Status Report June 2002
State of data holdings in the IOW data base as by March 2002:
- Monitoring (BMP) data from 1958 - 2001 (CTD, hydrochemical bottle data)
- current meter data Darss Sill (Baltic Sea) 1973 - 1992
- various (Baltic Sea) from 1970 - 2001
- various (Atlantic) 1976 - 1992
- data from 385 cruises, thereof 264 cruises in the Baltic Sea
- about 41 200 hydrographic stations (CTD profiles, hydrochemical bottle data),
thereof 34 226 in the Baltic with about 7 800 000 measured samples
(1 669 000 temperature, 1 290 000 oxygen, 1 635 000 salinity
still in preparation:
- data from about 65 cruises
We have begun with the processing of temperature/salinity/oxygen measurements from our database in the surface layer (0-10 m) to gain experience in handling the data. A lot of new unexpected errors have been detected in our dataset despite of the systematic data validation and error checking during the routine data entry procedures, and we are still busy in correcting them. The majority of such cases appeared in early records prior to CTD use.
We are currently specifying certain - as narrow as possible - validity limits separately for each parameter in certain regions and for various seasons. The first version of the BALTIC-software prepares a station map, generates an error file for each parameter (e.g. collects all values beyond the given validity limits), calculates Monthly Time Series (count, average and RMS), Long -Time and Monthly Climatology (count, average, RMS, min, max and trend) and draws monthly maps (like second figures) for the actually prescribed mesh size 1° x 1° x 10m x 1 month. Note that 'Sample Count' in the output means the total number of measurements used, while 'RMS' is the root mean square deviation of the monthly means belonging to different calendar years, while the scatter of samples within each particular month is neglected. Specifically, if several samples are available from a cell visited once and never again, 'RMS' will be zero even if 'Sample Count' is greater than one.
Output formats of processed data are presently lon x lat matrices or Surfer tables, see first figures. As can bee seen there are still a lot of white areas in the map. In a next step we will include the data of BSH and ICES. But we hope that the presentation of first results will lead to some cooperation with other institutes and additional data. We like to offer to interested participants the possibility not to provide us with original data but merely with statistical moments, in order to avoid potential user right problems and nevertheless improving the quantitative basis of BALTIC.