High-resolution Wind Resource Maps of Southeast Alaska

Metadata also available as - [Parseable text] - [XML]

Frequently-anticipated questions:


What does this data set describe?

Title: High-resolution Wind Resource Maps of Southeast Alaska
Abstract:
This file was created using the MesoMap system which consists of an integrated set of atmospheric simulation models, databases, and computers and storage systems. At the core of MesoMap is MASS (Mesoscale Atmospheric Simulation System), a numerical weather model, which simulates the physics of the atmosphere. MASS is coupled to a simpler wind flow model, WindMap, which is used to refine the spatial resolution of MASS and account for simple localized effects of terrain and surface roughness. MASS simulates weather conditions over a region for 366 historical days randomly selected from a 15-year period. When the runs are finished, the results are input into WindMap. Truewind subsequently validates the wind maps. The final product is a grid of cells each containing a single value of average wind speed (m/s) at a hub height of 30, 50, 70, and 100 meters and wind power (W/m^2) density at a hub height of 50 meters for a 40,000 square meter area.
Supplemental_Information:
The layers listed below are available as raster GeoTIF files and in Google Earth format. Attribute information for the following layers (entities) is included in this metadata file under the "Entity_and_Attribute_Information" section. Each layer is listed and described in detail under its own heading starting "Entity_Type_Label." Layers include:
AK_SE_spd30m     average wind speed (m/s) at a hub height of 30m
AK_SE_spd50m     average wind speed (m/s) at a hub height of 50m
AK_SE_spd70m     average wind speed (m/s) at a hub height of 70m
AK_SE_spd100m     average wind speed (m/s) at a hub height of 100m
AK_SE_pwr50m     wind power (W/m^2) density at a hub height of 50m
  1. How should this data set be cited?

    AWS Truewind, LLC, and Authority, Alaska Energy , 2006, High-resolution Wind Resource Maps of Southeast Alaska: Wind Energy WND 2006-2A, State of Alaska, Department of Commerce, Community & Economic Development, Alaska Energy Authority, Anchorage, AK.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -141.640039
    East_Bounding_Coordinate: -127.996348
    North_Bounding_Coordinate: 60.648682
    South_Bounding_Coordinate: 54.153350

  3. What does it look like?

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

    Calendar_Date: 2006
    Currentness_Reference: publication date

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

    Geospatial_Data_Presentation_Form: raster digital data

  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 3331 x 3785 x 1, type Pixel

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

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 7
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -141.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 200.000000
      Ordinates (y-coordinates) are specified to the nearest 200.000000
      Planar coordinates are specified in meters

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.

  7. How does the data set describe geographic features?

    AK_SE_spd30m.tif
    Object type is raster, describing average wind speed (m/s) at a hub height of 30m (Source: State of Alaska, AEA)

    File Type
    The file format of the image (Source: State of Alaska, AEA)

    TIFF, 32-bit grey scale

    File Size
    The file size of the video (Source: State of Alaska, AEA)

    48.1 Mb

    Line (row)
    The number of lines or rows in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3331
    Units:pixels

    Sample (column)
    The number of samples or columns in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3785
    Units:pixels

    AK_SE_spd50m.tif
    Object type is raster, describing average wind speed (m/s) at a hub height of 50m (Source: State of Alaska, AEA)

    File Type
    The file format of the image (Source: State of Alaska, AEA)

    TIFF, 32-bit grey scale

    File Size
    The file size of the video (Source: State of Alaska, AEA)

    48.1 Mb

    Line (row)
    The number of lines or rows in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3331
    Units:pixels

    Sample (column)
    The number of samples or columns in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3785
    Units:pixels

    AK_SE_spd70m.tif
    Object type is raster, describing average wind speed (m/s) at a hub height of 70m (Source: State of Alaska, AEA)

    File Type
    The file format of the image (Source: State of Alaska, AEA)

    TIFF, 32-bit grey scale

    File Size
    The file size of the video (Source: State of Alaska, AEA)

    48.1 Mb

    Line (row)
    The number of lines or rows in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3331
    Units:pixels

    Sample (column)
    The number of samples or columns in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3785
    Units:pixels

    AK_SE_spd100m.tif
    Object type is raster, describing average wind speed (m/s) at a hub height of 100m (Source: State of Alaska, AEA)

    File Type
    The file format of the image (Source: State of Alaska, AEA)

    TIFF, 32-bit grey scale

    File Size
    The file size of the video (Source: State of Alaska, AEA)

    48.1 Mb

    Line (row)
    The number of lines or rows in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3331
    Units:pixels

    Sample (column)
    The number of samples or columns in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3785
    Units:pixels

    AK_SE_pwr50m.tif
    Object type is raster, describing wind power (W/m^2) density at a hub height of 50m (Source: State of Alaska, AEA)

    File Type
    The file format of the image (Source: State of Alaska, AEA)

    TIFF, 32-bit grey scale

    File Size
    The file size of the video (Source: State of Alaska, AEA)

    48.1 Mb

    Line (row)
    The number of lines or rows in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3331
    Units:pixels

    Sample (column)
    The number of samples or columns in the image (Source: State of Alaska, AEA)

    Range of values
    Minimum:1
    Maximum:3785
    Units:pixels


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?

