Multidimensional Data and GIS Steve Kopp Nawajish Noman

Multidimensional Data and GIS Steve Kopp Nawajish Noman ESRI

Multidimensional Data T Data cube (3 D) or hypercube (4 D, 5 D…) Y • Temperature varying with time and altitude X

Multidimensional Data Time = 3 Time = 2 Time = 1

Multidimensional Data Time = 3 Time = 2 Time = 1

Multidimensional Data Time = 1 Time = 2 Data Cube Time = 3 Time Slices

Multidimensional Data Includes variation in (x, y, z, t)

What is Net. CDF? Net. CDF (network Common Data Form) A platform independent format for representing multidimensional array-orientated scientific data. Self Describing - a net. CDF file includes information about the data it contains. Direct Access - a small subset of a large dataset may be accessed efficiently, without first reading through all the preceding data. Sharable - one writer and multiple readers may simultaneously access the same net. CDF file. Net. CDF is new to the GIS community but widely used by scientific communities for around many years

Why Net. CDF? Most commonly used format in the oceanographic and atmospheric science for observational data and numerical modeling • • • The National Center for Atmospheric Research (NCAR) University Corporation for Atmospheric Research (UCAR) NOAA's Climate Diagnostics Center (CDC) Los Alamos National Laboratory (LANL) The National Center for Supercomputing Applications US Air Force and Navy Atmospheric Research in Australia Defense UK Hydrographic Office NATO. . .

What is a Net. CDF file? Net. CDF is a binary file A Net. CDF file consists of: Global Attributes: Describe the contents of the file Dimensions: Define the structure of the data (e. g Time, Depth, Latitude, Longitude) Variables: Holds the data in arrays shaped by Dimensions Variable Attributes: Describes the contents of each variable CDL (network Common Data form Language) description takes the following form net. CDF name { dimensions: . . . variables: . . . data: . . . }

Storing Data in a net. CDF File netcdf mynetcdf{ dimensions: X=4; Y=4; Time=UNLIMITED; variables: float X(X); float Y(Y); int Time(Time); float Temperature(Time, Y, X); data: X = 10, 20, 30, 40; Y = 110, 120, 130, 140; Time = 31, 59, 90; }

Storing Data in a net. CDF File netcdf mynetcdf{ dimensions: X=4; Y=5; Time=UNLIMITED; variables: float X(X); float Y(Y); int Time(Time); float Temperature(Time, Y, X); data: X = 10, 20, 30, 40; Y = 110, 120, 130, 140; Time = 31, 59, 90; Temperature = 111, 211, 311, 411; } Time = 1 Y = 1 X = 1 to 4

Storing Data in a net. CDF File netcdf mynetcdf{ dimensions: X=4; Y=5; Time=UNLIMITED; variables: float X(X); float Y(Y); int Time(Time); float Temperature(Time, Y, X); data: X = 10, 20, 30, 40; Y = 110, 120, 130, 140; Time = 31, 59, 90; Temperature = 111, 211, 311, 411, 121, 221, 321, 421, 131, 231, 331, 431, 141, 241, 341, 441; } Time = 1 Y = 1 to 4 X = 1 to 4

Storing Data in a net. CDF File netcdf mynetcdf{ dimensions: X=4; Y=5; Time=UNLIMITED; variables: float X(X); float Y(Y); int Time(Time); float Temperature(Time, Y, X); data: X = 10, 20, 30, 40; Y = 110, 120, 130, 140; Time = 31, 59, 90; Temperature = 111, 211, 311, 411, 121, 221, 321, 421, 131, 231, 331, 431, 141, 241, 341, 441, 112, 212, 312, 412, 122, 222, 322, 422, 132, 232, 332, 432, 142, 242, 342, 442, 113, 213, 313, 413, 123, 223, 323, 423, 133, 233, 333, 433, 143, 243, 343, 443; } Time = 1 to 3 Y = 1 to 4 X = 1 to 4

