Ocean Station Papa, at 50°N, 145°W in the Alaska Gyre (Figure 1), started as a weather station in the 1940s. In 1956, oceanographers began collecting a suite of standard measurements from the cool subarctic waters at Ocean Station Papa (OSP), including temperature, salinity, oxygen, and plankton.Three years later, a series of sampling stations was added along the 1400-kilometer ‘Line P’ from the Canadian coast to OSRto aid in understanding ocean variability.

From 1956 to 1981, weather ships made the transit to and from OSP every six weeks, resulting in high temporal resolution sampling. The weather ship era ended in 1981 when satellites began providing better data for forecasting ocean weather. Since then, Canadian research vessels have continued to sample along Line P two to five times each year. In this recent era, transport of carbon within the ocean has become a major research focus.