| Contributors | Affiliation | Role |
|---|---|---|
| Johnson, Zackary I. | Duke University | Principal Investigator, Contact |
| Hunt, Dana | Duke University | Co-Principal Investigator |
| Rauch, Shannon | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
Inorganic nutrients from the Pivers Island Coastal Observatory (PICO) from 2010 to 2012. Data include nitrate (NO3), nitrite (NO2), phosphate (PO4), and silicate (SiOH4) reported in micromolar units (uM).
Note: Nutrients were not all measured at all time points, thus, some dates have no data ('nd') in the 'NO3', 'NO2', 'PO4', and/or 'SiOH4' columns.
Water was filtered through a 0.22 um Sterivex cartridge filter, Millipore #SVGPL10RC using a peristaltic pump input line at 1 m for later nutrient analysis (NO3, NO2, PO4, SiOH4). Water was sampled in duplicate into HCl-cleaned HDPE bottles (VWR#414004-110) and stored at -80 degrees C until later analysis using an Astoria-Pacific A2 autoanalyzer, following the manufacturer’s recommended protocols by running each replicate sample in duplicate.
Certified reference materials were used to verify protocols (Inorganic Ventures: QCP-NT, QCP-NUT-1, CGSI1-1). The detection limits were: NO2 = 0.05 uM, NO3 = 0.1 uM, PO4 = 0.05 uM, SiOH4 = 0.2 uM. Values measured below these limits are reported as zero.
Samples that had a mean concentration (mean of replicated samples) below the nominal detection limit are reported as zero.
Quality Scores (qflag) as follows:
1 = excellent (no known issues),
2 = suspect,
3 = poor (known reason to suspect data).
BCO-DMO Processing Notes:
- Created 'replicate' column and re-arranged data so that replicates are in rows, not columns.
- Modified parameter names to conform with BCO-DMO naming conventions.
- Replaced blanks with 'nd' to indicate 'no data'.
- Separated date into month, day, and year columns.
| File |
|---|
inorg_nutrients.csv (Comma Separated Values (.csv), 98.18 KB) MD5:bacbaeca6c408a279f089e8f9f6be4b1 Primary data file for dataset ID 4033 |
| Parameter | Description | Units |
| deployment | Deployment name/id number. | text |
| lat | Latitude of sampling location. Positive = North. | decimal degrees |
| lon | Longitude of sampling location. Positive = East. | decimal degrees |
| year | Year (local time) of the sampling event. | YYYY |
| month_local | Month (local time) when the sampling event occurred. | mm (01 to 12) |
| PID_num | Unique, sequential "occupation" number for sampling. (The unique time/day when sampling occurred.) | dimensionless |
| day_local | Day of month (local time) when the sampling event occurred. | dd (01 to 31) |
| time_local | Time (local) when the sampling event occurred; 24-hour clock. | HHMM.mm |
| time_qflag | Quality score for time_local: | dimensionless |
| depth | Depth of water sampling. | meters |
| replicate | Replicate identifier. (All of the "A" nutrient samples are from the same bottle, however "A" replicates for nutrients are unrelated | text |
| NO2 | Nitrite concentration. | micromolar (uM) |
| NO2_qflag | Quality score for NO2: | dimensionless |
| NO3 | Nitrate concentration. | micromolar (uM) |
| NO3_qflag | Quality score for NO3: | dimensionless |
| PO4 | Phosphate concentration. | micromolar (uM) |
| PO4_qflag | Quality score for PO4: | dimensionless |
| SiOH4 | Silicate concentration. | micromolar (uM) |
| SiOH4_qflag | Quality score for SiOH4: | dimensionless |
| yrday | Consecutive day of year for a specified year, as a decimal. The fraction of the value represents the time within the day (e.g. a value of 1.5 means January 1 at 1200 hours). | dimensionless |
| ISO_DateTime_Local | Date-time (local) formatted to ISO 8601 standard. | YYYY-MM-DDTHH:MM:SS.ss |
| Dataset-specific Instrument Name | Nutrient Autoanalyzer |
| Generic Instrument Name | Nutrient Autoanalyzer |
| Dataset-specific Description | Nutrient concentrations were determined using an Astoria-Pacific A2 Autoanalyzer. |
| Generic Instrument Description | Nutrient Autoanalyzer is a generic term used when specific type, make and model were not specified. In general, a Nutrient Autoanalyzer is an automated flow-thru system for doing nutrient analysis (nitrate, ammonium, orthophosphate, and silicate) on seawater samples. |
| Website | |
| Platform | Duke University Marine Lab |
| Start Date | 2010-06-28 |
| End Date | 2012-06-26 |
| Description | The PICO time series is sampled weekly (or more frequently) to capture physical, chemical and biological variability in the coastal ocean. This time series enables the investigator to collaborate with a number of researchers and will serve as a long-term research focus.
Project information: http://oceanography.ml.duke.edu/johnson/research/pico/ |
From the project website:
Carbon dioxide is rising at ~3% per year in the atmosphere and oceans leading to increases in dissolved inorganic carbon and a reduction in pH. This trend is expected to continue for the foreseeable future and ocean pH is predicted to decrease substantially making the ocean more acidic, potentially affecting the marine ecosystem. However, coastal estuaries are highly dynamic systems that often experience dramatic changes in environmental variables over short periods of times. In this study, the investigators are measuring key variables of the marine carbon system along with other potential forcing variables and characteristics of the ecosystem that may be affected by these pH changes. The goal of this project is to determine the time-scales and magnitude of natural variability that will be superimposed on any long term trends in ocean chemistry.
Other PICO-related projects in BCO-DMO:
Ocean Acidification: microbes as sentinels of adaptive responses to multiple stressors: contrasting estuarine and open ocean environments
| Funding Source | Award |
|---|---|
| NSF Division of Ocean Sciences (NSF OCE) | |
| NSF Ocean Sciences Research Initiation Grants (NSF OCE-RIG) |