Adiabatic Charts

WBAN-31 is a form on which the Weather Bureau, Army and Navy recorded weather observations in the upper air as observed by rawinsonde and radiosonde. The collection includes thousands of these Adiabatic Charts, with the physical archive collection beginning primarily in the 1930s and ending in the mid 1990s and represents stations located throughout the world. The major parameters presented are pressure (Mb), height of pressure level, temperature (degrees C), dew point depression (degrees C), wind direction, and wind speed (knots). In the mid-1970s, the plotting of adiabatic charts was transitioned from paper forms to digital records. Many of the records in the latter part of the collection are computer printouts rather than the historical analog forms of the early 20th century. The bulk of this collection is available only on microfilm.