View of the ocean surface with a ship on the horizon

Characterisation of candidate OC-SVC sites - El Hierro

 

View of the ocean surface with a ship on the horizon
View of the ocean surface with a ship on the horizon

Climatological characterisation of candidate ocean sites for Copernicus OC-SVC infrastructure - El Hierro (Canary Islands).

Last Updated

28 March 2023

Published on

28 July 2022

EUMETSAT manages the operations of Ocean Colour products derived from the Ocean and Land Colour Imager (OLCI) instrument flown on the Sentinel-3 satellites from the European Commission Copernicus Programme. Ocean Colour System Vicarious Calibration (OC-SVC) with radiometric measurements at sea is required to achieve the quality of the Ocean Colour products defined in the mission requirements. OC-SVC requires a dedicated infrastructure at a favourable location. EUMETSAT has initiated activities on behalf of the EC to investigate the Copernicus OC-SVC infrastructure.

This study is part of a survey to find the best location for potential Copernicus OC-SVC infrastructure in European waters in terms of atmospheric, oceanographic and logistical site characteristics. The study follows Phase-1 and Phase-2 activities of the Copernicus OC-SVC roadmap and precedes the proposed Phase-4 activity. Phase-1 and Phase-2 were respectively the Scientific, Technical and Operational Requirements, and the Preliminary Design, Project Plan and Costing. The proposed Phase-4 is the Technical Definition, Specification, and Detailed Design study.

This study climatologically characterised the El Hierro in the Canaries (Spain) in terms of multiple atmospheric, oceanographic, logistical and other relevant parameters, in order to assess its suitability for the Copernicus OC-SVC infrastructure.

El Hierro location: 27.5876N, 18.1573W

Location of the El Hierro site in the Canaries and monthly distributions of chlorophyll-a concentrations around the Canaries including El Hierro
Figure 1: Location of the El Hierro site in the Canaries and monthly distributions of chlorophyll-a concentrations around the Canaries including El Hierro.

Objectives

The objective of the study was to gather environmental data from available datasets and process them to provide a climatological characterisation of the El Hierro site and its surroundings.

In particular, geographic, atmospheric, oceanographic and anthropic conditions were assessed and analysed with respect to the requirements set in Phase-1, for the selection of an appropriate site to operate the field segment of an OC-SVC infrastructure. The study also included a description of the logistics envisioned to support the development and operations of the future Copernicus OC-SVC infrastructure, in case the site would be selected.


Overview

El Hierro island is the second-smallest and the farthest south and west island of the Canary Archipelago, with a long Marine Reserve and with 60% of its inland territory protected to preserve its natural and cultural diversity as an UNESCO Biosphere Reserve.

Every single requirement established in the Statement of Work (SoW) to determine the feasibility of an OC-CSV site has been successfully satisfied at the El Hierro site, double checking its validity through different databases that are consistent with each other. The El Hierro OC-SVC site enjoys high stability of subtropical atmosphere isolated from local and regional anthropogenic pollution contributions, with high light availability, high persistence of cloud-free conditions, low surface wind, and stable and spatially uniform maritime aerosols through most of the year. Moreover, from the oceanic point of view, the El Hierro OC-SVC site has well-mixed calm, clear, and stable ocean waters with no shear in the first 20m, minimal maritime traffic, and a very safe location close to a marine reserve.

The IEO-AEMET consortium provides a team of technicians and researches highly experienced in operational and scientific aspects of the region's atmosphere and ocean, as well as nearby ports, storage, and maintenance facilities to ensure proper long-term maintenance of heavy oceanographic equipment at the El Hierro OC-SVC site. El Hierro island has a high volume data communication system by optical fibre.

