polaris.ocean.overturning.compute_overturning

polaris.ocean.overturning.compute_overturning(transport: DataArray, vert_dim: str = 'nVertLevels') → DataArray

Compute the overturning stream function at layer interfaces

The stream function is zero at the surface and, at each interface, is the transport toward increasing line.coord summed along the line and over the layers above the interface. The velocity across the line, integrated along it, is then minus the vertical derivative of the stream function.

Parameters:

• transport (xarray.DataArray) – Transport from compute_line_transport(), with dimensions nLineEdges and vert_dim

• vert_dim (str, optional) – The vertical dimension, indexed from the top

Returns:

overturning (xarray.DataArray) – The overturning stream function (m3 s-1) with nLineEdges removed and vert_dim replaced by nVertLevelsP1