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 data       graph  M    files  8-day average satellite (Sentinel 3A and 3B) chlorophyll and suspended matter concentrations
for coastal British Columbia and southeast Alaska 		   ?   F   I   M   background (external link) RSS Subscribe Hakai Institute sentinel_3A_POLYMER_8Day

The Dataset's Variables and Attributes

Row Type Variable Name Attribute Name Data Type Value
attribute NC_GLOBAL cdm_data_type String Grid
attribute NC_GLOBAL citation String Costa, M., & Hakai Institute. (2023). Sentinel-3A OLCI Imagery - Automated daily POLYMER processed satellite chlorophyll concentrations for coastal British Columbia and southeast Alaska (Version v1). Hakai Institute
attribute NC_GLOBAL contributor_name String Maycira Costa - Spectral Laboratory
attribute NC_GLOBAL contributor_role String Principal Investigator - Collaborator - Originator
attribute NC_GLOBAL Conventions String CF-1.6, COARDS, ACDD-1.3
attribute NC_GLOBAL creator_institution String Hakai Institute
attribute NC_GLOBAL creator_name String Hakai Institute
attribute NC_GLOBAL creator_type String institution
attribute NC_GLOBAL creator_url String https://www.hakai.org/ (external link)
attribute NC_GLOBAL date_created String 2023-08-01
attribute NC_GLOBAL defaultGraphQuery String chl_conc_mean[last][0][0:last][0:last]&.draw=surface&.vars=longitude|latitude|temp
attribute NC_GLOBAL Easternmost_Easting double -121.50242544017246
attribute NC_GLOBAL geospatial_lat_max double 59.5000898311175
attribute NC_GLOBAL geospatial_lat_min double 47.00098814229249
attribute NC_GLOBAL geospatial_lat_resolution double 0.0026949335249730503
attribute NC_GLOBAL geospatial_lat_units String degrees_north
attribute NC_GLOBAL geospatial_lon_max double -121.50242544017246
attribute NC_GLOBAL geospatial_lon_min double -139.00062881782247
attribute NC_GLOBAL geospatial_lon_resolution double 0.0026949335249730503
attribute NC_GLOBAL geospatial_lon_units String degrees_east
attribute NC_GLOBAL id String d1bef0b7-4d15-4bc1-bf34-faca6352891f
attribute NC_GLOBAL infoUrl String ???
attribute NC_GLOBAL institution String Hakai Institute
attribute NC_GLOBAL keywords String abundance and biomass, chlorophyll a, coastal zone, phytoplankton, remote sensing, water quality
attribute NC_GLOBAL license String https://creativecommons.org/licenses/by/4.0 (external link)
attribute NC_GLOBAL metadata_profile String beam
attribute NC_GLOBAL metadata_version String 0.5
attribute NC_GLOBAL naming_authority String ca.cioos
attribute NC_GLOBAL Northernmost_Northing double 59.5000898311175
attribute NC_GLOBAL platform String satellite
attribute NC_GLOBAL platform_vocabulary String https://vocab.nerc.ac.uk/collection/L06/current/ (external link)
attribute NC_GLOBAL product_type String BINNED-L3
attribute NC_GLOBAL product_version String 1
attribute NC_GLOBAL project String Oceanography
attribute NC_GLOBAL publisher_institution String Hakai Institute
attribute NC_GLOBAL publisher_name String Hakai Institute
attribute NC_GLOBAL publisher_type String institution
attribute NC_GLOBAL publisher_url String https://www.hakai.org/ (external link)
attribute NC_GLOBAL references String https://doi.org/ (external link)
attribute NC_GLOBAL sourceUrl String (local files)
attribute NC_GLOBAL Southernmost_Northing double 47.00098814229249
attribute NC_GLOBAL standard_name_vocabulary String CF Standard Name Table v70
attribute NC_GLOBAL summary String This is an ongoing dataset of fully processed 8-day average Sentinel 3A and 3B chlorophyll-a (Chla) and suspended particulate matter (SPM) imagery for coastal and offshore British Columbia (BC) and Southeast Alaska waters. Sentinel 3A and 3B are European Space Agency (ESA) oceanography satellites jointly operated with the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT). The ocean and land colour instrument (OLCI) onboard both satellites has a 300m spatial resolution, near daily temporal coverage (when 3A and 3B are combined), 21 spectral bands from 400-1200nm, high signal-to-noise ratio and an off-nadir swath centered to minimize ocean sun glint. These features make the instruments well suited to retrievals of biogeochemical products from optically complex coastal waters.

