To compile the annotated description for each section of the Atlas and to select the tables and illustrative material ready for electronic display, the authors used published research papers, monographs, reference books, which are listed in References.

To plot the maps, sections, and curves of the vertical distribution of hydrological and hydrochemical characteristics the following oceanographic data bases and data sets were used:

• Global data set of climate data on temperature, salinity and sound speed - GDEM (Generalized Digital Environmental Model, Version 2.5, 1998) available by the Internet <https://128.160.23.42/gdemv/gdemv.html>.
• CD-ROM: World Ocean Atlas (WOA’98).
• Integrated data base of the archived oceanographic data «OCEAN-1» on the Northern Pacific (POI FEB RAS).
• Data base of observations carried out in research cruises of the POI - «OCEAN-2».

GDEM presents itself a set of tested and monthly averaged  (special technique) profiles (tables) of oceanographic characteristics in the nods of a regular mesh of high horizontal resolution from 10 (the Japan/East Sea) up to 30 (the Bering Sea and Okhotsk Sea) arc minutes in latitude and longitude. To create the GDEM array the data source were all available observations stored in the data base MOODS (Master Oceanographic Observation Data Set) of the US Navy (about 7 million profiles for temperature and salinity in the World Ocean, 190 thousand - for the Sea of Japan) for the whole historical period of observations. By the number of the initial data on temperature and salinity this data set is at present (till 2001) the most complete of all known analogues, and the climate-averaged values calculated by these data are sufficiently reliable and representative. The method of GDEM creation and the results of its using and correlating to the Levitus’s analogue climate data [Levitus, 1982], averaged by another technique, are given in a series of special studies [Teague et al. 1990; Chu et al. 2001].

World Ocean Atlas (WOA’98) was developed at the US NODC on the basis of WOD’98. It comprises the objectively analyzed average climate data on temperature, salinity, and hydrochemical elements, as well as their statistics in the nods of a one-degree mesh and five-degree mesh [Antonov et al, 1999; Conkrigh et al, 1999].

Data base «OCEAN-1» was developed at the POI FEB RAS. It contains the archived data of hydrological observations for the Northern Pacific gathered from all available sources [Dmitrieva, Rostov, 1996]. These materials served the basis for the united data sets of the temperature and salinity data for the Bering Sea, Okhotsk Sea, and Japan/East Sea. For instance, the data set on the Japan/East Sea involves about 200 thousand observation stations for temperature and salinity and about 400 thousand temperature profiles. For the Bering Sea and Okhotsk Sea the number of primary data is about thrice less. At present, it is being carried out the data control, editing, and preparation of climate data set on a regular mesh of spatial coordinates. Data of «OCEAN-1» and «OCEAN-2» are just partially used in this version of the Atlas - to check maps of temperature and salinity distribution, and to analyze the hydrological characteristics in the considered areas. Some parts of these data are included in GDEM and WOD'98 as result of the International data exchange under IOC/IODE.

On the example of the Japan/East Sea, it is carried out the correlation of maps of spatial distribution of hydrological characteristics plotted according to the data taken from the «OCEAN-1» and GDEM, which yielded satisfactory results.

For the water areas covered with ice in winter or not sufficiently provided with observation data, the profiles of temperature and salinity in the GDEM were reconstructed by the technique which details are unknown. These areas were excluded when the maps were plotted. In the GDEM data for the coastal zone of the eastern part of the Bering Sea are absent. For this area, the lacking data were copied from the WOA’98 disk. The maps of some hydrochemical characteristics distribution for all seas were also constructed by the data of WOA’98. Due to non-sufficient provision by the observation data on some levels (especially in winter and in autumn) for the Okhotsk Sea and Bering Sea, in some cases they are approximate.

To plot the maps, sections, and schemes it was used special Software - Ocean Data View [Schlitzer, 2000; http://www.awi-bremerhaven.de/GEO/ODV/] and standard supplements. ODV contains the illustrative basis for constructing diagrams, special software, suitable interfaces, etc.

Main graphic material is represented in the Atlas as follows:

• Average for-many-years monthly maps of temperature, salinity, and sound speed distribution are given for standard levels: 0, 100, 200, 500 and 1000 m for all months of a year.
• Schemes of vertical sections of these characteristics along particular meridians and parallels are constructed in two scales, mainly, by the data averaged by main seasons.
• Selected curves of the vertical distribution of parameters for different areas are constructed by the mean monthly data.
• Maps of spatial distribution of hydrochemical characteristics are constructed by the average seasonal data on the following levels: content of dissolved oxygen - 0, 100, 200, 500, and 1000 m; phosphates, nitrates, and silicates - 0, 100, 200, and 500 m; chlorophyll - on the surface.
• Characteristics of the water circulation are represented as generalized schemes and maps of currents for one month of each season.
• Maps of actual spatial distribution of some hydrological and dynamic characteristics in the FES water area (water temperature, topography of the level surface, currents) obtained as a result of monitoring, are taken from the Internet.
• Maps of tides and margins of the ice edge location are generalized.

Auxiliary illustrations are included into some fragments of the descriptive part of the Atlas as the references to the authors’ copies of pictures taken from the originals as they are.

Fragments of the GDEM data on the Far Eastern Seas are presented as the tables of the average for many years data by months in the format of the DOC text files.

Software is presented as the loading modules.

All values of the air and water temperature are given by Celsius (°C), and salinity - per mille (1 g/kg = 1 ‰ ). Hydrochemical characteristics measurements are given in designations of the original (WOA’98): dissolved oxygen (ml/l), phosphates (µM), nitrates (µM), silicates (µM) and chlorophyll (µg/l).