Auxiliary Material for
The contribution of aeolian sand and dust to iron fertilization of phytoplankton blooms in
southwestern Ross Sea, Antarctica
V.H.L. Winton1,2,a,b, G.B. Dunbar1, N.A.N. Bertler1,2, M-A. Millet3, B. Delmonte4, C.B.
Atkins3, J.M. Chewings3, P. Andersson5
1
2
3
Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington,
New Zealand
GNS Science, National Isotope Centre, PO Box 31-312, Lower Hutt 5040, New Zealand
School of Geography, Environment and Earth Sciences, Victoria University of Wellington,
PO Box 600, Wellington, New Zealand
4
5
Dipartimento di Scienze dell’Ambiente a del Territorio, University of Milano-Bicocca,
Milano, Italy
Laboratory for Isotope Geology, Swedish Museum of Natural History, PO Box 50 007, 104
05 Stockholm, Sweden
a
b
Corresponding author holly.winton@postgrad.curtin.edu.au
Now at Department of Imaging and Applied Physics, Curtin University, GPO BOX U1987,
Perth WA 6102
Introduction
This data set contains sedimentological and iron geochemical data for 127 surface snow
samples that were collected on the sea ice in McMurdo Sound, Ross Sea in November 2009
and 2010. Sample information and mass accumulation rates of aeolian sand and dust (ASD)
are given in ts01.xls. The mass of dust was determined by melting and filtering ASD-laden
snow and weighing ASD captured on 0.4 µm pore-size polycarbonate membranes (e.g.
Dunbar et al., 2009). Particle size data for surface snow samples in McMurdo Sound was
determined using a Beckman-Coulter Laser. The particle size distribution data for McMurdo
Sound are given in ts02.xls and the data along the south-north transect are plotted in fs02.eps.
Soluble and total iron data for ASD were investigated by a stepwise leaching protocol and
subsequent total acid digestion as discussed in the paper and the data are given in ts03.xls.
We use the model of Boyd et al. (2010) to estimate the dissolved iron supply from ASD. The
constant parameters used in the calculations are given in ts04.xls and the iron geochemistry
data in ts03.xls. A sequence of satellite images described in text01.doc and fs01.esp were
used to determine the duration of sea iced break up in Southern McMurdo Sound for these
calculations.
1. ts01.xls Sample information and mass accumulation rates of aeolian sand and dust used in
this study.
1.1 Column “sample name”, name of the sample.
1.2 Column “latitude”, degrees, latitude of the sample.
1.3 Column “longitude”, degrees, longitude of the sample.
1.4 Column “date sampled”, date snow was collected.
1.5 Column “area”, cm2, area of snow sampled.
1.6 Column “snow mass”, kg, mass of snow sampled.
1.7 Column “dust mass”, g, mass of dust in filtered snow collected on 0.4 µm filter.
1.8 Column “mass accumulation rate”, g m-2 yr-1, mass accumulation rate of ASD.
2. tx02.xls Particle size distribution data for aeolian sand and dust laden snow in McMurdo
Sound.
2.1 Column “diameter”, µm, diameter size bin of aeolian sand and dust particles.
2.2 Column “volume”, percent, differential volume percent of that size bin for each sample.
3. tx03.xls Soluble and total iron geochemical data for snow samples from McMurdo Sound.
3.1 Column “sample name”, name of the sample.
3.2 Column “latitude”, degrees, latitude of the sample.
3.3 Column “longitude”, degrees, longitude of the sample.
3.4 Column “area of snow”, cm2, area of snow sampled.
3.5 Column “mass of dust”, mg, mass of dust in snow sampled.
3.6 Column “mass accumulation rate”, g m-2 yr-1, mass accumulation rate of ASD.
3.7 Column “mass of dust <10 µm”, mg, mass of dust <10 µm in snow sampled.
3.8 Column “mass accumulation rate <10 µm”, g m-2 yr-1, mass accumulation rate of ASD
particles <10 µm.
3.9 Column “dust <10 µm”, percent, percentage of ASD <10 µm.
3.10 Column “leaching solution” g, mass of MQ water used to leach Fe from ASD.
3.11 Column “concentration of soluble Fe leached”, ppb, concentration of soluble Fe leached
from ASD.
3.12 Column ““concentration of soluble Fe leached”, µmol L-1, concentration of soluble Fe
leached from ASD.
3.13 Column “concentration of particulate Fe”, ug g-1, concentration of particulate Fe from
ASD.
3.14 Column “total Fe fraction”, weight percent, fraction of total Fe in ASD.
3.15 Column “soluble Fe fraction”, percent, fraction of soluble Fe in ASD
3.16 Column “cumulative soluble Fe”, µmol L-1, concentration of cumulative soluble Fe from
all leaches.
3.17 Column ““cumulative soluble Fe”, percent, percentage of cumulative soluble Fe from all
leaches.
3.18 Column “Fe flux”, mg m-2 yr-1, flux of Fe in bulk ASD.
3.19 Column “Fe flux <10 µm”, mg m-2 yr-1, flux of Fe in the ASD fraction <10 µm.
3.20 Column “Fe flux”, µmol L-1, flux of Fe in bulk ASD.
3.21 Column “Fe flux <10 µm”, µmol L-1, flux of Fe in the ASD fraction <10 µm.
4. tx04.xls Constant parameters used in Fe supply calculations.
4.1 Column “parameter”, parameters used in Fe supply calculations.
4.2 Column “min”, minimum, minimum value used to “bracket” the likely range of
variability.
4.3 Column “max”, maximum, maximum value used to “bracket” the likely range of
variability
4.4 Column, “reference”, reference for the values in columns 4.1-4.3.
5. text.01.doc McMurdo Sound sea ice break out in 2009.
Text file describes the sequence of ice break out, disintegration and northward advection of
first year sea ice in 2009 Satellite images are shown in fs01.eps.
6. fs01.eps Satellite images illustrating the duration of Southern McMurdo Sound sea ice
sequence in 2009/2010. Source: http://lancemodis.eosdis.nasa.gov/imagery/subsets/?project=antarctica
7. fs02.eps Map of McMurdo Sound showing the particle size distribution along transect XY. a) Location of McMurdo Sound within the Ross Sea. EAIS: East Antarctic Ice Sheet. b)
Map of McMurdo Sound with sample locations and potential source areas of unconsolidated
sediment. Grey area: region defined as representative of McMurdo Sound. c) Particle size
distribution curves. Central grid particle size data sourced from Atkins and Dunbar [2009].