At the University of Victoria (BC, Canada), the SPECTRAL remote sensing laboratory has performed extensive evaluation of methods for the best regional Chla and SPM retrievals. Validation with in-situ data showed the best results using Level-1 imagery processed with the POLYnomial based algorithm applied to MERIS (POLYMER) processor. Following validation, the SPECTRAL laboratory and the MOD(ularity) Squad developed an automated processing system that: 1) downloads imagery from the Marine Copernicus Online Data Access (CODA) web service; 2) applies POLYMER and flagging and; 3) mosaics the imagery for fully processed Chla and SPM concentrations over the study region. Additionally, an interactive public web interface was created to view the near real time outputs at www.algaeexplorer.ca (provided in resources). Full validation details are provided in Giannini et al. (2021) and processing details in Jacoby et al. (2019) and Marchese et al. (2022) referenced in the resources.

In 2022, the Hakai Institute took responsibility of the project, added processing of 3B imagery and 8-day averaging of 3A and 3B imagery, created automated submission to the Canadian Integrated Ocean Observing System (CIOOS) and updated the Algae Explorer web interface to include all products. Averaging imagery over 8 days considerably improves spatial coverage in cloudy regions such as the northeast Pacific.

This product provides the best known regional OLCI Chla and SPM retrievals shown to have low systematic biases (<1%) and follow expected seasonal and spatial trends; however, relative percent difference between validation data and satellite retrievals was high notably for Chla (~83%) due to the underestimation of high Chla concentrations and potentially an artifact of spatial-temporal mismatches between validation samples and image pixels. The SPECTRAL laboratory has performed initial radiometric comparisons of 3A and 3B imagery and shown highly comparable data; however, comparison of biogeochemical outputs is still in progress. Further uncertainties exist in high turbidity regions (Fraser River plume and fjords) where uncorrectable poor-quality pixels are sometimes observed. Additionally, an unresolved data striping issue is periodically present and observed as a narrow band of distorted pixels, which sometimes evades the land mask and, crosses images diagonally above Vancouver Island. Efforts are underway to correct this issue. Data users should consider these uncertainties and issues when using the data.

Satellite remote sensing is increasingly used to study surface ocean processes at the spatial and temporal resolutions required for understanding long term variability under a changing climate. Chlorophyll-a is the most widely used measure of phytoplankton biomass and crucial for understanding phytoplankton which are the base of the marine food web and control ocean biogeochemical cycling. Suspended particulate matter is a key water quality indicator (i.e. turbidity) with increased concentrations reducing light availability to aquatic species.

Funding for validation and automation development was provided by the UBC/UVic Hakai Coastal Initiative postdoctoral fellowship, NSERC NCE Marine Environmental Observation Prediction and Response (MEOPAR) network, Canadian Space Agency (CSA), Canadian Foundation for Innovation (CFI) and NSERC Discover Grant awarded to Maycira Costa.

