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Wednesday, February 6, 2019. 12:00PM. Toward Evaluating & Bias Correcting CM4s Surface Climate for the Conterminous USA. Keith Dixon, GFDL. Sponsored by NOAA GFDL. More information here.

This presentation's main thrust will be to compare the GFDL CM4 model’s representation of several surface temperature characteristics over the 48 contiguous states to those of some common observation-based data products. The period of interest is 1981-2014. Several analyses make use of a subset of the ClimDEX indices (Climate Indices of Extremes; www.climdex.org) and adopt a regional perspective akin to that used in the Fourth National Climate Assessment (nca2018.globalchange.gov). Preliminary results show substantial regional and seasonal differences in diagnostics computed from CM4 surface temperatures, with some tendency towards cool biases and smaller than observed diurnal temperature ranges. Additionally, results from the application of one bias correction method illustrate the extent to which, for the historical period, such statistical methods can account for model biases and provide outputs at finer spatial resolution -- factors important to several types of climate impacts studies. Plans for upcoming analyses will be discussed, including potentially expanding analyses to CM4 and ESM4 historical and future projections, examining additional surface variables, applying different bias correction and statistical downscaling techniques, and making statistically refined output available for use in in-house impacts studies. As this is an ongoing project, we are open to ideas and potential internal collaborations regarding the expansion of these analyses of the modeled and observed CONUS surface climate.