GLOSS Status October 1996

For the last few years, usually coinciding with a GLOSS GE meeting, the PSMSL has provided a summary of the status of GLOSS from its viewpoint. This summary has usually been made in October so as not to bias the statistics because of the seasonal cycle of data receipts.

An 'operational' station from a PSMSL viewpoint means that recent MSL monthly and annual values have been received at Bidston, have been checked as far as possible, and have been included in the databank. For each of the GLOSS stations we have used the year of the last data entered into the databank, if any, to place the station into one of four categories:

Category 1: 'Operational' stations for which the latest data is 1992 or later;
Category 2: 'Probably operational' stations for which the latest data is within the period 1982-1991;
Category 3: 'Historical' stations for which the latest data is earlier than 1982;
Category 4: For which no PSMSL data exist.

Table 1 lists the number of stations which fall into each category for all stations, then for the subset which have been 'committed to GLOSS'. ('Committed to GLOSS' means that formal commitments have been made by national authorities to IOC to keep gauges operational). Also shown are the numbers in each category reported at previous GLOSS meetings with the category definitions adjusted backwards one, two, three etc. years appropriately.

Note that before 1993 we used the 'GLOSS90' definition of GLOSS (306 stations total), whereas 1993 onwards we have used 'GLOSS93' (308 stations total). However, I don't believe that modifies the statistics to a great extent.

It can be seen that there has been significant progress in the last year, with the number of Category 1 stations being larger than previously.

                            Table 1

      Number of Stations in Each Category (All Stations)

 Cat.    Bidston   Miami     Vienna    Paris           Pre-
         GE Mtg.   GE Mtg.   IUGG      GE Mtg.         Bordeaux
                                                         GE Mtg.
                                                            
         Jun 89    Oct 90    Aug 91    Oct 92  Oct 93  Oct 94  Oct 95 Oct 96

   1     105       133       136       158     177     183     168    186
   2     51        50        57        46      33      35      59     46
   3     47        42        36        29      26      26      22     21
   4     103       81        77        73      72      64      59     55

Total    306       306       306       306     308     308     308    308

   Number of Stations in Each Category (Committed to GLOSS)

 Cat.    Bidston   Miami     Vienna    Paris           Pre-
         GE Mtg.   GE Mtg.   IUGG      GE Mtg.         Bordeaux
                                                         GE Mtg.
                                                            
         Jun 89    Oct 90    Aug 91    Oct 92  Oct 93  Oct 94  Oct 95 Oct 96

   1     98        122       118       135     151     156     140    156
   2     45        40        47        38      25      26      45     34
   3     28        25        21        15      13      12      10     9
   4     44        28        29        27      28      23      22     18

Total    215       215       215       215     217     217     217    217

using 'GLOSS Definition'
         90        90        90        90      93      93      93     93

A full breakdown of the status of each of the 308 GLOSS gauges is available from the PSMSL or by inspecting the 1996 GLOSS status map.