![COPERNICUS/MARINE/OC_GLO_BGC/TRANSPARENCY_OLCI_4KM](https://developers.google.com/earth-engine/datasets/images/COPERNICUS/COPERNICUS_MARINE_OC_GLO_BGC_TRANSPARENCY_OLCI_4KM_sample.png)

Dataset Availability
:   2025-03-01T00:00:00Z--2026-10-01T00:00:00Z

Dataset Producer
:


    [Copernicus](https://doi.org/10.48670/moi-00279)

Cadence
:   1 Month

Tags
:
    [copernicus](https://developers.google.com/earth-engine/datasets/tags/copernicus.md.txt) [oceans](https://developers.google.com/earth-engine/datasets/tags/oceans.md.txt)

#### Description

The Global Ocean Colour (Copernicus-GlobColour) dataset is a Bio-Geo-Chemical
(BGC) product developed by ACRI-ST. Derived from multiple satellite sources
like SeaWiFS, MODIS, and OLCI. It provides a comprehensive range of
oceanographic variables, including: Chlorophyll (CHL),
Phytoplankton Functional types and sizes (PFT), Primary Production (PP),
Suspended Matter (SPM), Secchi Transparency Depth (ZSD),
Diffuse Attenuation (KD490), Particulate Backscattering (BBP),
Absorption Coefficient (CDM), Reflectance (RRS) and more.

This dataset provides global-scale data on ocean transparency.
Its primary layer is the Diffuse Attenuation Coefficient at 490nm (KD490)),
a key indicator of water clarity. Higher KD490values signify lower
transparency due to the rapid absorption of blue-green light by constituents
like phytoplankton or sediments. This L4 dataset, derived from the Ocean and
Land Colour Instrument (OLCI), is a valuable resource for monitoring marine
bio-geochemical processes and assessing water quality.

Documentation:

- [User's Guide](https://documentation.marine.copernicus.eu/PUM/CMEMS-OC-PUM.pdf)

- [Quality Information Document](https://documentation.marine.copernicus.eu/QUID/CMEMS-OC-QUID-009-101to104-111-113-116-118.pdf)

- [Copernicus Marine Datastore](https://data.marine.copernicus.eu/products)

NOTE: The provider may remove Copernicus Marine data (especially Near
Real-Time, NRT, observations) from their repository after some time,
possibly aggregating that data into different (e.g., monthly) products.
However, the corresponding assets remain available in the Earth Engine
collection.

### Bands

**Bands**

Pixel size: 4638.3 meters (all bands)

| Name | Units | Pixel Size | Description |
|---|---|---|---|
| `KD490` | 1/m | 4638.3 meters | Diffuse attenuation coefficient at 490 nm |
| `KD490_uncertainty` | % | 4638.3 meters | Diffuse attenuation coefficient at 490 nm - The uncertainty as measured in hundredths of a percent (e.g., a value of 5000 means 50%). |
| `flags` |   | 4638.3 meters | Land water mask bit. - 0: Water - 1: Land |

### Terms of Use

**Terms of Use**

This dataset is released for use under Service Level Agreement (SLA),
using the acronym "CMEMS" or the shortened name "Copernicus Marine Service"
both denote the E.U. Copernicus Marine Environment Monitoring Service.
Highlights and key features of the licence are provided in this document
[License](https://marine.copernicus.eu/user-corner/service-commitments-and-licence)

### Citations

Citations:

- Copernicus Global Ocean Colour: Global Ocean Satellite Observations,
  ACRI-ST company (Sophia Antipolis, France) is providing Bio-Geo-Chemical
  (BGC) products based on the Copernicus-GlobColour processor.
  [doi:10.48670/moi-00279](https://doi.org/10.48670/moi-00279)

### Explore with Earth Engine

> [!NOTE]
> **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)

### Code Editor (JavaScript)

```javascript
var dataset =
    ee.ImageCollection('COPERNICUS/MARINE/OC_GLO_BGC/TRANSPARENCY_OLCI_4KM')
        .filter(ee.Filter.date('2025-03-01', '2025-06-01'));

var KD490 = dataset.select('KD490');
var vis = {
  min: 0.021,
  max: 0.212,
  palette:
      ['D7F9D0', '91CA85', '5AB05D', '129450', '0F7347', '195437', '122414'],
};
Map.setCenter(71, 52, 2);
Map.addLayer(KD490, vis, 'KD490');
```
[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/COPERNICUS/COPERNICUS_MARINE_OC_GLO_BGC_TRANSPARENCY_OLCI_4KM) [Global Ocean Colour: Bio-Geo-Chemical, L4, from Satellite Observations, Transparency, OLCI, 4KM](https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_MARINE_OC_GLO_BGC_TRANSPARENCY_OLCI_4KM.md.txt) The Global Ocean Colour (Copernicus-GlobColour) dataset is a Bio-Geo-Chemical (BGC) product developed by ACRI-ST. Derived from multiple satellite sources like SeaWiFS, MODIS, and OLCI. It provides a comprehensive range of oceanographic variables, including: Chlorophyll (CHL), Phytoplankton Functional types and sizes (PFT), Primary Production (PP), Suspended Matter (SPM), Secchi Transparency Depth ... COPERNICUS/MARINE/OC_GLO_BGC/TRANSPARENCY_OLCI_4KM, copernicus,oceans 2025-03-01T00:00:00Z/2026-10-01T00:00:00Z -90 -180 90 180 Google Earth Engine https://developers.google.com/earth-engine/datasets

- [](https://doi.org/https://doi.org/10.48670/moi-00279)
- [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_MARINE_OC_GLO_BGC_TRANSPARENCY_OLCI_4KM)