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The WOCE Global Hydrographic climatology (WGHC) described in this report is intended to 
improve the quality, spatial and time resolutions and the geographical coverage compared to 
the first version of the global climatology produced in the former WHP SAC (Gouretski and 
Jancke, 1998). 
2. Data basis 
The data basis used for this study is composed of several data sets, which are described 
below. 
2.1 World Ocean Database 1998 (WOD98) 
The WOD98 database was used as a main data source for the study and contains about 1,5 
million temperature-salinity profiles (Levitus et al., 1998). WOD98 consists of profile data 
from several oceanographic instrument types. Since both temperature and salinity data are 
needed for our analysis only the following data types were selected: 
a) Ocean Station Data, referred to measurements made from a stationary ship. 
Temperature was measured by reversing thermometers, whereas seawater samples 
were gathered with special bottles, 
b) Conductivity-Temperature-Depth (CTD) data, obtained by instruments, capable to 
measure pressure, temperature, conductivity and oxygen at a relatively high vertical 
resolution. 
Compared with the previous version (WOA94) the WOD98 has been expanded considerably. 
According to Levitus et al. (1998) there is a much better data coverage in many years and 
regions since the publication of WOA94. Another improvement is a new duplicate checking 
scheme, which resulted in the elimination of ”near-duplicates” that existed in WOA94. After 
the publication of the WOA98 database, substantial amounts of additional historical data 
have become available, resulting in a new data base World Ocean Atlas 2001 (WOA01). 
However, this database was not available to us when the compilation of the WGHC 
climatology started. 
2.2 WOCE data 
The World Ocean Circulation Experiment (WOCE) has been a component of the World 
Climate Research Programme WCRP. This unique oceanographic experiment has set 
standards for making the essential high quality hydrographic observations on the global 
basis. Except for a few cruises, hydrographic observations during the WOCE were made 
between 1990 and 1998. 
Though the total amount of the WOCE profiles is small compared with the whole content of 
the database used in this work, the WOCE Hydrographic Programme produced a data-set of 
unprecedented quality, which also substantially improved the data coverage for the deeper 
layers of the World Ocean. The total number of WOCE profiles obtained during the one-time 
and repeat hydrographic cruises included into the combined data-set amounts to ca. 9000 
stations. Our subset of WOCE stations is more complete compared with that of the WOA01 
dataset.