GIST CD-ROM Set Overview 1.0 General Description Within the overall scientific strategy of the World Climate Research Programme (WCRP) of the World Meteorological Organization (WMO), the Global Energy and Water-cycle Experiment (GEWEX) has been launched to study on the global scale the fast climate system mechanisms controlling radiation, clouds and rain, evaporation and fresh water storage. The GEWEX Continental-scale International Project (GCIP) initiative is the first major project under GEWEX. Descriptions of the objectives of GCIP are provided in the GCIP scientific and implementation plans (WMO, 1992; IGPO 1993, 1994a, b). The first of the GCIP Initial Data Sets (GIDS-1) was compiled as a static systems test of the GCIP data management system. GIDS-1 made use of existing experimental and operational capabilities to produce a composite observational and model-output data set which was derived from new observation and assimilation schemes. GIDS-1 contains data from the west-central Mississippi River basin with data from 1 February 1992 to 30 April 1992. Data are primarily based on the STORM-Fronts Experiment Systems Test (STORM-FEST) which was conducted from 1 February to 15 March 1992 over the central United States augmented by additional hydrological, geographical and surface characterization data. A subset of GIDS-1 data is also available on CD-ROM. The GCIP Integrated Systems Test (GIST) was the second of the GCIP Initial Data Sets to be collected prior to the start of the 5-year Enhanced Observing Period (EOP) scheduled to begin October 1995. GIST was essentially a GCIP pilot study to test the data collection and provide initial analyses in a significant geographic area in the Missis- sippi River Basin (Arkansas-Red River Basin) where significant variations in atmospheric, hydrologic, and land surface occur. In addition to the numerous operational measurements available in the Arkansas-Red River Basin, GIST coordinated with other Research programs such as the Department of Energy (DOE) Atmospheric Radiation Measurements (ARM) and the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX) to create a high spatial and temporal resolution data set. GIST data collection took place from 1 April through 31 August 1994 in the domain of 31 to 40 degrees N latitude and 91 to 107 degrees W longitude. During that period, intensive operations for VORTEX took place 1 April through 15 June 1994, and the ARM Program conducted two Intensive Observing Periods (April and July-August 1994). The Arkansas- Red River Basin is one of several intensively observed areas representing different climatic and soil hydrology regimes that will be identified throughout the GCIP Mississippi River Basin region over the course of GCIP. In addition, GIST was conducted during a hydrologically important time of year (i.e., early spring into summer snowmelt/runoff). 2.0 GIST Objectives and Approach The purpose of compiling the GIST data set was to create a prototype data set that would be similar to future data sets collected during the EOP. The GIST data set also provides a basis for the test of the existing observational networks (as well as enhanced research observations) for suitability in meeting GCIP requirements prior to the start of the EOP. This data set contains similar quality controlled surface and upper air composite data sets as required by GCIP. Further, this data set provides the observations to serve the following GCIP data analysis and modeling requirements: 1) Development and refining of algorithms and analysis techniques to obtain precipitation, cloud, moisture, radiative flux, and cloud heating fields (e.g., development of an algorithm to derive the vertical distribution of hydrometers from WSR-88D reflectivities over the GCIP domain). 2) Provision of optimal data sets for initialization and validating mesoscale model forecasts of cloud and precipitation patterns and for assessing and improving moist physics and radiation parameterizations in such models. 3) Enhancement of the closure scheme for the heating and moistening budgets of the atmosphere at the scale of a GCM grid element (roughly 100 km on a side) with estimates of all variables and processes at both this scale and the subgrid scales representative of cloud-mesoscale and global climate models. 4) Obtaining sufficient information from ground hydrology measurements (e.g., streamflow runoff, evaporation) and already existent high density coverage by rain gages to provide development and validation data sets for coupled mesoscale-hydrology models. The GIST region has substantial gradients in soil moisture and biomass. These required measurements include 3-D thermal, wind, and moisture fields of the atmosphere, precip- itation rate, streamflow rate, soil moisture content, and radiative flux and surface energy budget measurements at commensurate scales. Determination of an effective surface temperature for calculating the sensible heat transport from the surface has been demonstrated by the first ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment to be problematic. These questions stress the need for careful interpretations of available measurements of the sensible heat flux and the development of new parameterizations. Further information on all the datasets included in GIST can be found in IGPO 1994c. Note that this set of CD-ROMs contains only a subset of the complete GIST dataset. Information on access to the complete GIST dataset is described in section 4.0. 