Photosynthetically Active Radiation (PAR) Long-term Mean, 2003-2018 - American Samoa

Solar irradiance is one of the most important factors influencing coral reefs. As a majority of their nutrients are obtained from symbiotic photosynthesizing organisms, reef-building corals need sunlight as a fundamental source of energy. Seasonally low irradiance at high latitudes may be linked to reduced growth rates in corals and may limit reef calcification to shallower depths than that observed at lower latitudes. However, high levels of irradiance can lead to light-induced damage, production of free radicals, and in combination with increased temperatures, can exacerbate coral bleaching. Irradiance is here represented by PAR (photosynthetically active radiation), which is the spectrum of light that is important for photosynthesis. This layer represents the mean of 8-day time series of PAR (mol/m2/day) from 2003-2018.

Data for PAR for the time period 2003-2018 were obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite instrument from the NASA OceanColor website as 8-day 4-km composites.

The PAR long-term mean was calculated by taking the average of all 8-day data from 2003-2018 for each pixel. A quality control mask was applied to remove spurious data associated with shallow water, following Gove et al., 2013. Nearshore map pixels with no data were filled with values from the nearest neighboring valid offshore pixel by using a grid of points and the Near Analysis tool in ArcGIS then converting points to raster.

Data source: https://oceanwatch.pifsc.noaa.gov/erddap/griddap/aqua_par_8d_2018_0.graph

Data e Risorse

Campo Valore
access_constraints []
bbox-east-long -167.82502007000386
bbox-north-lat -10.776496516692129
bbox-south-lat -14.732041047992729
bbox-west-long -171.33852794285266
contact-email pifsc.info@noaa.gov
coupled-resource [{"title": [], "href": ["#DataIdentification"], "uuid": []}, {"title": [], "href": ["#DataIdentification"], "uuid": []}]
dataset-reference-date [{"type": "creation", "value": "2021-09-07"}, {"type": "issued", "value": "2021-09-07"}, {"type": "revision", "value": "2021-09-07"}]
graphic-preview-description Sample image.
graphic-preview-file http://pacioos.org/metadata/browse/as_noaa_all_par_avg.png
guid as_noaa_all_par_avg
licence []
lineage 2021-09-07T00:00:00Z OGC web services (WMS and WFS) enabled by PacIOOS via GeoServer. Original data from source provider may have been reformatted, reprojected, or adjusted in other ways to optimize these capabilities.
metadata-date 2024-11-14
metadata-language eng
metadata_type geospatial
old-spatial {"type": "Polygon", "coordinates": [[[-171.33852794285266, -14.732041047992729], [-167.82502007000386, -14.732041047992729], [-167.82502007000386, -10.776496516692129], [-171.33852794285266, -10.776496516692129], [-171.33852794285266, -14.732041047992729]]]}
resource-type dataset
responsible-party [{"name": "NOAA Pacific Islands Fisheries Science Center (PIFSC)", "roles": ["pointOfContact"]}]
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spatial-data-service-type Open Geospatial Consortium Web Coverage Service (WCS)
spatial_harvester true
Gruppi
  • AmeriGEOSS
  • National Provider
  • North America
Tag
  • AmeriGEO
  • AmeriGEOSS
  • CKAN
  • GEO
  • GEOSS
  • National
  • North America
  • United States
  • american samoa
  • aquatic ecosystems
  • biosphere
  • coastal areas
  • coastal processes
  • coral reef
  • coral reefs
  • earth science
  • ecosystems
  • human dimensions
  • human settlements
  • manua
  • marine ecosystems
  • ocean
  • ocean optics
  • oceans
  • ofu
  • olosega
  • pacific islands ocean observing system
  • pacific ocean
  • pacioos
  • photosynthetically active radiation
  • polynesia
  • reef
  • reef habitat
  • rose atoll
  • south pacific ocean
  • swains
  • tau
  • tutuila
  • vegetation
isopen False
metadata_created 2025-09-23T21:27:01.246844
metadata_modified 2025-09-23T21:27:01.246852
notes Solar irradiance is one of the most important factors influencing coral reefs. As a majority of their nutrients are obtained from symbiotic photosynthesizing organisms, reef-building corals need sunlight as a fundamental source of energy. Seasonally low irradiance at high latitudes may be linked to reduced growth rates in corals and may limit reef calcification to shallower depths than that observed at lower latitudes. However, high levels of irradiance can lead to light-induced damage, production of free radicals, and in combination with increased temperatures, can exacerbate coral bleaching. Irradiance is here represented by PAR (photosynthetically active radiation), which is the spectrum of light that is important for photosynthesis. This layer represents the mean of 8-day time series of PAR (mol/m2/day) from 2003-2018. Data for PAR for the time period 2003-2018 were obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite instrument from the NASA OceanColor website as 8-day 4-km composites. The PAR long-term mean was calculated by taking the average of all 8-day data from 2003-2018 for each pixel. A quality control mask was applied to remove spurious data associated with shallow water, following Gove et al., 2013. Nearshore map pixels with no data were filled with values from the nearest neighboring valid offshore pixel by using a grid of points and the Near Analysis tool in ArcGIS then converting points to raster. Data source: https://oceanwatch.pifsc.noaa.gov/erddap/griddap/aqua_par_8d_2018_0.graph
num_resources 13
num_tags 39
title Photosynthetically Active Radiation (PAR) Long-term Mean, 2003-2018 - American Samoa