ERA5.1: Corrections to ERA5 Stratospheric Temperature 2000-2006

In ECMWF Technical Memo 859 released in January 2020, Simmons and his coauthors report that "the ERA5 analyses of lower stratospheric temperature exhibit a pronounced cold bias for the years 2000 to 2006. This is due to specifying background error covariances for the data assimilation that were inappropriate prior to availability during 2006 of GNSS radio occultation data in sufficient numbers to constrain a cold bias of the assimilating ERA5 model. A new set of analyses, termed ERA5.1, has thus been produced for the period from 2000 to 2006 using the background error covariances that were used to produce the ERA5 analyses for the years 1979 to 1999. ERA5.1 also includes the more restrictive ensemble assimilation of SBUV ozone data that was used in production of ERA5 for 1979 to 1999."

"ERA5.1 provides analyses with better global-mean temperatures in the stratosphere and uppermost troposphere than provided by ERA5. ERA5.1 stands up well in comparison with ERA-Interim and other reanalyses in the lower stratosphere, although there are also lower-stratospheric temperature differences between ERA5 and other reanalyses in the 1980s and 1990s. These are due in part to differences in radiosonde temperature bias adjustment. The pronounced near-tropopause cold bias of ERA5 from 2000 to 2006 has implications for the representation of stratospheric humidity, for which ERA5.1 performs better, though by no means perfectly. ERA5.1 does not exhibit the spuriously high values of ozone that occur close to the South Pole in the polar nights of 2003 and 2004 in the ERA5 analyses. Synoptic evolution in the extratropical stratosphere is seen to be very similar in two cases involving splitting of the stratospheric polar vortex and secondary vortex formation by dynamical instability. The ERA5.1 representation of the QBO agrees slightly better with radiosonde wind data than that of ERA5. The dataset formed by merging ERA5.1 with ERA5 is generally more homogeneous over time than ERA5 alone. It nevertheless is problematic for global-mean upper stratospheric temperature for all but the most recent ten or so years."

"ERA5.1 is very close to ERA5 in the lower and middle troposphere."

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Questions? Email Resource Support Contact:

  • Dave Stepaniak
    davestep@ucar.edu
    UCAR/NCAR - Research Data Archive

Temporal Range

  • Begin:  2000-01-01T00:00:00Z
    End:  2006-12-31T23:00:00Z

Keywords

Resource Type dataset
Temporal Range Begin 2000-01-01T00:00:00Z
Temporal Range End 2006-12-31T23:00:00Z
Temporal Resolution N/A
Bounding Box North Lat 90
Bounding Box South Lat -90
Bounding Box West Long -180
Bounding Box East Long 180
Spatial Representation grid
Spatial Resolution 0.25 degree
Related Links

Related Resource #1 : ERA5
Additional Information N/A
Resource Format NetCDF4 (Binary)
WMO_GRIB1 (Binary)
Standardized Resource Format GRIB
NetCDF
Asset Size 78310994 MB
Legal Constraints

Creative Commons Attribution 4.0 International License
Access Constraints None
Software Implementation Language N/A

Resource Support Name Dave Stepaniak
Resource Support Email davestep@ucar.edu
Resource Support Organization UCAR/NCAR - Research Data Archive
Distributor NCAR Research Data Archive
Metadata Contact Name N/A
Metadata Contact Email rdahelp@ucar.edu
Metadata Contact Organization NCAR Research Data Archive

Author European Centre for Medium-Range Weather Forecasts
Publisher Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory
Publication Date 2020-06-12
Digital Object Identifier (DOI) https://doi.org/10.5065/CBTN-V814
Alternate Identifier d633002
Resource Version N/A
Topic Category climatologyMeteorologyAtmosphere
Progress completed
Metadata Date 2024-08-04T02:11:36Z
Metadata Record Identifier edu.ucar.rda::d633002
Metadata Language eng; USA
Suggested Citation European Centre for Medium-Range Weather Forecasts. (2020). ERA5.1: Corrections to ERA5 Stratospheric Temperature 2000-2006. Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. https://doi.org/10.5065/CBTN-V814. Accessed 25 November 2024.

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