outline recent field observations of cohesive and mixed sediment particle properties in estuarine...

OutlineRecent Field Observations of Cohesive and Mixed SedimentParticle Properties in Estuarine and Coastal Environments

Carl Friedrichs, Virginia Institute of Marine Science

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100 mg/l Time-series of suspended sediment concentration in York River estuary, Virginia

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Outline

Review of Specific Set of New Articles:

• “Recent” = Publication date 2011, 2012 or 2013 (~since last INTERCOH).• “Field Observations” = Not controlled lab experiments or theory alone.• “Cohesive & Mixed Sediment Particle Properties” = Mostly flocculating

sediment, but also can be mixed with sand, pellets, etc. (but not fluid mud).• “Estuarine & Coastal” = Mainly estuaries, but a few coastal examples.• Also must contain interesting figures.

Recent Field Observations of Cohesive and Mixed SedimentParticle Properties in Estuarine and Coastal Environments


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Outline

Review of Specific Set of New Articles:

• “Recent” = Publication date 2011, 2012 or 2013 (~since last INTERCOH).• “Field Observations” = Not controlled lab experiments or theory alone.• “Cohesive & Mixed Sediment Particle Properties” = Mostly flocculating

sediment, but also can be mixed with sand, pellets, etc. (but not fluid mud).• “Estuarine & Coastal” = Mainly estuaries, but a few coastal examples.• Also must contain interesting figures.



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Apologies to lab and theory focused work!Apologies to great publications from 2010 and earlier!Apologies for my innate biases!

Classic texts

[Mehta 2013] [Winterwerp, van Kesteren 2004]

“Stand on the Shoulders of Giants” – Isaac Newton

Classic texts[Mehta, McAnally 2008] [Winterwerp 2004]

Google Scholar“Stand on the Shoulders of Giants” – Also the official motto of Google Scholar (Seriously!)

Bainbridge, Wolanski, Álvarez-Romero, Lewis, Brodie (2012). Fine sediment and nutrient dynamics related to particle size and floc formation in a Burdekin River flood plume, Australia. Marine Pollution Bulletin. http://dx.doi.org/10.1016/j.marpolbul.2012.01.043

Braithwaite, Bowers, Nimmo Smith, Graham (2012). Controls on floc growth in an energetic tidal channel. Journal of Geophysical Research. http://dx.doi.org/10.1029/2011JC007094

Cartwright, Friedrichs, Sanford (2011). In situ characterization of estuarine suspended sediment in the presence of muddy flocs and pellets. In: P. Wang, J.D. Rosati, and T.M. Roberts (eds.), Coastal Sediments 2011, http://www.vims.edu/~cfried/cv/2011/Cartwright_etal_2011_Coastal_Seds.pdf

Fall, Friedrichs, Cartwright (2013). Relationships among fine sediment settling and suspension, bed erodibility, and particle type in the York River estuary Virginia. In prep from M.S. Thesis, Virginia Institute of Marine Science. http://www.vims.edu/~cfried/cv/2012/Fall_2012_MS_Thesis.pdf

Fettweis, Baeye, Lee, Chen, Jason (2012). Hydro-meteorological influences and multimodal suspended particle size distributions in the Belgian nearshore area (southern North Sea). Geo-Marine Letters. http://dx.doi.org/10.1007/s00367-011-0266-7

Hill, Newgard, Law, Milligan (2013). Flocculation on a muddy intertidal flat in Willapa Bay, Washington, Part II: Observations of suspended particle size in a secondary channel and adjacent flat. Continental Shelf Research. http://dx.doi.org/10.1016/j.csr.2012.06.006

Lee, Fettweis, Toorman, Molz (2012). Multimodality of a particle size distribution of cohesive suspended particulate matters in a coastal zone. Journal of Geophysical Research. http://dx.doi.org/10.1029/2011JC007552

Lefebvre, Ouillon, Vinh, Arfi, Panché, Mari, Thuoc, Torréton (2012). Seasonal variability of cohesive sediment aggregation in the Bach Dang–Cam Estuary, Haiphong (Vietnam). Geo-Marine Letters. http://dx.doi.org/10.1007/s00367-011-0273-8

Malpezzi, Sanford, Crump (2013). Abundance and distribution of transparent exopolymer particles in the estuarine turbidity maximum of Chesapeake Bay. Marine Ecology Progress Series. http://dx.doi.org/10.3354/meps10362

Manning, Baugh, Soulsby, Spearman, Whitehouse (2011). Cohesive Sediment Flocculation and the Application to Settling Flux Modelling. In: (Ginsberg, S. S., ed.) Sediment Transport. http://cdn.intechweb.org/pdfs/15517.pdf

