The NCAR Upper Air Database (UADB) contains global observations
beginning in the 1920s and extends to a near current date. Upper air
soundings from about 50 different sources have been consolidated
into products that are well documented and provide the longest
possible, duplicate-free, station time series. Historical sampling
methods have been accounted for by creating two product lines, one
with soundings that have wind (UADB-Wind) and another with
temperature and humidity (UADB-TRH) measurements. This approach
maximizes the amount of data consolidated, and when profiles have
simultaneous temperature, humidity, and wind measurements, they are
replicated in both products.
The first consolidation step was compositing stations with identical
WMO station numbers across all data sources. The UADB-TRH product
has nearly 1100 stations that report for 20 years or more, and over
400 stations have time series of 50 years or longer. The UADB-Wind
product has about 1600 stations that report for 20 years or more,
and over 500 stations have soundings for at least 50 years. Next
stations with different WMO station numbers, but that are located at
identical latitudes and longitudes, or nearly so (within 40
kilometers) were combined, accounting for WMO station number changes
and small position relocations. The result is that even longer
station time series are created; extensions occur at over 240 and
250 locations in the UADB-TRH and UADB-Wind products, respectively.
The composited and combined products are both available.