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Dataset Overview | National Centers for Environmental Information (NCEI)

Integrated Global Radiosonde Archive (IGRA), Version 2

IGRA 2

browse graphicUpper air balloon
Integrated Global Radiosonde Archive (IGRA) Version 2 consists of quality-controlled radiosonde observations of temperature, humidity, and wind at stations across all continents. Data are drawn from more than 30 different sources. The earliest year of data is 1905, and the data are updated on a daily basis. Record length, vertical extent and resolution, and availability of variables varies among stations and over time. In addition to the merged and quality-controlled set of soundings, several supplementary products are included: sounding-derived moisture and stability parameters for each suitable sounding; monthly means at mandatory pressure levels; the Radiosonde Atmospheric Temperature Products for Assessing Climate (RATPAC) in which post-1997 data are based on IGRA 2; and station history information derived from documented changes in instruments and observing practice as well as from instrument codes received along with the sounding data. The change to Version 2.2 includes two additional data streams which permits further updating of the IGRA data records that use the new BUFR format. Version 2.2 began in 2023.
  • Cite as: Durre, Imke; Yin, Xungang; Vose, Russell S.; Applequist, Scott; Arnfield, Jeff; Korzeniewski, Bryant; Hundermark, Bruce. (2016) Integrated Global Radiosonde Archive (IGRA), Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. DOI:10.7289/V5X63K0Q [access date].
gov.noaa.ncdc:C00975
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Distributor NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Dataset Point of Contact Customer Engagement Branch
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
1-828-271-4800
NCEI.IGRA@noaa.gov
Time Period 1905-01-01 to Present
Spatial Bounding Box Coordinates
West: -180.0
East: 180.0
South: -90.0
North: 90.0
Spatial Coverage Map
General Documentation
Processing Documents
Associated Resources
Publication Dates
  • revision: 2023-02-01
  • publication: 2016-08-01
Edition Version 2
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Ongoing - data is continually being updated
Data Update Frequency Daily
Purpose The data are intended for use for any application or analysis that requires historical radiosonde observations. Known applications of IGRA one include products of homogenized radiosonde data, air pollution modeling, reanalyses, wind energy research, climate assessments, and many others.
Use Limitations
  • Data have not been adjusted for inhomogeneities due to station relocation, equipment changes, or changes in observing practice. NCEI scientists have applied a comprehensive set of quality control procedures to the data to remove gross errors. However, they did not attempt to remove jumps and other discontinuities caused by changes in instrumentation, observing practice, or station location. Users studying long-term trends may wish to use the NOAA Radiosonde Atmospheric Temperature Products for Assessing Climate (RATPAC) or one of the available non-NOAA IGRA-derived, homogeneity-adjusted radiosonde datasets.
Dataset Citation
  • Cite as: Durre, Imke; Yin, Xungang; Vose, Russell S.; Applequist, Scott; Arnfield, Jeff; Korzeniewski, Bryant; Hundermark, Bruce. (2016) Integrated Global Radiosonde Archive (IGRA), Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. DOI:10.7289/V5X63K0Q [access date].
Cited Authors
  • Durre, Imke
    NOAA National Centers for Environmental Information
  • Yin, Xungang
    NOAA National Centers for Environmental Information
  • Vose, Russell
    NOAA National Centers for Environmental Information
  • Applequiest, Scott
    NOAA National Centers for Environmental Information
  • Arnfield, Jeff
    NOAA National Centers for Environmental Information
  • Korzeniewski, Bryant
    NOAA National Centers for Environmental Information
  • Hundermark, Bruce
    NOAA National Centers for Environmental Information
Principal Investigators
  • Durre, Imke
    NOAA National Centers for Environmental Information
  • Yin, Xungang
    NOAA National Centers for Environmental Information
Collaborators
  • Vose, Russell
    NOAA National Centers for Environmental Information
  • Applequiest, Scott
    NOAA National Centers for Environmental Information
  • Arnfield, Jeff
    NOAA National Centers for Environmental Information
  • Korzeniewski, Bryant
    NOAA National Centers for Environmental Information
  • Hundermark, Bruce
    NOAA National Centers for Environmental Information
Publishers
  • NOAA National Centers for Environmental Information
Theme keywords Global Change Master Directory (GCMD) Science Keywords
  • Earth Science > Atmosphere > Altitude > Geopotential Height
  • Earth Science > Atmosphere > Atmospheric Water Vapor > Water Vapor Indicators > Humidity
