- 1 - Roy Jenne 11 October 1991 rev. 4 Mar 1992 Daily World Meteorological Data A. Daily World Data (CAC) This is about the daily world station data prepared by CAC. NCAR has the data for 1979-on. An update for July 1989 - present will soon arrive. This daily data is derived from the 3-hourly world synoptic data that arrives at NMC in real-time by communications. The code forms have special groups for precipitation and max/min temperature. These groups are included for some hours of the day. If the groups are missing, CAC derives daily temperature data from the 3-hour data if enough data are present. There is now a project under formation that involves several centers including NCAR. This project will result in updates, and has the hope of recovering data for missing months and will extend the archive back in time. This dataset of world daily station data has started to receive heavy use by the research community during the past few years. 1. Paul Dyke, Texas A & M, is under contract to use this data (1977-91) to produce a lot of data on CD-ROM for agricultural use. % I gave CAC information about Paul's project. There are now good discussions between CAC - Paul - NCDC - NCAR. % I told CAC that, in principle, there is data to calculate dailies back to 1967. The various groups are interested in this idea. We could help supply the inputs. 2. Daily data for July 1989-on We don't have it. NCDC is probably missing 70% of it. CAC is getting it together on an Exabyte tape and will send copies to NCAR, NCDC, and Paul Dyke. Lloyd Thomas (x 8071) at CAC called Dennis Joseph about the format. They talked about a VMS backup format (sounds potentially messy). They will send the data in an ASCII format. CAC data through May 1991 is ready to put onto Exabyte tape at NMC. June-August 1991 will be ready by November 1; then CAC will send the tape. 3. Monthly Data on the CAC Tape The tape has monthly data derived form the daily data. It also has monthly data that are sent separately by stations in CLIMAT reports. CAC also gets some paper data from places like the Sahel, and puts that data on the tape. 4. CAC expert, Verne Patterson, retired from CAC a year or so ago, but he still does consulting (once or so a week). % He confirmed that daily data for 1977-78 was low quality. He would like to re-do it. He is enthusiastic about going further back in time. % Dave Miskus, CAC, is acting as the CAC coordinator on this (301) 763- 4670. He worked closely with Dave on the project a few years ago. Jim Laver is head of the Analysis and Information Branch (was Fred Finger). Miskus is in this branch and works closely with Jim. 5. Work in Texas Paul Dyke, (Texas) has computers and grant money and can enlist about fifteen undergraduates from Texas A & M. (telephone 817-770-6612) % He told me that he has some of the software to prepare daily data from three-hour data, but needs help from Verne Patterson. This is now in the bag, I think. % This could fill in the four missing months and give us earlier data. The missing months are July and Sept. 1984; June and Sept. 1986. % Paul also has a special need for daily precipitation for East Africa. NCAR has some special data of those countries. However, we want the results of a merge project at a university. 6. Sort of Data Both Dyke and NCDC are aiming for time series data by station. This is good, but I told CAC we should also have a synoptic sort of the data. 7. New Variables The new data, 1989-on, has some new variables: Dave Miskus is sending me a list. It includes water vapor. If we can recalculate the series, we should add a few new variables, not an infinite number. 8. CD-ROM Paul Dyke was going to make some. Now it sounds as if NCDC will do that job. 9. Projects at NCAR Roland Madden and Dennis Shea are using these data. Wilhelm (Willy) May, ext. 1356, is here from Germany until 01 May 1992 and needs the data as soon as possible. B. Sources of Daily Data (written December 1991) Surface synoptic reports are generally taken each three or six hours by stations around the world. These reports are usually sent over GTS and received by NMC and other weather centers. At certain times of day, the stations report max or min temperature, and precipitation. NCAR has an archive of these basic 3-hour data from NMC for July 1976-on, and from the USAF (DS 463.0) for 1967-1980. In addition, NCAR has TD13 from massive USAF projects that were done 20-30 years ago to key enter old surface synoptic data from many countries. Daily data could be extracted from these three large datasets that would provide data for about 