    AWS Truewind, LLC

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

    AWS Truewind
    c/o Michael Brower
    463 New Karner Road
    Albany, New York 12205
    United States

    (518) 213-0044 (voice)


Why was the data set created?

The purpose of creating this file was to use MesoMap to create high-resolution wind resource maps of the state and to provide wind resource data in a format enabling the assessment potential wind development sites in a GIS. By combining a sophisticated numerical weather model capable of simulating large-scale wind patterns with a microscale wind flow model responsive to local terrain and surface conditions, they enable the mapping of wind resources with much greater accuracy than has been possible in the past. In addition, they do not require surface wind data to make accurate predictions. While on-site measurements will be required to confirm the predicted wind resource at any particular location, mesoscale-microscale modeling can greatly reduce the time and cost required to identify and evaluate potential wind project sites.


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: 2006 (process 1 of 5)
    The MesoMap system creates a wind resource map in several steps. First, the MASS model simulates weather conditions over 366 days selected from a 15-year period. The days are chosen through a stratified random sampling scheme so that each month and season is represented equally in the sample; only the year is randomized. Each simulation generates wind and other weather variables (including temperature, pressure, moisture, turbulent kinetic energy, and heat flux) in three dimensions throughout the model domain, and the information is stored at hourly intervals. When the runs are finished, the results are compiled into summary data files, which are then input into the WindMap program for the final mapping stage. The two main products are usually (1) color-coded maps of mean wind speed and power density at various heights above ground and (2) data files containing wind speed and direction frequency distribution parameters. For the standard MesoMap configuration MASS is run on the following nested grids: First (outer) grid level: 30 km, Second (intermediate) grid level: 8 km, Third (inner) grid level: 2.5 km.

    Person who carried out this activity:

    Brower, Michael
    AWS Truewind, LLC
    Principal
    463 New Karner Road
    Albany, New York 12205
    United States

    (518) 213-0044 (voice)

    Date: 2006 (process 2 of 5)
    Metadata imported.

    Date: 2006 (process 3 of 5)
    Written summary of the data processing procedures that are performed on the raw measured data in order to create an annual dataset of "typical" wind speeds, which could then be used to calculate potential power production from wind turbines. There are various methods and reasons for adjusting the raw data, so the purpose of these notes is to document what is typically done in AEA reports. See the associated PDF file, <http://akenergyinventory.org/metadata/WND2006_process.pdf> for more information.

    Person who carried out this activity:

    Jensen, James
    AEA
    Project Manager
    813 W. Northern Lights Blvd.
    Anchorage, AK, Alaska 99503
    United States

    (907) 771-3043 (voice)

    Date: 2009 (process 4 of 5)
    The raw, raster grid filed were converted to GeoTIF (K.R. Papp, AEA, 18-Jun, 2009) via ArcGIS 9.3 software. The dataset will be viewable/distributed online via the Alaska Energy Data Inventory (<http://akenergyinventory.org>) project through a WMS (Web Mapping Service) feed provided by the Geographic Information Network of Alaska, a partner of the Alaska Energy Data Inventory project.

    Date: 2009 (process 5 of 5)
    Formal FGDC metadata (this document) was rewritten for the entire Southeast, AK wind dataset (K.R. Papp, AEA, 18-Jun, 2009). The original 2006 metadata, each describing an individual layer, have been combined into this single dataset (i.e. all wind speed heights and power). The dataset will be viewable/distributed online via the Alaska Energy Data Inventory (<http://akenergyinventory.org>) project.

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

    AWS Truewind, LLC, and Authority, Alaska Energy , 2006, Gridded Wind Parameters of Southeast Alaska: Wind Energy WND 2006-2B, State of Alaska, Department of Commerce, Community & Economic Development, Alaska Energy Authority, Anchorage, AK.

    Online Links:

    AWS Truewind, LLC, and Authority, Alaska Energy , 2006, High-resolution Wind Resource Maps of Alaska: Wind Energy WND 2006-1A, State of Alaska, Department of Commerce, Community & Economic Development, Alaska Energy Authority, Anchorage, AK.

