The presentation will introduce a new radiosonde dataset from the National Climatic data Center that replaces the Comprehensive Aerological Reference Data Set (CARDS). The dataset consists of radiosonde and pilot balloon observations at more than 1,000 globally distributed stations for the period 1938 to present. Observations include pressure, temperature, geopotential height, dew-point depression, wind direction, and wind speed at standard, surface, tropopause, and significant levels.

The dataset was created by merging data from 11 different sources and applying a suite of quality assurance procedures to the resulting merged dataset. Quality-control checks consist of the removal of duplicate soundings and levels; gross value checks on all data elements; checks ensuring consistency between pressure and geopotential height as well as surface pressure and station elevation; climatological checks on geopotential height, temperature, and surface pressure; and several other minor checks. The performance of the QC procedures was evaluated by carefully inspecting individual soundings from which values were deleted as well as time series at selected pressure levels.

The data will be updated on a monthly basis and will be made available from the National Climatic Data Center.