id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
451	Extend top extent of equatorial grids produced by HYCOM Global Analysis tools from 47 N to 60 N	jjr8	jjr8	"Currently, the tools that work with the equatorial region of the HYCOM Global Analysis are restricted to the latitudinal extent of the Mercator section of the original HYCOM grid: about 47 N to 66 S. Unfortunately 47 N is just not far enough north for some of our projects in the northwest Atlantic. For example, we have one study that involves the so-called ""northeast distant region"" (NED), which extends above 47 N. The HYCOM tools should be enhanced to extend the northern extent of the Mercator grid from 47 N to 60 N.

Unfortunately, this is complicated to implement. It requires that values of the Mercator grid from 47-60 N be interpolated from the ""bi-polar"" region of the grid. To keep this simple to implement and reasonably fast at run time, and to avoid smoothing out sharp gradients, we should use nearest neighbor interpolation. The density of bi-polar cells above 47 N significantly exceeds that of the Mercator grid, so artificial gradients should not be introduced. We can precompute a lookup table that specifies which bi-polar cell to use for a given Mercator cell so that, at run time, it is only necessary to download the bi-polar cells and do a bunch of lookups (efficiently implemented by the numpy {{{take()}}} function, written in C)."	Task	closed	Medium	0.8	Tools - Data Products - HYCOM		fixed