Gridded ERA-40 Reanalysis Data for Western Arctic Linkage Experiment (WALE)


This data set includes monthly-mean air temperature and precipitation data for areas in Alaska and northwestern Canada, between 55°N and 65°N, and 160W° and 110°W. The data are from the ECMWF Re-Analysis (ERA-40) data set and are converted to the 25 km EASE-Grid over the study area. Data coverage is from 1990 through 2001. The data consist of X binary file downloads, containing monthly gridded output in EASE-Grid format. These data are archived at the Western Arctic Linkage Experiment (WALE) Web site.

Citing These Data

Please contact the investigator for a citation for these data.

Overview Table

Category Description
Data format 25 km EASE-Grid, 361 x 361 ASCII arrays, formatted as "361(F8.2,1x)"
Spatial coverage and resolution Southernmost Latitude: 55°N
Northernmost Latitude: 65°N
Westernmost Longitude: 160°W
Easternmost Longitude: 110°W

Spatial resolution: 25 km
Temporal coverage and resolution Monthly, 1990 to 2001
File naming convention ...
File size 1.146 MB per file
Parameter(s) Surface air temperature (degrees Kelvin), precipitation (mm)
Procedures for obtaining data Data are available at

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. References and Related Publications
5. Document Information

1. Contacts and Acknowledgments


James Maslanik
Sheldon Drobot

Colorado Center for Astrodynamical Research
Boulder, Colorado USA

Amanda Lynch
Wu Wanli

Monash University
Melbourne, Australia

Ute Herzfeld
Institute for Arctic and Alpine Research
University of Colorado
Boulder, Colorado USA


This research was supported by the National Science Foundation (NSF) Office of Polar Programs (OPP) Arctic System Science (ARCSS) Program grant ARC-0095047.

2. Detailed Data Description


Data are in 25 km EASE-Grid format.

File and Directory Structure

Data are stored in a 361 x 361 ASCII array; data are formatted as "361(F8.2, 1x)".

File Naming Convention

Files are named according to the following convention.





Spatial Coverage

Southernmost Latitude: 55°N
Northernmost Latitude: 65°N
Westernmost Longitude: 160°W
Easternmost Longitude: 110°W

Spatial Resolution

25 km

Grid/Projection Description

For more information about the Equal-Area Scalable Earth Grid (EASE-Grid) format, see All About EASE-Grid.

Temporal Coverage

1990 to 2001

Temporal Resolution



Surface air temperature (degrees Celsius)

Precipitation (mm)

3. Data Acquisition and Processing

Data Acquisition Methods

Data were collected from Eugenie Euskirchen at the University of Alaska, and then re-gridded to the EASE-Grid by Chuck Fowler at the University of Colorado.

Processing Steps

Data were converted to EASE-Grid through bilinear interpolation.

4. References and Related Publications

Drobot, S.D., James A. Maslanik, W. Wu, U.C. Herzfeld, and C. Fowler. 2006. Uncertainty in temperature and precipitation data sets over terrestrial regions of the western Arctic. Submitted to Earth Interactions.

Herzfeld, U.C., J. Maslanik, S. Drobot, and W. Wu. 2006. Temporal and spatial variability of climate components in Alaska and northwestern Canada: analysis and assessment using algebraic similarity mapping. Submitted to Earth Interactions.

Wu, W., A.H. Lynch, and A. Rivers. 2005. Estimating the uncertainty in a regional climate model related to initial and lateral boundary conditions. J. Climate 18: 917-933. doi:10.1175/JCLI-3293.1

Wu. W., S. Drobot, J. Maslanik, U.C. Herzfeld, and A. Lynch. 2006. An integrated analysis of surface climate in the northern high latitudes with modeling and observation. Submitted to Earth Interactions.

All About EASE-Grid EASE-Grid documentation

Related information at other Web sites:

Western Arctic Linkage Experiment site WALE data and information
ECMWF Re-Analysis (ERA-40) ERA-40 project site

5. Document Information

Acronyms and Abbreviations

The following acronyms and abbreviations are used in this document.

ARCSS Arctic System Science
ASCII American Standard Code for Information Interchange
AVHRR Advanced Very High Resolution Radiometer
EASE-Grid Equal-Area Scalable Earth Grid
ECMWF European Centre for Medium-Range Weather Forecasts
ERA-40 ECMFW ERA-40 Reanalysis
FTP File Transfer Protocol
NSF National Science Foundation
NCAR National Center for Atmospheric Research
OPP Office of Polar Programs
URL Uniform Resource Locator
WALE Western Arctic Linkages Experiment

Document Creation Date

26 June 2007

Document URL