87th AMS Annual Meeting

Thursday, 18 January 2007: 11:30 AM
A brief evaluation of precipitation from the North American Regional Reanalysis
206A (Henry B. Gonzalez Convention Center)
Melissa S. Bukovsky, University of Oklahoma, Norman, OK; and D. J. Karoly
Several aspects of the precipitation climatology from the North American Regional Reanalysis (NARR) are analyzed and compared with two other reanalyses and one set of gridded observations over a domain encompassing the United States. The National Center for Environmental Prediction's global reanalysis and the European Center for Medium-Range Weather Forecasts' global reanalysis are used for comparison and are judged, along with the NARR, against the Climate Prediction Center's hourly US objectively analyzed, gridded, observationally based precipitation dataset.

The relatively new NARR is a higher resolution dataset for use in atmospheric research. It, like other reanalyses, is only an estimate of the state of the atmosphere and, therefore, may not match observations. Usually, this is especially true of the precipitation field, but the NARR, unlike the other two popular reanalyses used in this study, incorporated precipitation observations in its assimilation and integration process. This gave the NARR precipitation more potential for use. To establish its reliability and the reliability of the other two reanalyses and to judge their usefulness, the spatial distribution, diurnal cycle, and annual cycle of precipitation are explored. Results show that while the NARR provides a much improved representation of precipitation over that of the other reanalyses examined, it does contain some inaccuracies and these have been highlighted as a warning to potential users of the data.

This work has been submitted to the Journal of Hydrometeorology under the same title. Until publication, it will be available at: http://weather.ou.edu/~bukovsky/reanalysis_note_revised.pdf

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