Black Sea Chlorophyll-a time series and trend from Observations Reprocessing
'''DEFINITION'''
The time series are derived from the regional chlorophyll reprocessed (MY) product as distributed by CMEMS. This dataset, derived from multi-sensor (SeaStar-SeaWiFS, AQUA-MODIS, NOAA20-VIIRS, NPP-VIIRS, Envisat-MERIS and Sentinel3-OLCI) Rrs spectra produced by CNR using an in-house processing chain, is obtained by means of two different regional algorithms developed with the BiOMaP data set (Zibordi et al., 2011): a band-ratio algorithm (B/R) (Zibordi et al., 2015) and a Multilayer Perceptron (MLP) neural net algorithm based on Rrs values at three individual wavelengths (490, 510 and 555 nm) (Kajiyama et al., 2018). The processing chain and the techniques used for algorithms merging are detailed in Colella et al. (2023). Monthly regional mean values are calculated by performing the average of 2D monthly mean (weighted by pixel area) over the region of interest. The deseasonalized time series is obtained by applying the X-11 seasonal adjustment methodology on the original time series as described in Colella et al. (2016), and then the Mann-Kendall test (Mann, 1945; Kendall, 1975) and Sens’s method (Sen, 1968) are subsequently applied to obtain the magnitude of trend.
'''CONTEXT '''
Phytoplankton and chlorophyll concentration as a proxy for phytoplankton respond rapidly to changes in environmental conditions, such as light, temperature, nutrients and mixing (Gregg and Rousseaux, 2014, Colella et al. 2016). The character of the response depends on the nature of the change drivers, and ranges from seasonal cycles to decadal oscillations (Basterretxea et al. 2018). Therefore, it is of critical importance to monitor chlorophyll concentration at multiple temporal and spatial scales, in order to be able to separate potential long-term climate signals from natural variability in the short term. In particular, phytoplankton in the Black Sea is known to respond to climate variability associated with the North Atlantic Oscillation (NAO) (Oguz et al .2003).
'''CMEMS KEY FINDINGS'''
In the Black Sea, the trend average for the 1997-2022 period is definitely negative (-1.33±1.12% per year). Nevertheless, this negative trend is lower than the one estimated in the previous release (related to 1997-2021). The negative trend is mainly due to the marked change on chlorophyll concentrations between 2002 and 2004. From 2004 onwards, minima and maxima are strongly variable year by year. However, on average, the minima/maxima variability can be considered quite constant with a continuous decrease of maxima from 2015 up to mid 2020 where signal seems to change again with relative high chlorophyll values in 2021 and 2022 (especially at the end of the year). The general negative trend in the Black Sea is also confirmed by the analysis of Sathyendranath et al. (2018), that reveals an increasing trend in chlorophyll concentration in all the European Seas, except for the Black Sea.
'''Figure caption'''
Black Sea time series and trend (1997-2022) of satellite chlorophyll, based on CMEMS product OCEANCOLOUR_BLK_BGC_L4_MY_009_154. The monthly regional average (weighted by pixel area) time series is shown in grey, with the deseasonalized time series in green and the trend in blue.
'''DOI (product):'''
Simple
- Alternate title
-
OMI_HEALTH_CHL_BLKSEA_OCEANCOLOUR_area_averaged_mean
- Date (Creation)
- 2018-02-12
- Edition
-
3.4
- Edition date
- 2023-11-30
- Identifier
- a78600a4-a280-47b5-8ddd-0dc8b5e9c9d9
- Credit
-
E.U. Copernicus Marine Service Information
- Maintenance and update frequency
- Annually
- Other
-
P0M0D0H/P0M0D0H
- Maintenance note
-
N/A
-
GEMET - INSPIRE themes, version 1.0
- Climate and Forecast Standard Names
-
- mass_concentration_of_chlorophyll_in_seawater
- 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
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Date (Creation)
- 2019-05-08
- Association Type
- Cross reference
- Initiative Type
- reference
- Aggregate Datasetindentifier
- 7277cedd-3404-4502-a80b-64a16be9110c
- Association Type
- Cross reference
- Initiative Type
- document
- Aggregate Datasetindentifier
- 0353efc7-c1e0-4420-baca-77d6bff6ab02
- Association Type
- Cross reference
- Initiative Type
- document
- Aggregate Datasetindentifier
- 75c2f83c-7159-492a-b383-a1cc3f5f2ede
- Association Type
- Cross reference
- Initiative Type
- document
- Metadata language
-
eng
- Topic category
-
- Oceans
- Description
-
bounding box
- Begin date
- 1997-01-01
Vertical extent
- Minimum value
- 0
- Maximum value
- 0
- Supplemental Information
-
display priority: 53800
- Codespace
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EPSG
- Number of dimensions
- 2
- Dimension name
- Row
- Resolution
- 1 km
- Dimension name
- Column
- Resolution
- 1 km
- Cell geometry
- Area
- Transformation parameter availability
- No
- Distribution format
-
-
NetCDF-4
(
Classic model
)
-
NetCDF-4
(
Classic model
)
Distributor
- OnLine resource
-
omi_health_chl_blksea_oceancolour_area_averaged_mean
(
WWW:STAC
)
For accessing native data and Analysis-ready Cloud-optimized data services, consult this STAC metadata endpoint
- OnLine resource
- omi_health_chl_blksea_oceancolour_area_averaged_mean ( OGC:WMTS )
- 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
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vertical level number: 1
- Included with dataset
- No
- Feature types
- Point series
- File identifier
- 8be6196d-67f6-454b-b067-1f9b6470bba9 XML
- Metadata language
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- Character set
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- Hierarchy level
- Series
- Hierarchy level name
-
Copernicus Marine Service product specification
- Date stamp
- 2024-03-25T08:32:43.394Z
- Metadata standard name
-
ISO 19139, MyOcean profile
- Metadata standard version
-
0.2