HR: 11:10h
AN: A32A-05    [Abstracts]
TI: Influence of Nesting Data and Domain on the Canadian Regional Climate Model's Hydrology.
AU: * Frigon, A
EM: frigon.anne@ouranos.ca
AF: Ouranos, 550 Sherbrooke West 19th floor, West Tower, Montreal, Qc H3A 1B9 Canada
AU: Michel, S
EM: michel_slivitzky@inrs-ete.uquebec.ca
AF: Ouranos, 550 Sherbrooke West 19th floor, West Tower, Montreal, Qc H3A 1B9 Canada
AU: Caya, D
EM: caya.daniel@ouranos.ca
AF: Ouranos, 550 Sherbrooke West 19th floor, West Tower, Montreal, Qc H3A 1B9 Canada
AU: Tapsoba, D
EM: tapsoba.dominique@ouranos.ca
AF: Ouranos, 550 Sherbrooke West 19th floor, West Tower, Montreal, Qc H3A 1B9 Canada
AB: Results from three 30-year runs (1961-1990) with the CRCM are used to investigate the effect of nesting data on the simulated climate over Quebec/Labrador (eastern Canada). The CRCM was run with a 45-km horizontal resolution, over a large domain covering most of North America (200x192 grid tiles), with 29 vertical levels and 15-minute time steps. Sea surface conditions (SST and sea-ice) were prescribed using monthly AMIP-II observations. In the various simulations, the CRCM was driven at its lateral boundaries by NCEP atmospheric objective reanalyses (NRA-1), ECMWF reanalyses (ERA-40 degraded to 2.5x2.5 degrees) and by CGCM2 output in current climate (Canadian GCM with CO$_{2}$ concentration following IS92a). Components of the model's hydrologic cycle are examined in detail for 12 rivers in northern Quebec and Labrador, totaling a combined drainage area of 435 000 km$^{2}$. Available streamflow observations are used to evaluate the model's climate when driven by reanalyses; the 30-year mean annual runoff is quite similar between simulations nested with NCEP and ECMWF reanalyses, and both have a negative bias when compared with observations. We also examine an additional 30-year CRCM run that was performed on a smaller domain (112x88 grid tiles), centered over Quebec, and nested with NCEP reanalyses. The model's mean annual runoff remains underestimated but the negative bias is reduced by about half on the smaller domain, mostly due to an increase in fall precipitation.
DE: 3354 Precipitation (1854)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting