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<br />... :~~ <br /> <br />mE BUREAU OF RECLAMATION'S ENVIRONMENTAL DATA NETWORK <br /> <br />F. E" Politte <br />M. D. Hale <br />D. A.. Matthews <br /> <br />U.S. Bureau of Reclamation <br />Denver, Colorado <br /> <br />1. INTRODUCTION <br /> <br />The Bureau of Reclamation's research progr~ns in <br />weather modification require some unique analyses <br />and forecasts that are not available through the <br />National Weather Services (NWS) facsimile and tele-. <br />type circuits. With this requirement in mind, the <br />Bureau has developed an Environmental Data Network <br />(EDN). <br /> <br />2. ENVIRONMENTAL DATA NETWORK (EDN) <br /> <br />The heart of the EDN resides at the Bureau'~; Cen- <br />tral Computer Facility in Denver. At this facil- <br />ity are the computer mainframe, the data base, <br />programs, and the necessary communications'equip- <br />ment .to allow access to the computer from locations <br />anywhere in the United States. <br /> <br />3. HARDWARE <br /> <br />v <br /> <br />The computer system is composed of two Cont]~l <br />Data Corporation (CDC) computers; one a CybE~r 74-28 <br />and the other a Cyber 74-16. These computers share <br />couunon files, have 9 tape drivers, 20 peripheral <br />processors, and online storage capability. of more <br />than two billion characters. In addition, there <br />are the usual compliment of line printers and card <br />readers. <br /> <br />4. COMMUNICATIONS <br /> <br />A dedicated circuit links the Bureau's computer <br />system in Denver to the NWS co~puter facility <br />located at the National Meteorological Centf,r (NMC) <br />at Suitland, Maryland. Data flow between these two <br />systems from 6 a.m. to midnight Vlountain Time) <br />daily. Data bulletins that have been preselected <br />by the Bureau are sent from NMC to Denver and then <br />written to files that are available to the EDN <br />users. <br /> <br />Users can access the computer through reguls.r com- <br />mercial telephone dial-up or special dedicated <br />circuits. Regular dial-up through commerciaJ <br />sources is at 30 characters per second for inter- <br />acti ve terminals and up to 2,000 baud for rf,mote <br />job entry terminals. Special dedicated cireui ts <br />support line transmission speeds up to 9,600 baud. <br /> <br />S. DATA BASE <br /> <br />The data base consists of all the NWS rawinsonde <br />observations taken in the contiguous United States <br />and those taken at the Bureau's experimental sites <br /> <br />during the operating season, hourly surface weather <br />from over 275 stations located in the United States <br />and Canada, gridded field forecast data from the <br />NWS limited-area, fine-mesh grid model for periods <br />of 12 and 24 hours, severe weather warnings from <br />th~National Severe Storms Center located in Kansas <br />City, aviation forecasts for selected stations in <br />the western United States, and regional forecasts <br />prepared by the area forecast centers in the NWS <br />western region. <br /> <br />These data are. kept "Ii veil on the EON in disk files <br />until their "real time" use is over, then the sur- <br />face and rawinsonde data are written to magnetic <br />tape and archived. The archived data can be <br />reloaded on the computer at any time for analysis <br />or other uses. <br /> <br />6. PROGRAMS <br /> <br />There are over 30 operational programs on the EDN <br />that utilize the data base. These programs, and <br />related instructions, are described.in a user's <br />guide that is updated whenever changes occur. The <br />programs can be divided into three general <br />categories: <br /> <br />a. Analysis and plotting programs <br />b. Forecast programs <br />c. Models <br /> <br />Analysis or plotting programs. usually retrieve the <br />data from the data base and do a minimal amount of <br />data processing. This group of programs usually <br />displays the raw data on output media such as line <br />printers, flatbed plotters, or cathode ray tubes <br />(CRT). Figure 1 is a sample of a processed rawin- <br />sonde observation that has been displayed on a line <br />printer. <br /> <br />Forecast programs generally use the basic raw data <br />or model forecasts and make calculations and pre- <br />dictions to be used in the daily forecasts. This <br />group contains predicted soundings, streamline <br />forecasts (figure 2), and specific point forecasts. <br /> <br />Models such as the Great Plains Cumulus Model (see <br />Hirsch, 1971; Matthews, 1977), figure 3, interpret <br />raw data and calculate meaningful output data that <br />help determine the daily experimental activities in <br />"real time." <br /> <br />7. FUTURE PLANS <br /> <br />The Bureau has recently added an interactive graph- <br />ics package that will allow a modernization of the <br />