Photosynthetically Active Radiation (PAR) Average Annual Frequency of Anomalies, 2002-2013 - Hawaii

Metadata Updated: November 12, 2020

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 number of anomalies of irradiance from 2002-2013, with values presented as fraction of a year. 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 frequency of anomalies was calculated by taking the average number of weeks that exceeded the maximum monthly climatological PAR value 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.

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License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Date March 14, 2017
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) March 14, 2017 (creation), March 14, 2017 (issued), March 14, 2017 (revision)
Frequency Of Update

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Harvested from ioos

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Additional Metadata

Resource Type Dataset
Metadata Date March 14, 2017
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) March 14, 2017 (creation), March 14, 2017 (issued), March 14, 2017 (revision)
Responsible Party Ocean Tipping Points (OTP) (Point of Contact)
Contact Email
Guid hi_otp_all_par_anom_freq
Access Constraints
Bbox East Long -154.56326617912035
Bbox North Lat 22.42373568629166
Bbox South Lat 18.755036208219373
Bbox West Long -160.41246354980814
Coupled Resource [{"href": ["#DataIdentification"], "uuid": [], "title": []}, {"href": ["#DataIdentification"], "uuid": [], "title": []}, {"href": ["#DataIdentification"], "uuid": [], "title": []}]
Frequency Of Update
Graphic Preview Description Sample image.
Graphic Preview File http://pacioos.org/metadata/browse/hi_otp_all_par_anom_freq.png
Licence
Metadata Language eng
Metadata Type geospatial
Progress
Spatial Data Service Type Open Geospatial Consortium Web Coverage Service (WCS)
Spatial Reference System
Spatial Harvester True

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