Manning, Schoellhamer (2013). Factors controlling floc settling velocity along a longitudinal estuarine transect. Marine Geology. http://dx.doi.org/10.1016/j.margeo.2013.06.018

Papenmeier, Schrottke, Bartholomä (2013). Over time and space changing characteristics of estuarine suspended particles in the German Weser and Elbe estuaries. Journal of Sea Research. http://dx.doi.org/10.1016/j.seares.2013.03.010

Safak, Allison, Sheremet (2012). Floc variability under changing turbulent stresses and sediment availability on a wave energetic muddy shelf. Continental Shelf Research. http://dx.doi.org/10.1016/j.csr.2012.11.015

Schindler, Bass, Manning (2013). Effects of non-cohesive particles on suspended particle characteristics in a partially flocculated estuary during spring tides. Journal of Coastal Research. http://ics2013.org/papers/Paper3997_rev.pdf

Smith, Friedrichs (2011). Size and settling velocities of cohesive flocs and suspended sediment aggregates in a trailing suction hopper dredge plume. http://dx.doi.org/10.1016/j.csr.2010.04.002

Soulsby, Manning, Spearman, Whitehouse (2013). Settling velocity and mass settling flux of flocculated estuarine sediments. Marine Geology. http://dx.doi.org/10.1016/j.margeo.2013.04.006

van Leussen (2011). Macroflocs, fine-grained sediment transports, and their longitudinal variations in the Ems Estuary. Ocean Dynamics.http://dx.doi.org/10.1007/s10236-011-0384-9

Outline

Outline of Presentation:

• 1) Subpopulations in flocculated sediment suspensions• 2) Response of floc subpopulations to strong shear• 3) Floc resuspension and settling at low shear• 4) Spatial variability in floc properties• 5) Mixtures of flocs and other particle populations



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Outline





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EFFECTS OF BIOLOGY

Outline





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1) SUBPOPULATIONS Fettweis et al., Lee et al. 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

Average SPM (mg/L)

Tripod “Bla” at 6-mdepth, 1 km offshore

[Fettweis, Baeye, Lee, Chen, Yu 2012]

[Lee, Fettweis, Toorman, Molz 2012]

Vol.

Conc

. (m

L/m

m)

-- Tripod deployed Jan-Feb & April 2008.-- ADV 0.2 mab, LISST 2 mab, OBS 0.2 & 2 mab.-- CTD, ADP-- Curve-fitted multi-modal particle size distribution applied to LISST data.-- Primary particles, flocculi, microflocs, macroflocs.

1) SUBPOPULATIONS Lee et al.


Vol.

Conc

. (m

L/m

m)

Vol.

Conc

. (m

L/m

m)

Vol.

Conc

. (m

L/m

m)

Vol.

Conc

. (m

L/m

m)

1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

-- There is not a single peak in the PSD. -- Different components have distinct fractal dimensions.-- Sediment mass moves from one distinct subpopulation to another. -- Single peak model inadequate for this case.

1) SUSPOPULATIONS Lefebvre et al. 2012

[Lefebvre et al. 2012]

Example LISST data from profile in 7-m deep tidal estuary channel


-- Cruises in July 2008 and March 2009.-- Ship-based ADCP, LISST & CTD profiling.-- Four subpopulations seen here like off Belgium.-- Turbulence estimated from ADCP shear along with salinity stratification.-- Turbulence changed relative importance of subpopulations, but did not strongly shift the modal position of each subpopulation.

1) SUBPOPULATIONS Soulsby Manning 2013

[Soulsby, Manning, Spearman, Whitehouse 2013]


Compilation of INSEV floc settling camera data from Tamar, Gironde and Dollard

Example Tamar INSEV data

[Manning et al. 2011]

-- Compiled from several past field campaigns which utilized the INSSEV video settling camera system.-- There were often separate clusterings of flocs in the micro- and macrofloc ranges.-- Compilations of previously collected data from several estuaries show distinctly different response to shear stress, different excess density patterns, and inconsistency in fractal dimension for micro- versus macroflocs.

Outline





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2) HIGH SHEAR Panenmeier 2013 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Papenmeier, Schrottke, Bartholoma 2013]

November

August

-- Cruises along Elbe River estuary in August and November 2011.-- LISST profiles and water samples.-- ADCP for tidal velocity.-- Suspended sediment samples also disaggregated and sized.-- Little relationship found between changes in disaggregated components and changes in floc modes.-- In late fall, higher tidal velocities rapidly broke macroflocs down to microflocs.-- In summer, higher tidal velocities changed the size of macroflocs but did not break macroflocs into microflocs.-- Biology influences strength of macroflocs.-- Microflocs are strong and do not breakdown in fall or summer.

