- 15 April 2022
- New URL, updated contents, and addiotional ALERA2 data
- The URL is changed, contents are updated, and data of ALERA2 is added.
- 01 Oct 2008
- Additions to ens
- All 40 members from 22 Aug 2006 to 16 Jan 2007 are copied in ens directory and now available online.
- 01 Jul 2008
- New URL
- As of 2 July 2008, the URL of ALERA is changed as follows: http://www.jamstec.go.jp/esc/afes/alera/
- 18 January 2008
- Several surface pressure data rejected unexpectedly
- BUG REPORT: A bug has been found in the observation file conversion program. As a result, several surface pressure observations (out of about 5000) per analysis have been rejected unexpectedly. The impact is expected to be small.
- ALERA posted
- ALERA (AFES–LETKF experimental reanalysis) is posted on this server. It is accessible with an OPeNDAP client, such as GrADS and nco. Visit the ALERA page for details. Enjoy.
- System update on 1 June 2005
- An updated version of LETKF is used after 1 June 2005. In this update, vertical localization is introduced for surface pressure observations. The update has positive impact on the analysis performance evidenced by the reduced difference from CDAS (NCEP/NCAR Reanalysis).
- ALERA Publications
- A list of publications related to ALERA has been created.
- Spin-up period
- The first month (May 2005, or at least first ten days) is considered to be a spin-up period. Although the shock is very small, the second month (June 2005) could also be considered as a spin-up period for the updated system introduced on 1 June 2005. The data in early days are available for those who are interested in the spin-up process of LETKF.
- Discontinuity of ensemble spread
- There is a discontinuity of the ensemble spread around North America. The discontinuity appears at 0 and 12 UTC. The specific reason for the discontinuity has not been identified. Similar discontinuities are sporadically found other parts of the world as well.
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