Following is a summary of the main items discussed at our UOT/DAC meeting of 7 October. My intention is to build this summary into a complete report which will address details not given here and contain several annexes, for example the QC procedures of the Regional Centers. Would each of you review the summary and provide any comments you may have. I'm sure I missed or misinterpreted some of the discussion so please be frank in your comments. Do you have a particular annex you would like to include? You may recall that the report of DAC-2 was an informal note but in view of the need to publicize the DAC activity, I intend to issue this report in the IPO yellow series which goes to the entire WOCE community involved with IPO. My target for release is January (Bert).

Summary

The circulation of data within the UOT/DAC system began early in 1991, thus several months of experience with the new formats introduced by the GTSPP and the quality control procedures has been gained. While as of this writing none of the Regional Centers have returned flags associated with real time (RT) data to NODC, both AOML and SIO are near to doing so. AOML has quality controlled all 1991 real time data through July. CSIRO quality controls data in delayed mode (DM) from lines which they operate. These data are being sent to NODC and Brest as in the past under the original TOGA arrangement. The Bureau of Meteorology in Australia is mapping the Pacific and Indian Oceans and has a six months effort to develop objective QC Flags and an interface for subjective editing.

The collection of the RT data at MEDS is working rather well as is the transfer of that data to NODC for sorting and further distribution to the Regional Centers. The Regional Centers, however, have noted that duplicate removal is not efficient. There are a number of factors, or practices, that cause this. For example, the same BATHY arriving from more than one source may have been changed along the way, thus its difficult to identify as a duplication. Molinari indicated that AOML had up to 10 duplicates on occasion. The duplication removal routines and the practices of changing data prior to GTS insertion must be reviewed by IGOSS.

The 1990 delayed mode data set will be available from NODC early in 1992. The Regional Centers have reaffirmed their intent to QC those data during the first half of 1992.

The pros and cons of RT versus DM QC at the Regional Centers was discussed at length by the meeting. The general opinion expressed was that WOCE doesn't need the RT QC for PI research nor Special Analysis Centers (SAC) but there is a need to identify ships making consistent errors and a need to determine whether the network is producing data adequate to identify the oceanographic features of interest. Ships making errors must be provided feedback ASAP. The IGOSS Operations Officer agreed to make ship contacts when provided error information by the Regional Centers. MEDS/NODC should also explore ways of providing feedback to ships. Some feel that the RT QC can be handled by operational model centers like that of Leetmaa. The Regional Centers agreed to continue the RT QC for one or two years during which time a new mechanism could be devised with a focus on DM. More involvement of operators or programme managers carrying out QC (such as Bailey in Australia) would be a great assistance. Wilson reminded the meeting that the GTSPP wants to keep the scientific community connection for RT data QC and that requirement should be kept in mind when considering alternative QC practices.

A suggestion to produce a QC "error cookbook" that could be used by data handlers at various stages in the UOT data collection process was discussed. The idea is to provide historical information that would help in making decisions about the validity of data. Bailey indicated CSIRO, after several years of operating their Indian Ocean lines, is able to identify real and erroneous features and apply this knowledge in the QC process. No specific action was suggested. (IGOSS Manual 3 may have something like this already, IPO will check it out).

The XBT tracking of IPO was well received and the meeting agreed it should continue. One aspect of the tracking that should be improved is the measure of completeness of individual sections. Pazan has done some work on this sort of thing and will provide IPO information on his routines. MEDS and NODC offered to assist in the tracking.

The Global Center in Brest has made little progress towards incorporating the extra tropical WOCE data because of limited resources. (Note - A message received by James Crease, Chairman WOCE Data Management Committee, 1 October from B. Voituriez indicated that the UOT/DAC at Brest is funded). Rebert would like his "mission" defined in more detail than has been provided. He identified three purposes for a global Center as: 1) user services (delivery of data sets); 2) generation of derived products; and 3) data sets for models. The long-term archival and distribution of WOCE data are the function of the World Data Centers.

NODC has been providing the monthly data sets to the Regional Centers relatively early in each month but as a result, a good deal of data are being delivered late. For example, AOML demonstrated that data for a particular month , say for example May, is delivered by NODC in July, not in June. This happens because data for the month arrive after the cut off time (BATHY messages are not truly RT, they may be entered onto the GTS up to one month after observation time). The short cut-off has been imposed to satisfy a SIO requirement to prepare analyses for the IGOSS Products Bulletin that has a mid-month deadline. Two actions are suggested: NODC deliver the data after the 10th of each month and the IGOSS staff be asked to relax their mid month requirement for delivery of the SIO products.

The Regional Centers agreed to provide details of their QC procedures for inclusion in the UOT/DAC handbook, which will eventually be part of the WOCE Operations Manual. IPO will undertake preparation of the first draft of the Handbook. It was also suggested that an article be written for the WOCE newsletter explaining the who, what, and when of the UOT/DAC. It appears that some investigators and operators do not understand the WOCE procedures nor the on-going IGOSS/IODE procedures that have been adopted for WOCE. UOT/DAC needs to advertise its existence and service.