Site 1.

English Channel

 

 

 

 

Product User Guide
Version 2.1


Products

NRT Service

 

The demise of ENVISAT in April 2012 determined the end of the NRT service within CoastColour. However, all MERIS Archive products that have been processed are available via the CoastColour archive.

 

 

Data Archive

 

The CoastColour data archive contains, for all 27 sites and for the years 2005 to 2012, L1P, L2R, L2W, and MER_FSG_2P (megs8 processed) data products.

 

 

Data Access

The access to the data archive and NRT data is free and open. You can use the direct web access, which is good for downloading only a few data products. If you like to download more than just a couple of products, we kindly ask you to register for getting access to the FTP server. After registration, which is free of charge, a username and password will be sent to you. That account is also valid for the MERCI service (see below). megs8 processed data is available on demand; send your request to office@coastcolour.org.

 

Product Description

 

The Level 1P product is a refined top of atmosphere radiance product compared with the standard Level 1b product. It will provide improved geolocation and calibration, equalisation to reduce coherent noise, smile correction, pixel characterization information (cloud, snow, etc.), a precise coastline and a reformatting into NetCDF following Climate Forecast (CF) conventions.

 

The Level L2R product is the result of the atmospheric correction. It contains water leaving reflectance, normalised water leaving reflectance and different information about atmospheric properties.

The L2W product provides information about water properties such as IOPs, concentrations and other variables. It also contains an ortho-corrected geo-coding and different flags characterizing pixels.

 

The following table gives an overview of the product structure. A dataset is physically represented by one single NetCDF product file.

 

Dataset

Group of Variables

Contents

Status (May 2013)

L1P

TOA

Pre-processed MERIS TOA radiances.

Available

GEO

Ortho-corrected geo-coding.

Available

FLAGS

Flags characterising pixels

Available

L2R

RSURF

Contains water leaving reflectances, normalised water leaving reflectances, aerosol optical depth and angstrom exponent.

Available

GEO

Ortho-corrected geo-coding.

Available

FLAGS

Flags characterising pixels

Available

L2W

IOP

IOPs and optical water properties

Available

CONC

Concentration retrieval products (CHL, TSM, CDOM).

Available

OTH

Other water properties

Available

FLH

Fluorescence line height.

Available as BEAM Plug-in

GEO

Ortho-corrected geo-coding.

Available

FLAGS

Flags characterising pixels

Available

 

The following lists explain in detail the content of the dataset.

 

Standard products

The CoastColour products will include a set of basic quantities which will be generated over all sites:

 

Acronym*

Product

Dataset Group of variables


Surface reflectances


L2R RSURF

reflec

Directional water leaving radiance reflectance

   

norm_reflec

Fully normalized water leaving radiance reflectance

   


Inherent optical properties


L2W IOP

a_total

Total absorption coefficient of all water constituents

   

bb_spm_443

Total scattering or backscattering coefficient

   

a_pig_443

Phytoplankton pigment absorption coefficient

   

a_ys_443

Yellow substance absorption coefficient

   


Water constituent concentrations

L2W CONC

conc_chl

Chlorophyll a concentration

   

conc_tsm

Total suspended matter

   


Water transparency/turbidity information


L2W OTH

Kd

Spectral downwelling irradiance attenuation coefficient

   

Z90_max

Maximal signal depth

   

Z_eu

Depth of euphotic layer

   

Z_SD

Secchi disc depth

   

K_min

Minimal downwelling irradiance attenuation coefficient

   

Turbidity

Formazin Nepholometric Units

   


Chlorophyll Indices


L2W FLH

FLH

Fluorescence line height

   

MCI

Maximum chlorophyll index

   


(*) - used in CoastColour products

 

 


Experimental products


An attempt will be made to generate additional experimental, site specific products, including (provisional list):


Acronym*

Product

Algorithm

 

1% depth of PAR

 

PPP

Primary Productivity or Potential Primary Productivity

requires the knowledge of PI parameters, PPP is without nutrient limitations

 

Phytoplankton Biomass estimates in gC m-3 or gC m-2 units

 

 

Concentrations of some taxonomic of functional groups such as coccolithophorides, Cyanobacteria etc

if abundant in dominating concentrations

 

Effective Fluorescence

Derived from difference of water leaving radiance reflectance between direct output of neural network and difference between top of atmosphere reflectance (RLtoa) and path radiance reflectance (RLpath).



(*) - used in CoastColour products