The current version of programs only allows to diagnose tracer budget within the North Atlantic subpolar gyre and the Nordic Seas. Further developments will extend this possibility to other regions. The definition of areas, in PAGO function sections_MODEL, must be compatible with sections: the whole perimeter of the area is either made of continental coasts or sections. This actually depends on the spatial resolution of the dataset. For example, the Strait of Belle Isle, that separates the island of Newfoundland from the Labrador Peninsula, is usually closed in climate models but may be open in high resolution datasets. Besides, the positive direction defined for each section closing the area must be considered carefully when defining the convergent transports in PAGO function volumes_MODEL. Data information within areas, i.e. temperature, salinity and volume (to keep track of volume changes as in z* models like GFDL-CM3) is loaded by PAGO function loaddata_*. Volume indices, calculated by PAGO function volumes_MODEL, are time series that describe heat, salt and freshwater (defined using a reference salinity of 34.8, to be modified in volumes_MODEL directly) budgets:

  • tracer content within the whole area (from surface to bottom),
  • tracer content within fixed vertical intervals. The limits of those intervals, defined in volumes_MODEL, is fixed but their actual depth depends on the depth of the data levels as there is no vertical interpolation of the data.
  • advective convergence to the area, from surface to bottom and for fixed vertical intervals.