7500 global stations for about 1940-on (with earlier data also). At present NCAR has daily data from CAC for 1979-present (DS 512). This will be re-done from the basic data in order to add elements, to give data for 4 lost months, to add at least 2 earlier years, and to fix problems during 1977-79. Later on , we hope to start projects that will extract daily data for the earlier years. The USAF at Asheville also has a dataset of summary of day data (TD34) that has daily data for 1931-74 with about 206, 270 station year - months of data. This was key entered from forms received from countries. ______________________________________ Appendix A CAC Daily Data 25 November 1991 They had a meeting a week ago with Paul Dyke. % CAC soon will send us the daily data that we lack for July 1989-on. % CAC actually sent us data for 1977-on. They added more verbal information at the start of 1977, but still sent us old format for awhile. % Verne is working 10 hours per week, which will increase to 15 hours. -- He will decide on the missing four months -- We will tell him about tapes for 3-hour and 6-hour data % NCDC has synop tapes from January 1973 (weekly tapes). % NCDC has $25K to process data for 1977-on soon. % Dyke has a contract with Rockefeller Institute to prepare data for 1974-on. % DS 463 is our Dick Davis set of 1967-on surface data. 3-month/tape, about 17,600 blocks per tape (65 bytes/report) (50 reports/block). So there are about 58 MB for a 3-month period. % Hope to determine all 1974-present data again and get extra parameters, as well as to clean up problems in early years (about 1977-1979). % We have the Dick Davis data from 1967-on. -- Dave asked about this -- We could send test tapes -- They will check on this Appendix B CAC Daily Data January 2, 1992 Talked with Dave Miskus, CAC, on January 2, 1992 % Texas has Jun. and Sep 1986 (missing at NCAR), but they are missing some information that we have. % Today CAC will finish getting the 1991 dailies and monthly data into a good format % Will send data for July 1989 through 1991 in a few days -- on Exabyte -- on round tapes cc: Willie May Rol Madden ______________________________________ Appendix C CAC Daily Data 28 January 1992 Visit by Paul Dyke and Bill Komar, Jr., Texas A&M, on 28 January 1992. 1. Surface 3-hour synoptic They have several programs coming up for which the basic 3-hour data will be needed. Many studies will be needed to see the various weather elements for the diurnal cycle. Mike Hutchins will visit from Australian University. He does diurnal work. He wants to visit NCAR for 2 or 3 weeks, probably during the summer of 1992. Verne (at CAC) needs 3-hour data for the one missing month (July 1984?). Then he will calculate the daily data. The 3-hourly surface data from NMC has the starting dates: % Jul. 1976 in NCAR archives % Jan. 1973 in NCDC archives 2. Texts % CD-ROM: Gave him the text. Their CD-ROM will be out in 60 days. % Send storage paper % Send compute text 3. Routines % He received Gbytes today % He would like a good sort routine--this takes a long time 4. Reanalysis Paul is very interested. Send him: -- copy of paper for COADS workshop -- copy of December 1991 bulletin paper 5. Media They like to use Exabyte tapes. 6. Daily data for entire period Data for the entire period (Sep. 1977 through Dec. 1991) will fit on one Exabyte tape (the 5,000 MB type). In this case, the character data has been compressed using the PKZIP routine, which gets good reviews for PCs. ______________________________________ Appendix D Status of Data at CAC 4 March 1992 CAC has defined a new and cleaner format for the daily data. They will convert data from Jan. 1987-now to that format. This has already been done for 1990 and 1991. But they are having systems problems on their VAX and that is slowing the progress. They will then send us the data for 1987-on. There are still two missing months, I think these are July and Sept. 1984. Asheville has sent the basic data to them. But it may be in some merged form. They are not sure what they have as yet. Project to decode all of the data again. They will probably put in a Global Change proposal (that includes Madden and Shea at NCAR) to do the new decode and extend data back in time. (From talk with Dave Miskus, CAC) cc: Willie May Rol Madden __________________________________________________________________________ 22 FEB 93 Steve Piper at Scripps is working on a one degree gridded tmin, tmax set derived from the old format version of this dataset. __________________________________________________________________________