Auxiliary Material for Paper 2011GL050366

Mechanism for export of sediment-derived iron in an upwelling regime 

S. A. Siedlecki 
Department of Geophysical Sciences, University of Chicago, 
Chicago, Illinois, USA

A. Mahadevan 
Woods Hole Oceanographic Institution, 
Woods Hole, Massachusetts, USA

D. E. Archer 
Department of Geophysical Sciences, University of Chicago, 
Chicago, Illinois, USA


Siedlecki, S. A., A. Mahadevan, and D. E. Archer (2012), Mechanism for export of 
sediment-derived iron in an upwelling regime, Geophys. Res. Lett., 39, L03601, 
doi:10.1029/2011GL050366. 

Introduction

This auxiliary material provides auxiliary methods and discussion to the paper 
including further detail into the sensitivity studies performed on the model 
parameters and two additional figures and one table.

1. 2011gl050366-txts01.doc  
Text S1. Auxiliary methods and discussion.

2. 2011gl050366-fs01.pdf 
Figure S1. Density initialization for the model taken from data collected off 
the coast of Newport, Oregon in August, 2009 using a CTD cast.

3. 2011gl050366-fs02.pdf  
Figure S2. The effect of eddies on the iron concentration on the shelf is shown 
by comparing panels (a) and (b). (a) Cross section of the time-averaged 
sedimentary iron concentration for downwelling periods from the oscillating wind 
scenario with a 10 day period from the simulation with too small of a domain to 
generate eddies. Colors are on a log scale. (b) same as (a), but from the 
simulation with a domain large enough (in the alongshore direction) to generate 
frontal instabilities and eddies.  Density contours are plotted in black with a 
contour interval of 0.2 kg/m^3 and the 1027 kg/m^3 isopycnal plotted in bold.

4. 2011gl050366-ts01.doc  
Table S1. Efficiency of exported sediment-derived iron for different model runs.  
The base case described in the main paper is underlined - 10 day period, no mean 
wind, with a source of 8.1 mol m^-1 yr^-1, 192 km domain, a pressure gradient of 
0.0004 N/m^3, scavenging rate of 0.00001 s^-1, and an uptake rate of 5 days. The 
period was changed in the oscillating wind scenario, while the magnitude 
remained the same. In the mean upwelling and downwelling cases, a mean wind was 
added to the 10-day period oscillating wind scenario.  Several different 
pressure gradients (pg), scavenging rates (scav. rate), and uptake rates were 
tried.     
T1.1 Column "Forcing" details which model parameter was changed in the 
sensitivity study
T1.2 Column "Export Efficiency" refers to the Efficiency of exported sediment-
derived iron outlined in the text and has no units.