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

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.