Photosynthetically Active Radiation (PAR) Average Annual Maximum Anomaly, 2002-2013 - Hawaii

Solar irradiance is one of the most important factors influencing coral reefs. As the majority of their nutrients are obtained from symbiotic photosynthesizing organisms, reef-building corals need irradiance 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. This layer represents the annual average of the maximum anomaly of irradiance (mol/m2/day) from 2002 -2013. Irradiance is here represented by PAR (photosynthetically active radiation), which is the spectrum of light that is important for photosynthesis. Monthly and 8-day 4-km (0.0417-degree) spatial resolution data were obtained from the MODIS (Moderate-resolution Imaging Spectroradiometer) Aqua satellite instrument from the NASA OceanColor website (http://oceancolor.gsfc.nasa.gov).

The PAR average annual maximum anomaly was calculated by taking the average of the annual maximum PAR values in exceedance of the maximum monthly climatological PAR from 2002-2013 for each pixel. A quality control mask was applied to remove spurious data associated with shallow water, following Gove et al., 2013. Monthly climatologies were calculated from monthly time series using only full years over the Ocean Tipping Points (OTP) project time frame of interest (2002-2013). Time series of anomalies were calculated by quantifying the number and magnitude of events from the 8-day time series that exceed the maximum climatological monthly mean. 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 and Resources

Field Value
access_constraints []
bbox-east-long -154.56326617912035
bbox-north-lat 22.42373568629166
bbox-south-lat 18.755036208219373
bbox-west-long -160.41246354980814
contact-email kappel@nceas.ucsb.edu
coupled-resource [{"href": ["#DataIdentification"], "uuid": [], "title": []}, {"href": ["#DataIdentification"], "uuid": [], "title": []}, {"href": ["#DataIdentification"], "uuid": [], "title": []}]
dataset-reference-date [{"type": "creation", "value": "2017-03-14"}, {"type": "issued", "value": "2017-03-14"}, {"type": "revision", "value": "2017-03-14"}]
graphic-preview-description Sample image.
graphic-preview-file http://pacioos.org/metadata/browse/hi_otp_all_par_anom_max.png
guid hi_otp_all_par_anom_max
licence []
metadata-date 2021-03-30
metadata-language eng
metadata_type geospatial
old-spatial {"type": "Polygon", "coordinates": [[[-160.41246355, 18.7550362082], [-154.563266179, 18.7550362082], [-154.563266179, 22.4237356863], [-160.41246355, 22.4237356863], [-160.41246355, 18.7550362082]]]}
resource-type dataset
responsible-party [{"name": "National Center for Ecological Analysis and Synthesis (NCEAS)", "roles": ["pointOfContact"]}]
spatial {"type": "Polygon", "coordinates": [[[-160.41246355, 18.7550362082], [-154.563266179, 18.7550362082], [-154.563266179, 22.4237356863], [-160.41246355, 22.4237356863], [-160.41246355, 18.7550362082]]]}
spatial-data-service-type Open Geospatial Consortium Web Coverage Service (WCS)
spatial_harvester true
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • amerigeo
  • amerigeoss
  • aquatic-ecosystems
  • biosphere
  • central-pacific-ocean
  • ckan
  • coastal-areas
  • coastal-processes
  • continent
  • coral-reef
  • coral-reefs
  • earth-science
  • ecosystems
  • geo
  • geoss
  • hawaii
  • hawaiian-islands
  • human-dimensions
  • human-settlements
  • marine-ecosystems
  • national
  • north-america
  • ocean
  • ocean-optics
  • oceans
  • pacific-islands-ocean-observing-system
  • pacific-ocean
  • pacioos
  • photosynthetically-active-radiation
  • reef
  • reef-habitat
  • united-states
  • united-states-of-america
  • vegetation
isopen False
metadata_created 2025-11-21T02:16:18.781726
metadata_modified 2025-11-21T02:16:18.781729
notes Solar irradiance is one of the most important factors influencing coral reefs. As the majority of their nutrients are obtained from symbiotic photosynthesizing organisms, reef-building corals need irradiance 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. This layer represents the annual average of the maximum anomaly of irradiance (mol/m2/day) from 2002 -2013. Irradiance is here represented by PAR (photosynthetically active radiation), which is the spectrum of light that is important for photosynthesis. Monthly and 8-day 4-km (0.0417-degree) spatial resolution data were obtained from the MODIS (Moderate-resolution Imaging Spectroradiometer) Aqua satellite instrument from the NASA OceanColor website (http://oceancolor.gsfc.nasa.gov). The PAR average annual maximum anomaly was calculated by taking the average of the annual maximum PAR values in exceedance of the maximum monthly climatological PAR from 2002-2013 for each pixel. A quality control mask was applied to remove spurious data associated with shallow water, following Gove et al., 2013. Monthly climatologies were calculated from monthly time series using only full years over the Ocean Tipping Points (OTP) project time frame of interest (2002-2013). Time series of anomalies were calculated by quantifying the number and magnitude of events from the 8-day time series that exceed the maximum climatological monthly mean. 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.
num_resources 17
num_tags 34
title Photosynthetically Active Radiation (PAR) Average Annual Maximum Anomaly, 2002-2013 - Hawaii