2) HIGH SHEAR Lee 2012 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations


6-m depth off Belgium.

-- Seasonal trends also seen off of Belgium – biology is important.-- In winter, moderately high stress readily breaks down macroflocs – all the way to flocculi and also down to primary particles to some degree.-- In late spring, flocs are stronger. Macroflocs are not completely destroyed by stress, and microflocs are not broken into flocculi.

2) HIGH Shear Safak 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Safak, Allison, Shemeret 2013]

Swell

Sea

-- Tripod at 4 m depth, LISST, PC-ADP-- Macroflocs broken up under strong waves.-- Otherwise little relation between stress and floc size.-- Macroflocs broken into microflocs, mode of macroflocs did not dramatically change.-- Mean floc size is approximation of micro vs. macrofloc abundance.

Outline





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3) SUSPENSION Manning_Schoellhamer 2013 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Manning, Schoellhamer 2013]

-- Ship-based sampling on 17 June 2008.-- INSSEV-FL version of setting velocity camera.-- Cruise from -2 hr LW through +2 hr HW-- The best single predictor of settling velocity was water velocity 39 min prior to sampling, not sediment concentration or salinity.-- Resuspension and settling lag largely influence Ws.

Stn 36

3) SUSPENSION Hill 2013 – floc suspension without breakup 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Hill, Newgard, Law, Milligan 2013]

Pea

k V

eloc

ity

-- 2 weeks, Feb/Mar 2010.-- LISST, 0.5 mab.-- Digital Floc Camera.-- ADP/ADCP.-- Channel 2-m deep at LW.-- Macroflocs survived resuspension.

3) SUSPENSION Fall 2012 – low stress 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Fall, Friedrichs, Cartwright 2013]

(a)

(b)

(c)

(d)

(e)

(f)

-- ADV at 0.4 mab in 6-m, May – Aug 2007.-- Backscatter calibrated by pump samples.-- 40 strongest tides in June (vs. July) phase averaged for Regime 1 (vs. Regime 2).-- Regime 1 separated into “washload” and (micro) “flocs”.-- (Micro) flocs resuspended without change in Ws.

3) TEP Malpezzi Sanford 2013 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Malpezzi, Sanford, Crump 2013]

Chl-a(volt)

Stn #

1-3

4-9

10-11

Fresh

ETM

Salt

ETM

ETM

ETM

TransparentExopolymer

Particle (TEP)concentration

-- 8 cruises in 2007 to 2008 in ETM region.-- CTD, water samples, lab analysis for TEP. Owen tube for Ws.-- In relatively low turbulence systems, (e.g., Chesapeake Bay), TEP is more important than shear in driving flocculation and settling.

Fraction of TSS withWs > 0.06 mm/s



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4) SPATIAL Bainbridge 2012 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Bainbridge, Wolanski, Alvarez-Romero, Lewis, Brodie 2012]

-- Transects along river plume, 12/2010 & 01/2011.-- Near surface samples shown below for 18 January 2011.-- Particle properties function of distance/time, but not turbulence (for this cruise).-- Dominant floc size increases strongly offshore.-- Organic fraction increases offshore.-- Settling velocity decreases offshore.

100 microns

4) SPATIAL Manning_Schoellhamer 2013 – location, velocity, NOT fractal dimension



-- Strong spatial variation in fractal dimension for both microflocs and macroflocs.-- Ws macrofloc / Ws microfloc also changes spatially.-- Wide variability in physical, biological and chemical processes which contribute to flocculation within SFB.-- Spatial floc data is required in order to accurately represent the diverse floc dynamics present in the Bay system.

Stn 36

4) SPATIAL Van Leussen 2011 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[van Leussen 2011]

A

10 mm

B

100mm

-- Water samples collected by boats following tide of entire tidal cycles in 1990s(?).-- Suspended sediment collected 2.8-m surface at maximum tidal flow, each homogenized, concentrated to 1 g/L, and placed in a settling column. Strong spatial variation was seen in resulting mean Ws.-- Ws was found to vary spatially in a manner similar to electrophoretic mobility measured by Malvern Zeta-sizer II.-- Electrophoretic mobility (related to zeta-potential) is governed by organic coatings along with cations in water.