    Online Links:

    AWS Truewind, LLC, and Authority, Alaska Energy , 2006, Gridded Wind Parameters of Alaska: Wind Energy WND 2006-1B, State of Alaska, Department of Commerce, Community & Economic Development, Alaska Energy Authority, Anchorage, AK.

    Online Links:


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

  1. How well have the observations been checked?

    Raster cell values of the average wind speed (m/s) and wind power (W/m^2) density were computed from the MASS (Mesoscale Atmospheric Simulation System), a numerical weather model, which simulates the physics of the atmosphere. The maps and data can then be compared with land and ocean surface wind measurements, and if significant discrepancies are observed, adjustments to the wind maps can be made. The usual geophysical and meteorological inputs were used. The WindMap program adjusted the wind resource estimates to reflect local topography and surface roughness changes on a grid spacing of 200 m. For the topographical data, we used the National Elevation Dataset, a digital terrain model produced on a 30 m grid by the US Geological Survey (USGS). For the land cover, we used the National Land Cover Dataset, which is derived from Landsat imagery. It was also produced by the USGS on a 30 m grid. In converting from land cover to surface roughness, certain roughness length values were assumed to be typical of conditions in the region. The displacement height is defined as the height at which the wind speed becomes zero in the logarithmic shear formula. For this project, we assumed that the displacement height was 10 times the surface roughness length, which was in turn defined to be approximately 7.5% of the vegetation height. For deciduous forests with a roughness length of 0.9 m, this resulted in a displacement height of 9 m.

  2. How accurate are the geographic locations?

    The WindMap program adjusted the wind resource estimates to reflect local topography and surface roughness changes on a grid spacing of 200 m. For the topographical data, we used the National Elevation Dataset, a digital terrain model produced on a 30 m grid by the US Geological Survey (USGS). For the land cover, we used the National Land Cover Dataset, which is derived from Landsat imagery. It was also produced by the USGS on a 30 m grid.

  3. How accurate are the heights or depths?

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

    The shaded raster images display the average wind speed (m/s) and wind power (W/m^2) density for a large portion of Southeast Alaska (areas east of the Alaska/Canada border).

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

    MASS is coupled to a simpler wind flow model, WindMap, which is used to refine the spatial resolution of MASS and account for simple localized effects of terrain and surface roughness. MASS simulates weather conditions over a region for 366 historical days randomly selected from a 15-year period. When the runs are finished, the results are input into WindMap. Truewind subsequently validates the wind maps.


How can someone get a copy of the data set?

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

Access_Constraints:
This report, map, and/or data set have been published as part of the Alaska Energy Data Inventory (AEDI) project. The rasters layers described in this dataset are currently viewable as read-only base layers through the AEDI website. The vector layers, however, may be accessed and downloaded at the user's convenience. All of the data are available directly from AWS Truewind, LLC.
Use_Constraints:
This map was created by AWS Truewind using the MesoMap system and historical weather data. Although it is believed to represent an accurate overall picture of the wind energy resource, estimates at any location should be confirmed by measurement. Please site AWS Truewind, LLC when using this data.

  1. Who distributes the data set? (Distributor 1 of 1)

    State of Alaska, Department of Commerce, Community & Economic Development, Alaska Energy Authority
    Wind Program Manager
    813 W. Northern Lights Blvd.
    Anchorage, AK 99504
    USA

    907-771-3043 (voice)
    907-771-3044 (FAX)
    jjensen@aidea.org

    Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays
    Contact_Instructions:
    Please view our web site (<http://akenergyinventory.org>) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
  2. What's the catalog number I need to order this data set?

    Wind Energy 2006-2A

  3. What legal disclaimers am I supposed to read?

    The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requester or anyone else exceed the fee paid for the electronic service or product.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    Geospatial software is required to view and manipulate this raster dataset, such as ENVI <http://www.ittvis.com/envi/>, ER Mapper <http://www.ermapper.com/> or ESRI ArcGIS <http://www.esri.com/software/arcgis/index.html>. Free versions of the software listed may be available to simply view the data. The Google Earth KMZ file contains network links to the WMS (Web Mapping Service) feed provided by the Geographic Information Network of Alaska, a partner of the Alaska Energy Data Inventory project.


Who wrote the metadata?

Dates:
Last modified: 23-Jun-2009
Last Reviewed: 23-Jun-2009
To be reviewed: 23-Jun-2011
Metadata author:
State of Alaska, Department of Commerce, Community & Economic Development, Alaska Energy Authority
Energy Data Project Manager
813 W. Northern Lights Blvd.
Anchorage, AK 99504
USA

907-771-3049 (voice)
907-451-5050 (FAX)
kpapp@aidea.org

Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays.
Contact_Instructions:
Please contact us through the e-mail address above whenever possible.
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.9.8 on Wed Jun 24 20:45:46 2009