Water temperature and salinity profiles from the Ocean Observatories Initiative Global Irminger Sea Array Apex profiler mooring from September 2014 to May 2020 (NCEI Accession 0285241)

This dataset is comprised of processed and edited temperature and salinity profiles from the OOI (Ocean Observatories Initiative) Global Irminger Sea Array Apex profiler mooring from September 2014 to May 2020 (https://oceanobservatories.org/array/global-irminger-sea-array/). The original dataset (including physical units) is available at https://ooinet.oceanobservatories.org/data_access/?search=GI02HYPM-WFP02-00-WFPENG000.

Methods: Vertical profile data were gridded using 5 m depth intervals taking the mean of upward and downward profiles. Salinity spikes were removed using a threshold of 0.01 over 5 m. Any salinity bins fresher than 34.72 were then removed. Salinity biases were corrected by referencing to a potential temperature of 2.5C, which was the deepest, most consistently sampled potential temperature of the dataset (Toole et al. 2017). The reference salinity at the reference isotherm was chosen to be 34.93 based on calibrated shipboard CTD measurements taken near the mooring on the OOI mooring service cruises from 2014 to 2019 (dataset references below). Salinity was calibrated by first subtracting the reference salinity from the raw value at the reference isotherm and then finding the ratio between this difference and the reference salinity. This gain correction was then multiplied by the full profile to produce the final salinity. The salinity is anchored to the reference salinity at the deep reference isotherm and this dataset should be used knowing that this is not necessarily realistic in this area of deep water mass formation. Caution should be used looking at properties near the reference isotherm. However, the salinity biases in the raw data are significant and without correction this time series is discontinuous whenever the mooring is replaced. The patterns in the upper part of the water column agree with nearby measurements (de Jong et al., 2023).

Final Data: All data are included in a single NetCDF file, ‘OOI_Irm_HYPM_cal_21Mar2021_NCEIannotated_15Nov2023.nc’. The included fields are: time [days since 2000-01-01], depth [meters], practical salinity ‘sal’ [psu], in-situ temperature ‘temp’ [C], latitude [degrees north], and longitude [degrees east]. The Gibbs Seawater oceanographic toolbox (McDougall et al., 2011) was used to calculate all variables.