C

100 mm

D

100mm

4) SPATIAL Braithwaite 2012 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Braithwaite, Bowers, Nimmo Smith, Graham 2012]

10 km

-- 20-m of water, upward-looking 1200 KHz, ADCP, LISST on frame 0.5 mab, two weeks in September 2008.-- ADCP used to calculated turbulence via “structure function method”-- With no time lags, a poor correlation was seen between median particle size and the size of the smallest turbulent eddies.-- Once horizontal advection of a longitudinal gradient of 8 micron/km was accounted for, median particle size agreed well with reasonable parameters applied to the Winterwerp (1998) floc model.-- Message: Winterwerp model works here, but don’t forget advection!

Winterwerp model + advection term

Observations



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• 1) Subpopulations in flocculated sediment suspensions• 2) Response of floc subpopulations to strong shear• 3) Floc resuspension and settling at low shear• 4) Spatial variability in flocculated sediment properties• 5) Mixtures of flocs and other particle populations

5) MIXED Smith 2011

[Smith, Friedrichs 2011]1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

-- Vessel-based spatial survey of dredge plume in ~ 14 m.-- Profiler sampled throughout water column for 2 hours, 10 June 2006.

-- Ws, size distribution, density via PICS video settling camera sampling in situ.-- PIV/PTV corrects for PICS motion, ~2000 particles sized by software in 30 sec., new sample every 2 min.-- Profiler also includes LISST, ADV, CTD, pump intake.-- Flocs, bed aggregates, primary grains defined by density.-- Science message: A full spectrum of densities can be present at any one diameter in mixed cohesive cases.-- 30 micron primary grains may settle faster than 300 micron macro flocs.

5) MIXED Schindler 2013 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Schindler, Bass, Manning 2013]

-- At high stress (4), microflocs strongly influenced by sand suspension.-- At lower stress (8), larger particles strongly influenced by muddy macroflocs.

-- Settling velocity of denser microflocs can be greater than that of less dense macroflocs.

-- ADV frame, moored vessel sampled at 0.5 mab in ~ 4 m, samples passed through LabSFLOC settling video camera, 10 June 2009.

5) MIXED Cartwright 2011

[Cartwright, Friedrichs, Sanford 2011]

63 mm – 125 mm sieve, York River 1/2013

[microscopy images Schaffner Lab, VIMS]

Ws = <w’C’>/<C>

LISS

T pa

rticl

e si

ze(lo

g10

mic

rons

)LI

SST

ADV-

base

d-- LISST and ADV on benthic tripod, ~ 40 cmab at 6-m depth.-- Particles dominated by flocs at times of low velocity.-- At higher velocities flocs break up, but then bulk Ws is dominated by resuspension of resilient fecal pellets.


5) MIXED Wang 2013 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Wang, Voulgaris, Li, Yang, Gao, Chen, Gao 2013]

Flocs at low velocity shear.

Influence of suspended fine sand on bulk particle properties at high velocity shear.

LISST-based D50 vs. ADV-based turbulent shear

ADCP, 3 ADVs on tripod (.2,.6,1 mab), LISST on profiler, 2 weeks in spring 2010.

ADV-based WS vs. ADV-based turbulent shear

5) MIXED Fall 2012 – pellets 1) Floc subpopulations2) High shear break-up3) Low shear resuspen.4) Spatial variability5) Mixed populations

[Fall, Friedrichs, Cartwright 2013]

(a)

(b)

(c)

(d)

(e)

(f)

WsDEP = fFWsFLOCS + fFWsPELLETS

= ~ 1.5 mm/s at peak tb

Assume: fF = 5/8, fP = 3/8

This gives:

WsPELLETS = ~ 2 mm/s

-- Pellets present during Regime 2.-- Ws separated into flocs + pellets.

Outline

Conclusions:




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Outline

Conclusions:




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[Papenmeier, Schrottke, Bartholoma 2013]

Outline





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[Hill, Newgard, Law, Milligan 2013] Time (hours)



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• 1) Subpopulations in flocculated sediment suspensions• 2) Response of floc subpopulations to strong shear• 3) Floc resuspension and settling at low shear• 4) Spatial variability in flocculated sediment properties• 5) Mixtures of flocs and other particle populations

63 mm – 125 mm sieve, York River 1/2013Ws = <w’C’>/<C>

LISS

TAD

V-ba

sed

[Cartwright, Friedrichs, Sanford 2011]

Outline

Conclusions:




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THANKS! -- QUESTIONS?EFFECTS OF BIOLOGY

outline recent field observations of cohesive and mixed sediment particle properties in estuarine...

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