1. CKD Workshop  30 March 2011  Jim Kinter  Data Lessons from Project Athena GrADS Station Data Model Used for in situ observational data Individual reports may be located anywhere in space and time Required metadata for each report: Station Identifier (8-character string) Longitude Latitude Level (for level-dependent variables) Time Linear time axis is used to organize reports

2. CKD Workshop  30 March 2011  Jim Kinter  Data Lessons from Project Athena Visualization in GrADS Display options include: Contour (lines or shaded) Grid fill (colors or numbers) Bar graph (with error bars) Scatter plot Winds: Vectors, Barbs, or Streamlines Output options include: Images Vector Graphics (e.g. Postscript) ASCII Binary or NetCDF file GIS-Compatible Formats  new!

3. CKD Workshop  30 March 2011  Jim Kinter  Data Lessons from Project Athena Data Analysis in GrADS GrADS expressions are formulas that contain: Operands (variables, functions, or constants) Operators (add, subtract, multiply, divide) Parentheses (to control the order of operation) Expression handling is recursive, so an expression may be embedded within another. Some examples: temp*9/5+32 aave((temp*9/5+32),global) hgt(lev=500)-hgt(lev=1000) ave(uwnd,lon=0,lon=360) sum(precip,t+0,t+24)

4. CKD Workshop  30 March 2011  Jim Kinter  Data Lessons from Project Athena 00z 6 Dec 2003 QuikSCAT Winds (HDF), Surface Obs (BUFR), and ETA Model SLP (GRIB)

5. CKD Workshop  30 March 2011  Jim Kinter  Data Lessons from Project Athena Analysis of Surface METAR Observations with Radar 18z 29 May 2009