data
- search.earthdata.nasa.gov /search/granules?p=C3467581150-OB_CLOUD ↗
Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data.
download · from NASA CMR
- NASA's Ocean Color Web - Data Distribution Site oceandata.sci.gsfc.nasa.gov/directdataaccess/Level-4%20Mapped/MERIS ↗
download · from NASA CMR
Where it is published
- DOI doi.org/10.5067/envisat/meris/rr/l4m/avw/2022.0 ↗
DOI / persistent id · from NASA CMR
Documentation and papers
- View the version history of this product. oceancolor.gsfc.nasa.gov/data/reprocessing ↗
documentation · from NASA CMR
- ENVISAT Homepage earthdata.nasa.gov/data/platforms/space-based-platforms/ENVISAT ↗
documentation · from NASA CMR
- MERIS Homepage earthdata.nasa.gov/data/instruments/MERIS ↗
documentation · from NASA CMR
- nasa.github.io /oceandata-notebooks ↗
Satellite data procesing can be difficult. We're here to help! Visit the Oceandata Help Hub to navigate learning content for accessing visualizing, and analyzing data products.
documentation · from NASA CMR
- oceancolor.gsfc.nasa.gov /files/atbd/atbd-obdaac-apparent-visible-wavelength.pdf ↗
Algorithm Theoretical Basis Document for Apparent Visible Wavelength (AVW)
documentation · from NASA CMR
Catalogue records · 3
- oceandata.sci.gsfc.nasa.gov /opendap/MERIS/L4SMI ↗
OPeNDAP Site for ENVISAT MERIS Standard Mapped Image (SMI) Product
metadata API · from NASA CMR
- CMR UMM-JSON cmr.earthdata.nasa.gov/search/concepts/C3467581150-OB_CLOUD.umm_json ↗
metadata API · from NASA CMR
- CMR record cmr.earthdata.nasa.gov/search/concepts/C3467581150-OB_CLOUD.html ↗
catalogue entry · from NASA CMR
Topics
- Stated by source
- Environmental Satellite · Light Transmission · Medium Resolution Imaging Spectrometer · Ocean Color · Surface Water · Visible Wavelengths · Water Color · Water Quality
- Inferred from text
- Oceanography 69%
Provenance · 1 source records, 18 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| NASA Earthdata CMR | C3467581150-OB_CLOUD | 8 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[field].anzsrc:group:3708 | enrichment · NASA CMR | taxonomy-embedding@1.1.0 | title+keywords+description (69%) |
| concepts[instrument].gcmd_instrument:meris | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/oceans/ocean-optics/ocean-color | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science-services/environmental-advisories/hydrological-advisories/water-quality | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/spectral-engineering/visible-wavelengths | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/terrestrial-hydrosphere/surface-water | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/terrestrial-hydrosphere/water-quality-water-chemistry/water-characteristics/light-transmission | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/terrestrial-hydrosphere/water-quality-water-chemistry/water-characteristics/water-color | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[platform].gcmd_platform:envisat | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| created_date | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| description | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/Abstract |
| publication_date | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| spatial | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/SpatialExtent |
| temporal | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/TemporalExtents |
| title | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/EntryTitle |
| updated_date | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| version_label | source · NASA CMR | connector:nasa_cmr@1.0.0 |