Ray Arritt, Dave Flory, Bill Gutowski, and Gene Takle NARCCAP: Status Report and Some Preliminary Results

North America Regional Climate Change Assessment Program: Participants Raymond Arritt, David Flory, William Gutowski, Gene Takle, Iowa State University, USA Richard Jones, W. Moufouma-Okia, Hadley Centre, UK Daniel Caya, Sébastien Biner, OURANOS, Canada Phil Duffy, Lawrence Livermore National Laboratories, USA Filippo Giorgi, Abdus Salam ICTP, Italy Isaac Held, NOAA Geophysical Fluid Dynamics Laboratory, USA René Laprise, Univ. de Québec à Montréal, Canada Ruby Leung, Y. Qian, Pacific Northwest National Laboratories, USA Linda Mearns, Don Middleton, Doug Nychka, Phil Rasch, Tom Wigley, National Center for Atmospheric Research, USA Ana Nunes, John Roads, Scripps Institution of Oceanography, USA Steve Sain, Univ. of Colorado at Denver, USA Lisa Sloan, Mark Snyder, Univ. of California at Santa Cruz, USA

Current status Working data sets: UC - Santa Cruz (RCM3 designation) –Longitude variable differs other models with negative longitudes for western hemisphere. Precip and 500 mb heights through PNL (mm5p and wrfp designation) –Two files incomplete when transferred (Ruby has been contacted). Precip and 500 mb heights through Error in interpolation for 500 mb height from WRF. OURANOS (MRCC designation) –All files checked via checksums and are working fine. Precip and 500 mb height through full period.

Current status Not Working data sets: Hadley Centre (PRECIS) –Files provided as monthly mean values. Not usable as submitted but able to processes after using ncdump | ncgen. Monthly output rather than 3-hour. Scripps (ECPC) –Individual netCDF files provided for every output time step. No internal timestamp. Variable and dimension names, etc. differ from specs. Output through (All this is straightforward to fix, except timestamp.)

NARCCAP Plans Phase I: driven by Reanalysis 2 –establish uncertainty in RCMs Phase IIa: RCMs driven by AOGCM 20th century climate (nominally ) Phase IIb: RCMs driven by AOGCM SRES A2 scenario

The Matrix Any changes?

Some data issues Time coordinate: Days versus hours. –Recommendation: Hours would be simple integer; days may be easier for end users. Bounds for coordinate variables (space and time) –Recommendation: Drop bounds for spatial coordinates. Keep bounds for time. Include projection information in metadata (following ENSEMBLES)? –Recommendation: Yes. See example sent by Hadley Centre.

Some data issues Reporting domain: Send the entire domain to the archive or only the region inside the forcing frame (aka sponge zone)? –There does not appear to be any straightforward way of subsetting for users. –Recommendation: Exclude forcing frame Output transmittal to archive: ftp vs. mailing external hard drives (“FedEX Net”)? –Recommendation: External hard drives. (Hadley Centre may prefer DLT cartridges.)

Meetings "Downscaling to local and regional scales" (IAMAS session MS016) at the IUGG Conference in Perugia, Italy 2-13 July Designate a regular professional conference for NARCCAP meetings? Would help to save travel time and funds. –Recommendation: Fall AGU (consistent location; easy to reach). Propose a regional modeling session at each meeting; maybe a NARCCAP session at later stages.

preliminary Some preliminary results Results are shown here for from three RCMs. Observed precip is from the CRU 0.5 o data set. –probably underestimates precip in high terrain – need to look at other precip data sets

Analysis Regions Northern Plains: flat terrain, early summer precip maximum Pacific Northwest: mountainous terrain, winter precip maximum

Precipitation,

Mean annual cycle of precipitation

January 1980 – ENSO neutral January 1981 monthly mean 500 mb height reanalysis

July 1982 monthly mean 500 mb height reanalysis

500 mb heights January 1983 – strong El Niño

NARCCAP Project Timeline 1/0612/0712/0812/06 Start Current Climate GCM1 6/06 End reanalysis 9/06 AOGCM Boundaries available End Future climate GCM1 6/07 End Current GCM1 End Current and Future GCM2 Project Start Finish obs SST Finish delta SST Time slices RCMs ? current date current status