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The project "Baltic Atlas of Long-Term Inventory and Climatology" (BALTIC) of the Baltic Sea Research Institute Warnemünde (IOW) was first announced on the meeting of the ICES Working Group on Marine Data Management in April 2000 in Hamburg and to the ICES Baltic Committee Meeting in September 2000.

With the aim to support e.g. climate-related investigations, interdisciplinary studies, numerical modelling and regular monitoring, BALTIC is intended to provide the research community with a comprehensive "climate atlas" for the Baltic Sea, inspired by famous paradigms like the COADS (Woodruff et al. 1987) or the Levitus (1982) global oceanographic data sets, going beyond the well-known data collections of Bock (1971), Lenz (1971) or Janssen et al. (1999) in terms of a significantly more extensive observational data basis involved, but remaining pristine and unbiased by refraining from the incorporation of any numerical model data.

In the past years, a lot of historical CTD and bottle data had been reconstructed in the "Historical Data Rescue" (HDR) framework of the marine research institutes around the Baltic Sea. Starting from the data already available in the data banks of IOW, the Federal Maritime and Hydrographic Agency (BSH), and the International Council for the Exploration of the Sea (ICES), the final goal is to build a collection of virtually all accessible oceanographic observation data of the Baltic Sea. In a preceding study, it had been found that indeed much more data than presently stored in the ICES database are available to be included into this project.

In a first stage, the atlas is only based on oceanographic temperature/salinity/pressure and oxygen/hydrogen sulphide/nutrient measurements with highest possible spatial and temporal resolution. In subsequent future steps, the intended additional quantities will be those immediately derived thereof, like e.g. density, sound speed, entropy, enthalpy, pycnocline depth, or halocline depth. In further stages of development, data like density anomaly, alkalinity, biological abundances, or pollution may be added.

BALTIC will be published as its first version in the digital supplement of the book

State and Evolution of the Baltic Sea, 1952 - 2005

A Detailed 50-Year Survey of Meteorology and Climate,
Physics, Chemistry, Biology, and Marine Environment

edited by R. Feistel, G. Nausch and N. Wasmund

Wiley 2008

and future extensions of it are intended to follow. To accomplish its destination as a comprehensive observational long-term data set, freely available for research and educational purposes, data from as many as possible research cruises need to be incorporated. This applies particularly to data which may have been measured in the context of specific projects or studies, safely kept in some data bank but without being looked at ever since. Hence, from its very beginning, BALTIC is a project open for support by interested cooperation partners. To overcome well-known mutual concerns in this regard, it has two data exchange policies:

A) Partners provide IOW with their original readings. IOW performs additional quality checks and processes the data into the BALTIC data base. IOW does not use these data for any other purpose, and does not pass them to third parties without permission. This costs little effort, but may cause concern about a violation of originator rights.
B) Partners perform the additional BALTIC quality checks on their own and compute for the BALTIC grid cells the statistical moments, as required for their seamless concatenation with the existing set at IOW. This method costs higher efforts, but does not interfere with the originator rights.

Up to now, the secure second policy has not been employed yet.

The 'backbone' of the BALTIC atlas is the data holding in the IOW database, collected by IOW and its precursor institutions since 1952. This basic data was extended with national (disjoint) data sets provided by partners supporting the BALTIC project, BSH (Germany), SMHI (Sweden), NERI (Denmark) and IMGW (Poland). In the following step, data from the ICES data bank were added, excluding the duplicates, i.e. all ICES data identical with the national data included already before. The data sets provided by the BED (Sweden) did not exceed the already existing ones from ICES and MIRYB (Poland). Additionally, data from EMI (Estonia) and GEOMAR (Germany) became available at a later project phase.

Status Report March 2007

Status Report September 2006

Status Report October 2005

Status Report October 2003

First update 06 September 2002

Status Report June 2002

Status Report March 2001

* Status Report March 2007

Table 1: Measured parameters given as GF3 codes (IOC 1987) and time periods covered by the BALTIC partners. SSAL is included in PSAL, HSUL is included in DOXY as negative oxygen equivalent.

Table 2: Measured parameters given as GF3 codes (IOC 1987, see also chapter 22) and sample numbers provided by the BALTIC partners. SSAL is included in PSAL, HSUL is included in DOXY as negative oxygen equivalent.

