Delta-X: Total Suspended Solids Concentration across MRD, LA, USA, 2021

This dataset provides measurements of total suspended solids concentrations made on discrete water samples collected in surface waters (~0.5 m) on the southern coast of Louisiana, USA during the Delta-X 2021 Spring campaign. Samples were collected in the Atchafalaya River and Terrebonne Basins from 2021-03-25 to 2021-04-22. During the field campaign, samples were collected in multiple channels of varying width (from a few meters to >100m), near Delta-X intensive study sites, and in open bays and lakes and at locations in the nearshore Gulf of Mexico. For each in situ collection, the water sample volume was filtered, and the suspended particles retained on the filter were weighed after drying. The total suspended solids (TSS) concentration was calculated as the difference of the filter weight (before and after filtration) divided by the volume filtered, reported in units mg L-1.

This dataset includes one file in comma-separated values (*.csv) format. 

 

This dataset provides measurements of total suspended solids concentrations made on discrete water samples collected in surface waters (~0.5 m) on the southern coast of Louisiana, USA during the Delta-X 2021 Spring campaign. Samples were collected in the Atchafalaya River and Terrebonne Basins from 2021-03-25 to 2021-04-22. During the field campaign, samples were collected in multiple channels of varying width (from a few meters to >100m), near Delta-X intensive study sites, and in open bays and lakes and at locations in the nearshore Gulf of Mexico. For each in situ collection, the water sample volume was filtered, and the suspended particles retained on the filter were weighed after drying. The TSS concentration was calculated as the difference of the filter weight (before and after filtration) divided by the volume filtered, reported in units mg L-1.

Project: Delta-X

The Delta-X mission is a 5-year NASA Earth Venture Suborbital-3 mission to study the Mississippi River Delta in the United States, which is growing and sinking in different areas. River deltas and their wetlands are drowning as a result of sea level rise and reduced sediment inputs. The Delta-X mission will determine which parts will survive and continue to grow, and which parts will be lost. Delta-X begins with airborne and in situ data acquisition and carries through data analysis, model integration, and validation to predict the extent and spatial patterns of future deltaic land loss or gain.

Related Datasets:

Castaneda, E., A.I. Christensen, M. Simard, D.J. Jensen, R. Twilley, and R. Lane. 2020. Pre-Delta-X: Total Suspended Solids of Surface Water across MRD, LA, USA, 2015-2016. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1802

• Contains TSS measurements from the Pre-Delta-X Spring 2015 and Fall 2016 campaigns. See Table 1 for variables measured during the Pre-Delta-X campaigns.

Spatial Coverage: Atchafalaya and Terrebonne Basins, Mississippi River Delta (MRD) floodplain, southern coast of Louisiana, USA

Spatial Resolution: Points

Temporal Coverage: 2021-03-25 to 2021-04-22

Temporal Resolution: One-time measurements

Site Boundaries: Latitude and longitude are given in decimal degrees.

Site	Westernmost Longitude	Easternmost Longitude	Northernmost Latitude	Southernmost Latitude
Atchafalaya and Terrebonne Basins	-91.47	-90.57	29.75	28.79

Data File Information

This dataset contains one file in .csv format: DeltaX_TotalSuspSolids_Spring2021.csv. The file contains measurements of total suspended solids concentrations made on discrete water samples collected in surface waters (~0.5 m) on the southern coast of Louisiana. Three replicates of TSS measurements were made per sample, which provided a mean and standard deviation for each sample. Missing values are indicated by -9999

Table 1. Data dictionary for DeltaX_TotalSuspSolids_Spring2021.csv

Variable	Units	Description	Collected during Pre-Delta-X campaign?
basin		Atchafalaya or Terrebonne	Yes
site_id		Name of site. See Table 2, Section 5: Data Acquisition, Materials, and Methods for site_id naming convention.	Yes
campaign		e.g. Spring_2021	Yes
latitude	Decimal degrees	Latitude of sampling location	Yes
longitude	Decimal degrees	Longitude of sampling location	Yes
date	YYYY-MM-DD	Date of sampling and measurement	Yes
time	HH:MM:SS	UTC time of sampling	Yes
depth	meters	Depth of sampling	No
tss_concentration	mg L-1	Average total suspended solids (TSS) concentration	Yes
sd_tss_concentration	mg L-1	Standard deviation of TSS concentration measurements	No

