Temperature and Salinity Timeseries data from the GAK1 Mooring, Seward, AK, 1998-2017 (Gulf Watch Alaska Environmental Drivers Component)

This data set consists of measurements collected by moored instruments from the mooring's establishment in 1998 to 2017. After 2017, these data continue under the auspices of the NGA LTER project in a separate archive. Two different types of instruments have been deployed at GAK1. SeaBird Electronic's MicroCAT (SBE 37) measures temperature and conductivity with salinity calculated assuming a constant pressure. Some deployments include an SBE SeaCAT (SBE 16) which measure temperature, conductivity, and pressure along with occasional optical sensors like PAR, Fluorescence, and Turbidity. The optical measurements are included when they are available, but are not the primary focus of this data set. Conductivity was not always retained in the original files after salinity was calculated. GulfWatch Alaska's GAK1 project continues a 50-year time series of temperature and salinity measurements at a hydrographic station called GAK1. GAK1 is at 59° 50.7' N, 149° 28.0' W, within the Alaska Coastal Current and connected to the inner Gulf of Alaska shelf circulation. Sampling at GAK1, which began in 1970, now consists of monthly CTD profiles and a year-round mooring with 6-7 temperature/conductivity recorders distributed throughout the water column. Several different investigators have maintained the GAK1 mooring over its lifetime. Earlier versions of this archive have included files in a variety of formats. Files in this archive have consistent parameter names, ISO standard time format, and file names that include the measurement depth. Files for each deployment are grouped together in a compressed zip file. Within each zip are separate ASCII comma delimited files (CSV) for each measurement depth. The pressure/depth records in the 2002-2003 files have been additionally corrected due to mooring movement and equipment loss that occurred that year.