Upper-air station inventory

Sources & data notes

Source: NOAA NCEI Integrated Global Radiosonde Archive (IGRA) v2 station list, https://www.ncei.noaa.gov/pub/data/igra/igra2-station-list.txt (copy supplied to the build, not downloaded by this script), retrieved 14 September 2026. Column positions parsed per the NCEI format description igra2-list-format.txt (last updated 19 January 2023). Basemap tiles are fetched live from OpenStreetMap and Esri; choose No basemap if you are offline. Mobile stations (ships, ice islands) excluded because the inventory records them with sentinel coordinates rather than a position: 102. Records excluded because the source line carries no station ID, name or coordinate at all: 1. In the file used for this build that is a single record, at line 955, reporting 1946 to 2025 and 70,410 soundings with every other field blank. It sorts between HUM00012982 and ICM00004089, and ICM00004018 Keflavik is otherwise absent from the inventory, so the blanked record is probably Keflavik. That is an inference from sort position and absence, not a NOAA statement, and the record is not plotted because no coordinate is published for it. Elevation is blank where the source carried the missing sentinel (−999.9). Presence in this inventory does not mean the station has soundings usable in AERMET. The sounding count is a total over the period of record, not a measure of twice-daily coverage; a station can show a long record and still have too few 00Z/12Z ascents for a given year. Confirm the actual sounding availability in the station data file before selecting an upper-air site, and confirm representativeness on the terms of 40 CFR Part 51 Appendix W.