61aa24e9-87f9-4252-a751-672e7a268eed Scenarios Network for Alaska and Arctic Planning uaf-snap-data-tools@alaska.edu 2022-08-18T10:18:41 ISO 19115:2003/19139 1.0 3 365 1 73 2.5 144 2.5 EPSG:4326 Historical and Projected Daily Quantile Mapped Near Surface Wind Velocity - 2.5 degrees CMIP5/AR5 2015-05-15 This data includes quantile-mapped historical and projected model runs of AR5 daily mean near surface wind velocity (m/s) for each day of every year from 1958 - 2100 at 2.5 x 2.5 degree spatial resolution across 3 AR5 models. They are 365 multi-band geotiff files, one file per year, each band representing one day of the year, with no leap years. Matthew Leonawicz Angelica Floyd Tom Kurkowski Michael Lindgren John Walsh Scott Rupp Scenarios Network for Alaska and Arctic Planning uaf-snap-data-tools@alaska.edu https://catalog.snap.uaf.edu/geonetwork/srv/api/records/61aa24e9-87f9-4252-a751-672e7a268eed/attachments/vas_mean_preview.png wind historical projected modeled https://creativecommons.org/licenses/by/4.0/ 2.5 eng climatologyMeteorologyAtmosphere 1958-01-01 2100-12-31 -180.00 180.00 -90.00 90.00 Variable info uas: eastward component of wind, this value is positive if the wind is flowing from the west to the east vas: northern component of wind, this value is positive if the wind is flowing from the south to the north To combine the wind vectors, use the Pythagorean theorem. a^2 + b^2 = c^2 Specifications Models used: AR5 GCMs (historical runs, 1850-2005) GFDL-CM3 IPSL-CM5A-LR MRI-CGCM RCPs (projected runs, 2006-2100) 6.0 8.5 Quantile mapping methodology GCMs were quantile-mapped with respect to 1958-2001 ERA-40 reanalysis data by various methods as documented in: Gudmundsson, L., Bremnes, J. B., Haugen, J. E., and Engen Skaugen, T.: Technical Note: Downscaling RCM precipitation to the station scale using quantile mapping – a comparison of methods, Hydrol. Earth Syst. Sci. Discuss., 9, 6185-6201, doi:10.5194/hessd-9-6185-2012, 2012. A similar comparison of methods was made and the Local Linear Least Squares Regression quantile mapping method, available in the R package 'qmap', was chosen as the most appropriate method. Deltas resulting from the mapping were then applied to 2002-2100 GCM output to complete the 1958-2100 quantile-mapped GCM products. http://www.ecmwf.int/products/data/archive/descriptions/e4/index.html http://cran.r-project.org/web/packages/qmap/index.html Model selection methodology Per _Walsh et al. 2008. Global Climate Model Performance over Alaska and Greenland. Journal of Climate. v. 21 pp. 6156-6174._ Model selection used in AR5 products is more rigorous, and a publication is in preparation (Leonawicz M. and Walsh J. 20xx). GeoTIFF 1.0 ckan.snap.uaf.edu/dataset/historical-and-projected-daily-quantile-mapped-near-surface-wind-velocity-2-5-degrees-cmip5-ar WWW:LINK-1.0-http--link SNAP downscaled data products are value added products that build off of other datasets that have been accepted by the scientific community as some of the highest quality climate data available. Please see www.snap.uaf.edu to explore how our data is produced.