OVERVIEW

CZNet Cluster: Coastal

Contact: cznetcoastal@udel.edu

File description(s):

MilfordNeck_RX_220318-240709.csv - Redox potential (RX) at 6 depths below ground surface at each redox probe. Each column header is the name of a transect (site id) plus the variable (RX) plus the sensor depth (5, 15, 25, 35, 45, 120) in centimeters. Index column is the date and time of measurement (YYYY-MM-DD HH:MM:SS) in Eastern Standard Time. File name includes the date range (start date-end date as YYMMDD) of the dataset in Eastern Standard Time.

MN_RXsites.csv - Monitoring location names (site ids), depth intervals, location coordinates, and general description.

Keywords: Delaware; Milford Neck; Critical Zone; CZNet; CCZN; Soil; Redox Potential; Soil; Oxidation; Reduction; Biogeochemistry; Hydrology

TEMPORAL

Date start (YYYY-MM-DD): 2022-03-18

Date end (YYYY-MM-DD): 2024-07-09

SITE INFORMATION

Location: Milford Neck

Site description: Delaware Forested site

Installation date (YYYY-MM-DD): 2022-03-18

Site type: Soil

VARIABLE INFORMATION

Variable type: Chemistry

Variables: Redox Potential

Variables ODM2: reductionPotential

Variable abbreviations: Redox Potential - RX

No data value: NAN

Data flag: 999

Data flag meaning: Sensor malfunctioned at the time

TIME SERIES RESULTS INFORMATION

Units type: Redox Potential

Units name: millivolts

Units abbreviation: millivolts - mV

Status: Ongoing

Sample medium: Soil

Aggregation statistic: Continuous

UTC Offset Information: 5 hours (05:00:00)

METHOD INFORMATION

Method name: Redox Probe, SWAP Instruments ORP-120-B, Campbell Datalogger CR1000X

Method type: Instrument deployment

Method description: The redox probe was set to record continuously at 15-minute intervals on the CR1000X. Data were periodically downloaded from the Datalogger by stopping the Datalogger, downloading, replacing the battery, then restarting the deployment. There may be gaps in the data that occurred during this downloading period.

Method reference: Guimond, J. A., Seyfferth, A. L., Moffett, K. B., and Michael, H. A. (2020). A physical-biogeochemical mechanism for positive feedback between marsh crabs and carbon efflux. Environmental Research Letters, 15(3), 34024. https://doi.org/10.1088/1748-9326/ab60e2

Vepraskas, M. J., and J. L. Cox. (2002). "Redox potential measurements." NC State University, December 2002. https://files.knowyourh2o.com/pdfs/RedoxWriteup.pdf

Smit, Sander. (2022). Redox: redoxpotential probes. Paleo Terra. https://paleoterra.nl/index.html.

Processing information: Redox potential was processed by adding +200mV to the output from the datalogger.

Data validation and quality assurance: The probes cannot hold a calibration so the accuracy was checked with a calibration solution before deployment. The pre-installation check was performed using Hach Company +200mV ORP solution. The probes were submerged in this solution with a reference electrode to ensure that the sensors were reading potential correctly. The reference probe KCl solution is refilled when low and reference probes are checked during data downloads using an additional reference electrode connected to the datalogger as a sensor.