3.0 Directory Structure The set of GIST CD-ROMs contains four precipitation composites, three surface composites, two hydrology datasets, National Weather Service, ARM-CART and VORTEX sounding data, NOAA 405 MHz Wind Profiler Demonstration Network (WPDN) data, and several different types of imagery. For each composite/dataset, the data, associated documentation, station information, etc. are all located in separate directories. The first CD-ROM in the GIST CD-ROM set is divided into five (5) high- level directories (i.e., docs, hydro, precip, sfc_met, and stn_list). The second of the GIST CD-ROM set is divided into five (5) high-level directories (i.e., docs, images, prof_405, sounding, stn_list). Several of these high-level directories are further divided into subdirectories, depending on the nature of the data contained within that directory. Each directory contains a distinct set of data. Different composites and datasets are located in separate directories. Directory names and data file names are never more than eight prefix characters followed by three suffix characters and are compatible with personal computer name limitations. File sizes vary according to the type of data contained in the dataset or composite. Detailed descriptions of the data, quality control processing, etc. for each dataset are located in the /docs directory of each CD-ROM. The /stn_list directory contains the station info for the data on both GIST CD-ROMs. Both the /docs and the /stn_list directories have been duplicated on each of the GIST CD-ROMs. The user should review all associated documents for each dataset which is extracted from either CD- ROM. A brief description of the data contained in each high-level directory is given below. 3.1 GIST CD-ROM 1 Figure 1 - GIST CD-ROM 1 Directory Structure |----/docs | |____/hydro | | | |____/usgsflow | |____/usgsresv | |____/precip | | | |____/15mcomp / ____| |____/dlycomp | |____/hlycomp | |____/abrfcmsc | |____/sfc_met | | | |____/dly_coop | |____/hlycomp | |____/sao_spec | |____/stn_list 3.1.1 /hydro This directory contains the GIST hydrology data from the United States Geological Survey (USGS). The USGS stream flow data are located in a single file. The subdirectory is /usgsflow. The file has been given a name which describes the data it contains (e.g., the USGS stream flow data file is named strmflw.usg). The USGS reservoir data are located in a single file (i.e., resrvr.usg) in the /usgsresv subdirectory. Refer to the appropriate documents in the /docs directory of this GIST CD-ROM for a detailed data description of these datasets. 3.1.2 /precip This directory contains the GIST in-situ precipitation data. Refer to either the 15-minute, hourly, daily, or ABRFC misc. precipitation dataset documents in the /docs directory of either GIST CD-ROM for a detailed data description. The 15-minute and hourly precipitation composites in daily files are located in the /15mcomp and /hlycomp subdirectories, respectively. These files are named YYMMDD.pqc where YY is the UTC year, MM is the UTC month, and DD is the UTC day that the data are valid. For example, the file for 20 May 1994 would be named 940520.pqc. The daily precipitation composite in monthly files are located in the /dlycomp subdirectory. The files in this area are named YYMM.pqc where YY is the UTC year and MM is the UTC month that the data are valid. An example for April 1994 would be 9404.pqc. The ABRFC miscellaneous precipitation data are located in the /abrfcmsc subdirectory. The files are named SSSSSSSS.msc where SSSSSSSS is the station identification. The length of the file name varies according to the station identification. 3.1.3 /sfc_met This directory contains the GIST surface meteorological data. The /sfc_met directory contains three subdirectories. The National Climatic Data Center (NCDC) Summary of the Day Co-operative Observer dataset is located in the /dly_coop subdirectory. The GIST Hourly Composite in daily files is located in the /hlycomp subdirectory. The NCDC Surface Aviation Observation (SAO) "Specials" dataset in daily files is located in the /sao_spec subdirectory. In each subdirectory, the data files are named YYMMDD.xxx where YY is the year, MM is the month and DD is the day that the data are valid. The 'xxx' suffix is set to `dqc' for the NCDC Summary of the Day Co-operative Observer data and to `qcf' for the GIST Hourly Composite and NCDC SAO data. An example of the file name for the NCDC SAO "Specials" data for 5 April 1994 would be 940405.qcf. Refer to the appropriate composite and dataset documentation in the /docs directory of either GIST CD-ROM for a detailed data description. 3.1.4 /stn_list This directory contains the station information for the data on both of the GIST CD-ROMs. General station metadata such as network, station latitude, longitude, elevation, occurrence, station identifier and station name are listed in the station information file. Two files containing identical information, one sorted by station identifier (stn_list.IDN) and the other sorted by station name (stn_list.NAM), have been provided. 