Ik denk dat je okt-nov 2010 ook moet vergelijken
Bericht van: Ruben (Ås, nabij Oslo, Noorwegen) , 17-10-2016 20:40
In mijn ogen was toch de meest bijzondere winter sinds 1997. En bovendien de enige recente winter die in het eerste deel kou wist te produceren. Mid-oktober en november kenden toen al een behoorlijk negatieve AO. Volgens Cohen (zie link) is het persisterende -AO patroon terug te leiden tot een tweetal troposfeer-stratosfeer events waarvan de eerste in mid-november plaatsvond.
De 6 stappen van Cohen:
1) rapid advance of Siberian snow cover in October,
2) a strengthened Siberian high with colder than normal temperatures and higher sea level pressure (SLP) anomalies,
3) increased upward Eliassen Palm (EP) flux or the three dimensional wave activity flux (WAF [Plumb, 1985]),
4) a stratospheric warming,
5) downward propagation of the associated height and wind anomalies from the stratosphere down to the surface and finally
6) a negative surface AO (Figure S2). Typically the cycle begins with the advance in snow cover in October and concludes with a lower tropospheric AO response beginning in mid to late January.
En
"As will shortly be demonstrated, both strong negative AO events can be shown to originate as regional perturbations across Northern Eurasia. The first tropospheric precursor that initiated the mid-November minor stratospheric warming we estimate existed from the second half of October until mid-November. The second tropospheric precursor that initiated a major stratospheric warming existed at the end of January."
De 6 stappen van Cohen:
1) rapid advance of Siberian snow cover in October,
2) a strengthened Siberian high with colder than normal temperatures and higher sea level pressure (SLP) anomalies,
3) increased upward Eliassen Palm (EP) flux or the three dimensional wave activity flux (WAF [Plumb, 1985]),
4) a stratospheric warming,
5) downward propagation of the associated height and wind anomalies from the stratosphere down to the surface and finally
6) a negative surface AO (Figure S2). Typically the cycle begins with the advance in snow cover in October and concludes with a lower tropospheric AO response beginning in mid to late January.
En
"As will shortly be demonstrated, both strong negative AO events can be shown to originate as regional perturbations across Northern Eurasia. The first tropospheric precursor that initiated the mid-November minor stratospheric warming we estimate existed from the second half of October until mid-November. The second tropospheric precursor that initiated a major stratospheric warming existed at the end of January."
