Investigating added value of regional climate modeling in North American winter storm track simulations
- Univ. of Quebec, Montreal (Canada). Regional Center for Climate Studies and Simulation (ESCER) and Dept. of Earth and Atmospheric Sciences
- Univ. of Quebec, Montreal (Canada). Regional Center for Climate Studies and Simulation (ESCER) and Dept. of Geography
- Environment and Climate Change Canada (ECCC), Montreal, QC (Canada). Center Research in Numerical Prediction (RPN)
Extratropical Cyclone (EC) characteristics depend on a combination of large-scale factors and regional processes. However, the latter are considered to be poorly represented in global climate models (GCMs), partly because their resolution is too coarse. This work describes a framework using possibilities given by regional climate models (RCMs) to gain insight into storm activity during winter over North America (NA). Recent past climate period (1981–2005) is considered to assess EC activity over NA using the NCEP regional reanalysis (NARR) as a reference, along with the European reanalysis ERA-Interim (ERAI) and two CMIP5 GCMs used to drive the Canadian Regional Climate Model—version 5 (CRCM5) and the corresponding regional-scale simulations. While ERAI and GCM simulations show basic agreement with NARR in terms of climatological storm track patterns, detailed bias analyses show that, on the one hand, ERAI presents statistically significant positive biases in terms of EC genesis and therefore occurrence while capturing their intensity fairly well. On the other hand, GCMs present large negative intensity biases in the overall NA domain and particularly over NA eastern coast. In addition, storm occurrence over the northwestern topographic regions is highly overestimated. When the CRCM5 is driven by ERAI, no significant skill deterioration arises and, more importantly, all storm characteristics near areas with marked relief and over regions with large water masses are significantly improved with respect to ERAI. Conversely, in GCMdriven simulations, the added value contributed by CRCM5 is less prominent and systematic, except over western NA areas with high topography and over the Western Atlantic coastlines where the most frequent and intense ECs are located. Despite this significant added-value on seasonalmean characteristics, a caveat is raised on the RCM ability to handle storm temporal ‘seriality’, as a measure of their temporal variability at a given location. In fact, the driving models induce some significant footprints on the RCM skill to reproduce the intra-seasonal pattern of storm activity.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE; Canadian Network for Regional Climate and Weather Processes (CNRCWP); Natural Sciences and Engineering Research Council of Canada (NSERC)
- Contributing Organization:
- Environment and Climate Change Canada (ECCC). Canadian Centre for Climate Modelling and Analysis (CCCMA); European Centre for Medium-Range Weather Forecasts (ECMWF); National Oceanic and Atmospheric Administration (NOAA), Washington, DC (United States). National Centers for Environmental Prediction (NCEP); Max Planck Society
- OSTI ID:
- 1461847
- Journal Information:
- Climate Dynamics, Vol. 50, Issue 5-6; ISSN 0930-7575
- Publisher:
- Springer-VerlagCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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