lat-lon rebuild piece by piece

Author: ifenty

Tutorials_as_Jupyter_Notebooks/ECCO_v4_Interpolating_to_latlon.ipynb

@@ -4,15 +4,39 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# ECCOv4 Loading llc binary files in the 'compact' format\n",
+    "# Interpolating fields from the model llc grid to lat-lon\n",
     "\n",
-    "## Objective\n",
+    "## Objectives\n",
+    "\n",
+    "1. Learn how to interpolate scalar and vector fields from ECCOv4's lat-lon-cap 90 (llc90) model grid to the more common regular latitude-longitude grid.  \n",
+    "\n",
+    "2. Learn how to save these interpolated fields as netCDF for later analysis \n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Introduction\n",
+    "\n",
+    "Recall the orientations of the 13 tiles of the ECCOv4 native llc90 model grid.\n",
+    "\n",
+    "![llc90 tile layout](../figures/llc90_0.png)\n",
+    "\n",
+    "Tiles 7-12 are rotated 90 degrees counter-clockwise relative to tiles 0-5.\n",
+    "\n",
+    "In this tutorial we demonstrate two methods for mapping scalar and vector fields from the llc90 model grid to \"regular\" latitude-longitude grids of arbitrary resolution.  \n",
+    "\n",
+    "> **Note:**  *There are many methods on can use to map between the grids (e.g., nearest neighbor, bilinear interpolation, bin-averaging, etc.), each with its own advantages and disadvantages.)*\n",
+    "\n",
+    "## How to interpolate scalar ECCO fields to a lat-lon grid\n",
     "\n",
-    "To teach how to loading ECCO binary files written by the MITgcm in the llc 'compact' format. \n",
+    "Scalar fields are the most straightforward fields to interpolate.\n",
     "\n",
-    "## Introduciton\n",
+    "### Preliminaries: Load fields\n",
     "\n",
-    "When the MITgcm saves diagnostic and other fields to files it does so using the so-called 'compact' format.  The compact format distributes the arrays from the 13 lat-lon-cap tiles in a somewhat unintuitive manner. Fortunately, it is not difficult to extract the 13 tiles from 'compact' format files. This tutorial will show you how to use the 'read_llc_to_tiles' subroutine to read and re-organize MITgcm's files written in compact format into a more familiar 13-tile layout."
+    "First, let's load the all 13 tiles for sea surface height and the model grid parameters."
    ]
   },
   {