ca13_winterextreme_orbitalvelocities, California

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Frequently anticipated questions:

What does this data set describe?

Title: ca13_winterextreme_orbitalvelocities, California
Abstract:
Ecologists have long recognized that the structure and function of benthic marine ecosystems are closely linked to oceanographic processes. Quantifying the natural spatial and temporal variability of disturbances affecting benthic marine ecosystems is thus critical for planning and management of areas such as marine protected areas and for permitting offshore activities such as trawling, dredging, and the placement of sea-floor engineering structures (cables and pipelines for example).
The oceanographic processes that disturb the continental shelf include the actions of surface waves, internal waves, and currents (tidal, density, wave-driven, wind-driven, and geostrophic). Because the North Pacific Ocean can generate extremely large surface waves that yield relatively high near-bed wave orbital velocities, wave-generated near bed currents are often considered to be the dominant mechanism for seabed disturbances along the California coast (Sherwood and others, 1994; Storlazzi and Jaffe, 2002; Storlazzi and others, 2003).
In this study, bathymetric data compiled as part of the CSMP project and within the 3nm limit were supplemented with deeper water bathymetric data (NOAA, <http://maps.ngdc.noaa.gov/>, last
  1. How should this data set be cited?

    Erikson, Li H. , Storlazzi, Curt D. , Golden, Nadine E. , and Lowe, Erik N. , 2014, ca13_winterextreme_orbitalvelocities, California:.

    This is part of the following larger work.

    Erikson, Li H. , Storlazzi, Curt D. , Golden, Nadine E. , and Lowe, Erik N. , 2014, Wave and Orbital Velocity Model Data for the California Continental Shelf: U.S. Geological Survey, Santa Cruz, CA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -120.839014
    East_Bounding_Coordinate: -118.941814
    North_Bounding_Coordinate: 34.647677
    South_Bounding_Coordinate: 33.872477

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 2004
    Ending_Date: 2013
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: GeoTiff

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions, type Grid Cell

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 11
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -117.00000
      Latitude_of_Projection_Origin: 0.00000
      False_Easting: 500000.0
      False_Northing: 0.00

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 2.0
      Ordinates (y-coordinates) are specified to the nearest 2.0
      Planar coordinates are specified in Meters

      The horizontal datum used is NAD83.
      The ellipsoid used is GRS80.
      The semi-major axis of the ellipsoid used is 6378137.00 meters.
      The flattening of the ellipsoid used is 1/298.257223563.

  7. How does the data set describe geographic features?

    Entity_and_Attribute_Overview: See Process_Description
    Entity_and_Attribute_Detail_Citation: USGS

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Li Erikson
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Physical Scientist
    400 Natural Bridges Dr.
    Santa Cruz, CA 95060-5792
    USA

    (831) 460-7563 (voice)
    (831) 427-4709 (FAX)
    lerikson@usgs.gov

Why was the data set created?

These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify bathymetric features. These data are not intended to be used for navigation.

How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: 2013 (process 1 of 1)
    A total of 15 grids encompassing the entire California State open coastline were generated and used in the SWAN simulations. All grids were curvi-linear with approximate cross- and along-shore resolutions of 30-50m and 60-100m in the shallow inshore regions, respectively. Model grid cells were smaller in the cross-shore direction, in shallow water, and around complex bathymetry to allow for better representation of wave refraction and shoaling. Latitudinal extents were defined based on local geography and computation limitations. The offshore extent of the model grids were define by 64 Wave Information System (WIS, <http://wis.usace.army.mil/>) model output stations located approximately 20km offshore along the entire California coast. The WIS database consists of continuous hourly wave and wind parameter time-series spanning the years 1980 through 2011 (31 years). These data were used to calculate seasonal mean and extreme (arithmetic mean of highest 5%) statistics at the 64 WIS output locations. Computed wave parameters (significant wave heights, peak period, and peak wave direction) were then applied at the boundaries of the 16 SWAN grids. Winds at the most centrally located WIS station of each grid were applied uniformly across the SWAN domains to allow for inclusion of locally wind-generated waves in addition to (usually greater) energy contributions from distantly generated swell waves. Seasons were defined as winter from December through February, spring from March through May, summer from June through August, and fall from September through November. Geoprocessing was done using ArcMap (version 10.1, ESRI, 2012). Geoprocessing steps for each Delph ascii file: 1) Convert ascii.txt to ArcGIS grid; 2) Project grid to GCS_NAD_1983_2011, D_NAD_1983_2011; 3) Clipped grid to block boundaries; 4) Convert grid to GeoTiff, and 5) Symbolize layer.

    Person who carried out this activity:

    Nadine Golden
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Geographer
    400 Natural Bridges Dr.
    Santa Cruz, CA 95060-5792
    USA

    (831) 460-7530 (voice)
    ngolden@usgs.gov

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    Not applicable for raster data.

  2. How accurate are the geographic locations?

    Estimated to be no less than 2 m, owing to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.

  3. How accurate are the heights or depths?

    Estimated to be no less than 20 cm, owing to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.

  4. Where are the gaps in the data? What is missing?

    Complete

  5. How consistent are the relationships among the observations, including topology?

    Unspecified

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Who wrote the metadata?

Dates:
Last modified: 08-Jan-2014
Last Reviewed: 16-Jan-2014
Metadata author:
Nadine Golden
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Geographer
400 Natural Bridges Dr.
Santa Cruz, CA 95060-5792
USA

(831) 460-7530 (voice)
(831) 427-4709 (FAX)
ngolden@usgs.gov

Metadata standard:
Content Standard for Digital Geospatial Metadata ("CSDGM version 2") (FGDC-STD-001-1998)

Generated by mp version 2.9.12 on Fri Nov 14 14:05:13 2014