AnaWEGE

The programme is a suite of scripts in shell script (sh) with ncks/nco and cdo commands, and an R script. The programme downloads and concatenates NCEP reanalysis SLP for the North Atlantic region, then computes the analogues for various distance/metrics (rms, correlations...). It runs on linux or macosX computers. It is more comfortable to have a powerful multicore computer to do the job.

By default, the analogues are computed by minimizing an rms (or Euclidean) distance. 20 "best" analogues are computed for each day between 1st Jan. 1948 and the current day. The analogues are taken from a different year than the "target" day, and are separated by at most 30 calendar days.

The R code can run in parallel on multicore computers (with the "parallel" package). It has been tested on our computing cluster with n=12 processors.

The programme is provided as is. It is free for academic use. Please contact Pascal Yiou for a commercial use.

The programme is a suite of scripts in shell script (sh) with ncks/nco and cdo commands, and an R script. The programme downloads and concatenates NCEP reanalysis SLP for the North Atlantic region, then computes the analogues for various distance/metrics (rms, correlations...). It runs on linux or macosX computers. It is more comfortable to have a powerful multicore computer to do the job.

By default, the analogues are computed by minimizing an rms (or Euclidean) distance. 20 "best" analogues are computed for each day between 1st Jan. 1948 and the current day. The analogues are taken from a different year than the "target" day, and are separated by at most 30 calendar days.

The R code can run in parallel on multicore computers (with the "parallel" package). It has been tested on our computing cluster with n=12 processors.

The programme is provided as is. It is free for academic use. Please contact Pascal Yiou for a commercial use.

CASTf90 (Circulation Analogue Simulation Tool in Fortran90) is a suite of shell script (sh) with ncks/nco and cdo commands, and a fortran90 program. CASTf90 first downloads fields from NCEP reanalysis ("surface" variables or variables on pressure levels, sea level pressure, slp, is the default) and then searches for a given simulation period the most similar cases within a given data base period according to a given distance (default is rms) measure. Finally it writes the N most similar days including the calculated distances for them to an output file.

The fortran program can run in parallel with shared memory using openMP. The purpose is the same as for "Analogue software", but it can do the calculations somewhat faster and comes with some options that allow for more flexibility in terms of time periods, variables and distances. For details see howto.pdf.

The programme is provided as is. It is free for academic use.

Please contact Pascal Yiou for a commercial use.

The AnaWEGE stochastic weather generator was modified into a forecast mode to simulate large ensembles of temperature and NAO index forecasts, from 5 to 80 days ahead. The performance of this system is evaluated by:

Yiou, P. and Déandréis, C.: Stochastic Ensemble Climate Forecast with an Analogue Model, Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2018-199, accepted, 2019.

The R code for simulations is available at the link underneath. The archive also contains temperature data for Berlin, De Bilt, Orly, Toulouse and Madrid (from ECA&D), and a daily NAO index (from NOAA)

The programme is provided as is. It is free for academic use. Please contact Pascal Yiou for a commercial use.

CECILL

AnaWEGE has been licensed under CECILL.

CECILL is the first license defining the principles of use and dissemination of Free Software in conformance with French law, following the principles of the GNU GPL. This license is meant to be used by companies, research institutions and all organisations willing to release software under a GPL-like license while ensuring a standard level of legal safety.

More information on CECILL can be found here.