NACP

A High-Resolution Daily Surface Weather Database for NACP InvestigationsPeter E. Thornton1, Robert B. Cook2, W. Mac Post2, Bruce E. Wilson2, and Craig Hartsough1

1 National Center for Atmospheric Research (NCAR)*, Earth and Sun System Laboratory, Boulder, CO 80307-30002 Environmental Sciences Division, Oak Ridge National Laboratory (ORNL)#, Oak Ridge, Tennessee 37831-6407

MAST-DCModeling and Synthesis Thematic Data Center

Example: Daymet Climatological Summary Data Preliminary Merged Dataset ResultsProject OverviewBackground

As one component of the recently funded NACP Modeling and Synthesis Thematic Data Center (MAST-DC), we are producing high-resolution daily surface weather fields on a 1 km grid over North America.

This project builds on previous efforts that resulted in the construction of a 1 km gridded daily surface weather dataset for an 18-year period over the conterminous United States (The Daymet U.S. database, online at www.daymet.org). Examples of the 18-year climatological summary of these daily data are shown in the center panel, illustrating the spatial and topographic resolution that users can expect from the final North American dataset.

Major milestones in this three-year effort:

Year 1 –

• Update U.S. database of surface observations to 2005.

• Produce new U.S. daily gridded data through 2005 (including Alaska)

• Preliminary development of tools for automated query, subsetting, and retrieval of daily data (via OpenDAP).

• Establish contact with Canadian and Mexican sources for surface weather observations.

Year 2 –

• Merge all available observations from U.S., Canadian, and Mexican data sources.

• Generate preliminary continental grids.

• Continue development of automated data interface tools.

Year 3 –

• Update all surface observations.

• Produce final continental gridded datasets

• Finalize data interface tools

• Transfer final datasets and software to MAST-DC for operational updates.

SupportThis work is supported by the National Aeronautics and Space Administration under Agreement No. 05-NACP-05-12, issued through the Science Mission Directorate

U.S. – Canada

Under previous support to P.E. Thornton from NASA’s Advanced Information Systems Technology Program (AIST, NASA Ames Research Grant No. NAG 2-1646), we developed a user interface that streamlines the process of ingesting and merging surface weather observations from multiple data sources (Figure 1).

Through a collaboration with researchers in Agriculture and Agri-Food Canada, under a surface weather interpolation intercomparison project (managed by Harvey Hill), we obtained use of a large daily surface weather observation dataset (approximately 6000 stations, Figure 2) for a long period of record (1961-2003). We were able to accomplish a preliminary merger of our existing U.S dataset with the Canadian observations, and generate a new gridded product spanning large parts of the conterminous U.S. and Canada (Figure 3).

These results serve as an early example of the final datasets that will be produced, and also as a demonstration of the technological infrastructure required to handle these large data volumes and multiple data sources.

Figure 1.

Web-based user interface to Daymet software.

Figure 2.

Merged dataset of U.S. and Canadian surface observations

Figure 3.

a) Maximum Temperature, b) Minimum Temperature, c) Precipitation, d) Vapor pressure

a)

d)c)

b)

* Support for NCAR is provided by the National Science Foundation. # ORNL is managed by the University of Tennessee-Battelle LLC under contract DE-AC05-00OR22725 with the U.S. Department of Energy