• Name:  Secchi Disk Depth
• Description - The Worldwide Ocean Optics Database is a collection of several hundred ocean optics data sets gathered over time that encompass much of the world's oceans.
• Source - World Ocean Optics Database (W.O.O.D.)
• GCMD Metadata Record
• Data (zipped ESRI ASCII grids with geo-referenced BMP images)
  • Winter (JFM)
  • Spring (AMJ)
  • Summer (JAS)
  • Autumn (OND)

Geospatial version of this legend

• Name: Compensation Depth (estimated from the above Secchi disk data)
• Description - This gross estimate uses the so-called "clear water formula".  Z_c=4.6/(1.7/S_d) where Sd is the Secchi depth, and 1.7 is an empirical value for clear water.
• Source - Calculated from the above data, found at World Ocean Optics Database (W.O.O.D.)
• GCMD Metadata Record
• Data (zipped ESRI ASCII grids with geo-referenced BMP images)
  • Winter (JFM)
  • Spring (AMJ)
  • Summer (JAS)
  • Autumn (OND)

Geospatial version of this legend

• Name:  Kd490
• Description - Diffuse attenuation coefficient (Kd) is a descriptor of the underwater light fields that varies with depth, solar altitude and time. It is an indicator of the penetrative component of solar radiation.  Kd490 is Kd measured at 490 nm.  
• Source - Ocean Colour Web
• GCMD Metadata Record
• Data (zipped ESRI ASCII grids with geo-referenced JPG images)
  • Annual
  • Winter (JFM)
  • Spring (AMJ)
  • Summer (JAS)
  • Autumn (OND)

Geospatial version of this legend

• Name: PAR
• Description - Photosynthetically Active Radiation (PAR) is the quantum energy flux from the sun in the spectral range 400-700 nm.  The algorithms estimates daily (i.e. 24 hour average) PAR reaching the ocean surface. 
• Source - Ocean Colour Web
• GCMD Metadata Record
• Data (zipped ESRI ASCII grids with geo-referenced JPG images)
  • Annual
  • Winter (JFM)
  • Spring (AMJ)
  • Summer (JAS)
  • Autumn (OND)

Geospatial version of this legend