During the Delta-X Campaigns, in situ water samples for laboratory-based measurements of total suspended solids (TSS) concentration were collected at a number of sites across the Atchafalaya and Terrebonne basins. These sampling sites spanned large and small channels at locations chosen to cover a representative range of suspended solids concentration from a variety of hydrodynamic and physical settings typically encountered across the Atchafalaya and Terrebonne basins. This dataset is used to calibrate and validate Delta-X’s algorithms used for the retrieval of total suspended solids concentration from AVIRIS-NG imagery and to inform and validate Delta-X’s sediment transport models. These TSS concentrations measurements represent discrete measurements and are paired with other measurements of in situ water-quality indicators, beam attenuation coefficient at 670 nm, average suspended particle size, suspended particle size distributions, and in situ and airborne water reflectance (all provided as separate datasets). These location- and time-specific measurements are compared to numerical models to calibrate and validate its parameters. The models quantify the mesoscale (i.e., on the order of 1 ha) patterns of soil accretion that control land loss and gain and predict the resilience of deltaic floodplains under projected relative sea-level rise. Understanding and mitigating the impact of the relative sea-level rise on coastal deltas is urgent. If ignored, relative sea-level rise will very soon have devastating consequences on the livelihood of the half-billion people that live in these low-lying coastal regions.

Three replicates of TSS measurements were made per sample, which provided a mean and standard deviation for each sample. The microbalance used to weigh the filters was calibrated before any new batch of measurement. Blanks were produced and measured for every ~20 samples by filtering 300 mL of Milli-Q water following the exact same procedure as for the samples. The blanks were strictly used to ensure that there were no bias in the measured weights due to potential balance drift between pre- and post-weighing filters.   

Study Sites

The Spring 2021 campaign collected TSS data at different locations across the Atchafalaya and Terrebonne Basins (Figure 2). Each sampling site was named using a combination of abbreviations provided in Table 1 as follows: BBB_MMDD_TN where BBB is the abbreviation for the basin (WLD or TB), MMDD is the month and day of 2021 (e.g., 0327 for March 27, 2021), T is the abbreviation for the station type (F for Full station, D for Dry station, and B for Basic station), and N is the sequential number of the station of each type sampled that day (B1 for first basic station, S1 for first full station, S2 for second full station, etc.).

Table 2: Site names.

Abbreviated Site name	Full Site name
WLD	Atchafalaya Basin (including Wax Lake Delta)
TB	Terrebonne Basin
S	Full station (Water samples for TSS was collected along with water reflectance, measurements from the Laser In-Situ Scattering and Transmissometer instrument (LISST), and water-quality indicators from ProDSS probe)
D	Dry stations (No Water samples for TSS was collected, but measurements of water reflectance, measurements from the LISST, and water-quality indicators from ProDSS probe were collected)
B	Basic station (only measurements of LISST, and water-quality indicators from ProDSS probe were collected)

Figure 2:  TSS sampling sites for the Spring 2021 Delta-X campaign.

Sampling Procedure

Each in situ water sample was collected directly from the boat by submerging a 4-L van Dorn sampler about 0.5 m beneath the surface. The volume sampled was then transferred in its entirety into a 4-L amber plastic bottle (HDPE) and kept in a cooler with ice until analysis in the lab within a few hours. The van Dorn sampler was rinsed multiple times with site water before collecting the sample. In the lab, three sub-samples (typically 150 to 300 mL for most samples, but up to 1000 mL in coastal ocean samples) from the 4-L sample were then filtered through three different pre-combusted and pre-weighed 47-mm-diameter, 0.7-µm glass-fiber filters (Whatman® GF/F). After filtration, the filters were kept frozen at -20^oC until return to the laboratory. The filters were dried at 75^oC for 24 hours and cooled in a desiccator before being weighed again. Filter preparation, filtration procedure and drying times followed the recommendations of Neukermans et al. (2012) and filters were weighed in the laboratory using a Sartorius Cubis MSE3.6P000DM Microbalance (readability of 1 µg). The microbalance used to weigh the filters was calibrated before any new batch of measurement. Blanks were produced and measured for every ~20 samples by filtering 300 mL of Milli-Q water following the exact same procedure as for the samples. The blanks were strictly used to ensure that there were no bias in the measured weights due to potential balance drift between pre and post-weighing filters.   

Neukermans, G., K. Ruddick, H. Loisel, & P. Roose. (2012). Optimization and quality control of suspended particulate matter concentration measurement using turbidity measurements. Limnology and Oceanography Methods, 10, pp. 1011–1023. https://doi.org/10.4319/lom.2012.10.1011.