Supporting Information for
Freshening anomalies in the Indonesian Throughflow and impacts on the Leeuwin
Current during 2010-11
Ming Feng1*, Jessica Benthuysen2, Ningning Zhang1,3, Dirk Slawinski1
1
CSIRO Oceans and Atmosphere Flagship, Floreat, Western Australia, Australia
2
Australian Institute of Marine Sciences, Townsville, Queensland, Australia
3
Ocean University of China, Qingdao, China
Contents of this file
Figure S1, Figure S2, Figure S3, Figure S4, Figure S5, Figure S6, Figure S7
Additional Supporting Information
Figure S1. (a) Horizontally-averaged salinity (psu) in the Indonesian-Australian Basin,
defined by a region deeper than 200 m from 110°E to the west coast of Australian and
South of Indonesia to 22°S in Argo data. (b) Salinity in the Leeuwin Current at 32°S,
115°E in BRAN. (c) Sea surface salinity from the Indonesian-Australian Basin (grey
contour) and the Leeuwin Current (black contour), derived from the gridded Argo data.
Figure S2. Sea surface salinity anomalies (psu) derived from BRAN 3p5 model output in
the eastern Indian Ocean and western Pacific region (relative to 2005-2011 monthly
climatology) in (a) August 2010, (b) October 2010, (c) December 2010, (d) February
2011, (e) April 2011, and (f) June 2011.
Figure S3: Time series of spatially averaged (100°E-130°E, 7°S-22°S) anomalies of
salinity tendency S , freshwater flux ( E  P) S , advection u  S and the sum of
t
hm
freshwater flux and advection. Terms are averaged in the mixed layer, which is calculated
from BRAN temperature and salinity outputs based on the 0.125   standard. The
velocity data are from BRAN output. The evaporation and precipitation data are from
ERA Interim reanalysis products. 5-month moving average is applied to remove
intraseasonal variations. The anomalies are obtained by removing climatological mean
during January 2005 – December 2011.
Figure S4. Upper ocean salinity (psu; contours) and salinity anomaly (psu; shading) along
meridional sections of (a) 100.5°E and (b) 110.5°E in February 2011, derived from the
gridded Argo product.
Figure S5: Upper ocean temperature and salinity across the Leeuwin Current at 32°S in
the gridded Argo data for February 2011 (left column), February climatology (middle) ,
and their difference (right): temperature (a-c) and salinity (d-f).
Figure S6. (top) The Leeuwin Current geostrophic meridional transport at 32°S for July
2010-June 2011 from BRAN, referenced to 300 m. The transports are calculated using
temperature and salinity in 2010-2011 (thick black curve), temperature and salinity
climatology in February (thin black curve), temperature in 2010-2011 and climatology
salinity in February (thick grey curve), and climatology temperature in February and
salinity in 2010-2011 (thin grey dashed curve). (bottom) The percent contribution by
temperature (black curve) and salinity (grey curve) to the geostrophic transport anomaly
calculated from monthly climatology.
Figure S7. (a) Horizontally-averaged salinity (psu) from the Indonesian-Australian Basin,
defined by a region deeper than 200 m from 110°E to the west coast of Australian and
South of Indonesia to 22°S in BRAN. (b) Salinity in the Leeuwin Current at 32°S, 115°E
in BRAN. (c) Sea surface salinity from the Indonesian-Australian Basin (grey contour)
and the Leeuwin Current (black contour) in BRAN.
Introduction
This file contains supplementary figures for the main text.
Figure S1. (a) Horizontally-averaged salinity (psu) in the Indonesian-Australian Basin,
defined by a region deeper than 200 m from 110°E to the west coast of Australian and
South of Indonesia to 22°S in Argo data. (b) Salinity in the Leeuwin Current at 32°S,
115°E in BRAN. (c) Sea surface salinity from the Indonesian-Australian Basin (grey
contour) and the Leeuwin Current (black contour), derived from the gridded Argo data.
Figure S2. Sea surface salinity anomalies (psu) derived from BRAN 3p5 model output in
the eastern Indian Ocean and western Pacific region (relative to 2005-2011 monthly
climatology) in (a) August 2010, (b) October 2010, (c) December 2010, (d) February
2011, (e) April 2011, and (f) June 2011.
Figure S3: Time series of spatially averaged (100°E-130°E, 7°S-22°S) anomalies of
salinity tendency S , freshwater flux ( E  P) S , advection u  S and the sum of
t
hm
freshwater flux and advection. Terms are averaged in the mixed layer, which is calculated
from BRAN temperature and salinity outputs based on the 0.125   standard. The
velocity data are from BRAN output. The evaporation and precipitation data are from
ERA Interim reanalysis products. 5-month moving average is applied to remove
intraseasonal variations. The anomalies are obtained by removing climatological mean
during January 2005 – December 2011.
(a) salinity and salinity anomaly along 100.5°E section
0
0.5
34.2
-50
0.4
34.4 34.6
35.8
0.3
-100
34.8
0.2
34.8
z(m)
-150
0.1
35.6
0
-200
-0.1
-250
35.4
-0.2
-300
35.2
-350
-400
40°S
-0.3
-0.4
35
-0.5
35°S
30°S
25°S
20°S
latitude
15°S
10°S
5°S
(b) salinity and salinity anomaly along 110.5°E section
0
0.5
34
-50
0.4
34.2
34.6
34.4
-100
0.2
35.6
35.8
-150
z(m)
0.3
34.8
-200
35.4
-250
35.2
35
0.1
0
35.2
35.8
-0.1
-0.2
-300
-0.3
35
-350
-0.4
34.8
-400
40°S
-0.5
35°S
30°S
25°S
20°S
latitude
15°S
10°S
5°S
Figure S4. Upper ocean salinity (psu; contours) and salinity anomaly (psu; shading) along
meridional sections of (a) 100.5°E and (b) 110.5°E in February 2011, derived from
gridded Argo product.
Figure S5: Upper ocean temperature and salinity across the Leeuwin Current at 32°S in
Argo data for February 2011 (left column), February climatology (middle) , and their
difference (right): temperature (a-c) and salinity (d-f).
Figure S6. (top) The Leeuwin Current geostrophic meridional transport for July 2010June 2011 from BRAN, referenced to 300 m. The transport is calculated by integrating
from 112ºE to the coast at 32°S from monthly mean data and the monthly climatology.
The transport corresponds to the meridional geostrophic velocity calculated from
combination 1 (thick black curve), combination 2 (thick grey curve), combination 3 (thin
grey dashed curve), and combination 4 (thin black curve).
(bottom) The percent contribution by temperature (black curve) and salinity (grey curve)
to the geostrophic transport anomaly with respect to the monthly climatology.
Figure S7. (a) Horizontally-averaged salinity (psu) in the Indonesian-Australian Basin,
defined by a region deeper than 200 m from 110°E to the west coast of Australian and
South of Indonesia to 22°S in BRAN. (b) Salinity in the Leeuwin Current at 32°S, 115°E
in BRAN. (c) Sea surface salinity from the Indonesian-Australian Basin (grey contour)
and the Leeuwin Current (black contour) in BRAN.