Journal Article

The effect of horizontal resolution on simulation quality in the Community Atmospheric Model, CAM5.1

Wehner, Michael F., Gettelman, Andrew, Chen, Cheng‐Ta, Collins, William D., Paciorek, Christopher, Prabhat, Gleckler, Peter J., Sperber, Kenneth R., Reed, Kevin A., Li, Fuyu, Bacmeister, Julio, Jablonowski, Christiane

2014

Overview

We present an analysis of version 5.1 of the Community Atmospheric Model (CAM5.1) at a high horizontal resolution. Intercomparison of this global model at approximately 0.25°, 1°, and 2° is presented for extreme daily precipitation as well as for a suite of seasonal mean fields. In general, extreme precipitation amounts are larger in high resolution than in lower‐resolution configurations. In many but not all locations and/or seasons, extreme daily precipitation rates in the high‐resolution configuration are higher and more realistic. The high‐resolution configuration produces tropical cyclones up to category 5 on the Saffir‐Simpson scale and a comparison to observations reveals both realistic and unrealistic model behavior. In the absence of extensive model tuning at high resolution, simulation of many of the mean fields analyzed in this study is degraded compared to the tuned lower‐resolution public released version of the model. Key Points The effects of increasing resolution in an atmospheric model are presented Global models at 25 km can realistically simulate tropical cyclone statistics Increased resolution alone does not improve model defects

• Publisher: John Wiley & Sons, Inc,American Geophysical Union (AGU)
• Subject: Atmospheric models / Cyclones / Daily precipitation / Defects / extreme precipitation / Extreme weather / Fields / GEOSCIENCES / global atmospheric modeling / high resolution / Hurricanes / Intercomparison / Precipitation / Resolution / Seasons / Simulation / Statistical methods / Tropical climate / Tropical cyclones