El Hierro Site Logistics main characteristics
Figure 2: El Hierro site logistics main characteristics

Data sources

Parameter Dataset Temporal extent used in analysis Website or database used for data access
1. GEOGRAPHY
a) Site location shown on nautical charts, showing bathymetry and neighbouring land El Hierro island and west of the canary archipelago   IEO, digital institutional repository of the Spanish Institute of Oceanography
b) Sea bottom depth and slope at site El Hierro island and west of the Canary archipelago 2010-present IEO
c) Cosine of Sun zenith angle at 10am LST     Calculations following equations in Iqbal (1983)
2. ATMOSPHERE
a) Fractional cloud cover ERA5 2000-2020 ECMWF MARS
  MM5 2015-2020 IARC archive
b) Wind velocity and direction Tacorón AEMET Met station 2010-2020 AEMET National Climatological Data Base (BNDC)
  ERA5 2000-2020 ECMWF MARS
  MM5 2015-2020 IARC archive
c) Aerosol type and optical thickness SCO (Cimel) Utilised for comparison of CAMS & MERRA-2 2006-2019 AERONET Aerosol Robotic Network
  CAMS global reanalysis EAC4 2006-2019 Copernicus Atmosphere Data Store
  MERRA-2 2006-2019 NASA EARTHDATA Giovanni website
d) Absorbing gases      
i) atmosphere pressure El Hierro Airport 2000-2020 AEMET National Climatological Data Base (BNDC)
  ERA5 2000-2020 ECMWF MARS
ii) Total column ozone Izaña Observatory (Brewer Triad) 1991-2020 EUBREWNET website
  ERA5 2000-2020 Copernicus Climate Data Store
iii) Total precipitable water Faro de Orchilla GNSS 2017-2020  
  ERA5 2000-2020 ECMWF MARS
iv) NO2 surface concentrations Izaña Observatory(FTIR) 2005-2019 Network for the Detection of Atmospheric Composition Change (NDACC)
  CAMS EAC4 2005-2019 Copernicus Atmosphere Data Store
  OMI Level 3 OMNO2d 2005-2019 NASA EARTHDATA Giovanni website
  Merged GOME/SCIA/GOME2 2005-2017 Tropospheric Emission Monitoring Internet Service (TEMIS)
3. OCEAN
a) Chlorophyll
In situ
Oceanographic cruises (IEO) 2011-2020 Vulcano/a
2006-2020 Raprocan
Twice a year
Spanish Institute of Oceanography Integrated Ocean Observing System (IEOOS)
Climatological Joint Research Centre (JRC) Environmental Marine Information System (EMIS) MERIS: 1/5/2002 to 31/12/2020
MODIS AQUA: 1/7/2002 to 31/12/2015
SEAWIFS: 1/9/1997 to 31/12/2004
JRC EMIS webpage
Reanalysis CMEMS: Atlantic -Iberian Biscay Irish (IBI)- Ocean Biogeochemistry Reanalysis system 1993-2019 Atlantic-Iberian Biscay Irish- Ocean BioGeoChemistry NON ASSIMILATIVE Hindcast
Satellite CMEMS: Merged Sensor product SeaWiFS, MODIS, MERIS, VIIRS-SNPP&JPSS1, OLCI-S3A&S3B 4/9/1997 to 30/6/2020 Copernicus Marine Service
b) Apparent Optical Properties CMEMS: North Atlantic Ocean, Ocean Optics products L3 (ESA-CCI) 4/9/1997 to 30/6/2020

Copernicus Marine Service

c) Inherent Optical Properties      
i) Coloured Dissolved Organic Matter (CDOM) absorption at 440nm aCDOM (m-1)
Climatological
JRC EMIS MERIS: 1/5/2002 to 31/12/2020
MODIS AQUA: 1/7/2002 to 31/12/2015
SEAWIFS: 1/9/1997 to 31/12/2004
EMIS - MERIS Monthly climatology absorption coefficient due to chromophoric dissolved organic matter and non-pigmented particles at 443nm (2km) in m^-1
Satellite CMEMS: Merged Sensor product SeaWiFS, MODIS, MERIS, VIIRS-SNPP&JPSS1, OLCI-S3A&S3B 4/9/1997 to 30/6/2020