It is requested that Giannini et al. (2021), Jacoby et al. (2019) and Marchese et al. (2022) are referenced if data is used for published research and the ESA acknowledged as the data provider.
attribute NC_GLOBAL TileSize String 64:64
attribute NC_GLOBAL time_coverage_end String 2024-04-26T00:00:00Z
attribute NC_GLOBAL time_coverage_start String 2020-06-27T00:00:00Z
attribute NC_GLOBAL title String 8-day average satellite (Sentinel 3A and 3B) chlorophyll and suspended matter concentrations for coastal British Columbia and southeast Alaska
attribute NC_GLOBAL Westernmost_Easting double -139.00062881782247
dimension time   double nValues=295, evenlySpaced=false, averageSpacing=4 days 18h 12m 15s
attribute time _CoordinateAxisType String Time
attribute time actual_range double 1.593216E9, 1.7140896E9
attribute time axis String T
attribute time ioos_category String Time
attribute time long_name String Time
attribute time standard_name String time
attribute time time_origin String 01-JAN-1970 00:00:00
attribute time units String seconds since 1970-01-01T00:00:00Z
dimension latitude   double nValues=4639, evenlySpaced=true, averageSpacing=-0.0026949335249730503
attribute latitude _CoordinateAxisType String Lat
attribute latitude actual_range double 47.00098814229249, 59.5000898311175
attribute latitude axis String Y
attribute latitude ioos_category String Location
attribute latitude long_name String Latitude
attribute latitude standard_name String latitude
attribute latitude units String degrees_north
attribute latitude valid_max double 59.5000898311175
attribute latitude valid_min double 47.00098814229249
dimension longitude   double nValues=6494, evenlySpaced=true, averageSpacing=0.0026949335249730503
attribute longitude _CoordinateAxisType String Lon
attribute longitude actual_range double -139.00062881782247, -121.50242544017246
attribute longitude axis String X
attribute longitude ioos_category String Location
attribute longitude long_name String Longitude
attribute longitude standard_name String longitude
attribute longitude units String degrees_east
attribute longitude valid_max double -121.50242544017246
attribute longitude valid_min double -139.00062881782247
variable num_obs   int time, latitude, longitude
attribute num_obs _FillValue int -1
attribute num_obs long_name String Num Obs
variable num_passes   short time, latitude, longitude
attribute num_passes _FillValue short -1
attribute num_passes long_name String Num Passes
variable logchl_mean   float time, latitude, longitude
attribute logchl_mean _FillValue float NaN
attribute logchl_mean long_name String Logchl Mean
variable logchl_sigma   float time, latitude, longitude
attribute logchl_sigma _FillValue float NaN
attribute logchl_sigma long_name String Logchl Sigma
variable logchl_counts   float time, latitude, longitude
attribute logchl_counts _FillValue float NaN
attribute logchl_counts long_name String Logchl Counts
variable logchl_p50   float time, latitude, longitude
attribute logchl_p50 _FillValue float NaN
attribute logchl_p50 long_name String Logchl P50
variable SPM_mean   float time, latitude, longitude
attribute SPM_mean _FillValue float NaN
attribute SPM_mean cell_method String time: mean (interval: 1 day comments: previous 8 day from present inclusively)
attribute SPM_mean colorBarMaximum float 50.0
attribute SPM_mean colorBarMinimum float 0.02
attribute SPM_mean colorBarPalette String Spectrum
attribute SPM_mean colorBarScale String Log
attribute SPM_mean long_name String SPM Mean
attribute SPM_mean units String mg/m^3
variable SPM_sigma   float time, latitude, longitude
attribute SPM_sigma _FillValue float NaN
attribute SPM_sigma cell_method String time: standard deviation (interval: 1 day comments: previous 8 day from present inclusively)
attribute SPM_sigma colorBarMaximum float 5.0
attribute SPM_sigma colorBarMinimum float 0.005
attribute SPM_sigma colorBarPalette String KT_thermal
attribute SPM_sigma colorBarScale String Log
attribute SPM_sigma long_name String SPM Sigma
attribute SPM_sigma units String mg/m^3
variable SPM_counts   float time, latitude, longitude
attribute SPM_counts _FillValue float NaN
attribute SPM_counts cell_method String time: count (interval: 1 day comments: previous 8 day from present inclusively)
attribute SPM_counts long_name String SPM Counts
variable SPM_p50   float time, latitude, longitude
attribute SPM_p50 _FillValue float NaN
attribute SPM_p50 cell_method String time: median (interval: 1 day comments: previous 8 day from present inclusively)
attribute SPM_p50 colorBarMaximum float 50.0
attribute SPM_p50 colorBarMinimum float 0.02
attribute SPM_p50 colorBarPalette String Spectrum
attribute SPM_p50 colorBarScale String Log
attribute SPM_p50 long_name String SPM P50
attribute SPM_p50 units String mg/m^3
variable chl_conc_mean   float time, latitude, longitude
attribute chl_conc_mean _FillValue float NaN
attribute chl_conc_mean cell_method String time: mean (interval: 1 day comments: previous 8 day from present inclusively)
attribute chl_conc_mean colorBarMaximum float 40.0
attribute chl_conc_mean colorBarMinimum float 0.15
attribute chl_conc_mean colorBarPalette String Spectrum
attribute chl_conc_mean colorBarScale String Log
attribute chl_conc_mean long_name String Chl Conc Mean
attribute chl_conc_mean standard_name String mass_concentration_of_chlorophyll_a_in_sea_water
attribute chl_conc_mean units String mg/m^3
variable chl_conc_sigma   float time, latitude, longitude
attribute chl_conc_sigma _FillValue float NaN
attribute chl_conc_sigma cell_method String time: standard deviation (interval: 1 day comments: previous 8 day from present inclusively)
attribute chl_conc_sigma colorBarMaximum float 5.0
attribute chl_conc_sigma colorBarMinimum float 0.005
attribute chl_conc_sigma colorBarPalette String KT_thermal
attribute chl_conc_sigma colorBarScale String Log
attribute chl_conc_sigma long_name String Chl Conc Sigma
attribute chl_conc_sigma standard_name String mass_concentration_of_chlorophyll_a_in_sea_water
attribute chl_conc_sigma units String mg/m^3
variable chl_conc_counts   float time, latitude, longitude
attribute chl_conc_counts _FillValue float NaN
attribute chl_conc_counts cell_method String time: count (interval: 1 day comments: previous 8 day from present inclusively)
attribute chl_conc_counts long_name String Chl Conc Counts
variable chl_conc_p50   float time, latitude, longitude
attribute chl_conc_p50 _FillValue float NaN
attribute chl_conc_p50 cell_method String time: median (interval: 1 day comments: previous 8 day from present inclusively)
attribute chl_conc_p50 colorBarMaximum float 40.0
attribute chl_conc_p50 colorBarMinimum float 0.15
attribute chl_conc_p50 colorBarPalette String Spectrum
attribute chl_conc_p50 colorBarScale String Log
attribute chl_conc_p50 long_name String Chl Conc P50
attribute chl_conc_p50 standard_name String mass_concentration_of_chlorophyll_a_in_sea_water
attribute chl_conc_p50 units String mg/m^3

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.


 
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