What is New in Version 2 of the Integrated Global Radiosonde Archive?

The Integrated Global Radiosonde Archive (IGRA) is a collection of historical and near-real-time radiosonde observations from around the globe that has been made available by the NOAA National Climatic Data Center (NCDC) since 2004. It has been used in a variety of applications, including basic research, climate assessments, and air pollution modeling. The archive consists of three components: quality-assured individual soundings, monthly means, and sounding-derived humidity and stability parameters. All of these components are updated on a regular basis and made available for download free of charge.

During the past decade, additional historical observations have been digitized, previously existing datasets not included in IGRA have become more easily accessible, and new radiosonde stations have started operation. Hence, NCDC undertook work on Version 2 of IGRA with the goals of enhancing spatial and temporal coverage, simplifying the process of adding new data sources and stations to the dataset, and incorporating the most commonly received suggestions from users of Version 1. The resulting new dataset, IGRA 2, contains approximately 30% more soundings and nearly twice as many stations as IGRA 1. Pilot balloon observations now extend back to 1905, and there is a significant improvement in the spatial coverage of both radiosonde and pilot balloon observations, particularly before the 1970s. In addition to the temperature, dewpoint depression, and wind observations available in IGRA 1, IGRA 2 soundings also include the variables of relative humidity and elapsed time since launch whenever they are available in the original data sources.

The presentation will include a brief overview of the new data sources and methodology, figures characterizing the nature of the improved coverage, and information on how to access the data.