Climatologies 1900 - 2005

BALTIC climatologies are data sets of the quintuples (mean, rms, min, max, count) for each particular cell (lon, lat, depth, month) averaged over the time period 1900 - 2005. The mean is computed by averaging the time series of monthly means with equal weight given to each non-empty month, in order not to bias the average by months with frequent samplings. The rms is the root mean square deviation of the monthly means from this average. The variables min, max and count, however, do not refer to the number and the extreme values of the monthly means, but rather to the set of single samples used for the computation of the monthly means. Thus, the rms value may be zero even if count > 0 and max > min, if all the samples of a certain cell belong to one and the same calendar month. This definition appeared to be more instructive to the user than the possible alternatives.

As an examples, we show here the climatologic surface temperatures for August:

The largest number of samples (18,252) is processed off Warnemünde (cell 12°E, 54°N). The highest (24.8°C, cell 27°E, 60°N) and the lowest (0°C, cell 26°E, 60°N) temperature for August was measured in the Gulf of Finland, while the highest mean value (19.63°C) is from the shallow Oder Bight (14°E, 53°N). The strongest data scatter (rms = 3.32°C) appears at the northern tip of Bay of Bothnia (23°E, 65 °N).

The next figure shows the climatologic surface salinity 1900-2005 of the Baltic Sea from the BALTIC atlas.

* Status Report September 2006

• The following foreign monitoring datasets were processed and quality-controlled:
  
  • Sweden (SMHI, 1979 - 1998)
  • Danmark (NERI, 1950 - 2002)
  • Poland (IMGW, 1979 - 2003)
  • ICES (1891 - 2003)

State of data holdings in the IOW data base as by September 2006:

• Monitoring (BMP) data from 1951 - 2006 (CTD, hydrochemical bottle data)
• various (Baltic Sea) from 1891 - 2006

     >> about 18 million measured samples, 13 million from IOW

     >> Number of samples 1891-2005:

Temperature:	3 967 303
Salinity:	3 881 587
Oxygen:	2 135 617

• data from 447projects in the Baltic Sea
  

• current meter data Darss Sill (Baltic Sea) 1973 – 1992
  
• various (Atlantic) 1976 - 1992

Example of a climatological map

Example of a station map (STD - Stations)

• The following monitoring datasets were processed and quality-controlled:
  
  • Sweden (SMHI, 1979 - 1998)
  • Danmark (NERI, 1950 - 2002)
  • Poland (IMGW, 1979 - 2002)
  • ICES (1978 - 2002)

State of data holdings in the IOW data base as by October 2005:

• Monitoring (BMP) data from 1951 - 2005 (CTD, hydrochemical bottle data)
• various (Baltic Sea) from 1970 - 2003

     >> about 15 million measured samples, 12 million from IOW

     >> Number of samples 1951 - 2005

• data from 440 projects in the Baltic Sea

• current meter data Darss Sill (Baltic Sea) 1973 - 1992
• various (Atlantic) 1976 - 1992

* Status Report October 2003

• the reconstruction of historical CTD- and bottle data is completed
• the quality control of the data due to certain validity limits has finished
• the processing of temperature/salinity/oxygen as well as nutrient measurements of the IOW database in layers of every ten meters has successfully been carried out
• we generated climatological monthly maps for each parameter in each layer and a mesh size of 1° x 1° (average, RMS, min, max and total number of samples)

State of data holdings in the IOW data base as by October 2003:

• Monitoring (BMP) data from 1951 - 2003 (CTD, hydrochemical bottle data)
• current meter data Darss Sill (Baltic Sea) 1973 - 1992
• various (Baltic Sea) from 1970 - 2003
• various (Atlantic) 1976 - 1992
• data from 472 cruises, thereof 305 cruises in the Baltic Sea
• about 52 700 hydrographic stations (CTD profiles, hydrochemical bottle data),
  thereof 44 700 in the Baltic with about 9 200 000 measured samples
  (1 907 000 temperature, 1 515 000 oxygen, 1 866 000 salinity)

* First update 06 September 2002

• dataset corrected
• interpolation of sea data from one region over the land to another sea region largely suppressed
• regions with no data left "white"
• color scale refined for salinity range in the Baltic Proper
  

    still in preparation: data from about 40 cruises

* First results August 2002

* 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.

* Status Report March 2001

This project was already announced on the meeting of the ICES Working Group on Marine Data Management in April 2000 in Hamburg and to the ICES Baltic Committee Meeting in September 2000. We would like to inform the HELCOM MONAS about this project and ask for collaboration and cooperation.

