The archive consists of all available Arctic rawinsonde data from fixed-position (mostly land) stations north of 65 degrees N. Data from drifting ice islands, ships, and aircraft dropsondes have been assembled as a separate archive.
Soundings data were obtained from the National Center for Atmospheric Research (NCAR) in Boulder, Colorado and the National Climatic Data Center (NCDC) in Asheville, North Carolina. Five original archives were used to compile the database. Sources are assigned identification codes (ID) of 1 through 5.
A considerable amount of overlap between original data sources exists. We have made an effort to choose the best available data from each original archive, based on error analyses and completeness of the soundings.
Appendix 1 lists all stations for which soundings are available. In the appendix, the year column indicates that sounding data are available for at least part of a given year. Millions of soundings are available, covering at least a 30-year period for most stations.
The station locations are shown in Figure 1. Note that the coverage is relatively uniform, with the exception of the lack of the interior of Greenland. Depending on the station, soundings are available from one to four times daily at 0000 GMT, 0600 GMT, 1200 GMT, and 1800 GMT. Most often, reports are available at 0000 GMT and 1200 GMT. Prior to 1952, reporting times were 0800 GMT and 1400 GMT.