Short Citation:
Office for Coastal Management, 2021: Light Attenuation (Kd490), https://www.fisheries.noaa.gov/inport/item/54385.

Item Identification

Title: Light Attenuation (Kd490)
Short Name: Kd490_annual_mean
Status: Completed
Abstract:

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.

Purpose:

To support coastal and ocean planning and other activities pursuant to the Energy Policy Act, Coastal Zone Management Act, Magnuson-Stevens Fishery Conservation and Management Act, National Environmental Policy Act, Rivers and Harbors Act and the Submerged Lands Act.

Supplemental Information:

The native coordinate system for this layer is WGS 1984 World Mercator (ESPG: 3395). Please note: all MarineCadastre.gov data served by the NOAA Office for Coastal Management and hosted through Esri REST services are in the WGS 1984 Web Mercator Auxiliary Sphere (EPSG: 3857) projection.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords Earth Science > Human Dimensions > Environmental Governance/Management
ISO 19115 Topic Category environment
ISO 19115 Topic Category farming
ISO 19115 Topic Category oceans
ISO 19115 Topic Category planningCadastre
None alternative energy planning
None biology
None coastal energy planning
None environment
None environmental
None environmental energy planning
None farming
None marine cadastre
None marine spatial planning
None national
None ocean energy planning
None oceans
None offshore energy planning
None planningCadastre
None renewable energy planning
None United States
None water column features
None water quality features

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America
None Atlantic
None national
None Pacific
None United States

Physical Location

City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Data Presentation Form: Map (digital)
Distribution Liability:

NOAA makes no warranties or representations whatsoever regarding the availability, quality, accuracy, content, completeness or suitability for the user's needs of such information. The services, information, and data made available on the Marine Cadastre web site are provided "as is" without warranties of any kind. These data are intended for coastal and ocean use planning. Not for navigation. http://www.marinecadastre.gov/about/disclaimer.html

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);

Support Roles

Data Steward

CC ID: 791638
Date Effective From: 2018-06
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 791639
Date Effective From: 2018-06
Date Effective To:
Contact (Organization): Office for Coastal Management (OCM)
Address: 2234 South Hobson Avenue
Charleston, SC 29405-2413
URL: https://www.coast.noaa.gov/

Metadata Contact

CC ID: 791641
Date Effective From: 2018-06
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 791640
Date Effective From: 2018-06
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Publication Date

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 791643
W° Bound: -179.999989
E° Bound: 179.999996
N° Bound: 74.710722
S° Bound: -17.584128

Access Information

Security Class: Unclassified
Data Use Constraints:

NOAA makes no warranties or representations whatsoever regarding the availability, quality, accuracy, content, completeness or suitability for the user's needs of such information. The services, information, and data made available on the Marine Cadastre web site are provided "as is" without warranties of any kind. These data are intended for coastal and ocean use planning. Not for navigation. http://www.marinecadastre.gov/about/disclaimer.html

Distribution Information

Distribution 1

CC ID: 791644
Download URL: ftp://ftp.coast.noaa.gov/pub/MSP/ORT/Kd490.zip
Distributor:
File Name: Kd(490)
Description:

Data access URL

Distribution 2

CC ID: 791645
Download URL: https://coast.noaa.gov/arcgis/rest/services/OceanReportingTool/
Distributor:
File Name: ORT Map Service
Description:

Data access URL

URLs

URL 1

CC ID: 791636
URL: https://marinecadastre.gov/oceanreports
Name: Ocean Reports
URL Type:
Online Resource
Description:

More information and online data visualization.

Technical Environment

Description:

Version 6.2 (Build 9200) ; Esri ArcGIS 10.5.1.7333

Data Quality

Accuracy:

The attributes in this dataset are believed to be accurate.

Horizontal Positional Accuracy:

Maximum scale of intended use is 1:80,000.

Completeness Report:

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.

Conceptual Consistency:

These data are believed to be logically consistent. Geometry is topologically clean.

Lineage

Sources

Monthly and Annual Summaries for Kd (490)

CC ID: 791633
Contact Name: NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group
Extent Type: Discrete
Extent Start Date/Time: 2018-08-01
Citation URL: https://oceancolor.gsfc.nasa.gov/atbd/kd_490/
Citation URL Name: Source Online Linkage
Citation URL Description:

URL where the source data were originally accessed.

Source Contribution:

Monthly and Annual Summaries for Kd (490)

Process Steps

Process Step 1

CC ID: 791634
Description:

(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 Details

Catalog Item ID: 54385
Metadata Record Created By: Anna Verrill
Metadata Record Created: 2018-10-25 12:07+0000
Metadata Record Last Modified By: Jesse Brass
Metadata Record Last Modified: 2019-10-01 13:32+0000
Metadata Record Published: 2018-10-26
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2019-10-27