The BALTIC project is still in the phase of conception and open for proposals and intentions of participation. We will keep interested parties informed about the progress of our activities on our website http://www.io-warnemuende.de/BALTIC. Please send suggestions and comments to sabine.feistel@io-warnemuende.de.

With the target to support e.g. climate-related investigations, interdisciplinary studies, numerical modelling and permanent monitoring, we intend to develop an encyclopaedic "climate atlas" for the Baltic Sea, similar to the famous Levitus global oceanographic data set, and going far beyond the already existing data collections of Bock/Lenz (1971) and Janssen/Backhaus/Schrum (1999).

In the recent years a lot of historical CTD and bottle data have been reconstructed in the HDR (historical data rescue) framework of the marine research institutes around the Baltic. Beginning with the data already available in the databanks of IOW, BSH and ICES we plan to build a collection of virtually all accessible data of the Baltic Sea. In a preceding study, we found out that we could include much more data than presently available at ICES.

In a first stage the atlas is based on oceanographic temperature/salinity/pressure measurements with higher vertical and time resolution and quantities immediately derived thereof e.g. density, sound speed, entropy, enthalpy, thermocline depth, halocline depth. In the next stage of development data like nutrients, pollution, alkalinity etc should be added. Later the atlas is to include accompanying information like topographical and shoreline data, GHCN (Global Historic Climate Network) data, PSMSL (Permanent Service of Mean Sea Level) data, river discharge data, and ice coverage data.

Our aim is to collect physical and chemical quantities as well as meteorological, economic and historical background quantities to unify, analyse and condense them. A variety of calculations like horizontal distributions on selected depths, at the surface, on the bottom, gridded monthly means, or time series at selected positions are planned. Finally we want to provide a comprehensive, processed numerical dataset on CD for interdisciplinary research projects in the Baltic region. A catalog of graphs and diagrams shall illustrate the results.

Inventory of currently available data

At IOW, e.g., data are available which are in the ICES data bank not yet. They are under reconstruction in the historical data rescue framework. Certainly, similar data exist at other Baltic institutes which may be used for this intended data collection.

Number of expeditions totally (1950-1999) : 460
thereof	H/C	CTD	Current
	369	264	190
doubtful	56	10	144
"East Edge" (Norway)    25 (to be inspected)

H/C	Hydro/Chemical Bottle Data in standard bottle depths mainly in Baltic Proper from 1950-2000 (depth, temperature, salinity, dissolved oxygen, hydrogen sulphide (H2S-S), nitrate (NO3-N) content, nitrite (NO2-N) content, phosphate (PO4-P) content, ammonium (NH4-N) content, silicate (SIO4-SI) content, total phosphorous (P) content, total nitrogen (N) content)
CTD	Bathysonde Data in 1m steps mainly in Baltic Proper from 1976-2000 (conductivity, temperature, oxygen, pressure)
Current	Mechanical Current Measurements mainly at Darss Sill from 1973-1992

Part of IOW data is identical with part of ICES data. Because not all of our data are in the database yet it is at time not possible to give the detailed number of single measurements.

At BSH/DOD Hamburg the following data are available

Parameter	Measurements
temperature	406455
salinity	357461
dissolved oxygen	317960
hydrogen sulphide (H2S-S)	4550
nitrate (NO3-N) content	149484
nitrite (NO2-N) content	149381
phosphate (PO4-P) content	153318
ammonium (NH4-N) content	72072
silicate (SIO4-SI) content	47930
total phosphorous (P) content	11260
total nitrogen (N) content	10358

Data available at ICES has still to be analyzed.

Accompanying information we already have:

• GHCN data (monthly mean air pressure, temperature, precipitation of the Global Historical Climate Network)
• PSMSL data (monthly mean sea level of the Permanent Service for Mean Sea Level)
• IDA (Ice Data Bank for Baltic Sea Climate Studies)
• ETOPO5 and Seifert/Kayser topography
• WVS derived shoreline data

Cooperating Institution so far: BSH/DOD, Hamburg (F.Nast, R.Schwabe)

Interested institutions so far:

• FIMR (Baltex/Bridge-Project, P.Alenius)
• Department of Systems Ecology, Stockholm (F.Wulff)
• PPSIO, Kaliningrad (V.Paka)

The BALTIC project is still in the phase of conception and open for proposals and intentions of participation. We will keep interested parties informed about the progress of our activities on our website.

last update: 23.03.2007

Criticism, ideas, suggestions to this page to: sabine.feistel@io-warnemuende.de