Transfer function between surface sediment diatom assemblages and sea-surface temperature and salinity of the Labrador Sea

Q-mode factor analysis (CABFAC) of 38 diatom species in 66 surface sediment samples from the Labrador Sea allowed the definition of six assemblages ex plaining 95.69% of the total variance. The first assemblage (40.12% of the total variance) is represented by Thalassiothrix longissima, a species char acteristic of the Irminger Current and associated with the West Greenland C urrent. The second assemblage (34.52% of the total variance) is represented by Thalassiosira gravida (resting spores), a cold water species associated with the Labrador Current. A third assemblage (11.43% of the variance) rep resented by Chaetoceros spp. is concentrated in the northeastern section of the Labrador Sea and associated with upwelling and high productivity. The fourth, the fifth and the sixth assemblages, represented, respectively, by Coscinodiscus marginatus, Coscinodiscus oculus iridis, and Coscinodiscus di visus, and Nitzschia frigida, are less significant and account, respectivel y, for 4.95, 2.62 and 2.04% of the total variance. Transfer functions deriv ed by relating factor assemblages to surface water temperature and salinity (August and February) give standard errors of estimate of +/-0.93 degrees C (August) and +/-0.64 degrees C (February) for temperature, and of +/-0.58 parts per thousand (August) and +/-0.45 parts per thousand (February) for salinity. High correlations between the measured and estimated parameters c onfirm the validity of the paleoecological equations for the reconstruction of the Labrador Sea paleoclimate. (C) 1999 Elsevier Science B.V. All right s reserved.