|Title:||Light Attenuation Kd490|
This dataset represents monthly and annual mean summaries for Kd490 for the time period from 2000/2001 to 2017/2018, depending on the month and data available (see processing steps). Kd (490) is the diffuse attenuation coefficient at 490 nm. The diffuse attenuation coefficient in water indicates how strongly light intensity at a specified wavelength is attenuated within the water column. This parameter has wide applicability in ocean optics, as it is directly related to the presence of scattering particles in the water column, either organic or inorganic, and thus is an indication of water clarity. The diffuse attenuation coefficient at 490 nm (Kd490) indicates the turbidity of the water column -- how visible light in the blue to green region of the spectrum penetrates within the water column. The value of Kd490 (m-1) represents the rate at which light at 490 nm is attenuated with depth. For example, a Kd490 of 0.1/meter means that light intensity will be reduced one natural log within 10 meters of water. Thus, for a Kd490 of 0.1, one attenuation length is 10 meters. Higher Kd490 value means smaller attenuation depth and lower clarity of ocean water.
To support ocean planning activities pursuant to the Executive Order Regarding the Ocean Policy to Advance the Economic, Security, and Environmental Interests of the United States, the Energy Policy Act, the National Environmental Policy Act, the Rivers and Harbors Act, and the Coastal Zone Management Act.
|ISO 19115 Topic Category||oceans|
|ISO 19115 Topic Category||planningCadastre|
|Global Change Master Directory (GCMD) Location Keywords||
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA
Data Set Information
|Data Set Scope Code:||Data Set|
|Maintenance Frequency:||As Needed|
|Data Presentation Form:||Map (digital)|
|Data Set Credit:||ORIGINATORS: NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group; Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS), Office for Coastal Management (OCM); Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS);|
Point of Contact
|Date Effective From:||2018-06|
|Date Effective To:|
|Contact (Organization):||NOAA Office for Coastal Management (NOAA/OCM)|
2234 South Hobson Ave
Charleston, SC 29405-2413
|Currentness Reference:||Publication Date|
Extent Group 1
Extent Group 1 / Geographic Area 1
|Data Use Constraints:||
For coastal and ocean planning
Version 6.2 (Build 9200) ; Esri ArcGIS 10.5.1.7333
The attributes in this dataset are believed to be accurate.
|Horizontal Positional Accuracy:||
Maximum scale of intended use is 1:80,000.
Spatial and attribute properties are believed to be complete, although attribute information has been simplified. Geometric thresholds from original data are preserved. No tests have been completed for exhaustiveness.
These data are believed to be logically consistent. Geometry is topologically clean.
Monthly and Annual Summaries for Kd (490)
|Contact Name:||NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group|
|Extent Start Date/Time:||2018-08-01|
|Citation URL Name:||Source Online Linkage|
|Citation URL Description:||
URL where the source data were originally accessed.
Monthly and Annual Summaries for Kd (490)
Process Step 1
(1) Downloaded the Level-3 Standard Mapped Image (SMI) for Kd490 data from MODIS for each monthly climatology (summary) and the entire mission composite at 4km resolution.* Additionally all Level-3 SMIs that were used to create the monthly climatology and entire mission composite were downloaded for descriptive statistic calculations. (2) R was used to create Geotiffs of each dataset (GCS WGS 1984). (3) Geotiffs converted to point features – X and Y coordinate field calculated - for the point dataset conversion (not relevant to raster dataset). (4) Point features were clipped by U.S. Economic Exclusion Zone and State waters. (5) All point features were combined into a single feature class. (6) Single point feature class and raster projected into WGS 1984 World Mercator. Temporal resolution for each monthly and annual mean: Kd 490 (m-1) January monthly mean 2001-2018 Kd 490 (m-1) February monthly mean 2000-2018 Kd 490 (m-1) March monthly mean 2000-2018 Kd 490 (m-1) April monthly mean 2000-2018 Kd 490 (m-1) May monthly mean 2000-2018 Kd 490 (m-1) June monthly mean 2000-2017 Kd 490 (m-1) July monthly mean 2000-2017 Kd 490 (m-1) August monthly mean 2000-2017 Kd 490 (m-1) September monthly mean 2000-2017 Kd 490 (m-1) October monthly mean 2000-2017 Kd 490 (m-1) November monthly mean 2000-2017 Kd 490 (m-1) December monthly mean 2000-2017 Kd 490 (m-1) Cumulative mean of entire mission (Annual means 2000-2017 with monthly means from Jan. to May 2018)
|Process Date/Time:||2018-08-01 00:00:00|
|Catalog Item ID:||66147|
|Metadata Record Created By:||Brianna Key|
|Metadata Record Created:||2021-12-22 03:53+0000|
|Metadata Record Last Modified By:||SysAdmin InPortAdmin|
|Metadata Record Last Modified:||2022-08-09 17:11+0000|
|Metadata Record Published:||2021-12-22|
|Metadata Publication Status:||Published Externally|
|Do Not Publish?:||N|
|Metadata Last Review Date:||2021-12-22|
|Metadata Review Frequency:||1 Year|
|Metadata Next Review Date:||2022-12-22|