On Sunday, September 27, 2015 at 8:00:20 AM UTC-4, Graham Easterling wrote:
SNIP
We will see if this pattern of a colder Atlantic persists, it's been around for a while now I think, late spring/early summer?
Col
It's been around most of the year, but changed gradually, especially over the last 4 months. It is now considerably further south. Back in June it was around 10 degrees further north, rather more intense, but didn't extend anywhere near as far eastward. In fact at the end of June SSTs were above normal in the eastern Atlantic everywhere from Ireland to northern Spain. It extended eastward in August.
From a purely observational point of view, based on past events, I expect it to drift further south & become less of a feature.
Graham
Penzance
Thought I'd return to this as it's starting to look like the cool anomaly is indeed drifting south and becoming less significant http://www1.ncdc.noaa.gov/pub/data/o...vy-anom-bb.gif
The trouble with anomaly maps is they give an impression of a pool of cool water, when in fact the just normally indicate a variance from the normal temperature gradient. Obvious I know, but it is important to look at actual SSTs at the same time, http://www.wetterzentrale.de/pics/Reursst.gif
Graham
Penzance 'andsome yesterday my lovelies http://www.easterling.freeserve.co.uk/hm.html
===========
Well, an area around 55 deg N did have record low SSTs for the period Jan-Aug 2015 but I agree with you about the analysis of anomalies.
The idea that Greenland ice melt is going to help to slow the AMOC is going to gain momentum, and it's worth considering. But talking with a colleague offered a simpler explanation - persistent anomalous westerlies across the North Atlantic since the latter part of last year have been forcing surface waters southwards via Ekman transportation.
Stephen.