The WOCE/ARGO Global Hydrographic Climatology (WAGHC) is concieved as the update of the previous WOCE Global Hydrographic Climatology (WGHC) (Gouretski and Koltermann, 2004). The following improvements have been made compared to the WGHC: 2) finer spatial resolution (0.25 degrees Lat/Lon compared to 0.5 degrees for WGHC); 3) finer vertical resolution (65 compared to 45 WGHC standard levels); 4) monthly temporal resolution compared to the all-data-mean WGHC parameters; 5) narrower overall time period; 6) calculation of the mean year corresponding to the optimally interpolated temperature and salinity values; 7) depth of the upper mixed layer. Similar to the WGHC the optimal spatial interpolation is performed on the local isopycnal surfaces. This approach diminishes the production of the artificial water masses. In addition to the isopycnally interpolated parameters parameter values interpolated on the isobaric levels are also provided. The monthly gridded vertical profiles extend to the depth of 1898 m, below only annual mean parameter values are available. Additionally, there is a dataset and a map available providing indexes for selected regions of the world ocean. Finally, the comparison with the last update of the NOAA World Ocean Atlas (Locarnini et al, 2013) was done.

The assessment of climate change impacts on the North Sea and the overlying atmosphere requires reliable reference data in order to identify change and impacts against a highly variable background with time scales from hours to multi-decadal. Therefore, in the frame work of the research programme "KLIWAS - Impacts of climate change on waterways and navigation - Searching for options of adaptation" of the German Federal Ministry of Transport, Building and Urban Development (BMVBS), a new climatology was developed in a close co-operation of the Federal Maritime and Hydrographic Agency (BSH), the German Meteorological Service (DWD) and the Integrated Climate Data Center (ICDC) of the University Hamburg. All available oceanographic in-situ data for temperature and salinity have been carefully checked for quality before further processing, while the atmospheric data had already been quality controlled by the DWD. More than 13 million temperature and 12 million salinity (starting in 1890) as well as more than 19 million atmospheric data (air temperature, dew point and air pressure starting in 1950) have been processed. Monthly averages have been created on specified grids for the ocean and atmosphere. For the first time oceanographic and meteorological climatologies are provided on a coordinated grid. The climatological data set is supposed to be growing with time and new data can be implemented as they are collected. it is planned to add additional parameters in future. The climatologies will be used to analyse the temporal and spatial variability in the North Sea area and deduce long-term trends. Additional the data sets will be needed for the validation of regional climate scenarios. The products are publicly available at the ICDC portal ( http://icdc.cen.uni-hamburg.de/1/projekte/knsc.html ).

The assessment of climate change impacts on the North Sea and the overlying atmosphere requires reliable reference data in order to identify change and impacts against a highly variable background with time scales from hours to multi-decadal. Therefore, in the frame work of the research programme "KLIWAS - Impacts of climate change on waterways and navigation - Searching for options of adaptation" of the German Federal Ministry of Transport, Building and Urban Development (BMVBS), a new climatology was developed in a close co-operation of the Federal Maritime and Hydrographic Agency (BSH), the German Meteorological Service (DWD) and the Integrated Climate Data Center (ICDC) of the University Hamburg. All available oceanographic in-situ data for temperature and salinity have been carefully checked for quality before further processing, while the atmospheric data had already been quality controlled by the DWD. More than 13 million temperature and 12 million salinity (starting in 1890) as well as more than 19 million atmospheric data (air temperature, dew point and air pressure starting in 1950) have been processed. Monthly averages have been created on specified grids for the ocean and atmosphere. For the first time oceanographic and meteorological climatologies are provided on a coordinated grid. The climatological data set is supposed to be growing with time and new data can be implemented as they are collected. it is planned to add additional parameters in future. The climatologies will be used to analyse the temporal and spatial variability in the North Sea area and deduce long-term trends. Additional the data sets will be needed for the validation of regional climate scenarios. The products are publicly available at the ICDC portal ( http://icdc.cen.uni-hamburg.de/1/projekte/knsc.html ). A corrected version of the climatology is available. For more information see Accuracy report.