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).