  • Earth Science > Atmosphere > Atmospheric Winds
  • Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
Global Climate Observing System (GCOS) Essential Climate Variables (ECVs)
  • Atmospheric - Upper-air - Upper-air Temperature
  • Atmospheric - Upper-air - Upper-air Wind Speed And Direction
  • Atmospheric - Upper-air - Upper-air Water Vapour
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Platform keywords Global Change Master Directory (GCMD) Platform Keywords
  • Balloons/Rockets > Radiosondes
  • Balloons/Rockets > PIBAL > Pilot Balloons
Instrument keywords Global Change Master Directory (GCMD) Instrument Keywords
  • Earth Remote Sensing Instruments > Passive Remote Sensing > Profilers/Sounders > Radiosondes
Place keywords Global Change Master Directory (GCMD) Location Keywords
  • Geographic Region > Global Land
Data Resolution keywords Global Change Master Directory (GCMD) Horizontal Data Resolution Keywords
  • Point Resolution
Global Change Master Directory (GCMD) Temporal Data Resolution Keywords
  • Hourly - < Daily
Global Change Master Directory (GCMD) Vertical Data Resolution Keywords
  • Hourly - < Daily
Stratum keywords Global Change Master Directory (GCMD) Location Keywords
  • Vertical Location > Boundary Layer
  • Vertical Location > Land Surface
  • Vertical Location > Troposphere
  • Vertical Location > Stratosphere
Use Constraints
  • Cite as: Durre, Imke; Yin, Xungang; Vose, Russell S.; Applequist, Scott; Arnfield, Jeff; Korzeniewski, Bryant; Hundermark, Bruce. (2016) Integrated Global Radiosonde Archive (IGRA), Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. DOI:10.7289/V5X63K0Q [access date].
  • Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
Access Constraints
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Fees
  • In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Lineage Statement Various data sources contribute to IGRA 2, along with several sources of metadata. The level of knowledge about each individual data source varies depending on the documentation and metadata that were provided along with the data. All data included in IGRA 2 were required to have adequate documentation of their digital format. Only observed values were included; estimated values were not. All stations included in IGRA 2 were required to be identified by either a known station identifier or by a station name, coordinates, and elevation. The data processing applied to the sources in order to create IGRA 2 are described in the Dataset Description Document.
Processor
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Processing Steps
  • First, all data sets were formatted into a common data format, duplicate soundings and data levels were removed or combined, and station metadata was collected for as many source stations as possible, and the format of this metadata was standardized across data sources. Then, the standardized source data were integrated into one data set and passed through a sequence of quality control procedures. Finally, some station records were composited with data from very nearby stations with non-overlapping periods of record. Then derived moisture instability parameters are calculated from this step as part of the daily update process to the final IGRA 2 sounding data. Monthly means of geopotential height, temperature, zonal and meridional wind components, and vapor pressure are calculated for the surface and standard pressure levels at 0000 and 1200 UTC. This step is performed on the sixth day of every month for data ending with the previous month.
    Rationale: The data and station metadata need to be in a standard format in preparation for later processing steps. Integration yields a data set with one observation per location, date, and time. Quality control procedures remove gross data problems. Composite step yields longer data records. The derived moisture instability parameters are useful for studies of the planetary boundary layer as well as for analyses of various measures of atmospheric water vapor content and stability. Monthly means are particularly useful for studies of long-term changes.
  • 2023-02-01T00:00:00Z - Product version progressed from 2.0 to 2.2. The change to Version 2.2 includes two additional data streams which permits further updating of the IGRA data records that use the new BUFR format.
Processing Environment The data were processed under Linux using a variety of Fortran 95 programs and bash scripts. Data sources were organized into a directory structure in which each source subdirectory is named with an eight-character data source code. In a few cases, when data sources of the same format covered mutually exclusive geographical regions, they were combined into what was from then on referred to as a single IGRA 2 data source. The IGRA 2 data SourceCodes are listed in the online documentation in the IGRA FTP directory.
