New Data Streams Available for ARM Mobile Facility Deployment Sites

 
Published: 15 July 2005

The pyeruc20isobX1.c1 datastream originates from data in a grid of points bordered by latitudes 34.300 and 42.539 and by longitudes -127.607 and -120.862; the RUC "bounding box."  This area is indicated by the blue corner squares; purple dots indicate MOLTS stations, and green triangles indicate ECMWF stations.

New climate datastreams are now available from Point Reyes National Seashore in California, where the first deployment of the ARM Mobile Facility is currently underway, and for the site of the ARM Mobile Facility’s next deployment at Niamey, Niger, Africa. The new datastreams, which are supplementary to the datastreams obtained by the Mobile Facility instruments, provide climate information as netCDF files for use by ARM researchers.

For climate analyses of Point Reyes National Seashore and the surrounding area, the pyeruc20isobX1.c1 data stream, provided by the National Centers for Environmental Prediction (NCEP), offers output of the Rapid Update Cycle (RUC) model, an atmospheric prediction system that was developed to serve users needing short-range weather forecasts. RUC provides a 3D objective analysis, updated every hour, over the contiguous United States and assimilates data from a variety of aircraft, satellite, and ground-based sources. A separate series of datastreams, specifically generated for ARM analysis, is supplied by the European Centre for Medium Range Weather Forecasts (ECMWF) and has been available continuously since April 2005 for Point Reyes National Seashore, and since May 2005 for Niamey. Whereas the RUC datastream offers information for a grid of points (see figure), the ECMWF streams are limited to specific points on the map: (38.11 N, 123.33 W) at Point Reyes, and (2.46 N, 13.52 W) at Niamey and (38.11 N, 122.92 W). The RUC and ECMWF datastreams use different algorithms and include slightly different measurements.

Another data set, the Model Output Location Time Series (MOLTS), is also now available for the Point Reyes area. Measurements included are products of NCEP’s mesoscale numerical weather prediction model and its associated 4D data assimilation system. These data are the hourly output at selected locations containing values for various surface parameters and “sounding” output at model levels. The MOLTS stations included in the surface (pyemoltsedassfcclass1X1.a1) and sounding (pyemoltsedassndclass1X1.a1) datastreams are from the same approximate area as the RUC stations-a large portion of the West Coast centered on Point Reyes. More information can be accessed at the web pages for the RUC, ECMWF, and MOLTS datastreams.