3.1.5 /docs This directory contains all of the GIST documentation. This directory contains detailed and general descriptions, formats, sample data, quality control processing, data remarks, and references for each composite/dataset on both GIST CD-ROMs. 3.2 GIST CD-ROM 2 Figure 2 - GIST CD-ROM 2 Directory Structure |----/docs | |____/images | | | |____/abrfc | |____/analyses | | | | | |____/eta500 | | |____/eta850 | | |____/eta1000 | | | |____/goes_ir | |____/goes_vis | |____/goes_wv | |____/msfc | |____/nowrad | |____/vegindex | |____/prof_405 | |____/sounding | | | |____/arm_cart | |____/nws | |____/vortex | | | |____/ncarclss | |____/nsslmbl | |____/stn_list 3.2.1 /images This directory contains the GIST imagery data. There are eight subdirectories under this high-level directory (i.e., /abrfc, /analyses, /goes_ir, /goes_vis, /goes_wv, /msfc, /nowrad, /vegindex). The files located in each subdirectory have names that indicate the date on which the imagery is valid. Refer to the imagery documents in the /docs directory of either GIST CD-ROM for a detailed data description of these datasets. The /abrfc directory contains 24-hour accumulated precipitation estimates as determined from WSR-88D radar precipitation algorithms (products known as STAGE III). The Arkansas-Red River Basin River Forecast Center (ABRFC) routinely produced composites of derived precipitation over the basin from all available radars. These Graphics Interchange Format (GIF) data files have names of the form s3YYMMDD.gif, where YY is the UTC year, MM is the UTC month, and DD is the UTC day that the imagery are valid. An example for ABRFC imagery for 2 April 1994 is s3940402.gif. The /analyses directory contains Eta Model 1000mb, 850mb and 500mb imagery. Plots created by the National Severe Storms Laboratory (NSSL) of the Eta Model output from the National Meteorological Center (NMC) were acquired and converted to GIF images by OFPS. The Eta Model 1000mb, Eta 850mb , and Eta 500mb imagery are located in the /eta1000, /eta850, and /eta500 subdirectories, respectively, under the /analyses directory. These Graphics Interchange Format (GIF) data files have names of the form saYYMMDD.gif for the 1000mb imagery and YYMMDD.gif for the 500mb and 850mb imagery. YY is the UTC year, MM is the UTC month, and DD is the UTC day that the imagery are valid. An example for Eta 500mb imagery for 2 April 1994 is 940402.gif. The /goes_ir subdirectory contains GOES-7 infrared imagery (4 Km resolution). This subdirectory contains GIF files for the complete GIST time period (1 April 1994 through 31 August 1994), nominally at 1200 UTC daily or closest available time. Each GIF file has a name of the form YYMMDD.gif, where YY is the UTC year, MM is the UTC month, and DD is the UTC day. An example for 24 May 1994 would be 940524.gif. The /goes_vis subdirectory contains GOES-7 visible imagery (2 Km resolution). This subdirectory contains GIF files for the complete GIST time period (1 April 1994 through 31 August 1994), nominally at 2100 UTC daily or closest available time. Each GIF file has a name of the form YYMMDDHH.gif, where YY is the UTC year, MM is the UTC month, DD is the UTC day, and HH is the UTC hour. An example for 24 May 1994 2100 hours would be 94052421.gif. The /goes_wv subdirectory contains GOES-7 water vapor imagery (8 Km resolution). This subdirectory contains GIF files for the complete GIST time period (1 April 1994 through 31 August 1994), nominally at 1200 UTC daily or closest available time. Each GIF file has a name of the form YYMMDDHH.gif, where YY is the UTC year, MM is the UTC month, DD is the UTC day, and HH is the UTC hour. An example for 24 May 1994 1200 hours would be 94052412.gif. The /msfc subdirectory contains the United States Radar Precipitation Rate imagery produced by NASA/Marshall Space Flight Center (MSFC). This subdirectory contains GIF files for the complete GIST time period (1 April 1994 through 31 August 1994), nominally at 1200 UTC daily or the closest available time. Each GIF file is named MMDDHHTT.gif, where MM is the UTC month, DD is the UTC day, HH is the UTC hour, and TT is the UTC minutes. An example for 24 May 1994 1200 hours would be 05241200.gif. The /nowrad subdirectory contains WSI, Inc. NOWRAD radar reflectivity composite imagery (8 Km resolution). This subdirectory contains GIF files for the complete GIST time period (1 April 1994 through 31 August 1994), nominally at 1200 UTC daily or the closest available time. Each GIF file is named YYMMDDHH.gif, where YY is the UTC year, MM is the UTC month, DD is the UTC day and HH is the UTC hour. An example for 24 May 1994 1200 hours would be 94052412.gif. The /vegindex subdirectory contains bi-weekly Advanced Very High Resolution Radiometer (AVHRR) derived vegetation index imagery for April through August of 1994. Each GIF file is named YYMMDD.gif where YY is the UTC year and MM is the UTC month, and DD is the first UTC day of the 2 week period that the image is valid. An example for the first bi-weekly image of April 1994 would be 940401.gif. 3.2.2 /prof_405 This directory contains the GIST 405 MHz Wind Profiler data, from the NOAA Wind Profiler Demonstration Network. The files in this directory are named XXXMMw60, where XXX is the three letter identifier for the reporting station and MM is the UTC month that the data are valid. An example for station BLM for April would be BLM04w60. Refer to the appropriate composite and dataset documentation in the /docs directory of either GIST CD-ROM for a detailed data description. 