ABSTRACT:

Water level data from the greater Charleston Harbor Region was collected by NOAA from 1975 to 1992 and was previously unpublished. The unpublished data includes 18 sites on the Ashley River, Cooper River, Wando River, and at Fort Sumpter (Figure 1). The data units are meters and have hourly intervals in Eastern Standard Time. These data are not published and only available by request because have not gone through the rigorous modern NOAA quality control process. We compared the historical records to modern data (e.g., Dykstra et al., 2022; USGS), finding minimal errors. Datum information from NOAA (e.g., https://tidesandcurrents.noaa.gov/benchmarks/8664022.html) were also validated and are summarized below with NAVD88 corrections, where available (Table 1). Some additional quality control was completed for 8664531 (8664531_QC.csv), identifying poor data from the first few days and low water levels where the record was unusually flat (<-0.75m MLLW). These former data points were replaced with ‘NaN’ and the later were replaced using a spline interpolation. Further data details are shown in Table 1, including site locations and length of records. This effort supports the research of Dykstra et al. (in-prep).

ABSTRACT:

Water levels and temperatures were collected in the greater Charleston Harbor Region during a six-month field campaign in 2021 (Figure 1). Nine HOBO sensors were deployed at Fort Moultrie (site: H0), Elliot Cut (site: EC), and further inland along the upper Wando River (sites: W32, W38, W43, W49), the Ashley River (site: A58), and the Cooper River (site: C73 x2). Sensors recorded pressure and temperature at 15-minute intervals. They were fixed near the bed at elevations within 20cm of the lowest recorded water levels (except for H0, the sensor was approximately 2m above the bed). One HOBO sensor collected atmospheric pressure at site C73 to correct for barometric effects. Water levels were surveyed at each site with a RTK GPS to convert local observations to a common vertical datum, NAVD88. Data post-processing was completed in MatlabTM following the HOBO manufacture documentation: Using a Reference Water Level and Using a Barometric Datafile (Onset Computer Corporation, 2008). Our quality control revealed that very low water levels exposed the sensor at W43 to the air for <3 hours. These data points were replaced using a spline interpolation. This effort supports the research of Dykstra et al. (in-prep).