Radiosonde Atmospheric Temperature Products for Assessing Climate (RATPAC), Version 2

RATPAC 2

browse graphicUpper air balloon
The Radiosonde Atmospheric Temperature Products for Assessing Climate (RATPAC) consist of time series of radiosonde-based temperature anomalies for the years 1958-present in which the temporal inhomogeneities resulting from changes in instruments and observing practices have been reduced to the extent possible. Developed through a collaborative effort involving NOAA scientists from the Air Resources Laboratory, the Geophysical Fluid Dynamics Laboratory, and NCEI, the RATPAC time series are based on data from 85 stations distributed around global land areas and are available on 13 atmospheric pressure levels: the surface, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, and 30 hPa. Two sub-products, RATPAC-A and RATPAC-B, were derived using different approaches to meet this need based largely in part on the Temporal Homogenization of Monthly Radiosonde Temperature Data (LKS) bias-adjusted dataset. RATPAC-A contains adjusted global, hemispheric, tropical, and extratropical mean temperature anomalies. From 1958 through 1995, the bases of the data are on spatial averages of LKS adjusted 87-station temperature data. After 1995, they are based on the Integrated Global Radiosonde Archive (IGRA) station data, combined using a first difference method. RATPAC-B contains data for individual stations as well as large-scale arithmetic averages corresponding to areas used for RATPAC-A. The station data consist of adjusted data produced by LKS for the period 1958-1997 and unadjusted data from IGRA after 1997. The regional mean time series in RATPAC-B are based on arithmetic averaging of these station data, rather than the first difference method used to create RATPAC-A. The difference between this version and the original version of RATPAC is that the IGRA component of Version 2 is taken from IGRA v2 rather than IGRA v1.
  • Cite as: Durre, Imke; Xungang, Yin; Vose, Russell S.; Applequist, Scott. Radiosonde Atmospheric Temperature Products for Assessing Climate, Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. DOI:10.7289/V5SF2T7J [access date].
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Distribution Formats
  • ASCII
    • File Compression: zip
Distributor Customer Engagement Branch
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
1-828-271-4800
ncei.orders@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.orders@noaa.gov
Time Period 1958 to Present (time interval: 1-month)
Spatial Bounding Box Coordinates
N: 90.0
S: -90.0
E: 180.0
W: -180.0
Spatial Coverage Map
Dataset Information
  • NOAA website for RATPAC
    Website for more information, documentation and background on the time series, with links to the data.
General Documentation
Processing Documents
Associated Resources
Publication Dates
  • creation: 2016-09
Edition Version 2.0
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 Monthly
Purpose RATPAC is intended to be used for the assessment of long-term changes in tropospheric and lower-stratospheric temperatures on large spatial scales. For analyses of interannual and longer-term changes in global, hemispheric, and tropical means, use of RATPAC-A is recommended since it contains the most robust large-scale averages. For individual station data, monthly data, or regional means on smaller scales, use of RATPAC-B, is recommended, albeit with careful attention to the potential of inhomogeneities influencing the analysis after 1997. For analyses that require data not included in RATPAC and that are less sensitive to long-term biases, users are referred to the Integrated Global Radiosonde Archive (IGRA).
Use Limitations
  • Approximately 15 of the 85 stations used have closed since the 1990s, resulting in a decrease in the station density over time. The impact of this reduction in the station network on the RATPAC time series has not been assessed.
Dataset Citation
  • Cite as: Durre, Imke; Xungang, Yin; Vose, Russell S.; Applequist, Scott. Radiosonde Atmospheric Temperature Products for Assessing Climate, Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. DOI:10.7289/V5SF2T7J [access date].
Cited Authors
  • Durre, Imke
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • Yin, Xungang
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • Vose, Russell
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • Applequiest, Scott
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Originators
  • Durre, Imke
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Collaborators
  • Yin, Xungang
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • Vose, Russell
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • Applequiest, Scott
    DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Publishers
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Theme keywords Global Change Master Directory (GCMD) Science Keywords
  • Earth Science
  • Earth Science > Atmosphere
  • Earth Science > Atmosphere > Atmospheric Temperature
  • Earth Science > Atmosphere > Atmospheric Temperature > Upper Air Temperature
Global Climate Observing System (GCOS) Essential Climate Variables (ECVs)
  • Atmospheric - Upper-air - Upper-air Temperature
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
  • RADIOSONDES
  • PIBAL > Pilot Balloons
Instrument keywords Global Change Master Directory (GCMD) Instrument Keywords
  • 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) Vertical Data Resolution Keywords
  • Point Resolution
Global Change Master Directory (GCMD) Temporal 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; Xungang, Yin; Vose, Russell S.; Applequist, Scott. Radiosonde Atmospheric Temperature Products for Assessing Climate, Version 2. [indicate subset used]. NOAA National Centers for Environmental Information. DOI:10.7289/V5SF2T7J [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 data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Lineage Statement The data sources and processing methods are documented in several peer-reviewed papers.