3.2.3 /sounding This directory contains the GIST upper air sounding data. The DOE/ARM Program sounding data are located in the /arm_cart subdirectory. The NWS sounding data are located in the /nws subdirectory. The VORTEX NCAR class sounding data are located in the /vortex/ncarclss subdirectory, and the VORTEX NSSL mobile class soundings are located in the /vortex/nsslmbl subdirectory. All of these subdirectories are further divided into another layer of subdirectories that contain the sounding data for a particular date. The subdirectories are named MMDD where MM is the UTC month and DD is the UTC day that the sounding data are valid. The subdirectory containing 15 May data is named /0515. The DOE/ARM Program sounding data files are named MMDDHHSS.gz where MM is the UTC month, DD is the UTC day, HH is the UTC hour, and SS is the station identification of the reporting station. The file containing 03 hour 8 April data for station C1 is named 040803C1.gz. The NWS sounding data files are named MDDHHSSS.gz where M is the UTC month (4 through 8 only), DD is the UTC day, HH is the UTC hour, and SSS is the station identification of the reporting station. The file containing 00 hour 1 April data for station ABQ is named 40100ABQ.gz. The NCAR class and NSSL mobile class sounding files are named HHMMSSS.gz where HH is the UTC hour, MM is the UTC minute, and SSS is the station identification. The file containing the sounding data for 22:11 hours on 15 April for Lubbock, TX is located in the /0415 subdirectory and is named 2211lub.gz. All of the sounding subdirectories contain compressed data files. These data files have been compressed using the GNUZIP program (i.e., `gzip' utility). The user must `gunzip' each file after extraction from the CD-ROM. Each `zipped' file is compressed by approximately 85%, and the user must allow approximately seven (7) times the compressed file size for the decompressed file. Note that when the files are decompressed, the `gz' suffix is dropped. The GNUZIP program is readily available from the Free Software Foundation, Inc. at 675 Massachusetts Avenue, Cambridge, MA 02139-3309 or via electronic mail at address: `gnu@prep.ai.mit.edu'. For a complete sounding data description, refer to the sounding documentation in the /docs directory of either GIST CD-ROM. 3.2.4 /stn_list This directory contains a duplication of the information provided in the /stn_list directory on GIST CD-ROM 1. 3.2.5 /docs This directory contains a duplication of the information provided in the /docs directory on GIST CD-ROM 1. 4.0 How to Obtain Additional GIST Data Additional GIST data may be obtained by accessing the OFPS CODIAC System via telnet or the World Wide Web (WWW). CODIAC offers the user a vehicle to identify datasets of interest, the facilities to view associated metadata, and the ability to automatically obtain data from geographically dispersed data centers via Internet file transfer or separate media (tape, disk, etc.). CODIAC may be accessed at the following WWW address: http://www.joss.ucar.edu/codiac/ Further details of CODIAC are available by calling: (303) 497-8987 or by sending email to codiac@joss.ucar.edu. 5.0 References IGPO (International GEWEX Project Office), 1993: Implementation Plan for the GEWEX Continental-Scale International Project (GCIP) - Volume I - Data Collection and Operational Model Upgrade. IGPO Publication Series No. 6, IGPO, Washington, D.C. IGPO (International GEWEX Project Office), 1994a: Implementation Plan for the GEWEX Continental-Scale International Project (GCIP) - Volume II - Research Plan. IGPO Publication Series No. 7, IGPO, Washington, D.C. IGPO (International GEWEX Project Office), 1994b: Implementation Plan for the GEWEX Continental-Scale International Project (GCIP) - Volume III - Strategic Plan for Data Management. IGPO Publication Series No. 8, IGPO, Washington, D.C. IGPO (International GEWEX Project Office), 1994c: Tactical Data Management Plan for the first of the GCIP Initial Data Sets (GIDS- 1). Currently in publication. Interim copies available from OFPS. USWRP (United States Weather Research Program, 1993: STORM-FEST Operations Summary and Data Inventory. USWRP Office/UCAR Office of Field Project Support, Boulder, Colorado. WMO (World Meteorological Organization), 1992: Scientific Plan for GEWEX Continental-Scale International Project (GCIP). WCRP- 67, WMO/TD No. 461, WMO, Geneva, Switzerland. Copyright (c) 1995 University Corporation for Atmospheric Research. All rights reserved. No part of this work covered by the copyrights herein may be reproduced or used in any form or by any means -- graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems -- without permission of the copyright owner. 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