Modèles pour cet hiver : vers un hiver doux ou froid ? : MAJ 3 octobre 2004




Années analogues ENSO / OCS / cycle solaire:



1994/95 1994/95  1994/95 
1987/88  1987/88  1987/88 Doux
1971/72 doux
1992/93 1992/93 doux
 1956/57 doux
1959/60 normal
1962/63   1962/63 froid
    1952/53 froid


Ainsi que l'hiver 79/80 normal




2. The Multivariate ENSO Index (MEI) is based on six main observed variables over the tropical Pacific. These six variables are: sea-level pressure (P), zonal (U) and meridional (V) components of the surface wind, sea surface temperature (S), surface air temperature (A), and total cloudiness fraction of the sky (C). These observations have been collected and published in COADS for many years. The MEI is computed separately for each of twelve sliding bi-monthly seasons (Dec/Jan, Jan/Feb,...,Nov/Dec). The closest analog years to 2004 are 1994, 1987, 1999 and 1971.
3. Other indices. In addition to MEI, OCS examined sea surface temperatures, the Eastern Pacific (EP), North Pacific (NP) and Pacific-North America (PNA) indices and compared this year's observations with those of previous years. The closest analog years using these indices are 1956, 1959, 1962, 1987, 1992 and 1994.
4. Solar cycle. Solar radiation changes are known to have effects on climate, although there is still debate within the climate community regarding the degree and character of those effects. Currently we are emerging from a very active solar period, which may be at least partly responsible for the rather mild winters in the last several years. A plot of sunspot numbers since 1950 appears here. The closest analog years are 1952, 1962, 1987, 1992 and 1994.






Source : Top-Karten - Plaut Guy - Thomas

14/10/2004 18:02