Copernicus Marine Service

iii) Particulate backscatter at 443nm bbp (m-1) CMEMS: Merged Sensor product SeaWiFS, MODIS, MERIS, VIIRS-SNPP&JPSS1, OLCI-S3A&S3B 1997-2020

Copernicus Marine Service

d) Currents
In situ
Spanish Deep Water Buoy Network
Tenerife buoy
1997-2019 Copernicus Marine Service
Puertos del Estado website
Climatological Drifter-Derived Climatology of Global Near-Surface Current 1979-2020 NOAA Physical Oceangrpahy Division (POD) Global Drifter Program page
Reanalysis CMEMS: Atlantic -IBI- Ocean Physics Reanalysis system 1993-2019 Copernicus Marine Service
Atlantic-Iberian Biscay Irish- Ocean Physics Reanalysis
e) Waves
In situ
Spanish Deep Water Buoy Network Tenerife buoy 1997-2019 Copernicus Marine Service
Puertos del Estado website
Reanalysis CMEMS: Atlantic -IBI- Ocean Wave Reanalysis 1993-2019 Copernicus Marine Service
Atlantic-Iberian Biscay Irish- Ocean Physics Reanalysis
f) Sea Surface Temperature
In situ i)
Oceanographic cruises (IEO) 2012-2020 Vulcano/a -Raprocan
Twice a year
Spanish Institute of Oceanography Integrated Ocean Observing System (IEOOS)
In situ ii) Spanish Deep Water Buoy Network
Tenerife buoy
2001-2019 Copernicus Marine Service
Puertos del Estado website
Climatological NOAA National Center for Environmental Information World Ocean Atlas (WOA) 2018 1955-2010 WOA 2018 - Data Access: Statistical mean of Temperature on 1° grid for all decades
Reanalysis CMEMS: Atlantic -IBI- Ocean Reanalysis system 1993-2019 Copernicus Marine Service
Atlantic-Iberian Biscay Irish- Ocean Physics Reanalysis
Satellite Global Ocean OSTIA Sea Surface Temperature 2007-present Global Ocean OSTIA Sea Surface Temperature and Sea Ice Analysis
g) Salinity
In situ i)
Oceanographic cruises (IEO) 2011-2020 Vulcano/a 2006-2020 Raprocan
Twice a year
Spanish Institute of Oceanography Integrated Ocean Observing System (IEOOS)
In situ ii) Spanish Deep Water Buoy Network
Tenerife buoy
1997-2019 Copernicus Marine Service
Puertos del Estado website
Climatological NOAA WOA 2018 1955-2010 WOA 2018 - Data Access: Statistical mean of Temperature on 1° grid for all decades
Reanalysis CMEMS: Atlantic -IBI- Ocean Reanalysis system 1993-2019 Copernicus Marine Service
Atlantic-Iberian Biscay Irish- Ocean Physics Reanalysis
4. OTHER
a) Map of nearby shipping routes EMODnet 2019 EMODnet Human Activities
a) Monthly shipping traffic statistics puertosdetenerife 2017-2019 Port authority of Santa Cruz de Tenerife report
a) Map of NO2 surface concentration CAMS EAC4 2005-2019 Copernicus Atmosphere Data Store
b) Map of nearby airline routes International Civil Aviation Organization (ICAO) 2019 ICAO history of some of our main achievements in GIS Aviation
b) Monthly airline traffic statistics AENA 2017-2019 Aeropuertos Españoles y Navegación Aérea
c) Fire occurrences in the surrounding areas (within 50km) Spanish Ministry of Agriculture, Fisheries and Food 2006-2015 Ministerio de Agricultura, Pesca y Alimentación

The analysis also included additional site-specific data.

COPERNICUS LOGOS