Auxiliary Material for paper 2008jc004902 Chalk-ex—Fate of CaCO3 particles in the mixed layer: Evolution of patch optical properties W. M. Balch Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, Maine, USA A. J. Plueddeman Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA B. C. Bowler and D. T. Drapeau Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, Maine, USA Balch, W. M., A. J. Plueddeman, B. C. Bowler, and D. T. Drapeau (2009), Chalk-ex—Fate of CaCO3 particles in the mixed layer: Evolution of patch optical properties, J. Geophys. Res., 114, C07020, doi:10.1029/2008JC004902. Introduction This section contains figures of supplemental material that support the results given in the aforementioned paper. All methods used to collect and process the data presented in these figures are identical to those provided in the main paper. Fig. S1 provides a microscopic image of the chalk particles as well as their size distribution. Fig. S2 provides the cruise track for patch S’01, Scanfish survey 3. It shows individual legs of the survey plus vertical sections of backscattering through the feature. Fig. S3 provides the backscattering probability histograms during the north ’01 chalk patch experiment. Results are provided from four layers, 1) 1-5m, 2) 5-13m, 3) 13-20m and 4) 20m-30m as measured by the Scanfish. Fig. S4 provides the backscattering probability histograms for four surveys during the South ’03 chalk patch experiment. Aerial positions of S’03 patch are given in Fig. S5; each set of four panels shows bbp and density in the same four depth layers shown in Fig. S3. Fig. S6 shows the cruise track for patch S’03, scanfish survey 2, with vertical sections of backscattering for the survey legs. The cruise track for patch S’03, Scanfish survey 4, is shown in Fig. S7, again providing vertical sections of backscattering for individual survey legs. Backscattering probability histograms for four surveys during the North ’03 chalk patch experiment are given in Fig. S8. Fig. S9 demonstrates the aerial positions of the N’03 patch along with sections of backscattering. The cruise track for patch N’03, Scanfish survey 2, is shown in Fig. S10, along with individual legs of the survey and vertical sections of backscattering. Fig. S11 shows the cruise track for patch N’03, Scanfish survey 3, started ~24h after patch deployment. 1. 2008jc004902-fs01.jpg A) Transmission electron micrograph of Snow-Cal-90 chalk particles. One micrometer scale bar shown for reference. B) Size distribution of chalk particles used in Chalk-Ex, given as the percent by weight smaller than a given particle diameter (in micrometers). 2. 2008jc004902-fs02.jpg A) Cruise track for Scanfish survey 3, patch S’01 showing individual legs of survey. Panels B-H show vertical sections of bbp (530nm) minus pre-patch blank values for appropriate layers 1-4 (discussed in text). Leg numbers are shown on upper right of each panel. B) Leg 320-2248. C) Leg 320-2318, cross-over points and times: “d” 2343h. D) Leg 320-2352, cross-over points and times: “c” 0000h. E) Leg 321-0027, cross-over points and times: “b” 0046h. F) Leg 321-0058, cross-over points and times: “a” 0114h. G) Leg 321-0151, cross-over points and times: “a” 0152h, “b” 0156h, “c” 0159h, “d” 0203h, “e” 0204h, H) Leg 321-0232, cross-over points and times: “e” 0243h. All data presented as in Fig. 7. No chalk was evident in sections 6 (321-0135) and 8 (321-0224), thus the sections are not shown. All times EST. 3. 2008jc004902-fs03.jpg Backscattering probability histograms for four surveys during the north ’01 chalk patch experiment, showing the percent of total observations (Y axis; log scale) versus particulate backscattering (X axis; log scale). Results are shown from survey #3 (solid line) and the pre-chalk survey (dashed line) for comparison. Patch center of survey was estimated from vertical sock drifters set within the patch upon completion of patch. All locations subsequently Lagrangian-corrected to account for patch drift. Panels summarize the results of four vertical layers A) 1-5m, B) 5-13m, C) 13-20m and D) 20m-30m. Vertical solid line marks the median value for the pre-chalk survey. Vertical dashed line marks two standard deviations above the median. One can see that the pre-chalk survey had a distinct bimodal distribution, evidence of heterogeneities (patchiness) in the survey area not related to chalk. The upper mode was not apparent in post-chalk survey 3, and the single mode was identical to the lower mode of the pre-chalk survey, evidence that no chalk was detectable. 4. 2008jc004902-fs04.jpg Backscattering probability histograms for four surveys during the South ’03 chalk patch experiment. Each set of four histograms shows the results from four vertical layers in the patch: 1-5m, 5-13m, 13-20m and 20m-30m. A1-4) Survey 1 (3-5h after chalk deployment), B1-4) Survey 2 (10-14h after chalk deployment), C1-4) Survey 3 (24h after chalk deployment) and D1-4) Survey 4 (31h after chalk deployment). As in Fig. 3, the solid curves in each panel represent the data distribution for the survey and the dashed curve shows the pre-chalk survey for reference. Patch center of each survey estimated from vertical sock drifters set within the patch at time of patch generation. All data subsequently Lagrangian corrected to account for patch drift. Vertical solid line in each panel marks the median bbp value for the pre-chalk survey. Vertical dashed line marks two standard deviations above the median bbp value. 5. 