Net. CDF Data Sources • Community Climate Systems Model (CCSM) http: //www. ccsm. ucar. edu, https: //www. earthsystemgrid. org/ • • • The CCSM is fully-coupled, global climate model that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. 100 yrs of climate change forecast data (2000 -2099) Control runs (1870 -1999) and scenario runs Temperature, precipitation flux, surface snow thickness, snowfall flux, cloud water content, etc. Program for Climate Model Diagnosis and Intercomparison (PCMDI) http: //www-pcmdi. llnl. gov/

Net. CDF Data Sources • Vegetation and Ecosystem Modeling and Analysis Project (VEMAP) http: //dataportal. ucar. edu/vemap/main. html • • • VEMAP was a large, collaborative, multi-agency program to simulate and understand ecosystem dynamics for the continental United States. The VEMAP Data Portal is a central collection of files maintained and serviced by the NCAR Data Group Climate data interval: Annual, monthly, and daily. Data type: Historical and model results Data: Temperature, irradiance, precipitation, humidity, incident solar radiation, vapor pressure, elevation, land area, vegetation, water holding capacity of soil, etc.

Net. CDF Data Sources • British Atmospheric Data Center (BADC) http: //badc. nerc. ac. uk/data/ • • • The role of the BADC is to assist UK atmospheric researchers to locate, access and interpret atmospheric data. Many datasets are publicly available but datasets marked with key symbol have restricted access. Datasets are organized by projects or organizations. Climatology Interdisciplinary Data Collection (CIDC) has monthly means of over 70 Climate Parameters. Met Office - Historical Central England Temperature Data has the monthly series, which begins in 1659, is the longest available instrumental record of temperature in the world. The daily series begins in 1772.

Net. CDF Data Sources • National Oceanic & Atmospheric Administration (NOAA) • • National Digital Forecast Database (NDFD) http: //www. nws. noaa. gov/ndfd/ Radar Integrated Display with Geospatial Element (RIDGE) http: //www. srh. weather. gov/ridge/ Precipitation Analysis http: //www. srh. noaa. gov/rfcshare/precip_download. php Climate Diagnostics Center http: //www. cdc. noaa. gov/

Net. CDF in Arc. GIS • Net. CDF data is accessed as Raster • Feature • Table • Direct read (no scratch file) • Exports GIS data to net. CDF •

Gridded Data Raster Point Features

Net. CDF Tools Toolbox: Multidimension Tools • • Make Net. CDF Raster Layer Make Net. CDF Feature Layer Make Net. CDF Table View Raster to Net. CDF Feature to Net. CDF Table to Net. CDF Select by Dimension

Unidata Net. CDF Files by Cedric David Ø Catalog of Datasets l http: //motherlode. ucar. edu: 8080/thredds/catalog. html

NCEP NAM 12 km Data North American Model Ø Continuous grid over the continental US Ø Model runs are made at 06 Z, 12 Z, 18 Z and 00 Z Ø Forecasts every 3 hours out to 84 hours Ø Accessed With Ø l l OPENDAP HTTPServer WCS Netcdf. Server

Netcdf Server Ø Query for subset of data with Web Form Ø Download net. CDF file

Query Via URL Ø Format documented at l Ø http: //motherlode. ucar. edu: 8080/thredds/docs/Netcdf Server. html Example: l http: //motherlode. ucar. edu: 8080/thredds/nc. Server/mo del/NCEP/NAM/CONUS_12 km/NAM_CONUS_12 km _20060803_1800. grib 2? Data Type grid=Total_precipitation &north=35&south=30&west=-90&east=-85 &time_start=0. 0&time_end=12. 0 Bounding Box Start/End Time

NDFD Data Also Available Ø NWS National Digital Forecast Database Ø Gridded forecasts of sensible weather elements Ø 5 km resolution over continental US Ø http: //motherlode. ucar. edu: 8080/thredds/c atalog/model/NCEP/NDFD/CONUS_5 km/c atalog. html

Viewing Net. CDF in Arc. Map