FN Archimer Export Format PT J TI On the Movements of the North Atlantic Subpolar Front in the Preinstrumental Past* BT AF MARCHAL, Olivier WAELBROECK, Claire COLIN DE VERDIERE, Alain AS 1:1;2:2;3:3; FF 1:;2:;3:; C1 Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Lab Sci Climat & Environm, Saclay, France. Lab Phys Oceans, Brest, France. C2 WHOI, USA LSCE, FRANCE UBO, FRANCE UM LOPS IF 4.161 TC 7 UR https://archimer.ifremer.fr/doc/00318/42922/42423.pdf https://archimer.ifremer.fr/doc/00318/42922/42424.doc LA English DT Article DE ;Inverse methods;Kalman filters;Climate variability;Circulation/ Dynamics;Geographic location/entity;Oceanic variability;Variability;Mathematical and statistical techniques;Fronts;North Atlantic Ocean AB Three sediment records of sea surface temperature (SST) are analyzed that originate from distant locations in the North Atlantic, have centennial-to-multicentennial resolution, are based on the same reconstruction method and chronological assumptions, and span the past 15 000 yr. Using recursive least squares techniques, an estimate of the time-dependent North Atlantic SST field over the last 15 kyr is sought that is consistent with both the SST records and a surface ocean circulation model, given estimates of their respective error (co)variances. Under the authors' assumptions about data and model errors, it is found that the 10 degrees C mixed layer isotherm, which approximately traces the modern Subpolar Front, would have moved by ~15 degrees of latitude southward (northward) in the eastern North Atlantic at the onset (termination) of the Younger Dryas cold interval (YD), a result significant at the level of two standard deviations in the isotherm position. In contrast, meridional movements of the isotherm in the Newfoundland basin are estimated to be small and not significant. Thus, the isotherm would have pivoted twice around a region southeast of the Grand Banks, with a southwest-northeast orientation during the warm intervals of the Bolling-Allerod and the Holocene and a more zonal orientation and southerly position during the cold interval of the YD. This study provides an assessment of the significance of similar previous inferences and illustrates the potential of recursive least squares in paleoceanography. PY 2016 PD FEB SO Journal Of Climate SN 0894-8755 PU Amer Meteorological Soc VL 29 IS 4 UT 000370452200001 BP 1545 EP 1571 DI 10.1175/JCLI-D-15-0509.1 ID 42922 ER EF