2008jc004902-fs05.jpg Aerial positions of S’03 patch. Each set of four panels shows bbp (color-coded; m-1) and density (sigma-theta isopleths at 0.1 resolution) in four layers, 1) 1-5m, 2) 5-13m, 3) 13-20m and 4) 20m-30m as measured by an undulating Scanfish. Only backscattering values greater than 2 standard deviations above median pre-patch bbp value are shown in color. Reference “cross” at center of each four-panel survey series is a 1 kilometer reference bar for longitude and latitude coordinates, respectively. Positions of sample points within each layer are shown as black dots. A) Survey 1 (3-5 hours after last chalk was deployed), B) Survey 2 (10-14 hours after last chalk was deployed). C) Survey 3 (~24 hours after last chalk was deployed), and D) Survey 4 (~31 hours after last chalk was deployed). Arrows designate small areas of significant PIC backscattering. Center of survey area was a vertical sock drifter. All data were Lagrangian corrected according to this drifter in order to correct for patch drift. Grey lines indicate isopleths of density in increments of 0.1 sigma theta units. 6. 2008jc004902-fs06.jpg A) Cruise track for Scanfish survey 2, patch S’03 showing individual legs of survey (listed in inset). Panels B-G show vertical sections of bbp (530nm) minus pre-patch blank values for appropriate layers 1-4 (discussed in text). Leg numbers shown in top right of each panel. B) Leg 168-2332, cross-over points and times: “a” 0002h, “b” 0007h; C) Leg 169-0029; D) Leg 169-0055, cross-over points and times: “b” 0121h and “c” 0125h; E) Leg 169- 0146; F) Leg 169-0207, cross-over points and times: “c” 0230h and “a” 0235h; G) Leg 169-0300. All data presented as in Fig. 7. Arrows indicate regions of significant particulate backscattering. All times EDT. 7. 2008jc004902-fs07.jpg A) Cruise track for Scanfish survey 4, patch S’03 showing individual legs of survey. Panels B-G show vertical sections of bbp (530nm) minus pre-patch blank values for appropriate layers 1-4 (discussed in text). B) Leg 169-2051; C) Leg 169-2139; D) Leg 169-2219; E) Leg 169-2340; F) Leg 170-0023; G) Leg 170-0107. Arrow in panel G indicates subsurface patch of elevated bbp. All data presented as in Fig. 7. No chalk was evident in leg 4 (169-2255) thus the section is not shown. All times EDT. 8. 2008jc004902-fs08.jpg Backscattering probability histograms for four surveys during the North ’03 chalk patch experiment. Each set of four histograms shows the results from four vertical layers in the patch: 1-5m, 5-13m, 13-20m and 20-30m. A1-4) Survey 1 (4-7h after chalk deployment), B1-4) Survey 2 (12-14h after chalk deployment), C1-4) Survey 3 (24-28h after chalk deployment) and D1-4) Survey 4 (30-34h after chalk deployment). As in Figs. S3 and S4, the solid curves in each panel represent the data distribution for the survey and the dashed curve shows the pre-chalk survey for reference. Patch center of each survey estimated from vertical sock drifters set within the patch at time of patch generation. All data subsequently Lagrangian corrected to account for patch drift. Vertical solid line in each panel marks the median bbp value for the pre-chalk survey. Vertical dashed line marks two standard deviations above the median bbp value. 9. 2008jc004902-fs09.jpg Aerial positions of N’03 patch. Each set of four panels shows bbp (color-coded; m-1) in four layers, 1) 1-5m, 2) 5-13m, 3) 13-20m and 4) 20m-30m as measured by Scanfish. Only backscattering values greater than 2 standard deviations above median pre-patch bbp value are shown in color. Reference “cross” at center of each four-panel survey series is a 1 kilometer reference bar for longitude and latitude coordinates, respectively. Positions of sample points within each layer are shown as black dots. A) Survey 1 (4-7 hours after last chalk was deployed), B) Survey 2 (12-14 hours after last chalk was deployed), C) Survey 3 (24-28 hours after last chalk was deployed), and D) Survey 4 (30-34 hours after last chalk was deployed). Arrows highlight regions of particulate backscattering significantly above median background, pre-patch survey values. Center of survey area was a vertical sock drifter. All data were Lagrangian corrected according to this drifter in order to correct for patch drift. Grey lines indicate isopleths of density in increments of 0.1 sigma theta units. 10. 2008jc004902-fs10.jpg A) Cruise track for Scanfish survey 2, patch N’03 showing individual legs of survey (listed in inset). Panels B-G show vertical sections of bbp (530nm) minus pre-patch blank values for appropriate layers 1-4 (discussed in text). Leg numbers shown on upper right or left corner of each panel. B) Leg 165-0131, cross-over points and times: “a” 0140h, “b” 0141h; C) Leg 165-0155, cross-over points and times: “c” 0205h; D) Leg 165-0210, cross-over points and times: “c” 0212h, “d” 0221h and “a” 0222h; E) Leg 165-0233; F) Leg 165-0244. All data presented as in Fig. 7.Arrows indicate regions of significant particulate backscattering. No chalk was evident in legs 6 (165-0304)and 7(165-0330), thus these sections are not shown. All times are EDT. 11. 2008jc004902-fs11.jpg A) Cruise track for Scanfish survey 3, patch N’03, started ~24h after patch deployment, showing individual legs of survey (listed in inset). Panels B-F show vertical sections of bbp (530nm) minus pre-patch blank values for appropriate layers 1-4 (discussed in text). Leg numbers shown in upper left corner of each panel. B) Leg 165-1316, cross-over points and times: “a” 1353h, “b” 1359h; C) Leg 165-1426; D) Leg 165-1458, cross-over points and times: “c” 1518h and “a” 1522h; E) Leg 165-1544; F) Leg 165-1619, cross-over points and times: “b” 1655h and “c” 1701h. All data presented as in Fig. 7. Arrows indicate regions of significant particulate backscattering. All times are EDT.