Figure 1: (a) A Bering Strait summer satellite (MODIS) Sea Surface Temperature (SST) image marking moorings (black dots) and NCEP wind points (X) [from Woodgate et al., 2010].

(b-h) Bering Strait annual mean (AM) time-series from 1991 – 2011 of:

b) transport calculated from A3 (blue) or A2 (cyan), adjusted for changes in instrument depth (black) with error bars (dashed) calculated from variability;

c) near-bottom temperatures from A3 (blue) and A4 (magenta-dashed), and the NOAA SST product (red diamonds);

d) salinities from A3 (blue) and A4 (magenta);

e) heat fluxes: blue - from A3 only; red – including ACC correction (1×10²⁰J) and contributions from surface layer of 10m (lower bound) or 20m (upper bound) at SST, with black x indicate heat added from 20m surface layer;

f) freshwater fluxes: blue – from A3 only; red – including 800-1000km³ (lower and upper bounds) correction for stratification and ACC;

g) transport attributable to NCEP wind (heading 330º, i.e., northwestward) at each of 4 points (coloured X in (a)) and the average thereof (black); and

h) transport attributable to the pressure-head term from the annual (black) or weekly (green) fits.

Figure 2:  Time-series of:

a) 30-day (grey) and 365-day (red) smoothed NOAA SST data for the Bering Strait region;

b) annual mean SST (red diamonds) and A3 lower layer (LL) temperature (blue dots);

c) first day in year when 30-day smoothed SST (red diamonds) or A3 LL temperature is above 0ºC, with trends (as per Figure 1) in days/yr for 1998-2011 for SST (top left) and A3 (top right);

d) as per (c) for last day in year when temperatures above 0ºC (trends are not significant);

e) as per (c) for number of days above 0ºC;

f) and (g) annual mean NCEP winds at heading 330º (i.e., northwestward) at each of 4 points (coloured X in Figure 1a) and the average thereof (black) for 1982-2011 (f) and 1948-2011 (g).

Figure 3:  Bering Strait temperature-salinity (TS) and volume information inferred from A3.  (ACC and straitification  (neglected) add ~ 10% of the total volume to lower densities.)

First row: All A3 lower layer (LL) data from 1998 to 2011. Rows 2-5: A3 LL data from cold years 1991 (row 2) and 2001 (row 3) and warm years 2007 (row 4) and 2011 (row 5).

First column: Temperature-salinity (TS) plot with sigma-0 contours showing that year’s data (in color) and 1998-2011 data (grey).  Black box marks extract of TS plot shown in column 2. Yellow line is a western Arctic TS profile from 2002 (CBL2002 station 14 - 76º31.4’N, 168º51.8W in 750m water north of the Chukchi slope [Woodgate et al., 2005c]).

Second column: Volume of water (in TS classes) for that year (or group of years) infered from moored velocity measurements.  Positive/Negative values indicate net northward/southward transport.

Third column:  Volume of water per salinity class for that year (or group of years) above 0ºC (red), below 0ºC (blue), and total (black).  Grey lines indicate totals from each year 1998-2011.

Fourth column: Heat flux per sigma-0 class for that year (or group of years).  Grey lines indicate totals from each year 1998-2011. 

In first 3 columns, black dashed line marks 33.1 psu.