Processing Documents
Source Datasets
  • U.S. Air Force Upper Air Data Set (Ds3 Format)
    • Description of Source: Radiosonde and pilot balloon data from land stations and Volunteer Observing Ships
    • Temporal extent used: 1973 to 2008
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • NCEI Real-Time NCEP GTS Messages (TAC format)
    • Description of Source: Radiosonde and pilot balloon observations from land stations and Volunteer Observing Ships, transmitted in Traditional Alphanumeric Code (TAC) and provided to NCEI by the National Centers for Environmental Prediction (NCEP)
    • Temporal extent used: 2000 to Present
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • NWSTG BUFR Reports
    • Description of Source: Radiosonde and pilot balloon observations from land stations and Volunteer Observing Ships, transmitted by observing stations in BUFR and received daily at NCEI from the National Weather Service's Telecommunications Gateway (NWSTG)
    • Temporal extent used: 2017 to Present to Present
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • ECMWF BUFR Reports
    • Description of Source: Radiosonde and pilot balloon observations from land stations and Volunteer Observing Ships, transmitted in BUFR and received at NCEI from the European Centres for Medium-Range Weather Forecasts (ECMWF) once a month
    • Temporal extent used: 2017 to Present to Present
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • CDMP U.S. Winds Aloft from Monthly Forms and Daily Computation Sheets
    • Description of Source: Pilot balloon observations for the United States digitized by the Climate Data Modernization Program
    • Temporal extent used: 1918 to 1960
    • Spatial extent used: N:72 S:18 E:-66 W:-172
  • CDMP African forms
    • Description of Source: Radiosonde and pilot balloon observations for Kenya, Malawi, Niger, Tanzania, Zambia, digitized by the Climate Data Modernization Program
    • Temporal extent used: 1946 to 2004
    • Spatial extent used: N:38 S:-35 E:51 W:-18
  • Non-real-time data and monthly packages in NCEInon-real-time transfer format (NWS terminology); NCEI U.S. Rawindsonde Data (NCEI DSI-6301)
    • Description of Source: Radiosonde and pilot balloon data supplied by National Weather Service, some U.S. military, and U.S.-operated Caribbean stations, as well as, historically, some Canadian sites
    • Temporal extent used: 1946 to Present
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • Roshydromet GTS or Russian GTS
    • Description of Source: Global Telecommunications System messages received at Roshydromet
    • Temporal extent used: 1998 to 2010
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • NCEI "Global U/A Cards" (NCEI DSI-6310); NCAR C-Cards Raob Data; NCAR MIT Upper Air Data (DS 370.0)
    • Description of Source: Historical radiosonde and pilot balloon data with global coverage, obtained from NCAR; humidity from NCAR MIT data not included due to data problems.
    • Temporal extent used: 1949 to 1966
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • "Global U/A Cards", "Argentina National", "Korea National", "Australian GTS", "Australian U/A Thermo/Winds Merged", "Brazilian Upper Air", "Global Upper Air Cards"
    • Description of Source: Data archived at NCEI (then NCDC) during their early phase of the Comprehensive Aerological Reference Data Set (CARDS) project in so-called TD63 format
    • Temporal extent used: 1943 to 1993
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • Comprehensive Historical Upper Air Network
    • Description of Source: Some stations from the Comprehensive Historical Upper Air Network
    • Temporal extent used: 1905 to 2007
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • ERA-CLIM Historical Upper Air Data
    • ERA-CLIM Historical Upper Air Data
      Dataset website
    • Description of Source: Upper-air data, except those for moving ships, digitized for the ERA-CLIM reanalysis project, covering many parts of the world
    • Temporal extent used: 1909 to 1972
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • Historical Arctic Radiosonde Archive
    • Historical Arctic Radiosonde Archive
      Dataset Landing Page for source data.
    • Description of Source: Radiosonde data from stations located in the artic, except those obtained from NCDC by the data set creator
    • Temporal extent used: 1948 to 1996
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • UK READER Upper Air Data
    • UK READER Upper Air Data
      general information about the data
    • Description of Source: Antarctic data provided by the British Antarctic Survey
    • Temporal extent used: 1948 to 2008
    • Spatial extent used: N:90 S:-90 E:180 W:-180
  • Meteo-France African Temperature-Humidity Soundings and Winds Aloft
    • Description of Source: Radiosonde and pilot balloon observations for West Africa collected by a joint data rescue project involving Meteo-France, CNRS and ASECNA in the 80's.
    • Temporal extent used: 1940 to 1965
    • Spatial extent used: N:38 S:-35 E:51 W:-18
  • IORGC/JAMSTEC Data for Indonesia
    • Description of Source: Rawinsonde observations collected operationally by the Indonesian Meteorological and GeophysicalAgency (BMG) and acquired by Okamoto et al. (2003)
    • Spatial extent used: N:90 S:-90 E:180 W:-180
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Last Modified: 2023-06-23
For questions about the information on this page, please email: ncei.info@noaa.gov