Time series measurements of dissolved nitrous oxide, nutrients, and chlorophyll at stations in the South Shetland Islands

• Main Authors: Farias, Laura, Alcaman Arias, María Estrella
• Format: Dataset
• Language: English
• Published: PANGAEA 2024
• Subjects: 0.45 µm filter; colorimetric determination; Seal Autoanalyzer; Chlorophyll a; Coastal area Antarctica; CTD; Sea-Bird; SBE 19 Plus V2; DATE/TIME; DEPTH; water; derived; Dissolved nitrous oxide; Event label; Gear; Headspace Gas Chromatography; ECD detectorT; LATITUDE; LONGITUDE; MON; Monitoring; Nitrate; Nitrite; Nitrous oxide; dissolved; Nitrous oxide saturation; nutrients; Oxygen; Phosphate; Pigments; Turner fluorometer; Salinity; Silicate; South Shetland Islands; SSI_P1; SSI_P3; Station label; Temperature; Antarctic; Antarctic Peninsula; Greenwich; Greenwich Island; Holm-Hansen; Antarc*; Antarctica
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.969584; https://doi.org/10.1594/PANGAEA.969584

The data set comprises concentrations of dissolved nitrous oxide (N2O), an important green house gas, d nutrients and chlorophyll-a from surface ocean. Seawater samples collected in a time series stations located in Greenwich Island within the South Shetland Islands, an area n of the western Antarctic Peninsula influenced by the circumpolar current system and adjacent to Bellinghausen. Two specific marine sampling points (Station P1: -62,489S; -59,683W and station P3: -62,461; -59,677 W) were monitored over four late summer periods (February and early March) in the years 2017, 2018, 2019, and 2020. Physical variables were measured with a Conductivity Temperature Depth profiler (CTD; SeaBird19 plus). Seawater samples for biological and biogeochemical variables were superficially collected at a depth of 2, 5 or 10 meters using a handheld pump or Niskin bottles (5 and 10 m depth) aboard a Zodiac boat for nitrous oxide, nutrient, and chlorophyll analysis. Simultaneously, a CTD instrument was deployed to obtain temperature (°C) and salinity profiles. For chlorophyll a (Chl-a) measurements, triplicate 1-L samples of seawater from both 2 and 30 m depth were prefiltered with a 150-µm net to exclude large organisms, and then the remaining biomass was collected by subsequent filtration with 0.7-µm GF/F glass fiber filters. Each filter was frozen until processing, using acetone extraction protocols, after which extracts were analyzed by fluorometric (measured with a 10-AU Turner fluorometer (Turner, USA). ([Holm-Hansen & Riemann, 1978] techniques, respectively. Samples for the determination of inorganic nutrients (nitrite (NO2−), nitrate (NO3−) and phosphate (PO43−)) were also taken in triplicate stored in 15 mL polyethylene tubes and frozen at −20 °C in the dark until analysis. NO2−, NO3− and PO4−3 concentrations were measured with a Seal AutoAnalyzer 3 (AA3, SEAL Analytical, Mequon, WI, USA) [Grashoff et al., 2009]. N2O samples were taken in triplicate in 20 mL vials and carefully sealed to avoid air bubbles. They ...