Climate Data

Arctic System Reanalysis (ASR)

"The Arctic System Reanalysis (ASR) is produced using a high-resolution version of the Polar Weather Forecast Model (PWRF) and the WRF-VAR and High Resolution Land Data Assimilation (HRLDAS) data assimilation systems that have been optimized for the Arctic. ASR-Interim is a 30km data set which spans 2000 - 2012 and is available through the NCAR Research Data Archive. This version has 29 pressure levels, 27 surface and 10 upper air analysis variables, 74 surface and 16 upper air forecast variables, and 3 soil variables. Both the u- and v- winds relative to grid and relative to earth are present in the final version." -from RDA abstract on ASR

Key Strengths:

  • High resolution model and data assimilation framework (WRF 3.1) for Arctic
  • Many variables

Key Limitations:

  • Interim version has systematically low precipitation
  • Too few clouds leads to excessive shortwave and a deficit in longwave radiation. From: "The newer version of the ASR (ASR2) is not necessar- ily better than the older in reproducing the evolution of the Arctic cloud layer and the moisture content of the lower atmosphere. The different microphysical pa- rameterizations in ASR1 and ASR2 give rise to differ- ent distributions of liquid and ice in the clouds, where the parameterization applied in ASR1 (Morrison et al., 2005) seems to perform slightly better in the Arctic re- gion than ASR2 (Hong et al., 2004), at least for these observed conditions."

Years of Record

2000/01 to 2012/12
temporal metadataID:



Sub-daily | Monthly

Data Time Period Extended?

yes, data set is extended


Spatial Resolution

30 km; 71 levels; 10hPA top | 10 km

Ocean or Land


Missing Data Flag

spatially complete

Vertical Levels

Data Assimilation Method

Model Resolution used to create reanlaysis

30 km and 10 km

Earth system components and main variables

Suggested Data Citation

Byrd Polar Research Center/The Ohio State University. 2012. Arctic System Reanalysis (ASR) Project. Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. Accessed dd mmm yyyy.

Data Access: Please Cite data sources, following the data providers' instructions.

  1. Bromwich, D. H. et al (2014): Contrasting the regional Arctic System Reanalysis with the global ERA-Interim Reanalysis. Q. J. R. Meteorol. Soc (submitted)
  2. Wesslén C. et al (2014): The Arctic summer atmosphere: An evaluation of reanalyses using ASCOS data. Atmos. Chem. Phys., 14, 2605-2624
  3. Tilinina, N. et al (2014): New view of Arctic cyclone activity from the Arctic System Reanalysis. Geophys. Res. Letts., 41
  4. Hines, K. M., and D. H. Bromwich (2008), Development and testing of Polar WRF. Part I: Greenland ice sheet meteorology, Mon. Weather Rev., 136, 1971–1989
  5. Wilson, A. B., D. H. Bromwich, and K. M. Hines (2012), Evaluation of Polar WRF forecasts on the Arctic System Reanalysis Domain: 2. Atmospheric hydrologic cycle, J. Geophys. Res., 117, D04107
  6. Hines, K. M. et al (2011), Development and testing of Polar WRF. Part III: Arctic land, J. Clim., 24, 26–48
  7. Bromwich, D. H., et al (2010), Arctic System Reanalysis: Call for community involvement, Eos Trans. AGU, 91(2), 13–14
  8. Bromwich, D. H., L. Bai, K. M. Hines, S.-H. Wang, B. Kuo, M. C. Serreze, and J. E. Walsh: Progress and overview of the Arctic System Reanalysis. 11th Conference on Polar Meteorology and Oceanography, Boston, MA, May 1-4, 2011
  9. Bromwich, D. H., K. M. Hines, and L.-S. Bai (2009), Development and testing of Polar WRF: 2. Arctic Ocean, J. Geophys. Res., 114, D08122
  10. Wang, S.-H., D. H. Bromwich and L. Bai: Arctic System Reanalysis Interim (ASR-interim) output - A 30 km resolution dataset. 11th Conference on Polar Meteorology and Oceanography, Boston, MA, May 1-4, 2011
  11. Moore, G. W. K. (2014): A new look at Southeast Greenland barrier winds and katabatic flow. CLIVAR Exchanges Newsletter

Key Figures

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Cite this page

National Center for Atmospheric Research Staff (Eds). Last modified 02 Mar 2016. "The Climate Data Guide: Arctic System Reanalysis (ASR)." Retrieved from

Acknowledgement of any material taken from this page is appreciated. On behalf of experts who have contributed data, advice, and/or figures, please cite their work as well.