Processor
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Processing Steps
  • Preparation of the LKS Component: The Lanzante-Klein-Seidel (LKS) time series consist of Monthly means of temperature at 16 atmospheric pressure levels between the surface and 10 hPa for 87 carefully selected stations. The 10 and 20 hPa levels were not used in the RATPAC products because of the scarcity of data at those levels. In addition, the 1000-hPa level was not included because LKS found the 1000 hPa data to be more erratic and less reliable than other levels in the troposphere, probably due to problems arising from days when the surface pressure was less than 1000 hPa. RATPAC uses data from 85 of the 87 LKS stations. Because of problems with the data from India, RATPAC does not include the LKS station data for Bombay or Calcutta.
    Rationale: These time series have already been adjusted for inhomogeneities by a three-member expert team.
  • Creation of RATPAC-A: For RATPAC-A, the first difference ("FD") procedure was used to update the LKS data (Free et al. 2004). Since this method introduces a random error that increases with the number of time gaps in the data and with decreasing number of stations, reliable time series can be produced only for large Regions. Before 1996, the RATPAC-A time series represent area means of the adjusted LKS station data, without use of FD. Although the LKS dataset runs through 1997, IGRA data was substituted for 1996 and 1997 because the short record left after the adjustments makes LKS adjustments in 1996 and 1997 less reliable than those at earlier times. The FD method was applied to IGRA monthly means starting in 1996. In this method, the difference in temperature between one time step and the next (the "first difference") was taken, then large-scale means of the FD series were computed, and finally large-scale temperature series were reconstructed from the FD series (see Appendix of Free et al. (2005) for details). Prior to the application of the FD method, portions of the station time series around the times of known changes in instruments or procedures were eliminated from the IGRA data in an attempt to reduce the effect of inhomogeneities due to such changes (see Free et al. 2005 for details). Finally, an endpoint outlier trimming procedure was used to reduce the random errors introduced by the FD procedure. As described in Peterson et al. (1998) and Free et al. (2004), this procedure removes data exceeding a prescribed multiple of the STD of the original time series if the data fall at the end of a data segment (immediately before or after a gap). Here, the multiple, or trim factor, chosen was 1.0 STDs. This choice was based on sensitivity tests with reanalysis data as well as with the LKS data (Free et al. 2005).
    Rationale: To update the LKS time series in such a way that inhomogeneities are minimized.
  • Creation of RATPAC-B: Because the FD method used for RATPAC-A does not allow production of individual station time series, and to provide alternative large-scale mean time series for comparison with the FD time series, a set of updated station time series were also created by appending monthly mean station data from IGRA for 1998-present to the corresponding adjusted LKS station time series for 1958-1997 without any adjustment for inhomogeneities after 1997. For consistency, only those observation times from the IGRA data were used that were present in the LKS adjusted station data. The 00 UTC and 12 UTC observations were combined where both were available, and the updated station time series were also available for the two observation times separately. To minimize the discontinuity at 1997/1998, a factor equal to the difference between the means of the IGRA and LKS data for 1996-1997 was added to the IGRA monthly means. The effect was to shift the IGRA data so that the means of the two datasets for the last two years of the LKS time series were equal. If both time series were present for fewer than 9 months in those two years, the time period 1990-1997 was used instead. At one or more levels at ~14 stations, LKS found a discontinuity, but deleted data after the discontinuity rather than adjusting it because adjustment was not feasible. In creating RATPAC-B, the IGRA data for those levels at those stations were not appended after 1997 to avoid reintroducing known inhomogeneities.
    Rationale: To create alternative time series for comparison purposes.
  • Spatial averaging: In an effort to obtain spatially unbiased large-scale means, the uneven longitudinal distribution of stations was compensated for by creating regional means before averaging data into zonal bands. Each 30-degree zonal band was divided into three longitudinal regions of 120 degrees each: 30 degrees W to 90 degrees E, 90 degrees E to 150 degrees W and 150 degrees W to 30 degrees W. Hemispheric (0-90 degrees), tropical (30degreesS-30degreesN), and extratropical (30-90 degrees) means were calculated from these zonal means, already weighted using the cosine of the latitude of the midpoint of the zone. The global mean was the average of the hemispheric means.
  • Updates: The RATPAC time series are recalculated once a month on the sixth day of the month. This recalculation takes place immediately after the computation of the monthly means as part of the regular IGRA update system. After each recalculation, the recreated time series are uploaded to the public site and archived.
    Rationale: Regular updates for climate monitoring and assessments.
Processing Environment The data were processed under Linux using several Fortran 77 programs and one bash script.
Processing Documents
Source Datasets
  • Lanzante-Klein-Gaffen data
    • Description of Source: LKS adjusted time seriesof monthly-mean radiosonde-based temperature from the NOAA Air Resources Laboratory.
    • Temporal extent used: 1997 to 1998
    • Spatial extent used: N:-90 S:90 E:90 W:180
  • Integrated Global Radiosonde Archive V2
    • Integrated Global Radiosonde Archive V2
      IGRA informational website
    • Description of Source: Monthly means of temperature from the Integrated Global Radiosonde Archive
    • Temporal extent used: 1996 to Present
    • Spatial extent used: N:-90 S:90 E:90 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: 2018-11-05
For questions about the information on this page, please email: ncei.orders@noaa.gov