Norwegian Meteorological Institute met.no Are North Atlantic SST anomalies significant for the Nordic Seas SSTs? Arne Melsom Norwegian Meteorological Institute, P.O. Box 43, Blindern 0313 Oslo, Norway.

Main questions in subtask 1 of Principal Task 5: 1. To what degree is the SST variability in the Nordic Seas related to SST anomalies in the North Atlantic Ocean? 2. To what degree are the anomalies of the mass and heat transport into the Nordic Seas related to North Atlantic Ocean variability? NOClim spring meeting 2002

Norwegian Meteorological Institute met.no Reference domain: Filter: 5 year lowpass box filter Winter definition: Nov-Dec-Jan-Feb-Mar-Apr Period: NOClim spring meeting 2002 Lagged correlations of SST anomalies

Norwegian Meteorological Institute met.no NOClim spring meeting 2002 Confidence levels; lag: 7 years Reference domain:

Norwegian Meteorological Institute met.no Reference domain: NOClim spring meeting 2002 Lagged correlations of SST anomalies

Norwegian Meteorological Institute met.no Reference domain: NOClim spring meeting 2002 Lagged correlations of SST anomalies

Norwegian Meteorological Institute met.no NOClim spring meeting 2002 Confidence levels; ”lag”: -3 years

Norwegian Meteorological Institute met.no Hovmøller diagram of propagating SST anomalies in the North Atlantic Ocean start NOClim spring meeting 2002 Filter: 3 year lowpass box filter

Norwegian Meteorological Institute met.no SST anomalies in the northwestern N. Atlantic start Bifurcation point NOClim spring meeting 2002

Norwegian Meteorological Institute met.no : A warm episode NOClim spring meeting

Norwegian Meteorological Institute met.no : A warm episode NOClim spring meeting

Norwegian Meteorological Institute met.no : A warm episode NOClim spring meeting

Norwegian Meteorological Institute met.no : A cold episode NOClim spring meeting

Norwegian Meteorological Institute met.no : A cold episode NOClim spring meeting

Norwegian Meteorological Institute met.no : A cold episode NOClim spring meeting

Norwegian Meteorological Institute met.no Lagged correlations of SST anomalies Reference domain: Alternative data: Reynolds & Smith data (blended, i.e. in situ & remote sensing) Period: NOClim spring meeting 2002

Norwegian Meteorological Institute met.no Reference domain: NOClim spring meeting 2002 Confidence levels; lag: 3 years

Norwegian Meteorological Institute met.no Lagged correlations of SST anomalies NOClim spring meeting 2002

Norwegian Meteorological Institute met.no Lagged correlations of SST anomalies NOClim spring meeting 2002

Norwegian Meteorological Institute met.no Effects of atmosphere dynamics on the ocean’s mixed layer properties Mean winter fields, based on NCEP MSLP data for the period NOClim spring meeting 2002 Heat flux (sensible+latent)

Norwegian Meteorological Institute met.no Impact of NAO: North Atlantic tripole NOClim spring meeting 2002 From Marshall et al., 2001, J. Climatology : :

Norwegian Meteorological Institute met.no NOClim spring meeting 2002 ”Statistics are a highly logical and precise method for saying a half-truth inaccurately.” Conclusions  SST anomalies rarely propagate smoothly from the Gulf Stream to the northeastern North Atlantic; other possible source regions include the Labrador Sea and the eastern mid-latitudes  results do not conclusively verify that SST anomalies in the southern Norwegian Sea have their origins in the Gulf Stream system; another possible source region is the waters off the coasts of continental western Europe  the propagating features that are seen in the in situ data are much less evident when alternative blended SST data are analyzed  anomalies of other properties of the mixed layer (transports of heat and salt) that respond to wind forcing on much longer time scales may well behave differently