[ARCHIVE] Mediterranean Sea Monthly Attenuation Coefficient at 490nm from Multi Satellite and Sentinel-3 OLCI observations
'''This product has been archived'''
For operationnal and online products, please visit https://marine.copernicus.eu
'''Short description:'''
The Global Ocean Satellite monitoring and marine ecosystem study group (GOS) of the Italian National Research Council (CNR), in Rome operationally produces Level-4 product includes monthly averaged datasets of the diffuse attenuation coefficient of light at 490 nm (Kd490) for multi-sensor (MODIS-AQUA, NOAA20-VIIRS, NPP-VIIRS, Sentinel3A-OLCI at 300m of resolution) (at 1 km resolution) and Sentinel3A-OLCI observations (at 300m resolution). Kd490 is the diffuse attenuation coefficient of light at 490 nm, and is a measure of the turbidity of the water column, i.e., how visible light in the blue-green region of the spectrum penetrates the water column. It is directly related to the presence of absorbing and scattering matter in the water column and is estimated through the ratio between Rrs at 490 and 555 nm. For the multi-sensor dataset, single sensor Rrs fields are band-shifted, over the SeaWiFS native bands (using the QAAv6 model, Lee et al., 2002) and merged with a technique aimed at smoothing the differences among different sensors. This technique is developed by the GOS. The QAA allows the inversion of the radiative transfer equations to compute the Inherent Optical Properties. Level-4 product includes monthly averages along with the standard deviation and the number of observations in the period of integration.
'''Processing information:'''
Multi-sensor products are constituted by MODIS-AQUA, NOAA20-VIIRS, NPP-VIIRS and Sentinel3A-OLCI. For consistency with NASA L2 dataset, BRDF correction was applied to Sentinel3A-OLCI prior to band shifting and multi sensor merging. Hence, the single sensor OLCI data set is also distributed after BRDF correction. Single sensor NASA Level-2 data are destriped and then all Level-2 data are remapped at 1 km spatial resolution (300m for Sentinel3A-OLCI) using cylindrical equirectangular projection. Afterwards, single sensor Rrs fields are band-shifted, over the SeaWiFS native bands (using the QAAv6 model, Lee et al., 2002) and merged with a technique aimed at smoothing the differences among different sensors. This technique is developed by The Global Ocean Satellite monitoring and marine ecosystem study group (GOS) of the Italian National Research Council (CNR, Rome). Then geophysical fields (i.e. chlorophyll, kd490, bbp, aph and adg) are estimated via state-of-the-art algorithms for better product quality. Time averages are computed on the delayed-time data.
'''Description of observation methods/instruments:'''
Ocean colour technique exploits the emerging electromagnetic radiation from the sea surface in different wavelengths. The spectral variability of this signal defines the so-called ocean colour which is affected by the presence of phytoplankton.
'''Quality / Accuracy / Calibration information:'''
A detailed description of the calibration and validation activities performed over this product can be found on the CMEMS web portal.
'''Suitability, Expected type of users / uses:'''
This product is meant for use for educational purposes and for the managing of the marine safety, marine resources, marine and coastal environment and for climate and seasonal studies.
'''Dataset names :'''
*dataset-oc-med-opt-multi-l4-kd490_1km_monthly-rt-v02
*dataset-oc-med-opt-olci-l4-kd490_300m_monthly-rt
'''Files format:'''
*CF-1.4
*INSPIRE compliant
'''DOI (product) :'''
Simple
- Alternate title
- OCEANCOLOUR_MED_OPTICS_L4_NRT_OBSERVATIONS_009_039
- Date (Creation)
- 2013-03-13
- Edition
- 2.1
- Edition date
- 2021-04-26
- Identifier
- c012de84-bfc4-4030-9b12-2c1c2648f55f
- Credit
- E.U. Copernicus Marine Service Information
- Maintenance and update frequency
- Monthly
- Other
- /
- Maintenance note
- 13:00
- GEMET - INSPIRE themes, version 1.0
- Use limitation
- See Copernicus Marine Environment Monitoring Service Data commitments and licence at: http://marine.copernicus.eu/web/27-service-commitments-and-licence.php
- Access constraints
- Other restrictions
- Use constraints
- License
- Other constraints
- No limitations on public access
- Aggregate Datasetindentifier
- 7bdc830b-6321-4ffb-ae76-8707256c6d03
- Association Type
- Cross reference
- Initiative Type
- document
- Aggregate Datasetindentifier
- e0f8a482-d960-4c72-8976-8c63873ea4de
- Association Type
- Cross reference
- Initiative Type
- document
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Metadata language
- eng
- Topic category
-
- Oceans
- Description
- bounding box
- Begin date
- 2016-04-25
Vertical extent
- Supplemental Information
- display priority: 11705
- Reference system identifier
- EPSG / WGS 84 / Plate Carree (EPSG:32662)
- Number of dimensions
- 2
- Dimension name
- Row
- Resolution
- 0.3 km
- Dimension name
- Column
- Resolution
- 0.3 km
- Cell geometry
- Area
- Transformation parameter availability
- No
- Distribution format
-
-
NetCDF-4
(
Classic model
)
-
NetCDF-4
(
Classic model
)
- Hierarchy level
- Series
Conformance result
- Date (Publication)
- 2010-12-08
- Explanation
- See the referenced specification
- Statement
- The myOcean products depends on other products for production or validation. The detailed list of dependencies is given in ISO19115's aggregationInfo (ISO19139 Xpath = "gmd:MD_Metadata/gmd:identificationInfo/gmd:aggregationInfo[./gmd:MD_AggregateInformation/gmd:initiativeType/gmd:DS_InitiativeTypeCode/@codeListValue='upstream-validation' or 'upstream-production']")
- Attribute description
- observation
- Content type
- Physical measurement
- Descriptor
- vertical level number: 1
- Descriptor
- temporal resolution: monthly mean
- Included with dataset
- No
- Feature types
- Grid
- File identifier
- c012de84-bfc4-4030-9b12-2c1c2648f55f XML
- Metadata language
- English
- Character set
- UTF8
- Hierarchy level
- Series
- Hierarchy level name
- Copernicus Marine Service product specification
- Date stamp
- 2022-06-29T09:08:33.635Z
- Metadata standard name
- ISO 19139, MyOcean profile
- Metadata standard version
- 0.2